/*
 * Copyright (C) 2015 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.service.media;

import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;

Extend this class to implement a camera prewarm service. See MediaStore.META_DATA_STILL_IMAGE_CAMERA_PREWARM_SERVICE. /**
 * Extend this class to implement a camera prewarm service. See
 * {@link android.provider.MediaStore#META_DATA_STILL_IMAGE_CAMERA_PREWARM_SERVICE}.
 */
public abstract class CameraPrewarmService extends Service {

    
Intent action to bind the service as a prewarm service.
@hide
/**
     * Intent action to bind the service as a prewarm service.
     * @hide
     */
    public static final String ACTION_PREWARM =
            "android.service.media.CameraPrewarmService.ACTION_PREWARM";

    
Message sent by the client indicating that the camera intent has been fired.
@hide
/**
     * Message sent by the client indicating that the camera intent has been fired.
     * @hide
     */
    public static final int MSG_CAMERA_FIRED = 1;

    private final Handler mHandler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_CAMERA_FIRED:
                    mCameraIntentFired = true;
                    break;
                default:
                    super.handleMessage(msg);
            }
        }
    };
    private boolean mCameraIntentFired;

    @Override
    public IBinder onBind(Intent intent) {
        if (ACTION_PREWARM.equals(intent.getAction())) {
            onPrewarm();
            return new Messenger(mHandler).getBinder();
        } else {
            return null;
        }
    }

    @Override
    public boolean onUnbind(Intent intent) {
        if (ACTION_PREWARM.equals(intent.getAction())) {
            onCooldown(mCameraIntentFired);
        }
        return false;
    }

    
Called when the camera should be prewarmed.
/**
     * Called when the camera should be prewarmed.
     */
    public abstract void onPrewarm();

    
Called when prewarm phase is done, either because the camera launch intent has been fired
at this point or prewarm is no longer needed. A client should close the camera
immediately in the latter case.

In case the camera launch intent has been fired, there is no guarantee about the ordering
of these two events. Cooldown might happen either before or after the activity has been
created that handles the camera intent.
Params:
cameraIntentFired – Indicates whether the intent to launch the camera has been
                         fired./**
     * Called when prewarm phase is done, either because the camera launch intent has been fired
     * at this point or prewarm is no longer needed. A client should close the camera
     * immediately in the latter case.
     * <p>
     * In case the camera launch intent has been fired, there is no guarantee about the ordering
     * of these two events. Cooldown might happen either before or after the activity has been
     * created that handles the camera intent.
     *
     * @param cameraIntentFired Indicates whether the intent to launch the camera has been
     *                          fired.
     */
    public abstract void onCooldown(boolean cameraIntentFired);
}