xref: /frameworks/support/compat/java/android/support/v4/app/NotificationCompat.java

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.support.v4.app;

import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;

import static java.lang.annotation.RetentionPolicy.SOURCE;

import android.app.Activity;
import android.app.Notification;
import android.app.PendingIntent;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.annotation.ColorInt;
import android.support.annotation.IntDef;
import android.support.annotation.NonNull;
import android.support.annotation.RequiresApi;
import android.support.annotation.RestrictTo;
import android.support.v4.os.BuildCompat;
import android.support.v4.view.GravityCompat;
import android.view.Gravity;
import android.widget.RemoteViews;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/**
 * Helper for accessing features in {@link android.app.Notification}
 * introduced after API level 4 in a backwards compatible fashion.
 */
public class NotificationCompat {

    /**
     * Use all default values (where applicable).
     */
    public static final int DEFAULT_ALL = ~0;

    /**
     * Use the default notification sound. This will ignore any sound set using
     * {@link Builder#setSound}
     *
     * <p>
     * A notification that is noisy is more likely to be presented as a heads-up notification,
     * on some platforms.
     * </p>
     *
     * @see Builder#setDefaults
     */
    public static final int DEFAULT_SOUND = 1;

    /**
     * Use the default notification vibrate. This will ignore any vibrate set using
     * {@link Builder#setVibrate}. Using phone vibration requires the
     * {@link android.Manifest.permission#VIBRATE VIBRATE} permission.
     *
     * <p>
     * A notification that vibrates is more likely to be presented as a heads-up notification,
     * on some platforms.
     * </p>
     *
     * @see Builder#setDefaults
     */
    public static final int DEFAULT_VIBRATE = 2;

    /**
     * Use the default notification lights. This will ignore the
     * {@link #FLAG_SHOW_LIGHTS} bit, and values set with {@link Builder#setLights}.
     *
     * @see Builder#setDefaults
     */
    public static final int DEFAULT_LIGHTS = 4;

    /**
     * Use this constant as the value for audioStreamType to request that
     * the default stream type for notifications be used.  Currently the
     * default stream type is {@link AudioManager#STREAM_NOTIFICATION}.
     */
    public static final int STREAM_DEFAULT = -1;

    /**
     * Bit set in the Notification flags field when LEDs should be turned on
     * for this notification.
     */
    public static final int FLAG_SHOW_LIGHTS        = 0x00000001;

    /**
     * Bit set in the Notification flags field if this notification is in
     * reference to something that is ongoing, like a phone call.  It should
     * not be set if this notification is in reference to something that
     * happened at a particular point in time, like a missed phone call.
     */
    public static final int FLAG_ONGOING_EVENT      = 0x00000002;

    /**
     * Bit set in the Notification flags field if
     * the audio will be repeated until the notification is
     * cancelled or the notification window is opened.
     */
    public static final int FLAG_INSISTENT          = 0x00000004;

    /**
     * Bit set in the Notification flags field if the notification's sound,
     * vibrate and ticker should only be played if the notification is not already showing.
     */
    public static final int FLAG_ONLY_ALERT_ONCE    = 0x00000008;

    /**
     * Bit set in the Notification flags field if the notification should be canceled when
     * it is clicked by the user.
     */
    public static final int FLAG_AUTO_CANCEL        = 0x00000010;

    /**
     * Bit set in the Notification flags field if the notification should not be canceled
     * when the user clicks the Clear all button.
     */
    public static final int FLAG_NO_CLEAR           = 0x00000020;

    /**
     * Bit set in the Notification flags field if this notification represents a currently
     * running service.  This will normally be set for you by
     * {@link android.app.Service#startForeground}.
     */
    public static final int FLAG_FOREGROUND_SERVICE = 0x00000040;

    /**
     * Obsolete flag indicating high-priority notifications; use the priority field instead.
     *
     * @deprecated Use {@link NotificationCompat.Builder#setPriority(int)} with a positive value.
     */
    @Deprecated
    public static final int FLAG_HIGH_PRIORITY      = 0x00000080;

    /**
     * Bit set in the Notification flags field if this notification is relevant to the current
     * device only and it is not recommended that it bridge to other devices.
     */
    public static final int FLAG_LOCAL_ONLY         = 0x00000100;

    /**
     * Bit set in the Notification flags field if this notification is the group summary for a
     * group of notifications. Grouped notifications may display in a cluster or stack on devices
     * which support such rendering. Requires a group key also be set using
     * {@link Builder#setGroup}.
     */
    public static final int FLAG_GROUP_SUMMARY      = 0x00000200;

    /**
     * Default notification priority for {@link NotificationCompat.Builder#setPriority(int)}.
     * If your application does not prioritize its own notifications,
     * use this value for all notifications.
     */
    public static final int PRIORITY_DEFAULT = 0;

    /**
     * Lower notification priority for {@link NotificationCompat.Builder#setPriority(int)},
     * for items that are less important. The UI may choose to show
     * these items smaller, or at a different position in the list,
     * compared with your app's {@link #PRIORITY_DEFAULT} items.
     */
    public static final int PRIORITY_LOW = -1;

    /**
     * Lowest notification priority for {@link NotificationCompat.Builder#setPriority(int)};
     * these items might not be shown to the user except under
     * special circumstances, such as detailed notification logs.
     */
    public static final int PRIORITY_MIN = -2;

    /**
     * Higher notification priority for {@link NotificationCompat.Builder#setPriority(int)},
     * for more important notifications or alerts. The UI may choose
     * to show these items larger, or at a different position in
     * notification lists, compared with your app's {@link #PRIORITY_DEFAULT} items.
     */
    public static final int PRIORITY_HIGH = 1;

    /**
     * Highest notification priority for {@link NotificationCompat.Builder#setPriority(int)},
     * for your application's most important items that require the user's
     * prompt attention or input.
     */
    public static final int PRIORITY_MAX = 2;

    /**
     * Notification extras key: this is the title of the notification,
     * as supplied to {@link Builder#setContentTitle(CharSequence)}.
     */
    public static final String EXTRA_TITLE = "android.title";

    /**
     * Notification extras key: this is the title of the notification when shown in expanded form,
     * e.g. as supplied to {@link BigTextStyle#setBigContentTitle(CharSequence)}.
     */
    public static final String EXTRA_TITLE_BIG = EXTRA_TITLE + ".big";

    /**
     * Notification extras key: this is the main text payload, as supplied to
     * {@link Builder#setContentText(CharSequence)}.
     */
    public static final String EXTRA_TEXT = "android.text";

    /**
     * Notification extras key: this is a third line of text, as supplied to
     * {@link Builder#setSubText(CharSequence)}.
     */
    public static final String EXTRA_SUB_TEXT = "android.subText";

    /**
     * Notification extras key: this is the remote input history, as supplied to
     * {@link Builder#setRemoteInputHistory(CharSequence[])}.
     *
     * Apps can fill this through {@link Builder#setRemoteInputHistory(CharSequence[])}
     * with the most recent inputs that have been sent through a {@link RemoteInput} of this
     * Notification and are expected to clear it once the it is no longer relevant (e.g. for chat
     * notifications once the other party has responded).
     *
     * The extra with this key is of type CharSequence[] and contains the most recent entry at
     * the 0 index, the second most recent at the 1 index, etc.
     *
     * @see Builder#setRemoteInputHistory(CharSequence[])
     */
    public static final String EXTRA_REMOTE_INPUT_HISTORY = "android.remoteInputHistory";

    /**
     * Notification extras key: this is a small piece of additional text as supplied to
     * {@link Builder#setContentInfo(CharSequence)}.
     */
    public static final String EXTRA_INFO_TEXT = "android.infoText";

    /**
     * Notification extras key: this is a line of summary information intended to be shown
     * alongside expanded notifications, as supplied to (e.g.)
     * {@link BigTextStyle#setSummaryText(CharSequence)}.
     */
    public static final String EXTRA_SUMMARY_TEXT = "android.summaryText";

    /**
     * Notification extras key: this is the longer text shown in the big form of a
     * {@link BigTextStyle} notification, as supplied to
     * {@link BigTextStyle#bigText(CharSequence)}.
     */
    public static final String EXTRA_BIG_TEXT = "android.bigText";

    /**
     * Notification extras key: this is the resource ID of the notification's main small icon, as
     * supplied to {@link Builder#setSmallIcon(int)}.
     */
    public static final String EXTRA_SMALL_ICON = "android.icon";

    /**
     * Notification extras key: this is a bitmap to be used instead of the small icon when showing the
     * notification payload, as
     * supplied to {@link Builder#setLargeIcon(android.graphics.Bitmap)}.
     */
    public static final String EXTRA_LARGE_ICON = "android.largeIcon";

    /**
     * Notification extras key: this is a bitmap to be used instead of the one from
     * {@link Builder#setLargeIcon(android.graphics.Bitmap)} when the notification is
     * shown in its expanded form, as supplied to
     * {@link BigPictureStyle#bigLargeIcon(android.graphics.Bitmap)}.
     */
    public static final String EXTRA_LARGE_ICON_BIG = EXTRA_LARGE_ICON + ".big";

    /**
     * Notification extras key: this is the progress value supplied to
     * {@link Builder#setProgress(int, int, boolean)}.
     */
    public static final String EXTRA_PROGRESS = "android.progress";

    /**
     * Notification extras key: this is the maximum value supplied to
     * {@link Builder#setProgress(int, int, boolean)}.
     */
    public static final String EXTRA_PROGRESS_MAX = "android.progressMax";

    /**
     * Notification extras key: whether the progress bar is indeterminate, supplied to
     * {@link Builder#setProgress(int, int, boolean)}.
     */
    public static final String EXTRA_PROGRESS_INDETERMINATE = "android.progressIndeterminate";

    /**
     * Notification extras key: whether the when field set using {@link Builder#setWhen} should
     * be shown as a count-up timer (specifically a {@link android.widget.Chronometer}) instead
     * of a timestamp, as supplied to {@link Builder#setUsesChronometer(boolean)}.
     */
    public static final String EXTRA_SHOW_CHRONOMETER = "android.showChronometer";

    /**
     * Notification extras key: whether the when field set using {@link Builder#setWhen} should
     * be shown, as supplied to {@link Builder#setShowWhen(boolean)}.
     */
    public static final String EXTRA_SHOW_WHEN = "android.showWhen";

    /**
     * Notification extras key: this is a bitmap to be shown in {@link BigPictureStyle} expanded
     * notifications, supplied to {@link BigPictureStyle#bigPicture(android.graphics.Bitmap)}.
     */
    public static final String EXTRA_PICTURE = "android.picture";

    /**
     * Notification extras key: An array of CharSequences to show in {@link InboxStyle} expanded
     * notifications, each of which was supplied to {@link InboxStyle#addLine(CharSequence)}.
     */
    public static final String EXTRA_TEXT_LINES = "android.textLines";

    /**
     * Notification extras key: A string representing the name of the specific
     * {@link android.app.Notification.Style} used to create this notification.
     */
    public static final String EXTRA_TEMPLATE = "android.template";

    /**
     * Notification extras key: A String array containing the people that this
     * notification relates to, each of which was supplied to
     * {@link Builder#addPerson(String)}.
     */
    public static final String EXTRA_PEOPLE = "android.people";

    /**
     * Notification extras key: A
     * {@link android.content.ContentUris content URI} pointing to an image that can be displayed
     * in the background when the notification is selected. The URI must point to an image stream
     * suitable for passing into
     * {@link android.graphics.BitmapFactory#decodeStream(java.io.InputStream)
     * BitmapFactory.decodeStream}; all other content types will be ignored. The content provider
     * URI used for this purpose must require no permissions to read the image data.
     */
    public static final String EXTRA_BACKGROUND_IMAGE_URI = "android.backgroundImageUri";

    /**
     * Notification key: A
     * {@link android.media.session.MediaSession.Token} associated with a
     * {@link android.app.Notification.MediaStyle} notification.
     */
    public static final String EXTRA_MEDIA_SESSION = "android.mediaSession";

    /**
     * Notification extras key: the indices of actions to be shown in the compact view,
     * as supplied to (e.g.) {@link Notification.MediaStyle#setShowActionsInCompactView(int...)}.
     */
    public static final String EXTRA_COMPACT_ACTIONS = "android.compactActions";

    /**
     * Notification key: the username to be displayed for all messages sent by the user
     * including
     * direct replies
     * {@link MessagingStyle} notification.
     */
    public static final String EXTRA_SELF_DISPLAY_NAME = "android.selfDisplayName";

    /**
     * Notification key: a {@link String} to be displayed as the title to a conversation
     * represented by a {@link MessagingStyle}
     */
    public static final String EXTRA_CONVERSATION_TITLE = "android.conversationTitle";

    /**
     * Notification key: an array of {@link Bundle} objects representing
     * {@link MessagingStyle.Message} objects for a {@link MessagingStyle} notification.
     */
    public static final String EXTRA_MESSAGES = "android.messages";

    /**
     * Keys into the {@link #getExtras} Bundle: the audio contents of this notification.
     *
     * This is for use when rendering the notification on an audio-focused interface;
     * the audio contents are a complete sound sample that contains the contents/body of the
     * notification. This may be used in substitute of a Text-to-Speech reading of the
     * notification. For example if the notification represents a voice message this should point
     * to the audio of that message.
     *
     * The data stored under this key should be a String representation of a Uri that contains the
     * audio contents in one of the following formats: WAV, PCM 16-bit, AMR-WB.
     *
     * This extra is unnecessary if you are using {@code MessagingStyle} since each {@code Message}
     * has a field for holding data URI. That field can be used for audio.
     * See {@code Message#setData}.
     *
     * Example usage:
     * <pre>
     * {@code
     * NotificationCompat.Builder myBuilder = (build your Notification as normal);
     * myBuilder.getExtras().putString(EXTRA_AUDIO_CONTENTS_URI, myAudioUri.toString());
     * }
     * </pre>
     */
    public static final String EXTRA_AUDIO_CONTENTS_URI = "android.audioContents";

    /**
     * Value of {@link Notification#color} equal to 0 (also known as
     * {@link android.graphics.Color#TRANSPARENT Color.TRANSPARENT}),
     * telling the system not to decorate this notification with any special color but instead use
     * default colors when presenting this notification.
     */
    @ColorInt
    public static final int COLOR_DEFAULT = Color.TRANSPARENT;

    /** @hide */
    @Retention(SOURCE)
    @IntDef({VISIBILITY_PUBLIC, VISIBILITY_PRIVATE, VISIBILITY_SECRET})
    public @interface NotificationVisibility {}
    /**
     * Notification visibility: Show this notification in its entirety on all lockscreens.
     *
     * {@see android.app.Notification#visibility}
     */
    public static final int VISIBILITY_PUBLIC = 1;

    /**
     * Notification visibility: Show this notification on all lockscreens, but conceal sensitive or
     * private information on secure lockscreens.
     *
     * {@see android.app.Notification#visibility}
     */
    public static final int VISIBILITY_PRIVATE = 0;

    /**
     * Notification visibility: Do not reveal any part of this notification on a secure lockscreen.
     *
     * {@see android.app.Notification#visibility}
     */
    public static final int VISIBILITY_SECRET = -1;

    /**
     * Notification category: incoming call (voice or video) or similar synchronous communication request.
     */
    public static final String CATEGORY_CALL = NotificationCompatApi21.CATEGORY_CALL;

    /**
     * Notification category: incoming direct message (SMS, instant message, etc.).
     */
    public static final String CATEGORY_MESSAGE = NotificationCompatApi21.CATEGORY_MESSAGE;

    /**
     * Notification category: asynchronous bulk message (email).
     */
    public static final String CATEGORY_EMAIL = NotificationCompatApi21.CATEGORY_EMAIL;

    /**
     * Notification category: calendar event.
     */
    public static final String CATEGORY_EVENT = NotificationCompatApi21.CATEGORY_EVENT;

    /**
     * Notification category: promotion or advertisement.
     */
    public static final String CATEGORY_PROMO = NotificationCompatApi21.CATEGORY_PROMO;

    /**
     * Notification category: alarm or timer.
     */
    public static final String CATEGORY_ALARM = NotificationCompatApi21.CATEGORY_ALARM;

    /**
     * Notification category: progress of a long-running background operation.
     */
    public static final String CATEGORY_PROGRESS = NotificationCompatApi21.CATEGORY_PROGRESS;

    /**
     * Notification category: social network or sharing update.
     */
    public static final String CATEGORY_SOCIAL = NotificationCompatApi21.CATEGORY_SOCIAL;

    /**
     * Notification category: error in background operation or authentication status.
     */
    public static final String CATEGORY_ERROR = NotificationCompatApi21.CATEGORY_ERROR;

    /**
     * Notification category: media transport control for playback.
     */
    public static final String CATEGORY_TRANSPORT = NotificationCompatApi21.CATEGORY_TRANSPORT;

    /**
     * Notification category: system or device status update.  Reserved for system use.
     */
    public static final String CATEGORY_SYSTEM = NotificationCompatApi21.CATEGORY_SYSTEM;

    /**
     * Notification category: indication of running background service.
     */
    public static final String CATEGORY_SERVICE = NotificationCompatApi21.CATEGORY_SERVICE;

    /**
     * Notification category: user-scheduled reminder.
     */
    public static final String CATEGORY_REMINDER = NotificationCompatApi23.CATEGORY_REMINDER;

    /**
     * Notification category: a specific, timely recommendation for a single thing.
     * For example, a news app might want to recommend a news story it believes the user will
     * want to read next.
     */
    public static final String CATEGORY_RECOMMENDATION =
            NotificationCompatApi21.CATEGORY_RECOMMENDATION;

    /**
     * Notification category: ongoing information about device or contextual status.
     */
    public static final String CATEGORY_STATUS = NotificationCompatApi21.CATEGORY_STATUS;

    /** @hide */
    @Retention(RetentionPolicy.SOURCE)
    @RestrictTo(LIBRARY_GROUP)
    @IntDef({BADGE_ICON_NONE, BADGE_ICON_SMALL, BADGE_ICON_LARGE})
    public @interface BadgeIconType {}
    /**
     * If this notification is being shown as a badge, always show as a number.
     */
    public static final int BADGE_ICON_NONE = Notification.BADGE_ICON_NONE;

    /**
     * If this notification is being shown as a badge, use the icon provided to
     * {@link Builder#setSmallIcon(int)} to represent this notification.
     */
    public static final int BADGE_ICON_SMALL = Notification.BADGE_ICON_SMALL;

    /**
     * If this notification is being shown as a badge, use the icon provided to
     * {@link Builder#setLargeIcon(Bitmap) to represent this notification.
     */
    public static final int BADGE_ICON_LARGE = Notification.BADGE_ICON_LARGE;

    /**
     * Constant for {@link Builder#setGroupAlertBehavior(int)}, meaning that all notifications in a
     * group with sound or vibration ought to make sound or vibrate (respectively), so this
     * notification will not be muted when it is in a group.
     */
    public static final int GROUP_ALERT_ALL = 0;

    /**
     * Constant for {@link Builder#setGroupAlertBehavior(int)}, meaning that all children
     * notification in a group should be silenced (no sound or vibration) even if they would
     * otherwise make sound or vibrate. Use this constant to mute this notification if this
     * notification is a group child.
     *
     * <p> For example, you might want to use this constant if you post a number of children
     * notifications at once (say, after a periodic sync), and only need to notify the user
     * audibly once.
     */
    public static final int GROUP_ALERT_SUMMARY = 1;

    /**
     * Constant for {@link Builder#setGroupAlertBehavior(int)}, meaning that the summary
     * notification in a group should be silenced (no sound or vibration) even if they would
     * otherwise make sound or vibrate. Use this constant
     * to mute this notification if this notification is a group summary.
     *
     * <p>For example, you might want to use this constant if only the children notifications
     * in your group have content and the summary is only used to visually group notifications.
     */
    public static final int GROUP_ALERT_CHILDREN = 2;

    static final NotificationCompatImpl IMPL;

    interface NotificationCompatImpl {
        Notification build(Builder b, BuilderExtender extender);
        Action getAction(Notification n, int actionIndex);
        Action[] getActionsFromParcelableArrayList(ArrayList<Parcelable> parcelables);
        ArrayList<Parcelable> getParcelableArrayListForActions(Action[] actions);
        Bundle getBundleForUnreadConversation(NotificationCompatBase.UnreadConversation uc);
        NotificationCompatBase.UnreadConversation getUnreadConversationFromBundle(
                Bundle b, NotificationCompatBase.UnreadConversation.Factory factory,
                RemoteInputCompatBase.RemoteInput.Factory remoteInputFactory);
    }

    /**
     * Interface for appcompat to extend v4 builder with media style.
     *
     * @hide
     */
    @RestrictTo(LIBRARY_GROUP)
    protected static class BuilderExtender {
        public Notification build(Builder b, NotificationBuilderWithBuilderAccessor builder) {
            Notification n = builder.build();
            if (b.mContentView != null) {
                n.contentView = b.mContentView;
            }
            return n;
        }
    }

    static class NotificationCompatBaseImpl implements NotificationCompatImpl {

        public static class BuilderBase implements NotificationBuilderWithBuilderAccessor {

            private Notification.Builder mBuilder;

            BuilderBase(Context context, Notification n, CharSequence contentTitle,
                    CharSequence contentText, CharSequence contentInfo, RemoteViews tickerView,
                    int number, PendingIntent contentIntent, PendingIntent fullScreenIntent,
                    Bitmap largeIcon, int progressMax, int progress,
                    boolean progressIndeterminate) {
                mBuilder = new Notification.Builder(context)
                        .setWhen(n.when)
                        .setSmallIcon(n.icon, n.iconLevel)
                        .setContent(n.contentView)
                        .setTicker(n.tickerText, tickerView)
                        .setSound(n.sound, n.audioStreamType)
                        .setVibrate(n.vibrate)
                        .setLights(n.ledARGB, n.ledOnMS, n.ledOffMS)
                        .setOngoing((n.flags & Notification.FLAG_ONGOING_EVENT) != 0)
                        .setOnlyAlertOnce((n.flags & Notification.FLAG_ONLY_ALERT_ONCE) != 0)
                        .setAutoCancel((n.flags & Notification.FLAG_AUTO_CANCEL) != 0)
                        .setDefaults(n.defaults)
                        .setContentTitle(contentTitle)
                        .setContentText(contentText)
                        .setContentInfo(contentInfo)
                        .setContentIntent(contentIntent)
                        .setDeleteIntent(n.deleteIntent)
                        .setFullScreenIntent(fullScreenIntent,
                                (n.flags & Notification.FLAG_HIGH_PRIORITY) != 0)
                        .setLargeIcon(largeIcon)
                        .setNumber(number)
                        .setProgress(progressMax, progress, progressIndeterminate);
            }

            @Override
            public Notification.Builder getBuilder() {
                return mBuilder;
            }

            @Override
            public Notification build() {
                return mBuilder.getNotification();
            }
        }

        @Override
        public Notification build(Builder b, BuilderExtender extender) {
            BuilderBase builder =
                    new BuilderBase(b.mContext, b.mNotification,
                            b.resolveTitle(), b.resolveText(), b.mContentInfo, b.mTickerView,
                            b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                            b.mProgressMax, b.mProgress, b.mProgressIndeterminate);
            return extender.build(b, builder);
        }

        @Override
        public Action getAction(Notification n, int actionIndex) {
            return null;
        }

        @Override
        public Action[] getActionsFromParcelableArrayList(ArrayList<Parcelable> parcelables) {
            return null;
        }

        @Override
        public ArrayList<Parcelable> getParcelableArrayListForActions(Action[] actions) {
            return null;
        }

        @Override
        public Bundle getBundleForUnreadConversation(NotificationCompatBase.UnreadConversation uc) {
            return null;
        }

        @Override
        public NotificationCompatBase.UnreadConversation getUnreadConversationFromBundle(
                Bundle b, NotificationCompatBase.UnreadConversation.Factory factory,
                RemoteInputCompatBase.RemoteInput.Factory remoteInputFactory) {
            return null;
        }
    }

    @RequiresApi(16)
    static class NotificationCompatApi16Impl extends NotificationCompatBaseImpl {
        @Override
        public Notification build(Builder b, BuilderExtender extender) {
            NotificationCompatJellybean.Builder builder = new NotificationCompatJellybean.Builder(
                    b.mContext, b.mNotification, b.resolveTitle(), b.resolveText(), b.mContentInfo,
                    b.mTickerView, b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                    b.mProgressMax, b.mProgress, b.mProgressIndeterminate,
                    b.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mExtras,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey, b.mContentView, b.mBigContentView);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            Notification notification = extender.build(b, builder);
            if (b.mStyle != null) {
                Bundle extras = getExtras(notification);
                if (extras != null) {
                    b.mStyle.addCompatExtras(extras);
                }
            }
            return notification;
        }

        @Override
        public Action getAction(Notification n, int actionIndex) {
            return (Action) NotificationCompatJellybean.getAction(n, actionIndex, Action.FACTORY,
                    RemoteInput.FACTORY);
        }

        @Override
        public Action[] getActionsFromParcelableArrayList(
                ArrayList<Parcelable> parcelables) {
            return (Action[]) NotificationCompatJellybean.getActionsFromParcelableArrayList(
                    parcelables, Action.FACTORY, RemoteInput.FACTORY);
        }

        @Override
        public ArrayList<Parcelable> getParcelableArrayListForActions(
                Action[] actions) {
            return NotificationCompatJellybean.getParcelableArrayListForActions(actions);
        }
    }

    @RequiresApi(19)
    static class NotificationCompatApi19Impl extends NotificationCompatApi16Impl {
        @Override
        public Notification build(Builder b, BuilderExtender extender) {
            NotificationCompatKitKat.Builder builder = new NotificationCompatKitKat.Builder(
                    b.mContext, b.mNotification, b.resolveTitle(), b.resolveText(), b.mContentInfo,
                    b.mTickerView, b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                    b.mProgressMax, b.mProgress, b.mProgressIndeterminate, b.mShowWhen,
                    b.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly,
                    b.mPeople, b.mExtras, b.mGroupKey, b.mGroupSummary, b.mSortKey,
                    b.mContentView, b.mBigContentView);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            return extender.build(b, builder);
        }

        @Override
        public Action getAction(Notification n, int actionIndex) {
            return (Action) NotificationCompatKitKat.getAction(n, actionIndex, Action.FACTORY,
                    RemoteInput.FACTORY);
        }
    }

    @RequiresApi(20)
    static class NotificationCompatApi20Impl extends NotificationCompatApi19Impl {
        @Override
        public Notification build(Builder b, BuilderExtender extender) {
            NotificationCompatApi20.Builder builder = new NotificationCompatApi20.Builder(
                    b.mContext, b.mNotification, b.resolveTitle(), b.resolveText(), b.mContentInfo,
                    b.mTickerView, b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                    b.mProgressMax, b.mProgress, b.mProgressIndeterminate, b.mShowWhen,
                    b.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mPeople, b.mExtras,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey, b.mContentView, b.mBigContentView,
                    b.mGroupAlertBehavior);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            Notification notification = extender.build(b, builder);
            if (b.mStyle != null) {
                b.mStyle.addCompatExtras(getExtras(notification));
            }
            return notification;
        }

        @Override
        public Action getAction(Notification n, int actionIndex) {
            return (Action) NotificationCompatApi20.getAction(n, actionIndex, Action.FACTORY,
                    RemoteInput.FACTORY);
        }

        @Override
        public Action[] getActionsFromParcelableArrayList(
                ArrayList<Parcelable> parcelables) {
            return (Action[]) NotificationCompatApi20.getActionsFromParcelableArrayList(
                    parcelables, Action.FACTORY, RemoteInput.FACTORY);
        }

        @Override
        public ArrayList<Parcelable> getParcelableArrayListForActions(
                Action[] actions) {
            return NotificationCompatApi20.getParcelableArrayListForActions(actions);
        }
    }

    @RequiresApi(21)
    static class NotificationCompatApi21Impl extends NotificationCompatApi20Impl {
        @Override
        public Notification build(Builder b, BuilderExtender extender) {
            NotificationCompatApi21.Builder builder = new NotificationCompatApi21.Builder(
                    b.mContext, b.mNotification, b.resolveTitle(), b.resolveText(), b.mContentInfo,
                    b.mTickerView, b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                    b.mProgressMax, b.mProgress, b.mProgressIndeterminate, b.mShowWhen,
                    b.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mCategory,
                    b.mPeople, b.mExtras, b.mColor, b.mVisibility, b.mPublicVersion,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey, b.mContentView, b.mBigContentView,
                    b.mHeadsUpContentView, b.mGroupAlertBehavior);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            Notification notification = extender.build(b, builder);
            if (b.mStyle != null) {
                b.mStyle.addCompatExtras(getExtras(notification));
            }
            return notification;
        }

        @Override
        public Bundle getBundleForUnreadConversation(NotificationCompatBase.UnreadConversation uc) {
            return NotificationCompatApi21.getBundleForUnreadConversation(uc);
        }

        @Override
        public NotificationCompatBase.UnreadConversation getUnreadConversationFromBundle(
                Bundle b, NotificationCompatBase.UnreadConversation.Factory factory,
                RemoteInputCompatBase.RemoteInput.Factory remoteInputFactory) {
            return NotificationCompatApi21.getUnreadConversationFromBundle(
                    b, factory, remoteInputFactory);
        }
    }

    @RequiresApi(24)
    static class NotificationCompatApi24Impl extends NotificationCompatApi21Impl {
        @Override
        public Notification build(Builder b,
                BuilderExtender extender) {
            NotificationCompatApi24.Builder builder = new NotificationCompatApi24.Builder(
                    b.mContext, b.mNotification, b.mContentTitle, b.mContentText, b.mContentInfo,
                    b.mTickerView, b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                    b.mProgressMax, b.mProgress, b.mProgressIndeterminate, b.mShowWhen,
                    b.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mCategory,
                    b.mPeople, b.mExtras, b.mColor, b.mVisibility, b.mPublicVersion,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey, b.mRemoteInputHistory, b.mContentView,
                    b.mBigContentView, b.mHeadsUpContentView, b.mGroupAlertBehavior);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderApi24(builder, b.mStyle);
            Notification notification = extender.build(b, builder);
            if (b.mStyle != null) {
                b.mStyle.addCompatExtras(getExtras(notification));
            }
            return notification;
        }
    }

    @RequiresApi(26)
    static class NotificationCompatApi26Impl extends NotificationCompatApi24Impl {
        @Override
        public Notification build(Builder b,
                                  BuilderExtender extender) {
            NotificationCompatApi26.Builder builder = new NotificationCompatApi26.Builder(
                    b.mContext, b.mNotification, b.mContentTitle, b.mContentText, b.mContentInfo,
                    b.mTickerView, b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon,
                    b.mProgressMax, b.mProgress, b.mProgressIndeterminate, b.mShowWhen,
                    b.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mCategory,
                    b.mPeople, b.mExtras, b.mColor, b.mVisibility, b.mPublicVersion,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey, b.mRemoteInputHistory, b.mContentView,
                    b.mBigContentView, b.mHeadsUpContentView, b.mChannelId, b.mBadgeIcon,
                    b.mShortcutId, b.mTimeout, b.mColorized, b.mColorizedSet,
                    b.mGroupAlertBehavior);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderApi24(builder, b.mStyle);
            Notification notification = extender.build(b, builder);
            if (b.mStyle != null) {
                b.mStyle.addCompatExtras(getExtras(notification));
            }
            return notification;
        }
    }

    static void addActionsToBuilder(NotificationBuilderWithActions builder,
            ArrayList<Action> actions) {
        for (Action action : actions) {
            builder.addAction(action);
        }
    }

    @RequiresApi(16)
    static void addStyleToBuilderJellybean(NotificationBuilderWithBuilderAccessor builder,
            Style style) {
        if (style != null) {
            if (style instanceof BigTextStyle) {
                BigTextStyle bigTextStyle = (BigTextStyle) style;
                NotificationCompatJellybean.addBigTextStyle(builder,
                        bigTextStyle.mBigContentTitle,
                        bigTextStyle.mSummaryTextSet,
                        bigTextStyle.mSummaryText,
                        bigTextStyle.mBigText);
            } else if (style instanceof InboxStyle) {
                InboxStyle inboxStyle = (InboxStyle) style;
                NotificationCompatJellybean.addInboxStyle(builder,
                        inboxStyle.mBigContentTitle,
                        inboxStyle.mSummaryTextSet,
                        inboxStyle.mSummaryText,
                        inboxStyle.mTexts);
            } else if (style instanceof BigPictureStyle) {
                BigPictureStyle bigPictureStyle = (BigPictureStyle) style;
                NotificationCompatJellybean.addBigPictureStyle(builder,
                        bigPictureStyle.mBigContentTitle,
                        bigPictureStyle.mSummaryTextSet,
                        bigPictureStyle.mSummaryText,
                        bigPictureStyle.mPicture,
                        bigPictureStyle.mBigLargeIcon,
                        bigPictureStyle.mBigLargeIconSet);
            }
        }
    }

    @RequiresApi(24)
    static void addStyleToBuilderApi24(NotificationBuilderWithBuilderAccessor builder,
            Style style) {
        if (style != null) {
            if (style instanceof MessagingStyle) {
                MessagingStyle messagingStyle = (MessagingStyle) style;
                List<CharSequence> texts = new ArrayList<>();
                List<Long> timestamps = new ArrayList<>();
                List<CharSequence> senders = new ArrayList<>();
                List<String> dataMimeTypes = new ArrayList<>();
                List<Uri> dataUris = new ArrayList<>();

                for (MessagingStyle.Message message : messagingStyle.mMessages) {
                    texts.add(message.getText());
                    timestamps.add(message.getTimestamp());
                    senders.add(message.getSender());
                    dataMimeTypes.add(message.getDataMimeType());
                    dataUris.add(message.getDataUri());
                }
                NotificationCompatApi24.addMessagingStyle(builder, messagingStyle.mUserDisplayName,
                        messagingStyle.mConversationTitle, texts, timestamps, senders,
                        dataMimeTypes, dataUris);
            } else {
                addStyleToBuilderJellybean(builder, style);
            }
        }
    }

    static {
        if (BuildCompat.isAtLeastO()) {
            IMPL = new NotificationCompatApi26Impl();
        } else if (Build.VERSION.SDK_INT >= 24) {
            IMPL = new NotificationCompatApi24Impl();
        } else if (Build.VERSION.SDK_INT >= 21) {
            IMPL = new NotificationCompatApi21Impl();
        } else if (Build.VERSION.SDK_INT >= 20) {
            IMPL = new NotificationCompatApi20Impl();
        } else if (Build.VERSION.SDK_INT >= 19) {
            IMPL = new NotificationCompatApi19Impl();
        } else if (Build.VERSION.SDK_INT >= 16) {
            IMPL = new NotificationCompatApi16Impl();
        } else {
            IMPL = new NotificationCompatBaseImpl();
        }
    }

    /**
     * Builder class for {@link NotificationCompat} objects.  Allows easier control over
     * all the flags, as well as help constructing the typical notification layouts.
     * <p>
     * On platform versions that don't offer expanded notifications, methods that depend on
     * expanded notifications have no effect.
     * </p>
     * <p>
     * For example, action buttons won't appear on platforms prior to Android 4.1. Action
     * buttons depend on expanded notifications, which are only available in Android 4.1
     * and later.
     * <p>
     * For this reason, you should always ensure that UI controls in a notification are also
     * available in an {@link android.app.Activity} in your app, and you should always start that
     * {@link android.app.Activity} when users click the notification. To do this, use the
     * {@link NotificationCompat.Builder#setContentIntent setContentIntent()}
     * method.
     * </p>
     *
     */
    public static class Builder {
        /**
         * Maximum length of CharSequences accepted by Builder and friends.
         *
         * <p>
         * Avoids spamming the system with overly large strings such as full e-mails.
         */
        private static final int MAX_CHARSEQUENCE_LENGTH = 5 * 1024;

        // All these variables are declared public/hidden so they can be accessed by a builder
        // extender.

        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public Context mContext;

        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public CharSequence mContentTitle;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public CharSequence mContentText;
        PendingIntent mContentIntent;
        PendingIntent mFullScreenIntent;
        RemoteViews mTickerView;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public Bitmap mLargeIcon;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public CharSequence mContentInfo;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public int mNumber;
        int mPriority;
        boolean mShowWhen = true;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public boolean mUseChronometer;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public Style mStyle;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public CharSequence mSubText;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public CharSequence[] mRemoteInputHistory;
        int mProgressMax;
        int mProgress;
        boolean mProgressIndeterminate;
        String mGroupKey;
        boolean mGroupSummary;
        String mSortKey;
        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public ArrayList<Action> mActions = new ArrayList<Action>();
        boolean mLocalOnly = false;
        boolean mColorized;
        boolean mColorizedSet;
        String mCategory;
        Bundle mExtras;
        int mColor = COLOR_DEFAULT;
        int mVisibility = VISIBILITY_PRIVATE;
        Notification mPublicVersion;
        RemoteViews mContentView;
        RemoteViews mBigContentView;
        RemoteViews mHeadsUpContentView;
        String mChannelId;
        int mBadgeIcon = BADGE_ICON_NONE;
        String mShortcutId;
        long mTimeout;
        private int mGroupAlertBehavior = GROUP_ALERT_ALL;

        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public Notification mNotification = new Notification();
        public ArrayList<String> mPeople;

        /**
         * Constructor.
         *
         * Automatically sets the when field to {@link System#currentTimeMillis()
         * System.currentTimeMillis()} and the audio stream to the
         * {@link Notification#STREAM_DEFAULT}.
         *
         * @param context A {@link Context} that will be used to construct the
         *      RemoteViews. The Context will not be held past the lifetime of this
         *      Builder object.
         * @param channelId The constructed Notification will be posted on this
         *      NotificationChannel.
         */
        public Builder(@NonNull Context context, @NonNull String channelId) {
            mContext = context;
            mChannelId = channelId;

            // Set defaults to match the defaults of a Notification
            mNotification.when = System.currentTimeMillis();
            mNotification.audioStreamType = Notification.STREAM_DEFAULT;
            mPriority = PRIORITY_DEFAULT;
            mPeople = new ArrayList<String>();
        }

        /**
         * @deprecated use
         * {@link NotificationCompat.Builder#NotificationCompat.Builder(Context, String)} instead.
         * All posted Notifications must specify a NotificationChannel Id.
         */
        @Deprecated
        public Builder(Context context) {
            this(context, null);
        }

        /**
         * Set the time that the event occurred.  Notifications in the panel are
         * sorted by this time.
         */
        public Builder setWhen(long when) {
            mNotification.when = when;
            return this;
        }

        /**
         * Control whether the timestamp set with {@link #setWhen(long) setWhen} is shown
         * in the content view.
         */
        public Builder setShowWhen(boolean show) {
            mShowWhen = show;
            return this;
        }

        /**
         * Show the {@link Notification#when} field as a stopwatch.
         *
         * Instead of presenting <code>when</code> as a timestamp, the notification will show an
         * automatically updating display of the minutes and seconds since <code>when</code>.
         *
         * Useful when showing an elapsed time (like an ongoing phone call).
         *
         * @see android.widget.Chronometer
         * @see Notification#when
         */
        public Builder setUsesChronometer(boolean b) {
            mUseChronometer = b;
            return this;
        }

        /**
         * Set the small icon to use in the notification layouts.  Different classes of devices
         * may return different sizes.  See the UX guidelines for more information on how to
         * design these icons.
         *
         * @param icon A resource ID in the application's package of the drawable to use.
         */
        public Builder setSmallIcon(int icon) {
            mNotification.icon = icon;
            return this;
        }

        /**
         * A variant of {@link #setSmallIcon(int) setSmallIcon(int)} that takes an additional
         * level parameter for when the icon is a {@link android.graphics.drawable.LevelListDrawable
         * LevelListDrawable}.
         *
         * @param icon A resource ID in the application's package of the drawable to use.
         * @param level The level to use for the icon.
         *
         * @see android.graphics.drawable.LevelListDrawable
         */
        public Builder setSmallIcon(int icon, int level) {
            mNotification.icon = icon;
            mNotification.iconLevel = level;
            return this;
        }

        /**
         * Set the title (first row) of the notification, in a standard notification.
         */
        public Builder setContentTitle(CharSequence title) {
            mContentTitle = limitCharSequenceLength(title);
            return this;
        }

        /**
         * Set the text (second row) of the notification, in a standard notification.
         */
        public Builder setContentText(CharSequence text) {
            mContentText = limitCharSequenceLength(text);
            return this;
        }

        /**
         * Set the third line of text in the platform notification template.
         * Don't use if you're also using {@link #setProgress(int, int, boolean)};
         * they occupy the same location in the standard template.
         * <br>
         * If the platform does not provide large-format notifications, this method has no effect.
         * The third line of text only appears in expanded view.
         * <br>
         */
        public Builder setSubText(CharSequence text) {
            mSubText = limitCharSequenceLength(text);
            return this;
        }

        /**
         * Set the remote input history.
         *
         * This should be set to the most recent inputs that have been sent
         * through a {@link RemoteInput} of this Notification and cleared once the it is no
         * longer relevant (e.g. for chat notifications once the other party has responded).
         *
         * The most recent input must be stored at the 0 index, the second most recent at the
         * 1 index, etc. Note that the system will limit both how far back the inputs will be shown
         * and how much of each individual input is shown.
         *
         * <p>Note: The reply text will only be shown on notifications that have least one action
         * with a {@code RemoteInput}.</p>
         */
        public Builder setRemoteInputHistory(CharSequence[] text) {
            mRemoteInputHistory = text;
            return this;
        }

        /**
         * Set the large number at the right-hand side of the notification.  This is
         * equivalent to setContentInfo, although it might show the number in a different
         * font size for readability.
         */
        public Builder setNumber(int number) {
            mNumber = number;
            return this;
        }

        /**
         * Set the large text at the right-hand side of the notification.
         */
        public Builder setContentInfo(CharSequence info) {
            mContentInfo = limitCharSequenceLength(info);
            return this;
        }

        /**
         * Set the progress this notification represents, which may be
         * represented as a {@link android.widget.ProgressBar}.
         */
        public Builder setProgress(int max, int progress, boolean indeterminate) {
            mProgressMax = max;
            mProgress = progress;
            mProgressIndeterminate = indeterminate;
            return this;
        }

        /**
         * Supply a custom RemoteViews to use instead of the standard one.
         */
        public Builder setContent(RemoteViews views) {
            mNotification.contentView = views;
            return this;
        }

        /**
         * Supply a {@link PendingIntent} to send when the notification is clicked.
         * If you do not supply an intent, you can now add PendingIntents to individual
         * views to be launched when clicked by calling {@link RemoteViews#setOnClickPendingIntent
         * RemoteViews.setOnClickPendingIntent(int,PendingIntent)}.  Be sure to
         * read {@link Notification#contentIntent Notification.contentIntent} for
         * how to correctly use this.
         */
        public Builder setContentIntent(PendingIntent intent) {
            mContentIntent = intent;
            return this;
        }

        /**
         * Supply a {@link PendingIntent} to send when the notification is cleared by the user
         * directly from the notification panel.  For example, this intent is sent when the user
         * clicks the "Clear all" button, or the individual "X" buttons on notifications.  This
         * intent is not sent when the application calls
         * {@link android.app.NotificationManager#cancel NotificationManager.cancel(int)}.
         */
        public Builder setDeleteIntent(PendingIntent intent) {
            mNotification.deleteIntent = intent;
            return this;
        }

        /**
         * An intent to launch instead of posting the notification to the status bar.
         * Only for use with extremely high-priority notifications demanding the user's
         * <strong>immediate</strong> attention, such as an incoming phone call or
         * alarm clock that the user has explicitly set to a particular time.
         * If this facility is used for something else, please give the user an option
         * to turn it off and use a normal notification, as this can be extremely
         * disruptive.
         *
         * <p>
         * On some platforms, the system UI may choose to display a heads-up notification,
         * instead of launching this intent, while the user is using the device.
         * </p>
         *
         * @param intent The pending intent to launch.
         * @param highPriority Passing true will cause this notification to be sent
         *          even if other notifications are suppressed.
         */
        public Builder setFullScreenIntent(PendingIntent intent, boolean highPriority) {
            mFullScreenIntent = intent;
            setFlag(FLAG_HIGH_PRIORITY, highPriority);
            return this;
        }

        /**
         * Set the text that is displayed in the status bar when the notification first
         * arrives.
         */
        public Builder setTicker(CharSequence tickerText) {
            mNotification.tickerText = limitCharSequenceLength(tickerText);
            return this;
        }

        /**
         * Set the text that is displayed in the status bar when the notification first
         * arrives, and also a RemoteViews object that may be displayed instead on some
         * devices.
         */
        public Builder setTicker(CharSequence tickerText, RemoteViews views) {
            mNotification.tickerText = limitCharSequenceLength(tickerText);
            mTickerView = views;
            return this;
        }

        /**
         * Set the large icon that is shown in the ticker and notification.
         */
        public Builder setLargeIcon(Bitmap icon) {
            mLargeIcon = icon;
            return this;
        }

        /**
         * Set the sound to play.  It will play on the default stream.
         *
         * <p>
         * On some platforms, a notification that is noisy is more likely to be presented
         * as a heads-up notification.
         * </p>
         */
        public Builder setSound(Uri sound) {
            mNotification.sound = sound;
            mNotification.audioStreamType = Notification.STREAM_DEFAULT;
            return this;
        }

        /**
         * Set the sound to play.  It will play on the stream you supply.
         *
         * <p>
         * On some platforms, a notification that is noisy is more likely to be presented
         * as a heads-up notification.
         * </p>
         *
         * @see Notification#STREAM_DEFAULT
         * @see AudioManager for the <code>STREAM_</code> constants.
         */
        public Builder setSound(Uri sound, int streamType) {
            mNotification.sound = sound;
            mNotification.audioStreamType = streamType;
            return this;
        }

        /**
         * Set the vibration pattern to use.
         *
         * <p>
         * On some platforms, a notification that vibrates is more likely to be presented
         * as a heads-up notification.
         * </p>
         *
         * @see android.os.Vibrator for a discussion of the <code>pattern</code>
         * parameter.
         */
        public Builder setVibrate(long[] pattern) {
            mNotification.vibrate = pattern;
            return this;
        }

        /**
         * Set the argb value that you would like the LED on the device to blink, as well as the
         * rate.  The rate is specified in terms of the number of milliseconds to be on
         * and then the number of milliseconds to be off.
         */
        public Builder setLights(@ColorInt int argb, int onMs, int offMs) {
            mNotification.ledARGB = argb;
            mNotification.ledOnMS = onMs;
            mNotification.ledOffMS = offMs;
            boolean showLights = mNotification.ledOnMS != 0 && mNotification.ledOffMS != 0;
            mNotification.flags = (mNotification.flags & ~Notification.FLAG_SHOW_LIGHTS) |
                    (showLights ? Notification.FLAG_SHOW_LIGHTS : 0);
            return this;
        }

        /**
         * Set whether this is an ongoing notification.
         *
         * <p>Ongoing notifications differ from regular notifications in the following ways:
         * <ul>
         *   <li>Ongoing notifications are sorted above the regular notifications in the
         *   notification panel.</li>
         *   <li>Ongoing notifications do not have an 'X' close button, and are not affected
         *   by the "Clear all" button.
         * </ul>
         */
        public Builder setOngoing(boolean ongoing) {
            setFlag(Notification.FLAG_ONGOING_EVENT, ongoing);
            return this;
        }

        /**
         * Set whether this notification should be colorized. When set, the color set with
         * {@link #setColor(int)} will be used as the background color of this notification.
         * <p>
         * This should only be used for high priority ongoing tasks like navigation, an ongoing
         * call, or other similarly high-priority events for the user.
         * <p>
         * For most styles, the coloring will only be applied if the notification is for a
         * foreground service notification.
         * <p>
         * However, for MediaStyle and DecoratedMediaCustomViewStyle notifications
         * that have a media session attached there is no such requirement.
         * <p>
         * Calling this method on any version prior to {@link android.os.Build.VERSION_CODES#O} will
         * not have an effect on the notification and it won't be colorized.
         *
         * @see #setColor(int)
         */
        public Builder setColorized(boolean colorize) {
            mColorized = colorize;
            mColorizedSet = true;
            return this;
        }

        /**
         * Set this flag if you would only like the sound, vibrate
         * and ticker to be played if the notification is not already showing.
         */
        public Builder setOnlyAlertOnce(boolean onlyAlertOnce) {
            setFlag(Notification.FLAG_ONLY_ALERT_ONCE, onlyAlertOnce);
            return this;
        }

        /**
         * Setting this flag will make it so the notification is automatically
         * canceled when the user clicks it in the panel.  The PendingIntent
         * set with {@link #setDeleteIntent} will be broadcast when the notification
         * is canceled.
         */
        public Builder setAutoCancel(boolean autoCancel) {
            setFlag(Notification.FLAG_AUTO_CANCEL, autoCancel);
            return this;
        }

        /**
         * Set whether or not this notification is only relevant to the current device.
         *
         * <p>Some notifications can be bridged to other devices for remote display.
         * This hint can be set to recommend this notification not be bridged.
         */
        public Builder setLocalOnly(boolean b) {
            mLocalOnly = b;
            return this;
        }

        /**
         * Set the notification category.
         *
         * <p>Must be one of the predefined notification categories (see the <code>CATEGORY_*</code>
         * constants in {@link Notification}) that best describes this notification.
         * May be used by the system for ranking and filtering.
         */
        public Builder setCategory(String category) {
            mCategory = category;
            return this;
        }

        /**
         * Set the default notification options that will be used.
         * <p>
         * The value should be one or more of the following fields combined with
         * bitwise-or:
         * {@link Notification#DEFAULT_SOUND}, {@link Notification#DEFAULT_VIBRATE},
         * {@link Notification#DEFAULT_LIGHTS}.
         * <p>
         * For all default values, use {@link Notification#DEFAULT_ALL}.
         */
        public Builder setDefaults(int defaults) {
            mNotification.defaults = defaults;
            if ((defaults & Notification.DEFAULT_LIGHTS) != 0) {
                mNotification.flags |= Notification.FLAG_SHOW_LIGHTS;
            }
            return this;
        }

        private void setFlag(int mask, boolean value) {
            if (value) {
                mNotification.flags |= mask;
            } else {
                mNotification.flags &= ~mask;
            }
        }

        /**
         * Set the relative priority for this notification.
         *
         * Priority is an indication of how much of the user's
         * valuable attention should be consumed by this
         * notification. Low-priority notifications may be hidden from
         * the user in certain situations, while the user might be
         * interrupted for a higher-priority notification.
         * The system sets a notification's priority based on various factors including the
         * setPriority value. The effect may differ slightly on different platforms.
         *
         * @param pri Relative priority for this notification. Must be one of
         *     the priority constants defined by {@link NotificationCompat}.
         *     Acceptable values range from {@link
         *     NotificationCompat#PRIORITY_MIN} (-2) to {@link
         *     NotificationCompat#PRIORITY_MAX} (2).
         */
        public Builder setPriority(int pri) {
            mPriority = pri;
            return this;
        }

        /**
         * Add a person that is relevant to this notification.
         *
         * <P>
         * Depending on user preferences, this annotation may allow the notification to pass
         * through interruption filters, and to appear more prominently in the user interface.
         * </P>
         *
         * <P>
         * The person should be specified by the {@code String} representation of a
         * {@link android.provider.ContactsContract.Contacts#CONTENT_LOOKUP_URI}.
         * </P>
         *
         * <P>The system will also attempt to resolve {@code mailto:} and {@code tel:} schema
         * URIs.  The path part of these URIs must exist in the contacts database, in the
         * appropriate column, or the reference will be discarded as invalid. Telephone schema
         * URIs will be resolved by {@link android.provider.ContactsContract.PhoneLookup}.
         * </P>
         *
         * @param uri A URI for the person.
         * @see Notification#EXTRA_PEOPLE
         */
        public Builder addPerson(String uri) {
            mPeople.add(uri);
            return this;
        }

        /**
         * Set this notification to be part of a group of notifications sharing the same key.
         * Grouped notifications may display in a cluster or stack on devices which
         * support such rendering.
         *
         * <p>To make this notification the summary for its group, also call
         * {@link #setGroupSummary}. A sort order can be specified for group members by using
         * {@link #setSortKey}.
         * @param groupKey The group key of the group.
         * @return this object for method chaining
         */
        public Builder setGroup(String groupKey) {
            mGroupKey = groupKey;
            return this;
        }

        /**
         * Set this notification to be the group summary for a group of notifications.
         * Grouped notifications may display in a cluster or stack on devices which
         * support such rendering. Requires a group key also be set using {@link #setGroup}.
         * @param isGroupSummary Whether this notification should be a group summary.
         * @return this object for method chaining
         */
        public Builder setGroupSummary(boolean isGroupSummary) {
            mGroupSummary = isGroupSummary;
            return this;
        }

        /**
         * Set a sort key that orders this notification among other notifications from the
         * same package. This can be useful if an external sort was already applied and an app
         * would like to preserve this. Notifications will be sorted lexicographically using this
         * value, although providing different priorities in addition to providing sort key may
         * cause this value to be ignored.
         *
         * <p>This sort key can also be used to order members of a notification group. See
         * {@link Builder#setGroup}.
         *
         * @see String#compareTo(String)
         */
        public Builder setSortKey(String sortKey) {
            mSortKey = sortKey;
            return this;
        }

        /**
         * Merge additional metadata into this notification.
         *
         * <p>Values within the Bundle will replace existing extras values in this Builder.
         *
         * @see Notification#extras
         */
        public Builder addExtras(Bundle extras) {
            if (extras != null) {
                if (mExtras == null) {
                    mExtras = new Bundle(extras);
                } else {
                    mExtras.putAll(extras);
                }
            }
            return this;
        }

        /**
         * Set metadata for this notification.
         *
         * <p>A reference to the Bundle is held for the lifetime of this Builder, and the Bundle's
         * current contents are copied into the Notification each time {@link #build()} is
         * called.
         *
         * <p>Replaces any existing extras values with those from the provided Bundle.
         * Use {@link #addExtras} to merge in metadata instead.
         *
         * @see Notification#extras
         */
        public Builder setExtras(Bundle extras) {
            mExtras = extras;
            return this;
        }

        /**
         * Get the current metadata Bundle used by this notification Builder.
         *
         * <p>The returned Bundle is shared with this Builder.
         *
         * <p>The current contents of this Bundle are copied into the Notification each time
         * {@link #build()} is called.
         *
         * @see Notification#extras
         */
        public Bundle getExtras() {
            if (mExtras == null) {
                mExtras = new Bundle();
            }
            return mExtras;
        }

        /**
         * Add an action to this notification. Actions are typically displayed by
         * the system as a button adjacent to the notification content.
         * <br>
         * Action buttons won't appear on platforms prior to Android 4.1. Action
         * buttons depend on expanded notifications, which are only available in Android 4.1
         * and later. To ensure that an action button's functionality is always available, first
         * implement the functionality in the {@link android.app.Activity} that starts when a user
         * clicks the  notification (see {@link #setContentIntent setContentIntent()}), and then
         * enhance the notification by implementing the same functionality with
         * {@link #addAction addAction()}.
         *
         * @param icon Resource ID of a drawable that represents the action.
         * @param title Text describing the action.
         * @param intent {@link android.app.PendingIntent} to be fired when the action is invoked.
         */
        public Builder addAction(int icon, CharSequence title, PendingIntent intent) {
            mActions.add(new Action(icon, title, intent));
            return this;
        }

        /**
         * Add an action to this notification. Actions are typically displayed by
         * the system as a button adjacent to the notification content.
         * <br>
         * Action buttons won't appear on platforms prior to Android 4.1. Action
         * buttons depend on expanded notifications, which are only available in Android 4.1
         * and later. To ensure that an action button's functionality is always available, first
         * implement the functionality in the {@link android.app.Activity} that starts when a user
         * clicks the  notification (see {@link #setContentIntent setContentIntent()}), and then
         * enhance the notification by implementing the same functionality with
         * {@link #addAction addAction()}.
         *
         * @param action The action to add.
         */
        public Builder addAction(Action action) {
            mActions.add(action);
            return this;
        }

        /**
         * Add a rich notification style to be applied at build time.
         * <br>
         * If the platform does not provide rich notification styles, this method has no effect. The
         * user will always see the normal notification style.
         *
         * @param style Object responsible for modifying the notification style.
         */
        public Builder setStyle(Style style) {
            if (mStyle != style) {
                mStyle = style;
                if (mStyle != null) {
                    mStyle.setBuilder(this);
                }
            }
            return this;
        }

        /**
         * Sets {@link Notification#color}.
         *
         * @param argb The accent color to use
         *
         * @return The same Builder.
         */
        public Builder setColor(@ColorInt int argb) {
            mColor = argb;
            return this;
        }

        /**
         * Sets {@link Notification#visibility}.
         *
         * @param visibility One of {@link Notification#VISIBILITY_PRIVATE} (the default),
         *                   {@link Notification#VISIBILITY_PUBLIC}, or
         *                   {@link Notification#VISIBILITY_SECRET}.
         */
        public Builder setVisibility(@NotificationVisibility int visibility) {
            mVisibility = visibility;
            return this;
        }

        /**
         * Supply a replacement Notification whose contents should be shown in insecure contexts
         * (i.e. atop the secure lockscreen). See {@link Notification#visibility} and
         * {@link #VISIBILITY_PUBLIC}.
         *
         * @param n A replacement notification, presumably with some or all info redacted.
         * @return The same Builder.
         */
        public Builder setPublicVersion(Notification n) {
            mPublicVersion = n;
            return this;
        }

        /**
         * Supply custom RemoteViews to use instead of the platform template.
         *
         * This will override the layout that would otherwise be constructed by this Builder
         * object.
         */
        public Builder setCustomContentView(RemoteViews contentView) {
            mContentView = contentView;
            return this;
        }

        /**
         * Supply custom RemoteViews to use instead of the platform template in the expanded form.
         *
         * This will override the expanded layout that would otherwise be constructed by this
         * Builder object.
         *
         * No-op on versions prior to {@link android.os.Build.VERSION_CODES#JELLY_BEAN}.
         */
        public Builder setCustomBigContentView(RemoteViews contentView) {
            mBigContentView = contentView;
            return this;
        }

        /**
         * Supply custom RemoteViews to use instead of the platform template in the heads up dialog.
         *
         * This will override the heads-up layout that would otherwise be constructed by this
         * Builder object.
         *
         * No-op on versions prior to {@link android.os.Build.VERSION_CODES#LOLLIPOP}.
         */
        public Builder setCustomHeadsUpContentView(RemoteViews contentView) {
            mHeadsUpContentView = contentView;
            return this;
        }

        /**
         * Specifies the channel the notification should be delivered on.
         *
         * No-op on versions prior to {@link android.os.Build.VERSION_CODES#O} .
         */
        public Builder setChannelId(@NonNull String channelId) {
            mChannelId = channelId;
            return this;
        }

        /** @deprecated removed from API 26 */
        @Deprecated
        public Builder setChannel(@NonNull String channelId) {
            return setChannelId(channelId);
        }

        /**
         * Specifies the time at which this notification should be canceled, if it is not already
         * canceled.
         */
        public Builder setTimeoutAfter(long durationMs) {
            mTimeout = durationMs;
            return this;
        }

        /** @deprecated removed from API 26 */
        @Deprecated
        public Builder setTimeout(long durationMs) {
            return setTimeoutAfter(durationMs);
        }

        /**
         * If this notification is duplicative of a Launcher shortcut, sets the
         * {@link android.support.v4.content.pm.ShortcutInfoCompat#getId() id} of the shortcut, in
         * case the Launcher wants to hide the shortcut.
         *
         * <p><strong>Note:</strong>This field will be ignored by Launchers that don't support
         * badging or {@link android.support.v4.content.pm.ShortcutManagerCompat shortcuts}.
         *
         * @param shortcutId the {@link android.support.v4.content.pm.ShortcutInfoCompat#getId() id}
         *                   of the shortcut this notification supersedes
         */
        public Builder setShortcutId(String shortcutId) {
            mShortcutId = shortcutId;
            return this;
        }

        /**
         * Sets which icon to display as a badge for this notification.
         *
         * <p>Must be one of {@link #BADGE_ICON_NONE}, {@link #BADGE_ICON_SMALL},
         * {@link #BADGE_ICON_LARGE}.
         *
         * <p><strong>Note:</strong> This value might be ignored, for launchers that don't support
         * badge icons.
         */
        public Builder setBadgeIconType(@BadgeIconType int icon) {
            mBadgeIcon = icon;
            return this;
        }

        /**
         * Sets the group alert behavior for this notification. Use this method to mute this
         * notification if alerts for this notification's group should be handled by a different
         * notification. This is only applicable for notifications that belong to a
         * {@link #setGroup(String) group}.
         *
         * <p> The default value is {@link #GROUP_ALERT_ALL}.</p>
         */
        public Builder setGroupAlertBehavior(int groupAlertBehavior) {
            mGroupAlertBehavior = groupAlertBehavior;
            return this;
        }

        /**
         * Apply an extender to this notification builder. Extenders may be used to add
         * metadata or change options on this builder.
         */
        public Builder extend(Extender extender) {
            extender.extend(this);
            return this;
        }

        /**
         * @deprecated Use {@link #build()} instead.
         */
        @Deprecated
        public Notification getNotification() {
            return build();
        }

        /**
         * Combine all of the options that have been set and return a new {@link Notification}
         * object.
         */
        public Notification build() {
            return IMPL.build(this, getExtender());
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        protected BuilderExtender getExtender() {
            return new BuilderExtender();
        }

        protected static CharSequence limitCharSequenceLength(CharSequence cs) {
            if (cs == null) return cs;
            if (cs.length() > MAX_CHARSEQUENCE_LENGTH) {
                cs = cs.subSequence(0, MAX_CHARSEQUENCE_LENGTH);
            }
            return cs;
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        public RemoteViews getContentView() {
            return mContentView;
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        public RemoteViews getBigContentView() {
            return mBigContentView;
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        public RemoteViews getHeadsUpContentView() {
            return mHeadsUpContentView;
        }

        /**
         * return when if it is showing or 0 otherwise
         *
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        public long getWhenIfShowing() {
            return mShowWhen ? mNotification.when : 0;
        }

        /**
         * @return the priority set on the notification
         *
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        public int getPriority() {
            return mPriority;
        }

        /**
         * @return the color of the notification
         *
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        public int getColor() {
            return mColor;
        }


        /**
         * @return the text of the notification
         *
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        protected CharSequence resolveText() {
            return mContentText;
        }

        /**
         * @return the title of the notification
         *
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        protected CharSequence resolveTitle() {
            return mContentTitle;
        }
    }

    /**
     * An object that can apply a rich notification style to a {@link Notification.Builder}
     * object.
     * <br>
     * If the platform does not provide rich notification styles, methods in this class have no
     * effect.
     */
    public static abstract class Style {
        Builder mBuilder;
        CharSequence mBigContentTitle;
        CharSequence mSummaryText;
        boolean mSummaryTextSet = false;

        public void setBuilder(Builder builder) {
            if (mBuilder != builder) {
                mBuilder = builder;
                if (mBuilder != null) {
                    mBuilder.setStyle(this);
                }
            }
        }

        public Notification build() {
            Notification notification = null;
            if (mBuilder != null) {
                notification = mBuilder.build();
            }
            return notification;
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        // TODO: implement for all styles
        public void addCompatExtras(Bundle extras) {
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        // TODO: implement for all styles
        protected void restoreFromCompatExtras(Bundle extras) {
        }
    }

    /**
     * Helper class for generating large-format notifications that include a large image attachment.
     * <br>
     * If the platform does not provide large-format notifications, this method has no effect. The
     * user will always see the normal notification view.
     * <br>
     * This class is a "rebuilder": It attaches to a Builder object and modifies its behavior, like so:
     * <pre class="prettyprint">
     * Notification notification = new Notification.Builder(mContext)
     *     .setContentTitle(&quot;New photo from &quot; + sender.toString())
     *     .setContentText(subject)
     *     .setSmallIcon(R.drawable.new_post)
     *     .setLargeIcon(aBitmap)
     *     .setStyle(new Notification.BigPictureStyle()
     *         .bigPicture(aBigBitmap))
     *     .build();
     * </pre>
     *
     * @see Notification#bigContentView
     */
    public static class BigPictureStyle extends Style {
        Bitmap mPicture;
        Bitmap mBigLargeIcon;
        boolean mBigLargeIconSet;

        public BigPictureStyle() {
        }

        public BigPictureStyle(Builder builder) {
            setBuilder(builder);
        }

        /**
         * Overrides ContentTitle in the big form of the template.
         * This defaults to the value passed to setContentTitle().
         */
        public BigPictureStyle setBigContentTitle(CharSequence title) {
            mBigContentTitle = Builder.limitCharSequenceLength(title);
            return this;
        }

        /**
         * Set the first line of text after the detail section in the big form of the template.
         */
        public BigPictureStyle setSummaryText(CharSequence cs) {
            mSummaryText = Builder.limitCharSequenceLength(cs);
            mSummaryTextSet = true;
            return this;
        }

        /**
         * Provide the bitmap to be used as the payload for the BigPicture notification.
         */
        public BigPictureStyle bigPicture(Bitmap b) {
            mPicture = b;
            return this;
        }

        /**
         * Override the large icon when the big notification is shown.
         */
        public BigPictureStyle bigLargeIcon(Bitmap b) {
            mBigLargeIcon = b;
            mBigLargeIconSet = true;
            return this;
        }
    }

    /**
     * Helper class for generating large-format notifications that include a lot of text.
     *
     * <br>
     * If the platform does not provide large-format notifications, this method has no effect. The
     * user will always see the normal notification view.
     * <br>
     * This class is a "rebuilder": It attaches to a Builder object and modifies its behavior, like so:
     * <pre class="prettyprint">
     * Notification notification = new Notification.Builder(mContext)
     *     .setContentTitle(&quot;New mail from &quot; + sender.toString())
     *     .setContentText(subject)
     *     .setSmallIcon(R.drawable.new_mail)
     *     .setLargeIcon(aBitmap)
     *     .setStyle(new Notification.BigTextStyle()
     *         .bigText(aVeryLongString))
     *     .build();
     * </pre>
     *
     * @see Notification#bigContentView
     */
    public static class BigTextStyle extends Style {
        CharSequence mBigText;

        public BigTextStyle() {
        }

        public BigTextStyle(Builder builder) {
            setBuilder(builder);
        }

        /**
         * Overrides ContentTitle in the big form of the template.
         * This defaults to the value passed to setContentTitle().
         */
        public BigTextStyle setBigContentTitle(CharSequence title) {
            mBigContentTitle = Builder.limitCharSequenceLength(title);
            return this;
        }

        /**
         * Set the first line of text after the detail section in the big form of the template.
         */
        public BigTextStyle setSummaryText(CharSequence cs) {
            mSummaryText = Builder.limitCharSequenceLength(cs);
            mSummaryTextSet = true;
            return this;
        }

        /**
         * Provide the longer text to be displayed in the big form of the
         * template in place of the content text.
         */
        public BigTextStyle bigText(CharSequence cs) {
            mBigText = Builder.limitCharSequenceLength(cs);
            return this;
        }
    }

    /**
     * Helper class for generating large-format notifications that include multiple back-and-forth
     * messages of varying types between any number of people.
     *
     * <br>
     * In order to get a backwards compatible behavior, the app needs to use the v7 version of the
     * notification builder together with this style, otherwise the user will see the normal
     * notification view.
     *
     * <br>
     * Use {@link MessagingStyle#setConversationTitle(CharSequence)} to set a conversation title for
     * group chats with more than two people. This could be the user-created name of the group or,
     * if it doesn't have a specific name, a list of the participants in the conversation. Do not
     * set a conversation title for one-on-one chats, since platforms use the existence of this
     * field as a hint that the conversation is a group.
     *
     * <br>
     * This class is a "rebuilder": It attaches to a Builder object and modifies its behavior, like
     * so:
     * <pre class="prettyprint">
     *
     * Notification notification = new Notification.Builder()
     *     .setContentTitle(&quot;2 new messages with &quot; + sender.toString())
     *     .setContentText(subject)
     *     .setSmallIcon(R.drawable.new_message)
     *     .setLargeIcon(aBitmap)
     *     .setStyle(new Notification.MessagingStyle(resources.getString(R.string.reply_name))
     *         .addMessage(messages[0].getText(), messages[0].getTime(), messages[0].getSender())
     *         .addMessage(messages[1].getText(), messages[1].getTime(), messages[1].getSender()))
     *     .build();
     * </pre>
     */
    public static class MessagingStyle extends Style {

        /**
         * The maximum number of messages that will be retained in the Notification itself (the
         * number displayed is up to the platform).
         */
        public static final int MAXIMUM_RETAINED_MESSAGES = 25;

        CharSequence mUserDisplayName;
        CharSequence mConversationTitle;
        List<Message> mMessages = new ArrayList<>();

        MessagingStyle() {
        }

        /**
         * @param userDisplayName Required - the name to be displayed for any replies sent by the
         * user before the posting app reposts the notification with those messages after they've
         * been actually sent and in previous messages sent by the user added in
         * {@link #addMessage(Message)}
         */
        public MessagingStyle(@NonNull CharSequence userDisplayName) {
            mUserDisplayName = userDisplayName;
        }

        /**
         * Returns the name to be displayed for any replies sent by the user
         */
        public CharSequence getUserDisplayName() {
            return mUserDisplayName;
        }

        /**
         * Sets the title to be displayed on this conversation. This should only be used for
         * group messaging and left unset for one-on-one conversations.
         * @param conversationTitle Title displayed for this conversation.
         * @return this object for method chaining.
         */
        public MessagingStyle setConversationTitle(CharSequence conversationTitle) {
            mConversationTitle = conversationTitle;
            return this;
        }

        /**
         * Return the title to be displayed on this conversation. Can be <code>null</code> and
         * should be for one-on-one conversations
         */
        public CharSequence getConversationTitle() {
            return mConversationTitle;
        }

        /**
         * Adds a message for display by this notification. Convenience call for a simple
         * {@link Message} in {@link #addMessage(Message)}
         * @param text A {@link CharSequence} to be displayed as the message content
         * @param timestamp Time at which the message arrived
         * @param sender A {@link CharSequence} to be used for displaying the name of the
         * sender. Should be <code>null</code> for messages by the current user, in which case
         * the platform will insert {@link #getUserDisplayName()}.
         * Should be unique amongst all individuals in the conversation, and should be
         * consistent during re-posts of the notification.
         *
         * @see Message#Message(CharSequence, long, CharSequence)
         *
         * @return this object for method chaining
         */
        public MessagingStyle addMessage(CharSequence text, long timestamp, CharSequence sender) {
            mMessages.add(new Message(text, timestamp, sender));
            if (mMessages.size() > MAXIMUM_RETAINED_MESSAGES) {
                mMessages.remove(0);
            }
            return this;
        }

        /**
         * Adds a {@link Message} for display in this notification.
         * @param message The {@link Message} to be displayed
         * @return this object for method chaining
         */
        public MessagingStyle addMessage(Message message) {
            mMessages.add(message);
            if (mMessages.size() > MAXIMUM_RETAINED_MESSAGES) {
                mMessages.remove(0);
            }
            return this;
        }

        /**
         * Gets the list of {@code Message} objects that represent the notification
         */
        public List<Message> getMessages() {
            return mMessages;
        }

        /**
         * Retrieves a {@link MessagingStyle} from a {@link Notification}, enabling an application
         * that has set a {@link MessagingStyle} using {@link NotificationCompat} or
         * {@link android.app.Notification.Builder} to send messaging information to another
         * application using {@link NotificationCompat}, regardless of the API level of the system.
         * Returns {@code null} if there is no {@link MessagingStyle} set.
         */
        public static MessagingStyle extractMessagingStyleFromNotification(
                Notification notification) {
            MessagingStyle style;
            Bundle extras = NotificationCompat.getExtras(notification);
            if (extras != null && !extras.containsKey(EXTRA_SELF_DISPLAY_NAME)) {
                style = null;
            } else {
                try {
                    style = new MessagingStyle();
                    style.restoreFromCompatExtras(extras);
                } catch (ClassCastException e) {
                    style = null;
                }
            }
            return style;
        }

        @Override
        public void addCompatExtras(Bundle extras) {
            super.addCompatExtras(extras);
            if (mUserDisplayName != null) {
                extras.putCharSequence(EXTRA_SELF_DISPLAY_NAME, mUserDisplayName);
            }
            if (mConversationTitle != null) {
                extras.putCharSequence(EXTRA_CONVERSATION_TITLE, mConversationTitle);
            }
            if (!mMessages.isEmpty()) { extras.putParcelableArray(EXTRA_MESSAGES,
                    Message.getBundleArrayForMessages(mMessages));
            }
        }

        /**
         * @hide
         */
        @RestrictTo(LIBRARY_GROUP)
        @Override
        protected void restoreFromCompatExtras(Bundle extras) {
            mMessages.clear();
            mUserDisplayName = extras.getString(EXTRA_SELF_DISPLAY_NAME);
            mConversationTitle = extras.getString(EXTRA_CONVERSATION_TITLE);
            Parcelable[] parcelables = extras.getParcelableArray(EXTRA_MESSAGES);
            if (parcelables != null) {
                mMessages = Message.getMessagesFromBundleArray(parcelables);
            }
        }

        public static final class Message {

            static final String KEY_TEXT = "text";
            static final String KEY_TIMESTAMP = "time";
            static final String KEY_SENDER = "sender";
            static final String KEY_DATA_MIME_TYPE = "type";
            static final String KEY_DATA_URI= "uri";
            static final String KEY_EXTRAS_BUNDLE = "extras";

            private final CharSequence mText;
            private final long mTimestamp;
            private final CharSequence mSender;

            private Bundle mExtras = new Bundle();
            private String mDataMimeType;
            private Uri mDataUri;

            /**
             * Constructor
             * @param text A {@link CharSequence} to be displayed as the message content
             * @param timestamp Time at which the message arrived
             * @param sender A {@link CharSequence} to be used for displaying the name of the
             * sender. Should be <code>null</code> for messages by the current user, in which case
             * the platform will insert {@link MessagingStyle#getUserDisplayName()}.
             * Should be unique amongst all individuals in the conversation, and should be
             * consistent during re-posts of the notification.
             */
            public Message(CharSequence text, long timestamp, CharSequence sender){
                mText = text;
                mTimestamp = timestamp;
                mSender = sender;
            }

            /**
             * Sets a binary blob of data and an associated MIME type for a message. In the case
             * where the platform doesn't support the MIME type, the original text provided in the
             * constructor will be used.
             * @param dataMimeType The MIME type of the content. See
             * <a href="{@docRoot}notifications/messaging.html"> for the list of supported MIME
             * types on Android and Android Wear.
             * @param dataUri The uri containing the content whose type is given by the MIME type.
             * <p class="note">
             * <ol>
             *   <li>Notification Listeners including the System UI need permission to access the
             *       data the Uri points to. The recommended ways to do this are:</li>
             *   <li>Store the data in your own ContentProvider, making sure that other apps have
             *       the correct permission to access your provider. The preferred mechanism for
             *       providing access is to use per-URI permissions which are temporary and only
             *       grant access to the receiving application. An easy way to create a
             *       ContentProvider like this is to use the FileProvider helper class.</li>
             *   <li>Use the system MediaStore. The MediaStore is primarily aimed at video, audio
             *       and image MIME types, however beginning with Android 3.0 (API level 11) it can
             *       also store non-media types (see MediaStore.Files for more info). Files can be
             *       inserted into the MediaStore using scanFile() after which a content:// style
             *       Uri suitable for sharing is passed to the provided onScanCompleted() callback.
             *       Note that once added to the system MediaStore the content is accessible to any
             *       app on the device.</li>
             * </ol>
             * @return this object for method chaining
             */
            public Message setData(String dataMimeType, Uri dataUri) {
                mDataMimeType = dataMimeType;
                mDataUri = dataUri;
                return this;
            }

            /**
             * Get the text to be used for this message, or the fallback text if a type and content
             * Uri have been set
             */
            public CharSequence getText() {
                return mText;
            }

            /**
             * Get the time at which this message arrived
             */
            public long getTimestamp() {
                return mTimestamp;
            }

            /**
             * Get the extras Bundle for this message.
             */
            public Bundle getExtras() {
                return mExtras;
            }

            /**
             * Get the text used to display the contact's name in the messaging experience
             */
            public CharSequence getSender() {
                return mSender;
            }

            /**
             * Get the MIME type of the data pointed to by the Uri
             */
            public String getDataMimeType() {
                return mDataMimeType;
            }

            /**
             * Get the the Uri pointing to the content of the message. Can be null, in which case
             * {@see #getText()} is used.
             */
            public Uri getDataUri() {
                return mDataUri;
            }

            private Bundle toBundle() {
                Bundle bundle = new Bundle();
                if (mText != null) {
                    bundle.putCharSequence(KEY_TEXT, mText);
                }
                bundle.putLong(KEY_TIMESTAMP, mTimestamp);
                if (mSender != null) {
                    bundle.putCharSequence(KEY_SENDER, mSender);
                }
                if (mDataMimeType != null) {
                    bundle.putString(KEY_DATA_MIME_TYPE, mDataMimeType);
                }
                if (mDataUri != null) {
                    bundle.putParcelable(KEY_DATA_URI, mDataUri);
                }
                if (mExtras != null) {
                    bundle.putBundle(KEY_EXTRAS_BUNDLE, mExtras);
                }
                return bundle;
            }

            static Bundle[] getBundleArrayForMessages(List<Message> messages) {
                Bundle[] bundles = new Bundle[messages.size()];
                final int N = messages.size();
                for (int i = 0; i < N; i++) {
                    bundles[i] = messages.get(i).toBundle();
                }
                return bundles;
            }

            static List<Message> getMessagesFromBundleArray(Parcelable[] bundles) {
                List<Message> messages = new ArrayList<>(bundles.length);
                for (int i = 0; i < bundles.length; i++) {
                    if (bundles[i] instanceof Bundle) {
                        Message message = getMessageFromBundle((Bundle)bundles[i]);
                        if (message != null) {
                            messages.add(message);
                        }
                    }
                }
                return messages;
            }

            static Message getMessageFromBundle(Bundle bundle) {
                try {
                    if (!bundle.containsKey(KEY_TEXT) || !bundle.containsKey(KEY_TIMESTAMP)) {
                        return null;
                    } else {
                        Message message = new Message(bundle.getCharSequence(KEY_TEXT),
                                bundle.getLong(KEY_TIMESTAMP), bundle.getCharSequence(KEY_SENDER));
                        if (bundle.containsKey(KEY_DATA_MIME_TYPE) &&
                                bundle.containsKey(KEY_DATA_URI)) {
                            message.setData(bundle.getString(KEY_DATA_MIME_TYPE),
                                    (Uri) bundle.getParcelable(KEY_DATA_URI));
                        }
                        if (bundle.containsKey(KEY_EXTRAS_BUNDLE)) {
                            message.getExtras().putAll(bundle.getBundle(KEY_EXTRAS_BUNDLE));
                        }
                        return message;
                    }
                } catch (ClassCastException e) {
                    return null;
                }
            }
        }
    }

    /**
     * Helper class for generating large-format notifications that include a list of (up to 5) strings.
     *
     * <br>
     * If the platform does not provide large-format notifications, this method has no effect. The
     * user will always see the normal notification view.
     * <br>
     * This class is a "rebuilder": It attaches to a Builder object and modifies its behavior, like so:
     * <pre class="prettyprint">
     * Notification notification = new Notification.Builder()
     *     .setContentTitle(&quot;5 New mails from &quot; + sender.toString())
     *     .setContentText(subject)
     *     .setSmallIcon(R.drawable.new_mail)
     *     .setLargeIcon(aBitmap)
     *     .setStyle(new Notification.InboxStyle()
     *         .addLine(str1)
     *         .addLine(str2)
     *         .setContentTitle(&quot;&quot;)
     *         .setSummaryText(&quot;+3 more&quot;))
     *     .build();
     * </pre>
     *
     * @see Notification#bigContentView
     */
    public static class InboxStyle extends Style {
        ArrayList<CharSequence> mTexts = new ArrayList<CharSequence>();

        public InboxStyle() {
        }

        public InboxStyle(Builder builder) {
            setBuilder(builder);
        }

        /**
         * Overrides ContentTitle in the big form of the template.
         * This defaults to the value passed to setContentTitle().
         */
        public InboxStyle setBigContentTitle(CharSequence title) {
            mBigContentTitle = Builder.limitCharSequenceLength(title);
            return this;
        }

        /**
         * Set the first line of text after the detail section in the big form of the template.
         */
        public InboxStyle setSummaryText(CharSequence cs) {
            mSummaryText = Builder.limitCharSequenceLength(cs);
            mSummaryTextSet = true;
            return this;
        }

        /**
         * Append a line to the digest section of the Inbox notification.
         */
        public InboxStyle addLine(CharSequence cs) {
            mTexts.add(Builder.limitCharSequenceLength(cs));
            return this;
        }
    }

    /**
     * Structure to encapsulate a named action that can be shown as part of this notification.
     * It must include an icon, a label, and a {@link PendingIntent} to be fired when the action is
     * selected by the user. Action buttons won't appear on platforms prior to Android 4.1.
     * <p>
     * Apps should use {@link NotificationCompat.Builder#addAction(int, CharSequence, PendingIntent)}
     * or {@link NotificationCompat.Builder#addAction(NotificationCompat.Action)}
     * to attach actions.
     */
    public static class Action extends NotificationCompatBase.Action {
        final Bundle mExtras;
        private final RemoteInput[] mRemoteInputs;

        /**
         * Holds {@link RemoteInput}s that only accept data, meaning
         * {@link RemoteInput#getAllowFreeFormInput} is false, {@link RemoteInput#getChoices}
         * is null or empty, and {@link RemoteInput#getAllowedDataTypes is non-null and not
         * empty. These {@link RemoteInput}s will be ignored by devices that do not
         * support non-text-based {@link RemoteInput}s. See {@link Builder#build}.
         *
         * You can test if a RemoteInput matches these constraints using
         * {@link RemoteInput#isDataOnly}.
         */
        private final RemoteInput[] mDataOnlyRemoteInputs;

        private boolean mAllowGeneratedReplies;

        /**
         * Small icon representing the action.
         */
        public int icon;
        /**
         * Title of the action.
         */
        public CharSequence title;
        /**
         * Intent to send when the user invokes this action. May be null, in which case the action
         * may be rendered in a disabled presentation.
         */
        public PendingIntent actionIntent;

        public Action(int icon, CharSequence title, PendingIntent intent) {
            this(icon, title, intent, new Bundle(), null, null, true);
        }

        Action(int icon, CharSequence title, PendingIntent intent, Bundle extras,
                RemoteInput[] remoteInputs, RemoteInput[] dataOnlyRemoteInputs,
                boolean allowGeneratedReplies) {
            this.icon = icon;
            this.title = NotificationCompat.Builder.limitCharSequenceLength(title);
            this.actionIntent = intent;
            this.mExtras = extras != null ? extras : new Bundle();
            this.mRemoteInputs = remoteInputs;
            this.mDataOnlyRemoteInputs = dataOnlyRemoteInputs;
            this.mAllowGeneratedReplies = allowGeneratedReplies;
        }

        @Override
        public int getIcon() {
            return icon;
        }

        @Override
        public CharSequence getTitle() {
            return title;
        }

        @Override
        public PendingIntent getActionIntent() {
            return actionIntent;
        }

        /**
         * Get additional metadata carried around with this Action.
         */
        @Override
        public Bundle getExtras() {
            return mExtras;
        }

        /**
         * Return whether the platform should automatically generate possible replies for this
         * {@link Action}
         */
        @Override
        public boolean getAllowGeneratedReplies() {
            return mAllowGeneratedReplies;
        }

        /**
         * Get the list of inputs to be collected from the user when this action is sent.
         * May return null if no remote inputs were added. Only returns inputs which accept
         * a text input. For inputs which only accept data use {@link #getDataOnlyRemoteInputs}.
         */
        @Override
        public RemoteInput[] getRemoteInputs() {
            return mRemoteInputs;
        }

        /**
         * Get the list of inputs to be collected from the user that ONLY accept data when this
         * action is sent. These remote inputs are guaranteed to return true on a call to
         * {@link RemoteInput#isDataOnly}.
         *
         * <p>May return null if no data-only remote inputs were added.
         *
         * <p>This method exists so that legacy RemoteInput collectors that pre-date the addition
         * of non-textual RemoteInputs do not access these remote inputs.
         */
        @Override
        public RemoteInput[] getDataOnlyRemoteInputs() {
            return mDataOnlyRemoteInputs;
        }

        /**
         * Builder class for {@link Action} objects.
         */
        public static final class Builder {
            private final int mIcon;
            private final CharSequence mTitle;
            private final PendingIntent mIntent;
            private boolean mAllowGeneratedReplies = true;
            private final Bundle mExtras;
            private ArrayList<RemoteInput> mRemoteInputs;

            /**
             * Construct a new builder for {@link Action} object.
             * @param icon icon to show for this action
             * @param title the title of the action
             * @param intent the {@link PendingIntent} to fire when users trigger this action
             */
            public Builder(int icon, CharSequence title, PendingIntent intent) {
                this(icon, title, intent, new Bundle(), null, true);
            }

            /**
             * Construct a new builder for {@link Action} object using the fields from an
             * {@link Action}.
             * @param action the action to read fields from.
             */
            public Builder(Action action) {
                this(action.icon, action.title, action.actionIntent, new Bundle(action.mExtras),
                        action.getRemoteInputs(), action.getAllowGeneratedReplies());
            }

            private Builder(int icon, CharSequence title, PendingIntent intent, Bundle extras,
                    RemoteInput[] remoteInputs, boolean allowGeneratedReplies) {
                mIcon = icon;
                mTitle = NotificationCompat.Builder.limitCharSequenceLength(title);
                mIntent = intent;
                mExtras = extras;
                mRemoteInputs = remoteInputs == null ? null : new ArrayList<>(
                        Arrays.asList(remoteInputs));
                mAllowGeneratedReplies = allowGeneratedReplies;
            }

            /**
             * Merge additional metadata into this builder.
             *
             * <p>Values within the Bundle will replace existing extras values in this Builder.
             *
             * @see NotificationCompat.Action#getExtras
             */
            public Builder addExtras(Bundle extras) {
                if (extras != null) {
                    mExtras.putAll(extras);
                }
                return this;
            }

            /**
             * Get the metadata Bundle used by this Builder.
             *
             * <p>The returned Bundle is shared with this Builder.
             */
            public Bundle getExtras() {
                return mExtras;
            }

            /**
             * Add an input to be collected from the user when this action is sent.
             * Response values can be retrieved from the fired intent by using the
             * {@link RemoteInput#getResultsFromIntent} function.
             * @param remoteInput a {@link RemoteInput} to add to the action
             * @return this object for method chaining
             */
            public Builder addRemoteInput(RemoteInput remoteInput) {
                if (mRemoteInputs == null) {
                    mRemoteInputs = new ArrayList<RemoteInput>();
                }
                mRemoteInputs.add(remoteInput);
                return this;
            }

            /**
             * Set whether the platform should automatically generate possible replies to add to
             * {@link RemoteInput#getChoices()}. If the {@link Action} doesn't have a
             * {@link RemoteInput}, this has no effect.
             * @param allowGeneratedReplies {@code true} to allow generated replies, {@code false}
             * otherwise
             * @return this object for method chaining
             * The default value is {@code true}
             */
            public Builder setAllowGeneratedReplies(boolean allowGeneratedReplies) {
                mAllowGeneratedReplies = allowGeneratedReplies;
                return this;
            }

            /**
             * Apply an extender to this action builder. Extenders may be used to add
             * metadata or change options on this builder.
             */
            public Builder extend(Extender extender) {
                extender.extend(this);
                return this;
            }

            /**
             * Combine all of the options that have been set and return a new {@link Action}
             * object.
             * @return the built action
             */
            public Action build() {
                List<RemoteInput> dataOnlyInputs = new ArrayList<>();
                List<RemoteInput> textInputs = new ArrayList<>();
                if (mRemoteInputs != null) {
                    for (RemoteInput input : mRemoteInputs) {
                        if (input.isDataOnly()) {
                            dataOnlyInputs.add(input);
                        } else {
                            textInputs.add(input);
                        }
                    }
                }
                RemoteInput[] dataOnlyInputsArr = dataOnlyInputs.isEmpty()
                        ? null : dataOnlyInputs.toArray(new RemoteInput[dataOnlyInputs.size()]);
                RemoteInput[] textInputsArr = textInputs.isEmpty()
                        ? null : textInputs.toArray(new RemoteInput[textInputs.size()]);
                return new Action(mIcon, mTitle, mIntent, mExtras, textInputsArr,
                        dataOnlyInputsArr, mAllowGeneratedReplies);
            }
        }


        /**
         * Extender interface for use with {@link Builder#extend}. Extenders may be used to add
         * metadata or change options on an action builder.
         */
        public interface Extender {
            /**
             * Apply this extender to a notification action builder.
             * @param builder the builder to be modified.
             * @return the build object for chaining.
             */
            Builder extend(Builder builder);
        }

        /**
         * Wearable extender for notification actions. To add extensions to an action,
         * create a new {@link NotificationCompat.Action.WearableExtender} object using
         * the {@code WearableExtender()} constructor and apply it to a
         * {@link NotificationCompat.Action.Builder} using
         * {@link NotificationCompat.Action.Builder#extend}.
         *
         * <pre class="prettyprint">
         * NotificationCompat.Action action = new NotificationCompat.Action.Builder(
         *         R.drawable.archive_all, "Archive all", actionIntent)
         *         .extend(new NotificationCompat.Action.WearableExtender()
         *                 .setAvailableOffline(false))
         *         .build();</pre>
         */
        public static final class WearableExtender implements Extender {
            /** Notification action extra which contains wearable extensions */
            private static final String EXTRA_WEARABLE_EXTENSIONS = "android.wearable.EXTENSIONS";

            // Keys within EXTRA_WEARABLE_EXTENSIONS for wearable options.
            private static final String KEY_FLAGS = "flags";
            private static final String KEY_IN_PROGRESS_LABEL = "inProgressLabel";
            private static final String KEY_CONFIRM_LABEL = "confirmLabel";
            private static final String KEY_CANCEL_LABEL = "cancelLabel";

            // Flags bitwise-ored to mFlags
            private static final int FLAG_AVAILABLE_OFFLINE = 0x1;
            private static final int FLAG_HINT_LAUNCHES_ACTIVITY = 1 << 1;
            private static final int FLAG_HINT_DISPLAY_INLINE = 1 << 2;

            // Default value for flags integer
            private static final int DEFAULT_FLAGS = FLAG_AVAILABLE_OFFLINE;

            private int mFlags = DEFAULT_FLAGS;

            private CharSequence mInProgressLabel;
            private CharSequence mConfirmLabel;
            private CharSequence mCancelLabel;

            /**
             * Create a {@link NotificationCompat.Action.WearableExtender} with default
             * options.
             */
            public WearableExtender() {
            }

            /**
             * Create a {@link NotificationCompat.Action.WearableExtender} by reading
             * wearable options present in an existing notification action.
             * @param action the notification action to inspect.
             */
            public WearableExtender(Action action) {
                Bundle wearableBundle = action.getExtras().getBundle(EXTRA_WEARABLE_EXTENSIONS);
                if (wearableBundle != null) {
                    mFlags = wearableBundle.getInt(KEY_FLAGS, DEFAULT_FLAGS);
                    mInProgressLabel = wearableBundle.getCharSequence(KEY_IN_PROGRESS_LABEL);
                    mConfirmLabel = wearableBundle.getCharSequence(KEY_CONFIRM_LABEL);
                    mCancelLabel = wearableBundle.getCharSequence(KEY_CANCEL_LABEL);
                }
            }

            /**
             * Apply wearable extensions to a notification action that is being built. This is
             * typically called by the {@link NotificationCompat.Action.Builder#extend}
             * method of {@link NotificationCompat.Action.Builder}.
             */
            @Override
            public Action.Builder extend(Action.Builder builder) {
                Bundle wearableBundle = new Bundle();

                if (mFlags != DEFAULT_FLAGS) {
                    wearableBundle.putInt(KEY_FLAGS, mFlags);
                }
                if (mInProgressLabel != null) {
                    wearableBundle.putCharSequence(KEY_IN_PROGRESS_LABEL, mInProgressLabel);
                }
                if (mConfirmLabel != null) {
                    wearableBundle.putCharSequence(KEY_CONFIRM_LABEL, mConfirmLabel);
                }
                if (mCancelLabel != null) {
                    wearableBundle.putCharSequence(KEY_CANCEL_LABEL, mCancelLabel);
                }

                builder.getExtras().putBundle(EXTRA_WEARABLE_EXTENSIONS, wearableBundle);
                return builder;
            }

            @Override
            public WearableExtender clone() {
                WearableExtender that = new WearableExtender();
                that.mFlags = this.mFlags;
                that.mInProgressLabel = this.mInProgressLabel;
                that.mConfirmLabel = this.mConfirmLabel;
                that.mCancelLabel = this.mCancelLabel;
                return that;
            }

            /**
             * Set whether this action is available when the wearable device is not connected to
             * a companion device. The user can still trigger this action when the wearable device
             * is offline, but a visual hint will indicate that the action may not be available.
             * Defaults to true.
             */
            public WearableExtender setAvailableOffline(boolean availableOffline) {
                setFlag(FLAG_AVAILABLE_OFFLINE, availableOffline);
                return this;
            }

            /**
             * Get whether this action is available when the wearable device is not connected to
             * a companion device. The user can still trigger this action when the wearable device
             * is offline, but a visual hint will indicate that the action may not be available.
             * Defaults to true.
             */
            public boolean isAvailableOffline() {
                return (mFlags & FLAG_AVAILABLE_OFFLINE) != 0;
            }

            private void setFlag(int mask, boolean value) {
                if (value) {
                    mFlags |= mask;
                } else {
                    mFlags &= ~mask;
                }
            }

            /**
             * Set a label to display while the wearable is preparing to automatically execute the
             * action. This is usually a 'ing' verb ending in ellipsis like "Sending..."
             *
             * @param label the label to display while the action is being prepared to execute
             * @return this object for method chaining
             */
            public WearableExtender setInProgressLabel(CharSequence label) {
                mInProgressLabel = label;
                return this;
            }

            /**
             * Get the label to display while the wearable is preparing to automatically execute
             * the action. This is usually a 'ing' verb ending in ellipsis like "Sending..."
             *
             * @return the label to display while the action is being prepared to execute
             */
            public CharSequence getInProgressLabel() {
                return mInProgressLabel;
            }

            /**
             * Set a label to display to confirm that the action should be executed.
             * This is usually an imperative verb like "Send".
             *
             * @param label the label to confirm the action should be executed
             * @return this object for method chaining
             */
            public WearableExtender setConfirmLabel(CharSequence label) {
                mConfirmLabel = label;
                return this;
            }

            /**
             * Get the label to display to confirm that the action should be executed.
             * This is usually an imperative verb like "Send".
             *
             * @return the label to confirm the action should be executed
             */
            public CharSequence getConfirmLabel() {
                return mConfirmLabel;
            }

            /**
             * Set a label to display to cancel the action.
             * This is usually an imperative verb, like "Cancel".
             *
             * @param label the label to display to cancel the action
             * @return this object for method chaining
             */
            public WearableExtender setCancelLabel(CharSequence label) {
                mCancelLabel = label;
                return this;
            }

            /**
             * Get the label to display to cancel the action.
             * This is usually an imperative verb like "Cancel".
             *
             * @return the label to display to cancel the action
             */
            public CharSequence getCancelLabel() {
                return mCancelLabel;
            }

            /**
             * Set a hint that this Action will launch an {@link Activity} directly, telling the
             * platform that it can generate the appropriate transitions.
             * @param hintLaunchesActivity {@code true} if the content intent will launch
             * an activity and transitions should be generated, false otherwise.
             * @return this object for method chaining
             */
            public WearableExtender setHintLaunchesActivity(
                    boolean hintLaunchesActivity) {
                setFlag(FLAG_HINT_LAUNCHES_ACTIVITY, hintLaunchesActivity);
                return this;
            }

            /**
             * Get a hint that this Action will launch an {@link Activity} directly, telling the
             * platform that it can generate the appropriate transitions
             * @return {@code true} if the content intent will launch an activity and transitions
             * should be generated, false otherwise. The default value is {@code false} if this was
             * never set.
             */
            public boolean getHintLaunchesActivity() {
                return (mFlags & FLAG_HINT_LAUNCHES_ACTIVITY) != 0;
            }

            /**
             * Set a hint that this Action should be displayed inline - i.e. it will have a visual
             * representation directly on the notification surface in addition to the expanded
             * Notification
             *
             * @param hintDisplayInline {@code true} if action should be displayed inline, false
             *        otherwise
             * @return this object for method chaining
             */
            public WearableExtender setHintDisplayActionInline(
                    boolean hintDisplayInline) {
                setFlag(FLAG_HINT_DISPLAY_INLINE, hintDisplayInline);
                return this;
            }

            /**
             * Get a hint that this Action should be displayed inline - i.e. it should have a
             * visual representation directly on the notification surface in addition to the
             * expanded Notification
             *
             * @return {@code true} if the Action should be displayed inline, {@code false}
             *         otherwise. The default value is {@code false} if this was never set.
             */
            public boolean getHintDisplayActionInline() {
                return (mFlags & FLAG_HINT_DISPLAY_INLINE) != 0;
            }
        }

        /** @hide */
        @RestrictTo(LIBRARY_GROUP)
        public static final Factory FACTORY = new Factory() {
            @Override
            public NotificationCompatBase.Action build(int icon, CharSequence title,
                    PendingIntent actionIntent, Bundle extras,
                    RemoteInputCompatBase.RemoteInput[] remoteInputs,
                    RemoteInputCompatBase.RemoteInput[] dataOnlyRemoteInputs,
                    boolean allowGeneratedReplies) {
                return new Action(icon, title, actionIntent, extras,
                        (RemoteInput[]) remoteInputs, (RemoteInput[]) dataOnlyRemoteInputs,
                        allowGeneratedReplies);
            }

            @Override
            public Action[] newArray(int length) {
                return new Action[length];
            }
        };
    }


    /**
     * Extender interface for use with {@link Builder#extend}. Extenders may be used to add
     * metadata or change options on a notification builder.
     */
    public interface Extender {
        /**
         * Apply this extender to a notification builder.
         * @param builder the builder to be modified.
         * @return the build object for chaining.
         */
        Builder extend(Builder builder);
    }

    /**
     * Helper class to add wearable extensions to notifications.
     * <p class="note"> See
     * <a href="{@docRoot}wear/notifications/creating.html">Creating Notifications
     * for Android Wear</a> for more information on how to use this class.
     * <p>
     * To create a notification with wearable extensions:
     * <ol>
     *   <li>Create a {@link NotificationCompat.Builder}, setting any desired
     *   properties.
     *   <li>Create a {@link NotificationCompat.WearableExtender}.
     *   <li>Set wearable-specific properties using the
     *   {@code add} and {@code set} methods of {@link NotificationCompat.WearableExtender}.
     *   <li>Call {@link NotificationCompat.Builder#extend} to apply the extensions to a
     *   notification.
     *   <li>Post the notification to the notification
     *   system with the {@code NotificationManagerCompat.notify(...)} methods
     *   and not the {@code NotificationManager.notify(...)} methods.
     * </ol>
     *
     * <pre class="prettyprint">
     * Notification notification = new NotificationCompat.Builder(mContext)
     *         .setContentTitle(&quot;New mail from &quot; + sender.toString())
     *         .setContentText(subject)
     *         .setSmallIcon(R.drawable.new_mail)
     *         .extend(new NotificationCompat.WearableExtender()
     *                 .setContentIcon(R.drawable.new_mail))
     *         .build();
     * NotificationManagerCompat.from(mContext).notify(0, notification);</pre>
     *
     * <p>Wearable extensions can be accessed on an existing notification by using the
     * {@code WearableExtender(Notification)} constructor,
     * and then using the {@code get} methods to access values.
     *
     * <pre class="prettyprint">
     * NotificationCompat.WearableExtender wearableExtender =
     *         new NotificationCompat.WearableExtender(notification);
     * List&lt;Notification&gt; pages = wearableExtender.getPages();</pre>
     */
    public static final class WearableExtender implements Extender {
        /**
         * Sentinel value for an action index that is unset.
         */
        public static final int UNSET_ACTION_INDEX = -1;

        /**
         * Size value for use with {@link #setCustomSizePreset} to show this notification with
         * default sizing.
         * <p>For custom display notifications created using {@link #setDisplayIntent},
         * the default is {@link #SIZE_MEDIUM}. All other notifications size automatically based
         * on their content.
         */
        public static final int SIZE_DEFAULT = 0;

        /**
         * Size value for use with {@link #setCustomSizePreset} to show this notification
         * with an extra small size.
         * <p>This value is only applicable for custom display notifications created using
         * {@link #setDisplayIntent}.
         */
        public static final int SIZE_XSMALL = 1;

        /**
         * Size value for use with {@link #setCustomSizePreset} to show this notification
         * with a small size.
         * <p>This value is only applicable for custom display notifications created using
         * {@link #setDisplayIntent}.
         */
        public static final int SIZE_SMALL = 2;

        /**
         * Size value for use with {@link #setCustomSizePreset} to show this notification
         * with a medium size.
         * <p>This value is only applicable for custom display notifications created using
         * {@link #setDisplayIntent}.
         */
        public static final int SIZE_MEDIUM = 3;

        /**
         * Size value for use with {@link #setCustomSizePreset} to show this notification
         * with a large size.
         * <p>This value is only applicable for custom display notifications created using
         * {@link #setDisplayIntent}.
         */
        public static final int SIZE_LARGE = 4;

        /**
         * Size value for use with {@link #setCustomSizePreset} to show this notification
         * full screen.
         * <p>This value is only applicable for custom display notifications created using
         * {@link #setDisplayIntent}.
         */
        public static final int SIZE_FULL_SCREEN = 5;

        /**
         * Sentinel value for use with {@link #setHintScreenTimeout} to keep the screen on for a
         * short amount of time when this notification is displayed on the screen. This
         * is the default value.
         */
        public static final int SCREEN_TIMEOUT_SHORT = 0;

        /**
         * Sentinel value for use with {@link #setHintScreenTimeout} to keep the screen on
         * for a longer amount of time when this notification is displayed on the screen.
         */
        public static final int SCREEN_TIMEOUT_LONG = -1;

        /** Notification extra which contains wearable extensions */
        private static final String EXTRA_WEARABLE_EXTENSIONS = "android.wearable.EXTENSIONS";

        // Keys within EXTRA_WEARABLE_EXTENSIONS for wearable options.
        private static final String KEY_ACTIONS = "actions";
        private static final String KEY_FLAGS = "flags";
        private static final String KEY_DISPLAY_INTENT = "displayIntent";
        private static final String KEY_PAGES = "pages";
        private static final String KEY_BACKGROUND = "background";
        private static final String KEY_CONTENT_ICON = "contentIcon";
        private static final String KEY_CONTENT_ICON_GRAVITY = "contentIconGravity";
        private static final String KEY_CONTENT_ACTION_INDEX = "contentActionIndex";
        private static final String KEY_CUSTOM_SIZE_PRESET = "customSizePreset";
        private static final String KEY_CUSTOM_CONTENT_HEIGHT = "customContentHeight";
        private static final String KEY_GRAVITY = "gravity";
        private static final String KEY_HINT_SCREEN_TIMEOUT = "hintScreenTimeout";
        private static final String KEY_DISMISSAL_ID = "dismissalId";
        private static final String KEY_BRIDGE_TAG = "bridgeTag";

        // Flags bitwise-ored to mFlags
        private static final int FLAG_CONTENT_INTENT_AVAILABLE_OFFLINE = 0x1;
        private static final int FLAG_HINT_HIDE_ICON = 1 << 1;
        private static final int FLAG_HINT_SHOW_BACKGROUND_ONLY = 1 << 2;
        private static final int FLAG_START_SCROLL_BOTTOM = 1 << 3;
        private static final int FLAG_HINT_AVOID_BACKGROUND_CLIPPING = 1 << 4;
        private static final int FLAG_BIG_PICTURE_AMBIENT = 1 << 5;
        private static final int FLAG_HINT_CONTENT_INTENT_LAUNCHES_ACTIVITY = 1 << 6;

        // Default value for flags integer
        private static final int DEFAULT_FLAGS = FLAG_CONTENT_INTENT_AVAILABLE_OFFLINE;

        private static final int DEFAULT_CONTENT_ICON_GRAVITY = GravityCompat.END;
        private static final int DEFAULT_GRAVITY = Gravity.BOTTOM;

        private ArrayList<Action> mActions = new ArrayList<Action>();
        private int mFlags = DEFAULT_FLAGS;
        private PendingIntent mDisplayIntent;
        private ArrayList<Notification> mPages = new ArrayList<Notification>();
        private Bitmap mBackground;
        private int mContentIcon;
        private int mContentIconGravity = DEFAULT_CONTENT_ICON_GRAVITY;
        private int mContentActionIndex = UNSET_ACTION_INDEX;
        private int mCustomSizePreset = SIZE_DEFAULT;
        private int mCustomContentHeight;
        private int mGravity = DEFAULT_GRAVITY;
        private int mHintScreenTimeout;
        private String mDismissalId;
        private String mBridgeTag;

        /**
         * Create a {@link NotificationCompat.WearableExtender} with default
         * options.
         */
        public WearableExtender() {
        }

        public WearableExtender(Notification notification) {
            Bundle extras = getExtras(notification);
            Bundle wearableBundle = extras != null ? extras.getBundle(EXTRA_WEARABLE_EXTENSIONS)
                    : null;
            if (wearableBundle != null) {
                Action[] actions = IMPL.getActionsFromParcelableArrayList(
                        wearableBundle.getParcelableArrayList(KEY_ACTIONS));
                if (actions != null) {
                    Collections.addAll(mActions, actions);
                }

                mFlags = wearableBundle.getInt(KEY_FLAGS, DEFAULT_FLAGS);
                mDisplayIntent = wearableBundle.getParcelable(KEY_DISPLAY_INTENT);

                Notification[] pages = getNotificationArrayFromBundle(
                        wearableBundle, KEY_PAGES);
                if (pages != null) {
                    Collections.addAll(mPages, pages);
                }

                mBackground = wearableBundle.getParcelable(KEY_BACKGROUND);
                mContentIcon = wearableBundle.getInt(KEY_CONTENT_ICON);
                mContentIconGravity = wearableBundle.getInt(KEY_CONTENT_ICON_GRAVITY,
                        DEFAULT_CONTENT_ICON_GRAVITY);
                mContentActionIndex = wearableBundle.getInt(KEY_CONTENT_ACTION_INDEX,
                        UNSET_ACTION_INDEX);
                mCustomSizePreset = wearableBundle.getInt(KEY_CUSTOM_SIZE_PRESET,
                        SIZE_DEFAULT);
                mCustomContentHeight = wearableBundle.getInt(KEY_CUSTOM_CONTENT_HEIGHT);
                mGravity = wearableBundle.getInt(KEY_GRAVITY, DEFAULT_GRAVITY);
                mHintScreenTimeout = wearableBundle.getInt(KEY_HINT_SCREEN_TIMEOUT);
                mDismissalId = wearableBundle.getString(KEY_DISMISSAL_ID);
                mBridgeTag = wearableBundle.getString(KEY_BRIDGE_TAG);
            }
        }

        /**
         * Apply wearable extensions to a notification that is being built. This is typically
         * called by the {@link NotificationCompat.Builder#extend} method of
         * {@link NotificationCompat.Builder}.
         */
        @Override
        public NotificationCompat.Builder extend(NotificationCompat.Builder builder) {
            Bundle wearableBundle = new Bundle();

            if (!mActions.isEmpty()) {
                wearableBundle.putParcelableArrayList(KEY_ACTIONS,
                        IMPL.getParcelableArrayListForActions(mActions.toArray(
                                new Action[mActions.size()])));
            }
            if (mFlags != DEFAULT_FLAGS) {
                wearableBundle.putInt(KEY_FLAGS, mFlags);
            }
            if (mDisplayIntent != null) {
                wearableBundle.putParcelable(KEY_DISPLAY_INTENT, mDisplayIntent);
            }
            if (!mPages.isEmpty()) {
                wearableBundle.putParcelableArray(KEY_PAGES, mPages.toArray(
                        new Notification[mPages.size()]));
            }
            if (mBackground != null) {
                wearableBundle.putParcelable(KEY_BACKGROUND, mBackground);
            }
            if (mContentIcon != 0) {
                wearableBundle.putInt(KEY_CONTENT_ICON, mContentIcon);
            }
            if (mContentIconGravity != DEFAULT_CONTENT_ICON_GRAVITY) {
                wearableBundle.putInt(KEY_CONTENT_ICON_GRAVITY, mContentIconGravity);
            }
            if (mContentActionIndex != UNSET_ACTION_INDEX) {
                wearableBundle.putInt(KEY_CONTENT_ACTION_INDEX,
                        mContentActionIndex);
            }
            if (mCustomSizePreset != SIZE_DEFAULT) {
                wearableBundle.putInt(KEY_CUSTOM_SIZE_PRESET, mCustomSizePreset);
            }
            if (mCustomContentHeight != 0) {
                wearableBundle.putInt(KEY_CUSTOM_CONTENT_HEIGHT, mCustomContentHeight);
            }
            if (mGravity != DEFAULT_GRAVITY) {
                wearableBundle.putInt(KEY_GRAVITY, mGravity);
            }
            if (mHintScreenTimeout != 0) {
                wearableBundle.putInt(KEY_HINT_SCREEN_TIMEOUT, mHintScreenTimeout);
            }
            if (mDismissalId != null) {
                wearableBundle.putString(KEY_DISMISSAL_ID, mDismissalId);
            }
            if (mBridgeTag != null) {
                wearableBundle.putString(KEY_BRIDGE_TAG, mBridgeTag);
            }

            builder.getExtras().putBundle(EXTRA_WEARABLE_EXTENSIONS, wearableBundle);
            return builder;
        }

        @Override
        public WearableExtender clone() {
            WearableExtender that = new WearableExtender();
            that.mActions = new ArrayList<Action>(this.mActions);
            that.mFlags = this.mFlags;
            that.mDisplayIntent = this.mDisplayIntent;
            that.mPages = new ArrayList<Notification>(this.mPages);
            that.mBackground = this.mBackground;
            that.mContentIcon = this.mContentIcon;
            that.mContentIconGravity = this.mContentIconGravity;
            that.mContentActionIndex = this.mContentActionIndex;
            that.mCustomSizePreset = this.mCustomSizePreset;
            that.mCustomContentHeight = this.mCustomContentHeight;
            that.mGravity = this.mGravity;
            that.mHintScreenTimeout = this.mHintScreenTimeout;
            that.mDismissalId = this.mDismissalId;
            that.mBridgeTag = this.mBridgeTag;
            return that;
        }

        /**
         * Add a wearable action to this notification.
         *
         * <p>When wearable actions are added using this method, the set of actions that
         * show on a wearable device splits from devices that only show actions added
         * using {@link NotificationCompat.Builder#addAction}. This allows for customization
         * of which actions display on different devices.
         *
         * @param action the action to add to this notification
         * @return this object for method chaining
         * @see NotificationCompat.Action
         */
        public WearableExtender addAction(Action action) {
            mActions.add(action);
            return this;
        }

        /**
         * Adds wearable actions to this notification.
         *
         * <p>When wearable actions are added using this method, the set of actions that
         * show on a wearable device splits from devices that only show actions added
         * using {@link NotificationCompat.Builder#addAction}. This allows for customization
         * of which actions display on different devices.
         *
         * @param actions the actions to add to this notification
         * @return this object for method chaining
         * @see NotificationCompat.Action
         */
        public WearableExtender addActions(List<Action> actions) {
            mActions.addAll(actions);
            return this;
        }

        /**
         * Clear all wearable actions present on this builder.
         * @return this object for method chaining.
         * @see #addAction
         */
        public WearableExtender clearActions() {
            mActions.clear();
            return this;
        }

        /**
         * Get the wearable actions present on this notification.
         */
        public List<Action> getActions() {
            return mActions;
        }

        /**
         * Set an intent to launch inside of an activity view when displaying
         * this notification. The {@link PendingIntent} provided should be for an activity.
         *
         * <pre class="prettyprint">
         * Intent displayIntent = new Intent(context, MyDisplayActivity.class);
         * PendingIntent displayPendingIntent = PendingIntent.getActivity(context,
         *         0, displayIntent, PendingIntent.FLAG_UPDATE_CURRENT);
         * Notification notification = new NotificationCompat.Builder(context)
         *         .extend(new NotificationCompat.WearableExtender()
         *                 .setDisplayIntent(displayPendingIntent)
         *                 .setCustomSizePreset(NotificationCompat.WearableExtender.SIZE_MEDIUM))
         *         .build();</pre>
         *
         * <p>The activity to launch needs to allow embedding, must be exported, and
         * should have an empty task affinity. It is also recommended to use the device
         * default light theme.
         *
         * <p>Example AndroidManifest.xml entry:
         * <pre class="prettyprint">
         * &lt;activity android:name=&quot;com.example.MyDisplayActivity&quot;
         *     android:exported=&quot;true&quot;
         *     android:allowEmbedded=&quot;true&quot;
         *     android:taskAffinity=&quot;&quot;
         *     android:theme=&quot;@android:style/Theme.DeviceDefault.Light&quot; /&gt;</pre>
         *
         * @param intent the {@link PendingIntent} for an activity
         * @return this object for method chaining
         * @see NotificationCompat.WearableExtender#getDisplayIntent
         */
        public WearableExtender setDisplayIntent(PendingIntent intent) {
            mDisplayIntent = intent;
            return this;
        }

        /**
         * Get the intent to launch inside of an activity view when displaying this
         * notification. This {@code PendingIntent} should be for an activity.
         */
        public PendingIntent getDisplayIntent() {
            return mDisplayIntent;
        }

        /**
         * Add an additional page of content to display with this notification. The current
         * notification forms the first page, and pages added using this function form
         * subsequent pages. This field can be used to separate a notification into multiple
         * sections.
         *
         * @param page the notification to add as another page
         * @return this object for method chaining
         * @see NotificationCompat.WearableExtender#getPages
         */
        public WearableExtender addPage(Notification page) {
            mPages.add(page);
            return this;
        }

        /**
         * Add additional pages of content to display with this notification. The current
         * notification forms the first page, and pages added using this function form
         * subsequent pages. This field can be used to separate a notification into multiple
         * sections.
         *
         * @param pages a list of notifications
         * @return this object for method chaining
         * @see NotificationCompat.WearableExtender#getPages
         */
        public WearableExtender addPages(List<Notification> pages) {
            mPages.addAll(pages);
            return this;
        }

        /**
         * Clear all additional pages present on this builder.
         * @return this object for method chaining.
         * @see #addPage
         */
        public WearableExtender clearPages() {
            mPages.clear();
            return this;
        }

        /**
         * Get the array of additional pages of content for displaying this notification. The
         * current notification forms the first page, and elements within this array form
         * subsequent pages. This field can be used to separate a notification into multiple
         * sections.
         * @return the pages for this notification
         */
        public List<Notification> getPages() {
            return mPages;
        }

        /**
         * Set a background image to be displayed behind the notification content.
         * Contrary to the {@link NotificationCompat.BigPictureStyle}, this background
         * will work with any notification style.
         *
         * @param background the background bitmap
         * @return this object for method chaining
         * @see NotificationCompat.WearableExtender#getBackground
         */
        public WearableExtender setBackground(Bitmap background) {
            mBackground = background;
            return this;
        }

        /**
         * Get a background image to be displayed behind the notification content.
         * Contrary to the {@link NotificationCompat.BigPictureStyle}, this background
         * will work with any notification style.
         *
         * @return the background image
         * @see NotificationCompat.WearableExtender#setBackground
         */
        public Bitmap getBackground() {
            return mBackground;
        }

        /**
         * Set an icon that goes with the content of this notification.
         */
        public WearableExtender setContentIcon(int icon) {
            mContentIcon = icon;
            return this;
        }

        /**
         * Get an icon that goes with the content of this notification.
         */
        public int getContentIcon() {
            return mContentIcon;
        }

        /**
         * Set the gravity that the content icon should have within the notification display.
         * Supported values include {@link android.view.Gravity#START} and
         * {@link android.view.Gravity#END}. The default value is {@link android.view.Gravity#END}.
         * @see #setContentIcon
         */
        public WearableExtender setContentIconGravity(int contentIconGravity) {
            mContentIconGravity = contentIconGravity;
            return this;
        }

        /**
         * Get the gravity that the content icon should have within the notification display.
         * Supported values include {@link android.view.Gravity#START} and
         * {@link android.view.Gravity#END}. The default value is {@link android.view.Gravity#END}.
         * @see #getContentIcon
         */
        public int getContentIconGravity() {
            return mContentIconGravity;
        }

        /**
         * Set an action from this notification's actions to be clickable with the content of
         * this notification. This action will no longer display separately from the
         * notification's content.
         *
         * <p>For notifications with multiple pages, child pages can also have content actions
         * set, although the list of available actions comes from the main notification and not
         * from the child page's notification.
         *
         * @param actionIndex The index of the action to hoist onto the current notification page.
         *                    If wearable actions were added to the main notification, this index
         *                    will apply to that list, otherwise it will apply to the regular
         *                    actions list.
         */
        public WearableExtender setContentAction(int actionIndex) {
            mContentActionIndex = actionIndex;
            return this;
        }

        /**
         * Get the index of the notification action, if any, that was specified as being clickable
         * with the content of this notification. This action will no longer display separately
         * from the notification's content.
         *
         * <p>For notifications with multiple pages, child pages can also have content actions
         * set, although the list of available actions comes from the main notification and not
         * from the child page's notification.
         *
         * <p>If wearable specific actions were added to the main notification, this index will
         * apply to that list, otherwise it will apply to the regular actions list.
         *
         * @return the action index or {@link #UNSET_ACTION_INDEX} if no action was selected.
         */
        public int getContentAction() {
            return mContentActionIndex;
        }

        /**
         * Set the gravity that this notification should have within the available viewport space.
         * Supported values include {@link android.view.Gravity#TOP},
         * {@link android.view.Gravity#CENTER_VERTICAL} and {@link android.view.Gravity#BOTTOM}.
         * The default value is {@link android.view.Gravity#BOTTOM}.
         */
        public WearableExtender setGravity(int gravity) {
            mGravity = gravity;
            return this;
        }

        /**
         * Get the gravity that this notification should have within the available viewport space.
         * Supported values include {@link android.view.Gravity#TOP},
         * {@link android.view.Gravity#CENTER_VERTICAL} and {@link android.view.Gravity#BOTTOM}.
         * The default value is {@link android.view.Gravity#BOTTOM}.
         */
        public int getGravity() {
            return mGravity;
        }

        /**
         * Set the custom size preset for the display of this notification out of the available
         * presets found in {@link NotificationCompat.WearableExtender}, e.g.
         * {@link #SIZE_LARGE}.
         * <p>Some custom size presets are only applicable for custom display notifications created
         * using {@link NotificationCompat.WearableExtender#setDisplayIntent}. Check the
         * documentation for the preset in question. See also
         * {@link #setCustomContentHeight} and {@link #getCustomSizePreset}.
         */
        public WearableExtender setCustomSizePreset(int sizePreset) {
            mCustomSizePreset = sizePreset;
            return this;
        }

        /**
         * Get the custom size preset for the display of this notification out of the available
         * presets found in {@link NotificationCompat.WearableExtender}, e.g.
         * {@link #SIZE_LARGE}.
         * <p>Some custom size presets are only applicable for custom display notifications created
         * using {@link #setDisplayIntent}. Check the documentation for the preset in question.
         * See also {@link #setCustomContentHeight} and {@link #setCustomSizePreset}.
         */
        public int getCustomSizePreset() {
            return mCustomSizePreset;
        }

        /**
         * Set the custom height in pixels for the display of this notification's content.
         * <p>This option is only available for custom display notifications created
         * using {@link NotificationCompat.WearableExtender#setDisplayIntent}. See also
         * {@link NotificationCompat.WearableExtender#setCustomSizePreset} and
         * {@link #getCustomContentHeight}.
         */
        public WearableExtender setCustomContentHeight(int height) {
            mCustomContentHeight = height;
            return this;
        }

        /**
         * Get the custom height in pixels for the display of this notification's content.
         * <p>This option is only available for custom display notifications created
         * using {@link #setDisplayIntent}. See also {@link #setCustomSizePreset} and
         * {@link #setCustomContentHeight}.
         */
        public int getCustomContentHeight() {
            return mCustomContentHeight;
        }

        /**
         * Set whether the scrolling position for the contents of this notification should start
         * at the bottom of the contents instead of the top when the contents are too long to
         * display within the screen.  Default is false (start scroll at the top).
         */
        public WearableExtender setStartScrollBottom(boolean startScrollBottom) {
            setFlag(FLAG_START_SCROLL_BOTTOM, startScrollBottom);
            return this;
        }

        /**
         * Get whether the scrolling position for the contents of this notification should start
         * at the bottom of the contents instead of the top when the contents are too long to
         * display within the screen. Default is false (start scroll at the top).
         */
        public boolean getStartScrollBottom() {
            return (mFlags & FLAG_START_SCROLL_BOTTOM) != 0;
        }

        /**
         * Set whether the content intent is available when the wearable device is not connected
         * to a companion device.  The user can still trigger this intent when the wearable device
         * is offline, but a visual hint will indicate that the content intent may not be available.
         * Defaults to true.
         */
        public WearableExtender setContentIntentAvailableOffline(
                boolean contentIntentAvailableOffline) {
            setFlag(FLAG_CONTENT_INTENT_AVAILABLE_OFFLINE, contentIntentAvailableOffline);
            return this;
        }

        /**
         * Get whether the content intent is available when the wearable device is not connected
         * to a companion device.  The user can still trigger this intent when the wearable device
         * is offline, but a visual hint will indicate that the content intent may not be available.
         * Defaults to true.
         */
        public boolean getContentIntentAvailableOffline() {
            return (mFlags & FLAG_CONTENT_INTENT_AVAILABLE_OFFLINE) != 0;
        }

        /**
         * Set a hint that this notification's icon should not be displayed.
         * @param hintHideIcon {@code true} to hide the icon, {@code false} otherwise.
         * @return this object for method chaining
         */
        public WearableExtender setHintHideIcon(boolean hintHideIcon) {
            setFlag(FLAG_HINT_HIDE_ICON, hintHideIcon);
            return this;
        }

        /**
         * Get a hint that this notification's icon should not be displayed.
         * @return {@code true} if this icon should not be displayed, false otherwise.
         * The default value is {@code false} if this was never set.
         */
        public boolean getHintHideIcon() {
            return (mFlags & FLAG_HINT_HIDE_ICON) != 0;
        }

        /**
         * Set a visual hint that only the background image of this notification should be
         * displayed, and other semantic content should be hidden. This hint is only applicable
         * to sub-pages added using {@link #addPage}.
         */
        public WearableExtender setHintShowBackgroundOnly(boolean hintShowBackgroundOnly) {
            setFlag(FLAG_HINT_SHOW_BACKGROUND_ONLY, hintShowBackgroundOnly);
            return this;
        }

        /**
         * Get a visual hint that only the background image of this notification should be
         * displayed, and other semantic content should be hidden. This hint is only applicable
         * to sub-pages added using {@link NotificationCompat.WearableExtender#addPage}.
         */
        public boolean getHintShowBackgroundOnly() {
            return (mFlags & FLAG_HINT_SHOW_BACKGROUND_ONLY) != 0;
        }

        /**
         * Set a hint that this notification's background should not be clipped if possible,
         * and should instead be resized to fully display on the screen, retaining the aspect
         * ratio of the image. This can be useful for images like barcodes or qr codes.
         * @param hintAvoidBackgroundClipping {@code true} to avoid clipping if possible.
         * @return this object for method chaining
         */
        public WearableExtender setHintAvoidBackgroundClipping(
                boolean hintAvoidBackgroundClipping) {
            setFlag(FLAG_HINT_AVOID_BACKGROUND_CLIPPING, hintAvoidBackgroundClipping);
            return this;
        }

        /**
         * Get a hint that this notification's background should not be clipped if possible,
         * and should instead be resized to fully display on the screen, retaining the aspect
         * ratio of the image. This can be useful for images like barcodes or qr codes.
         * @return {@code true} if it's ok if the background is clipped on the screen, false
         * otherwise. The default value is {@code false} if this was never set.
         */
        public boolean getHintAvoidBackgroundClipping() {
            return (mFlags & FLAG_HINT_AVOID_BACKGROUND_CLIPPING) != 0;
        }

        /**
         * Set a hint that the screen should remain on for at least this duration when
         * this notification is displayed on the screen.
         * @param timeout The requested screen timeout in milliseconds. Can also be either
         *     {@link #SCREEN_TIMEOUT_SHORT} or {@link #SCREEN_TIMEOUT_LONG}.
         * @return this object for method chaining
         */
        public WearableExtender setHintScreenTimeout(int timeout) {
            mHintScreenTimeout = timeout;
            return this;
        }

        /**
         * Get the duration, in milliseconds, that the screen should remain on for
         * when this notification is displayed.
         * @return the duration in milliseconds if > 0, or either one of the sentinel values
         *     {@link #SCREEN_TIMEOUT_SHORT} or {@link #SCREEN_TIMEOUT_LONG}.
         */
        public int getHintScreenTimeout() {
            return mHintScreenTimeout;
        }

        /**
         * Set a hint that this notification's {@link BigPictureStyle} (if present) should be
         * converted to low-bit and displayed in ambient mode, especially useful for barcodes and
         * qr codes, as well as other simple black-and-white tickets.
         * @param hintAmbientBigPicture {@code true} to enable converstion and ambient.
         * @return this object for method chaining
         */
        public WearableExtender setHintAmbientBigPicture(boolean hintAmbientBigPicture) {
            setFlag(FLAG_BIG_PICTURE_AMBIENT, hintAmbientBigPicture);
            return this;
        }

        /**
         * Get a hint that this notification's {@link BigPictureStyle} (if present) should be
         * converted to low-bit and displayed in ambient mode, especially useful for barcodes and
         * qr codes, as well as other simple black-and-white tickets.
         * @return {@code true} if it should be displayed in ambient, false otherwise
         * otherwise. The default value is {@code false} if this was never set.
         */
        public boolean getHintAmbientBigPicture() {
            return (mFlags & FLAG_BIG_PICTURE_AMBIENT) != 0;
        }

        /**
         * Set a hint that this notification's content intent will launch an {@link Activity}
         * directly, telling the platform that it can generate the appropriate transitions.
         * @param hintContentIntentLaunchesActivity {@code true} if the content intent will launch
         * an activity and transitions should be generated, false otherwise.
         * @return this object for method chaining
         */
        public WearableExtender setHintContentIntentLaunchesActivity(
                boolean hintContentIntentLaunchesActivity) {
            setFlag(FLAG_HINT_CONTENT_INTENT_LAUNCHES_ACTIVITY, hintContentIntentLaunchesActivity);
            return this;
        }

        /**
         * Get a hint that this notification's content intent will launch an {@link Activity}
         * directly, telling the platform that it can generate the appropriate transitions
         * @return {@code true} if the content intent will launch an activity and transitions should
         * be generated, false otherwise. The default value is {@code false} if this was never set.
         */
        public boolean getHintContentIntentLaunchesActivity() {
            return (mFlags & FLAG_HINT_CONTENT_INTENT_LAUNCHES_ACTIVITY) != 0;
        }

        /**
         * Sets the dismissal id for this notification. If a notification is posted with a
         * dismissal id, then when that notification is canceled, notifications on other wearables
         * and the paired Android phone having that same dismissal id will also be canceled. See
         * <a href="{@docRoot}wear/notifications/index.html">Adding Wearable Features to
         * Notifications</a> for more information.
         * @param dismissalId the dismissal id of the notification.
         * @return this object for method chaining
         */
        public WearableExtender setDismissalId(String dismissalId) {
            mDismissalId = dismissalId;
            return this;
        }

        /**
         * Returns the dismissal id of the notification.
         * @return the dismissal id of the notification or null if it has not been set.
         */
        public String getDismissalId() {
            return mDismissalId;
        }

        /**
         * Sets a bridge tag for this notification. A bridge tag can be set for notifications
         * posted from a phone to provide finer-grained control on what notifications are bridged
         * to wearables. See <a href="{@docRoot}wear/notifications/index.html">Adding Wearable
         * Features to Notifications</a> for more information.
         * @param bridgeTag the bridge tag of the notification.
         * @return this object for method chaining
         */
        public WearableExtender setBridgeTag(String bridgeTag) {
            mBridgeTag = bridgeTag;
            return this;
        }

        /**
         * Returns the bridge tag of the notification.
         * @return the bridge tag or null if not present.
         */
        public String getBridgeTag() {
            return mBridgeTag;
        }

        private void setFlag(int mask, boolean value) {
            if (value) {
                mFlags |= mask;
            } else {
                mFlags &= ~mask;
            }
        }
    }

    /**
     * <p>Helper class to add Android Auto extensions to notifications. To create a notification
     * with car extensions:
     *
     * <ol>
     *  <li>Create an {@link NotificationCompat.Builder}, setting any desired
     *  properties.
     *  <li>Create a {@link CarExtender}.
     *  <li>Set car-specific properties using the {@code add} and {@code set} methods of
     *  {@link CarExtender}.
     *  <li>Call {@link android.support.v4.app.NotificationCompat.Builder#extend(NotificationCompat.Extender)}
     *  to apply the extensions to a notification.
     *  <li>Post the notification to the notification system with the
     *  {@code NotificationManagerCompat.notify(...)} methods and not the
     *  {@code NotificationManager.notify(...)} methods.
     * </ol>
     *
     * <pre class="prettyprint">
     * Notification notification = new NotificationCompat.Builder(context)
     *         ...
     *         .extend(new CarExtender()
     *                 .set*(...))
     *         .build();
     * </pre>
     *
     * <p>Car extensions can be accessed on an existing notification by using the
     * {@code CarExtender(Notification)} constructor, and then using the {@code get} methods
     * to access values.
     */
    public static final class CarExtender implements Extender {
        private static final String TAG = "CarExtender";

        private static final String EXTRA_CAR_EXTENDER = "android.car.EXTENSIONS";
        private static final String EXTRA_LARGE_ICON = "large_icon";
        private static final String EXTRA_CONVERSATION = "car_conversation";
        private static final String EXTRA_COLOR = "app_color";

        private Bitmap mLargeIcon;
        private UnreadConversation mUnreadConversation;
        private int mColor = NotificationCompat.COLOR_DEFAULT;

        /**
         * Create a {@link CarExtender} with default options.
         */
        public CarExtender() {
        }

        /**
         * Create a {@link CarExtender} from the CarExtender options of an existing Notification.
         *
         * @param notification The notification from which to copy options.
         */
        public CarExtender(Notification notification) {
            if (Build.VERSION.SDK_INT < 21) {
                return;
            }

            Bundle carBundle = getExtras(notification) == null
                    ? null : getExtras(notification).getBundle(EXTRA_CAR_EXTENDER);
            if (carBundle != null) {
                mLargeIcon = carBundle.getParcelable(EXTRA_LARGE_ICON);
                mColor = carBundle.getInt(EXTRA_COLOR, NotificationCompat.COLOR_DEFAULT);

                Bundle b = carBundle.getBundle(EXTRA_CONVERSATION);
                mUnreadConversation = (UnreadConversation) IMPL.getUnreadConversationFromBundle(
                        b, UnreadConversation.FACTORY, RemoteInput.FACTORY);
            }
        }

        /**
         * Apply car extensions to a notification that is being built. This is typically called by
         * the {@link android.support.v4.app.NotificationCompat.Builder#extend(NotificationCompat.Extender)}
         * method of {@link NotificationCompat.Builder}.
         */
        @Override
        public NotificationCompat.Builder extend(NotificationCompat.Builder builder) {
            if (Build.VERSION.SDK_INT < 21) {
                return builder;
            }

            Bundle carExtensions = new Bundle();

            if (mLargeIcon != null) {
                carExtensions.putParcelable(EXTRA_LARGE_ICON, mLargeIcon);
            }
            if (mColor != NotificationCompat.COLOR_DEFAULT) {
                carExtensions.putInt(EXTRA_COLOR, mColor);
            }

            if (mUnreadConversation != null) {
                Bundle b = IMPL.getBundleForUnreadConversation(mUnreadConversation);
                carExtensions.putBundle(EXTRA_CONVERSATION, b);
            }

            builder.getExtras().putBundle(EXTRA_CAR_EXTENDER, carExtensions);
            return builder;
        }

        /**
         * Sets the accent color to use when Android Auto presents the notification.
         *
         * Android Auto uses the color set with {@link android.support.v4.app.NotificationCompat.Builder#setColor(int)}
         * to accent the displayed notification. However, not all colors are acceptable in an
         * automotive setting. This method can be used to override the color provided in the
         * notification in such a situation.
         */
        public CarExtender setColor(@ColorInt int color) {
            mColor = color;
            return this;
        }

        /**
         * Gets the accent color.
         *
         * @see #setColor
         */
        @ColorInt
        public int getColor() {
            return mColor;
        }

        /**
         * Sets the large icon of the car notification.
         *
         * If no large icon is set in the extender, Android Auto will display the icon
         * specified by {@link android.support.v4.app.NotificationCompat.Builder#setLargeIcon(android.graphics.Bitmap)}
         *
         * @param largeIcon The large icon to use in the car notification.
         * @return This object for method chaining.
         */
        public CarExtender setLargeIcon(Bitmap largeIcon) {
            mLargeIcon = largeIcon;
            return this;
        }

        /**
         * Gets the large icon used in this car notification, or null if no icon has been set.
         *
         * @return The large icon for the car notification.
         * @see CarExtender#setLargeIcon
         */
        public Bitmap getLargeIcon() {
            return mLargeIcon;
        }

        /**
         * Sets the unread conversation in a message notification.
         *
         * @param unreadConversation The unread part of the conversation this notification conveys.
         * @return This object for method chaining.
         */
        public CarExtender setUnreadConversation(UnreadConversation unreadConversation) {
            mUnreadConversation = unreadConversation;
            return this;
        }

        /**
         * Returns the unread conversation conveyed by this notification.
         * @see #setUnreadConversation(UnreadConversation)
         */
        public UnreadConversation getUnreadConversation() {
            return mUnreadConversation;
        }

        /**
         * A class which holds the unread messages from a conversation.
         */
        public static class UnreadConversation extends NotificationCompatBase.UnreadConversation {
            private final String[] mMessages;
            private final RemoteInput mRemoteInput;
            private final PendingIntent mReplyPendingIntent;
            private final PendingIntent mReadPendingIntent;
            private final String[] mParticipants;
            private final long mLatestTimestamp;

            UnreadConversation(String[] messages, RemoteInput remoteInput,
                    PendingIntent replyPendingIntent, PendingIntent readPendingIntent,
                    String[] participants, long latestTimestamp) {
                mMessages = messages;
                mRemoteInput = remoteInput;
                mReadPendingIntent = readPendingIntent;
                mReplyPendingIntent = replyPendingIntent;
                mParticipants = participants;
                mLatestTimestamp = latestTimestamp;
            }

            /**
             * Gets the list of messages conveyed by this notification.
             */
            @Override
            public String[] getMessages() {
                return mMessages;
            }

            /**
             * Gets the remote input that will be used to convey the response to a message list, or
             * null if no such remote input exists.
             */
            @Override
            public RemoteInput getRemoteInput() {
                return mRemoteInput;
            }

            /**
             * Gets the pending intent that will be triggered when the user replies to this
             * notification.
             */
            @Override
            public PendingIntent getReplyPendingIntent() {
                return mReplyPendingIntent;
            }

            /**
             * Gets the pending intent that Android Auto will send after it reads aloud all messages
             * in this object's message list.
             */
            @Override
            public PendingIntent getReadPendingIntent() {
                return mReadPendingIntent;
            }

            /**
             * Gets the participants in the conversation.
             */
            @Override
            public String[] getParticipants() {
                return mParticipants;
            }

            /**
             * Gets the firs participant in the conversation.
             */
            @Override
            public String getParticipant() {
                return mParticipants.length > 0 ? mParticipants[0] : null;
            }

            /**
             * Gets the timestamp of the conversation.
             */
            @Override
            public long getLatestTimestamp() {
                return mLatestTimestamp;
            }

            static final Factory FACTORY = new Factory() {
                @Override
                public UnreadConversation build(
                        String[] messages, RemoteInputCompatBase.RemoteInput remoteInput,
                        PendingIntent replyPendingIntent, PendingIntent readPendingIntent,
                        String[] participants, long latestTimestamp) {
                    return new UnreadConversation(
                            messages, (RemoteInput) remoteInput, replyPendingIntent,
                            readPendingIntent,
                            participants, latestTimestamp);
                }
            };

            /**
             * Builder class for {@link CarExtender.UnreadConversation} objects.
             */
            public static class Builder {
                private final List<String> mMessages = new ArrayList<String>();
                private final String mParticipant;
                private RemoteInput mRemoteInput;
                private PendingIntent mReadPendingIntent;
                private PendingIntent mReplyPendingIntent;
                private long mLatestTimestamp;

                /**
                 * Constructs a new builder for {@link CarExtender.UnreadConversation}.
                 *
                 * @param name The name of the other participant in the conversation.
                 */
                public Builder(String name) {
                    mParticipant = name;
                }

                /**
                 * Appends a new unread message to the list of messages for this conversation.
                 *
                 * The messages should be added from oldest to newest.
                 *
                 * @param message The text of the new unread message.
                 * @return This object for method chaining.
                 */
                public Builder addMessage(String message) {
                    mMessages.add(message);
                    return this;
                }

                /**
                 * Sets the pending intent and remote input which will convey the reply to this
                 * notification.
                 *
                 * @param pendingIntent The pending intent which will be triggered on a reply.
                 * @param remoteInput The remote input parcelable which will carry the reply.
                 * @return This object for method chaining.
                 *
                 * @see CarExtender.UnreadConversation#getRemoteInput
                 * @see CarExtender.UnreadConversation#getReplyPendingIntent
                 */
                public Builder setReplyAction(
                        PendingIntent pendingIntent, RemoteInput remoteInput) {
                    mRemoteInput = remoteInput;
                    mReplyPendingIntent = pendingIntent;

                    return this;
                }

                /**
                 * Sets the pending intent that will be sent once the messages in this notification
                 * are read.
                 *
                 * @param pendingIntent The pending intent to use.
                 * @return This object for method chaining.
                 */
                public Builder setReadPendingIntent(PendingIntent pendingIntent) {
                    mReadPendingIntent = pendingIntent;
                    return this;
                }

                /**
                 * Sets the timestamp of the most recent message in an unread conversation.
                 *
                 * If a messaging notification has been posted by your application and has not
                 * yet been cancelled, posting a later notification with the same id and tag
                 * but without a newer timestamp may result in Android Auto not displaying a
                 * heads up notification for the later notification.
                 *
                 * @param timestamp The timestamp of the most recent message in the conversation.
                 * @return This object for method chaining.
                 */
                public Builder setLatestTimestamp(long timestamp) {
                    mLatestTimestamp = timestamp;
                    return this;
                }

                /**
                 * Builds a new unread conversation object.
                 *
                 * @return The new unread conversation object.
                 */
                public UnreadConversation build() {
                    String[] messages = mMessages.toArray(new String[mMessages.size()]);
                    String[] participants = { mParticipant };
                    return new UnreadConversation(messages, mRemoteInput, mReplyPendingIntent,
                            mReadPendingIntent, participants, mLatestTimestamp);
                }
            }
        }
    }


    /**
     * Get an array of Notification objects from a parcelable array bundle field.
     * Update the bundle to have a typed array so fetches in the future don't need
     * to do an array copy.
     */
    static Notification[] getNotificationArrayFromBundle(Bundle bundle, String key) {
        Parcelable[] array = bundle.getParcelableArray(key);
        if (array instanceof Notification[] || array == null) {
            return (Notification[]) array;
        }
        Notification[] typedArray = new Notification[array.length];
        for (int i = 0; i < array.length; i++) {
            typedArray[i] = (Notification) array[i];
        }
        bundle.putParcelableArray(key, typedArray);
        return typedArray;
    }

    /**
     * Gets the {@link Notification#extras} field from a notification in a backwards
     * compatible manner. Extras field was supported from JellyBean (Api level 16)
     * forwards. This function will return null on older api levels.
     */
    public static Bundle getExtras(Notification notification) {
        if (Build.VERSION.SDK_INT >= 19) {
            return notification.extras;
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getExtras(notification);
        } else {
            return null;
        }
    }

    /**
     * Get the number of actions in this notification in a backwards compatible
     * manner. Actions were supported from JellyBean (Api level 16) forwards.
     */
    public static int getActionCount(Notification notification) {
        if (Build.VERSION.SDK_INT >= 19) {
            return notification.actions != null ? notification.actions.length : 0;
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getActionCount(notification);
        } else {
            return 0;
        }
    }

    /**
     * Get an action on this notification in a backwards compatible
     * manner. Actions were supported from JellyBean (Api level 16) forwards.
     * @param notification The notification to inspect.
     * @param actionIndex The index of the action to retrieve.
     */
    public static Action getAction(Notification notification, int actionIndex) {
        return IMPL.getAction(notification, actionIndex);
    }

    /**
     * Get the category of this notification in a backwards compatible
     * manner.
     * @param notification The notification to inspect.
     */
    public static String getCategory(Notification notification) {
        if (Build.VERSION.SDK_INT >= 21) {
            return notification.category;
        } else {
            return null;
        }
    }

    /**
     * Get whether or not this notification is only relevant to the current device.
     *
     * <p>Some notifications can be bridged to other devices for remote display.
     * If this hint is set, it is recommend that this notification not be bridged.
     */
    public static boolean getLocalOnly(Notification notification) {
        if (Build.VERSION.SDK_INT >= 20) {
            return (notification.flags & Notification.FLAG_LOCAL_ONLY) != 0;
        } else if (Build.VERSION.SDK_INT >= 19) {
            return notification.extras.getBoolean(NotificationCompatJellybean.EXTRA_LOCAL_ONLY);
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getExtras(notification).getBoolean(
                    NotificationCompatJellybean.EXTRA_LOCAL_ONLY);
        } else {
            return false;
        }
    }

    /**
     * Get the key used to group this notification into a cluster or stack
     * with other notifications on devices which support such rendering.
     */
    public static String getGroup(Notification notification) {
        if (Build.VERSION.SDK_INT >= 20) {
            return notification.getGroup();
        } else if (Build.VERSION.SDK_INT >= 19) {
            return notification.extras.getString(NotificationCompatJellybean.EXTRA_GROUP_KEY);
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getExtras(notification).getString(
                    NotificationCompatJellybean.EXTRA_GROUP_KEY);
        } else {
            return null;
        }
    }

    /**
     * Get whether this notification to be the group summary for a group of notifications.
     * Grouped notifications may display in a cluster or stack on devices which
     * support such rendering. Requires a group key also be set using {@link Builder#setGroup}.
     * @return Whether this notification is a group summary.
     */
    public static boolean isGroupSummary(Notification notification) {
        if (Build.VERSION.SDK_INT >= 20) {
            return (notification.flags & Notification.FLAG_GROUP_SUMMARY) != 0;
        } else if (Build.VERSION.SDK_INT >= 19) {
            return notification.extras.getBoolean(NotificationCompatJellybean.EXTRA_GROUP_SUMMARY);
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getExtras(notification).getBoolean(
                    NotificationCompatJellybean.EXTRA_GROUP_SUMMARY);
        } else {
            return false;
        }
    }

    /**
     * Get a sort key that orders this notification among other notifications from the
     * same package. This can be useful if an external sort was already applied and an app
     * would like to preserve this. Notifications will be sorted lexicographically using this
     * value, although providing different priorities in addition to providing sort key may
     * cause this value to be ignored.
     *
     * <p>This sort key can also be used to order members of a notification group. See
     * {@link Builder#setGroup}.
     *
     * @see String#compareTo(String)
     */
    public static String getSortKey(Notification notification) {
        if (Build.VERSION.SDK_INT >= 20) {
            return notification.getSortKey();
        } else if (Build.VERSION.SDK_INT >= 19) {
            return notification.extras.getString(NotificationCompatJellybean.EXTRA_SORT_KEY);
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getExtras(notification).getString(
                    NotificationCompatJellybean.EXTRA_SORT_KEY);
        } else {
            return null;
        }
    }

    /**
     * @return the ID of the channel this notification posts to.
     */
    public static String getChannelId(Notification notification) {
        if (BuildCompat.isAtLeastO()) {
            return notification.getChannelId();
        } else {
            return null;
        }
    }

    /** @deprecated removed from API 26 */
    @Deprecated
    public static String getChannel(Notification notification) {
        return getChannelId(notification);
    }

    /**
     * Returns the time at which this notification should be canceled by the system, if it's not
     * canceled already.
     */
    public static long getTimeoutAfter(Notification notification) {
        if (BuildCompat.isAtLeastO()) {
            return notification.getTimeoutAfter();
        } else {
            return 0;
        }
    }

    /** @deprecated removed from API 26 */
    @Deprecated
    public static long getTimeout(Notification notification) {
        return getTimeoutAfter(notification);
    }

    /**
     * Returns what icon should be shown for this notification if it is being displayed in a
     * Launcher that supports badging. Will be one of {@link #BADGE_ICON_NONE},
     * {@link #BADGE_ICON_SMALL}, or {@link #BADGE_ICON_LARGE}.
     */
    public static int getBadgeIconType(Notification notification) {
        if (BuildCompat.isAtLeastO()) {
            return notification.getBadgeIconType();
        } else {
            return BADGE_ICON_NONE;
        }
    }

    /**
     * Returns the {@link android.support.v4.content.pm.ShortcutInfoCompat#getId() id} that this
     * notification supersedes, if any.
     */
    public static String getShortcutId(Notification notification) {
        if (BuildCompat.isAtLeastO()) {
            return notification.getShortcutId();
        } else {
            return null;
        }
    }

    /**
     * Returns which type of notifications in a group are responsible for audibly alerting the
     * user. See {@link #GROUP_ALERT_ALL}, {@link #GROUP_ALERT_CHILDREN},
     * {@link #GROUP_ALERT_SUMMARY}.
     */
    public static int getGroupAlertBehavior(Notification notification) {
        if (BuildCompat.isAtLeastO()) {
            return notification.getGroupAlertBehavior();
        } else {
            return GROUP_ALERT_ALL;
        }
    }
}