v4/app/ActivityCompat.java

/*
 * Copyright (C) 2011 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.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.content.ContextCompat;
import android.view.View;

import java.util.List;
import java.util.Map;

/**
 * Helper for accessing features in {@link android.app.Activity}
 * introduced after API level 4 in a backwards compatible fashion.
 */
public class ActivityCompat extends ContextCompat {
    /**
     * Invalidate the activity's options menu, if able.
     *
     * <p>Before API level 11 (Android 3.0/Honeycomb) the lifecycle of the
     * options menu was controlled primarily by the user's operation of
     * the hardware menu key. When the user presses down on the menu key
     * for the first time the menu was created and prepared by calls
     * to {@link Activity#onCreateOptionsMenu(android.view.Menu)} and
     * {@link Activity#onPrepareOptionsMenu(android.view.Menu)} respectively.
     * Subsequent presses of the menu key kept the existing instance of the
     * Menu itself and called {@link Activity#onPrepareOptionsMenu(android.view.Menu)}
     * to give the activity an opportunity to contextually alter the menu
     * before the menu panel was shown.</p>
     *
     * <p>In Android 3.0+ the Action Bar forces the options menu to be built early
     * so that items chosen to show as actions may be displayed when the activity
     * first becomes visible. The Activity method invalidateOptionsMenu forces
     * the entire menu to be destroyed and recreated from
     * {@link Activity#onCreateOptionsMenu(android.view.Menu)}, offering a similar
     * though heavier-weight opportunity to change the menu's contents. Normally
     * this functionality is used to support a changing configuration of Fragments.</p>
     *
     * <p>Applications may use this support helper to signal a significant change in
     * activity state that should cause the options menu to be rebuilt. If the app
     * is running on an older platform version that does not support menu invalidation
     * the app will still receive {@link Activity#onPrepareOptionsMenu(android.view.Menu)}
     * the next time the user presses the menu key and this method will return false.
     * If this method returns true the options menu was successfully invalidated.</p>
     *
     * @param activity Invalidate the options menu of this activity
     * @return true if this operation was supported and it completed; false if it was not available.
     */
    public static boolean invalidateOptionsMenu(Activity activity) {
        if (Build.VERSION.SDK_INT >= 11) {
            ActivityCompatHoneycomb.invalidateOptionsMenu(activity);
            return true;
        }
        return false;
    }

    /**
     * Start an activity with additional launch information, if able.
     *
     * <p>In Android 4.1+ additional options were introduced to allow for more
     * control on activity launch animations. Applications can use this method
     * along with {@link ActivityOptionsCompat} to use these animations when
     * available. When run on versions of the platform where this feature does
     * not exist the activity will be launched normally.</p>
     *
     * @param activity Context to launch activity from.
     * @param intent The description of the activity to start.
     * @param options Additional options for how the Activity should be started.
     *                May be null if there are no options. See
     *                {@link ActivityOptionsCompat} for how to build the Bundle
     *                supplied here; there are no supported definitions for
     *                building it manually.
     */
    public static void startActivity(Activity activity, Intent intent, @Nullable Bundle options) {
        if (Build.VERSION.SDK_INT >= 16) {
            ActivityCompatJB.startActivity(activity, intent, options);
        } else {
            activity.startActivity(intent);
        }
    }

    /**
     * Start new activity with options, if able, for which you would like a
     * result when it finished.
     *
     * <p>In Android 4.1+ additional options were introduced to allow for more
     * control on activity launch animations. Applications can use this method
     * along with {@link ActivityOptionsCompat} to use these animations when
     * available. When run on versions of the platform where this feature does
     * not exist the activity will be launched normally.</p>
     *
     * @param activity Origin activity to launch from.
     * @param intent The description of the activity to start.
     * @param requestCode If >= 0, this code will be returned in
     *                   onActivityResult() when the activity exits.
     * @param options Additional options for how the Activity should be started.
     *                May be null if there are no options. See
     *                {@link ActivityOptionsCompat} for how to build the Bundle
     *                supplied here; there are no supported definitions for
     *                building it manually.
     */
    public static void startActivityForResult(Activity activity, Intent intent, int requestCode,
            @Nullable Bundle options) {
        if (Build.VERSION.SDK_INT >= 16) {
            ActivityCompatJB.startActivityForResult(activity, intent, requestCode, options);
        } else {
            activity.startActivityForResult(intent, requestCode);
        }
    }

    /**
     * Finish this activity, and tries to finish all activities immediately below it
     * in the current task that have the same affinity.
     *
     * <p>On Android 4.1+ calling this method will call through to the native version of this
     * method. For other platforms {@link Activity#finish()} will be called instead.</p>
     */
    public static void finishAffinity(Activity activity) {
        if (Build.VERSION.SDK_INT >= 16) {
            ActivityCompatJB.finishAffinity(activity);
        } else {
            activity.finish();
        }
    }

    /**
     * Reverses the Activity Scene entry Transition and triggers the calling Activity
     * to reverse its exit Transition. When the exit Transition completes,
     * {@link Activity#finish()} is called. If no entry Transition was used, finish() is called
     * immediately and the Activity exit Transition is run.
     *
     * <p>On Android 4.4 or lower, this method only finishes the Activity with no
     * special exit transition.</p>
     */
    public static void finishAfterTransition(Activity activity) {
        if (Build.VERSION.SDK_INT >= 21 || Build.VERSION.CODENAME.equals("L")) {
            ActivityCompat21.finishAfterTransition(activity);
        } else {
            activity.finish();
        }
    }

    /**
     * When {@link android.app.ActivityOptions#makeSceneTransitionAnimation(Activity,
     * android.view.View, String)} was used to start an Activity, <var>listener</var>
     * will be called to handle shared elements on the <i>launched</i> Activity. This requires
     * {@link android.view.Window#FEATURE_CONTENT_TRANSITIONS}.
     *
     * @param listener Used to manipulate shared element transitions on the launched Activity.
     */
    public static void setEnterSharedElementListener(Activity activity,
            SharedElementListener listener) {
        if (Build.VERSION.SDK_INT >= 21 || Build.VERSION.CODENAME.equals("L")) {
            ActivityCompat21.setEnterSharedElementListener(activity, createListener(listener));
        }
    }

    /**
     * When {@link android.app.ActivityOptions#makeSceneTransitionAnimation(Activity,
     * android.view.View, String)} was used to start an Activity, <var>listener</var>
     * will be called to handle shared elements on the <i>launching</i> Activity. Most
     * calls will only come when returning from the started Activity.
     * This requires {@link android.view.Window#FEATURE_CONTENT_TRANSITIONS}.
     *
     * @param listener Used to manipulate shared element transitions on the launching Activity.
     */
    public static void setExitSharedElementListener(Activity activity,
            SharedElementListener listener) {
        if (Build.VERSION.SDK_INT >= 21 || Build.VERSION.CODENAME.equals("L")) {
            ActivityCompat21.setExitSharedElementListener(activity, createListener(listener));
        }
    }

    private static ActivityCompat21.SharedElementListener21 createListener(
            SharedElementListener listener) {
        ActivityCompat21.SharedElementListener21 newListener = null;
        if (listener != null) {
            newListener = new SharedElementListener21Impl(listener);
        }
        return newListener;
    }

    private static class SharedElementListener21Impl
            extends ActivityCompat21.SharedElementListener21 {
        private SharedElementListener mListener;

        public SharedElementListener21Impl(SharedElementListener listener) {
            mListener = listener;
        }

        @Override
        public void setSharedElementStart(List<String> sharedElementNames,
                List<View> sharedElements, List<View> sharedElementSnapshots) {
            mListener.setSharedElementStart(sharedElementNames, sharedElements,
                    sharedElementSnapshots);
        }

        @Override
        public void setSharedElementEnd(List<String> sharedElementNames, List<View> sharedElements,
                List<View> sharedElementSnapshots) {
            mListener.setSharedElementEnd(sharedElementNames, sharedElements,
                    sharedElementSnapshots);
        }

        @Override
        public void handleRejectedSharedElements(List<View> rejectedSharedElements) {
            mListener.handleRejectedSharedElements(rejectedSharedElements);
        }

        @Override
        public void remapSharedElements(List<String> names, Map<String, View> sharedElements) {
            mListener.remapSharedElements(names, sharedElements);
        }
    }
}