xref: /frameworks/support/v4/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 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.v4.view.GravityCompat;
import android.view.Gravity;
import android.widget.RemoteViews;

import java.util.ArrayList;
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.
     */
    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 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 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: 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: An array of people that this notification relates to, specified
     * by contacts provider contact URI.
     */
    public static final String EXTRA_PEOPLE = "android.people";

    /**
     * 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.
     */
    public static final int COLOR_DEFAULT = Color.TRANSPARENT;

    /**
     * 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: 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;

    private static final NotificationCompatImpl IMPL;

    interface NotificationCompatImpl {
        public Notification build(Builder b);
        public Bundle getExtras(Notification n);
        public int getActionCount(Notification n);
        public Action getAction(Notification n, int actionIndex);
        public Action[] getActionsFromParcelableArrayList(ArrayList<Parcelable> parcelables);
        public ArrayList<Parcelable> getParcelableArrayListForActions(Action[] actions);
        public String getCategory(Notification n);
        public boolean getLocalOnly(Notification n);
        public String getGroup(Notification n);
        public boolean isGroupSummary(Notification n);
        public String getSortKey(Notification n);
    }

    static class NotificationCompatImplBase implements NotificationCompatImpl {
        @Override
        public Notification build(Builder b) {
            Notification result = b.mNotification;
            result.setLatestEventInfo(b.mContext, b.mContentTitle,
                    b.mContentText, b.mContentIntent);
            // translate high priority requests into legacy flag
            if (b.mPriority > PRIORITY_DEFAULT) {
                result.flags |= FLAG_HIGH_PRIORITY;
            }
            return result;
        }

        @Override
        public Bundle getExtras(Notification n) {
            return null;
        }

        @Override
        public int getActionCount(Notification n) {
            return 0;
        }

        @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 String getCategory(Notification n) {
            return null;
        }

        @Override
        public boolean getLocalOnly(Notification n) {
            return false;
        }

        @Override
        public String getGroup(Notification n) {
            return null;
        }

        @Override
        public boolean isGroupSummary(Notification n) {
            return false;
        }

        @Override
        public String getSortKey(Notification n) {
            return null;
        }
    }

    static class NotificationCompatImplGingerbread extends NotificationCompatImplBase {
        @Override
        public Notification build(Builder b) {
            Notification result = b.mNotification;
            result.setLatestEventInfo(b.mContext, b.mContentTitle,
                    b.mContentText, b.mContentIntent);
            result = NotificationCompatGingerbread.add(result, b.mContext,
                    b.mContentTitle, b.mContentText, b.mContentIntent, b.mFullScreenIntent);
            // translate high priority requests into legacy flag
            if (b.mPriority > PRIORITY_DEFAULT) {
                result.flags |= FLAG_HIGH_PRIORITY;
            }
            return result;
        }
    }

    static class NotificationCompatImplHoneycomb extends NotificationCompatImplBase {
        @Override
        public Notification build(Builder b) {
            return NotificationCompatHoneycomb.add(b.mContext, b.mNotification,
                    b.mContentTitle, b.mContentText, b.mContentInfo, b.mTickerView,
                    b.mNumber, b.mContentIntent, b.mFullScreenIntent, b.mLargeIcon);
        }
    }

    static class NotificationCompatImplIceCreamSandwich extends NotificationCompatImplBase {
        @Override
        public Notification build(Builder b) {
            return NotificationCompatIceCreamSandwich.add(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);
        }
    }

    static class NotificationCompatImplJellybean extends NotificationCompatImplBase {
        @Override
        public Notification build(Builder b) {
            NotificationCompatJellybean.Builder builder = new NotificationCompatJellybean.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.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mExtras,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            return builder.build();
        }

        @Override
        public Bundle getExtras(Notification n) {
            return NotificationCompatJellybean.getExtras(n);
        }

        @Override
        public int getActionCount(Notification n) {
            return NotificationCompatJellybean.getActionCount(n);
        }

        @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);
        }

        @Override
        public boolean getLocalOnly(Notification n) {
            return NotificationCompatJellybean.getLocalOnly(n);
        }

        @Override
        public String getGroup(Notification n) {
            return NotificationCompatJellybean.getGroup(n);
        }

        @Override
        public boolean isGroupSummary(Notification n) {
            return NotificationCompatJellybean.isGroupSummary(n);
        }

        @Override
        public String getSortKey(Notification n) {
            return NotificationCompatJellybean.getSortKey(n);
        }
    }

    static class NotificationCompatImplKitKat extends NotificationCompatImplJellybean {
        @Override
        public Notification build(Builder b) {
            NotificationCompatKitKat.Builder builder = new NotificationCompatKitKat.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.mUseChronometer, b.mPriority, b.mSubText, b.mLocalOnly, b.mPeople, b.mExtras,
                    b.mGroupKey, b.mGroupSummary, b.mSortKey);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            return builder.build();
        }

        @Override
        public Bundle getExtras(Notification n) {
            return NotificationCompatKitKat.getExtras(n);
        }

        @Override
        public int getActionCount(Notification n) {
            return NotificationCompatKitKat.getActionCount(n);
        }

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

        @Override
        public boolean getLocalOnly(Notification n) {
            return NotificationCompatKitKat.getLocalOnly(n);
        }

        @Override
        public String getGroup(Notification n) {
            return NotificationCompatKitKat.getGroup(n);
        }

        @Override
        public boolean isGroupSummary(Notification n) {
            return NotificationCompatKitKat.isGroupSummary(n);
        }

        @Override
        public String getSortKey(Notification n) {
            return NotificationCompatKitKat.getSortKey(n);
        }
    }

    static class NotificationCompatImplApi20 extends NotificationCompatImplKitKat {
        @Override
        public Notification build(Builder b) {
            NotificationCompatApi20.Builder builder = new NotificationCompatApi20.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.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);
            addActionsToBuilder(builder, b.mActions);
            addStyleToBuilderJellybean(builder, b.mStyle);
            return builder.build();
        }

        @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);
        }

        @Override
        public boolean getLocalOnly(Notification n) {
            return NotificationCompatApi20.getLocalOnly(n);
        }

        @Override
        public String getGroup(Notification n) {
            return NotificationCompatApi20.getGroup(n);
        }

        @Override
        public boolean isGroupSummary(Notification n) {
            return NotificationCompatApi20.isGroupSummary(n);
        }

        @Override
        public String getSortKey(Notification n) {
            return NotificationCompatApi20.getSortKey(n);
        }
    }

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

    private 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);
            }
        }
    }

    static class NotificationCompatImplApi21 extends NotificationCompatImplApi20 {
        @Override
        public String getCategory(Notification notif) {
            return NotificationCompatApi21.getCategory(notif);
        }
    }

    static {
        // TODO: Replace this if clause when SDK_INT is incremented to 21.
        if (Build.VERSION.RELEASE.equals("L")) {
            IMPL = new NotificationCompatImplApi21();
        } else if (Build.VERSION.SDK_INT >= 20) {
            IMPL = new NotificationCompatImplApi20();
        } else if (Build.VERSION.SDK_INT >= 19) {
            IMPL = new NotificationCompatImplKitKat();
        } else if (Build.VERSION.SDK_INT >= 16) {
            IMPL = new NotificationCompatImplJellybean();
        } else if (Build.VERSION.SDK_INT >= 14) {
            IMPL = new NotificationCompatImplIceCreamSandwich();
        } else if (Build.VERSION.SDK_INT >= 11) {
            IMPL = new NotificationCompatImplHoneycomb();
        } else if (Build.VERSION.SDK_INT >= 9) {
            IMPL = new NotificationCompatImplGingerbread();
        } else {
            IMPL = new NotificationCompatImplBase();
        }
    }

    /**
     * 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 {
        Context mContext;

        CharSequence mContentTitle;
        CharSequence mContentText;
        PendingIntent mContentIntent;
        PendingIntent mFullScreenIntent;
        RemoteViews mTickerView;
        Bitmap mLargeIcon;
        CharSequence mContentInfo;
        int mNumber;
        int mPriority;
        boolean mUseChronometer;
        Style mStyle;
        CharSequence mSubText;
        int mProgressMax;
        int mProgress;
        boolean mProgressIndeterminate;
        String mGroupKey;
        boolean mGroupSummary;
        String mSortKey;
        ArrayList<Action> mActions = new ArrayList<Action>();
        boolean mLocalOnly = false;
        String mCategory;
        Bundle mExtras;
        int mColor = COLOR_DEFAULT;
        int mVisibility = VISIBILITY_PRIVATE;
        Notification mPublicVersion;

        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.
         */
        public Builder(Context context) {
            mContext = context;

            // 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>();
        }

        /**
         * 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;
        }

        /**
         * 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 drawble 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 drawble 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 = title;
            return this;
        }

        /**
         * Set the text (second row) of the notification, in a standard notification.
         */
        public Builder setContentText(CharSequence text) {
            mContentText = 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 = 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 = 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 = 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 = 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 blnk, 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(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 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.
         *
         * @see Notification#EXTRA_PEOPLE
         */
        public Builder addPerson(String handle) {
            mPeople.add(handle);
            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(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(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;
        }

        /**
         * 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 IMPL.build(this);
        }

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

    /**
     * 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;
        }
    }

    /**
     * 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 notif = 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 = 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 = 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 notif = 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 = 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 = 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 = cs;
            return this;
        }
    }

    /**
     * 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 noti = 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 = 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 = cs;
            mSummaryTextSet = true;
            return this;
        }

        /**
         * Append a line to the digest section of the Inbox notification.
         */
        public InboxStyle addLine(CharSequence cs) {
            mTexts.add(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 {
        private final Bundle mExtras;
        private final RemoteInput[] mRemoteInputs;

        /**
         * 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);
        }

        private Action(int icon, CharSequence title, PendingIntent intent, Bundle extras,
                RemoteInput[] remoteInputs) {
            this.icon = icon;
            this.title = title;
            this.actionIntent = intent;
            this.mExtras = extras != null ? extras : new Bundle();
            this.mRemoteInputs = remoteInputs;
        }

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

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

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

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

        /**
         * 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.
         */
        public RemoteInput[] getRemoteInputs() {
            return mRemoteInputs;
        }

        /**
         * Builder class for {@link Action} objects.
         */
        public static final class Builder {
            private final int mIcon;
            private final CharSequence mTitle;
            private final PendingIntent mIntent;
            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());
            }

            /**
             * 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));
            }

            private Builder(int icon, CharSequence title, PendingIntent intent, Bundle extras) {
                mIcon = icon;
                mTitle = title;
                mIntent = intent;
                mExtras = extras;
            }

            /**
             * 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;
            }

            /**
             * 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() {
                RemoteInput[] remoteInputs = mRemoteInputs != null
                        ? mRemoteInputs.toArray(new RemoteInput[mRemoteInputs.size()]) : null;
                return new Action(mIcon, mTitle, mIntent, mExtras, remoteInputs);
            }
        }


        /**
         * 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.
             */
            public 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";

            private static final String KEY_FLAGS = "flags";

            // Flags bitwise-ored to mFlags
            private static final int FLAG_AVAILABLE_OFFLINE = 0x1;

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

            private int mFlags = DEFAULT_FLAGS;

            /**
             * 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);
                }
            }

            /**
             * 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);
                }

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

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

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

            @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.
         */
        public 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 notif = 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, notif);</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_LARGE}. 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;

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

        // Keys within EXTRA_WEARABLE_OPTIONS 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";

        // 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;

        // 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;

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

        public WearableExtender(Notification notif) {
            Bundle extras = getExtras(notif);
            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);
            }
        }

        /**
         * 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);
            }

            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;
            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 notif = 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;
        }

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

    /**
     * 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.
     */
    private 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 notif) {
        return IMPL.getExtras(notif);
    }

    /**
     * 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 notif) {
        return IMPL.getActionCount(notif);
    }

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

    /**
    * Get the category of this notification in a backwards compatible
    * manner.
    * @param notif The notification to inspect.
    */
    public static String getCategory(Notification notif) {
        return IMPL.getCategory(notif);
    }

    /**
     * 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 notif) {
        return IMPL.getLocalOnly(notif);
    }

    /**
     * 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 notif) {
        return IMPL.getGroup(notif);
    }

    /**
     * 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 notif) {
        return IMPL.isGroupSummary(notif);
    }

    /**
     * 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 notif) {
        return IMPL.getSortKey(notif);
    }
}