Custom Android VideoView

MediaController.java

/*
 * Copyright (C) 2006 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 com.kuoruan.videoview.view;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.PixelFormat;
import android.media.AudioManager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.view.accessibility.AccessibilityManager;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;

import com.kuoruan.videoview.R;
import com.kuoruan.videoview.internal.PolicyCompat;

import java.util.Formatter;
import java.util.Locale;

/**
 * A view containing controls for a MediaPlayer. Typically contains the
 * buttons like "Play/Pause", "Rewind", "Fast Forward" and a progress
 * slider. It takes care of synchronizing the controls with the state
 * of the MediaPlayer.
 * The way to use this class is to instantiate it programmatically.
 * The MediaController will create a default set of controls
 * and put them in a window floating above your application. Specifically,
 * the controls will float above the view specified with setAnchorView().
 * The window will disappear if left idle for three seconds and reappear
 * when the user touches the anchor view.
 * Functions like show() and hide() have no effect when MediaController
 * is created in an xml layout.
 * MediaController will hide and
 * show the buttons according to these rules:
 * <ul>
 * <li> The "previous" and "next" buttons are hidden until setPrevNextListeners()
 * has been called
 * <li> The "previous" and "next" buttons are visible but disabled if
 * setPrevNextListeners() was called with null listeners
 * <li> The "rewind" and "fastforward" buttons are shown unless requested
 * otherwise by using the MediaController(Context, boolean) constructor
 * with the boolean set to false
 * </ul>
 */
public class MediaController extends FrameLayout {

    private MediaPlayerControl mPlayer;
    private final Context mContext;
    private View mAnchor;
    private View mRoot;
    private WindowManager mWindowManager;
    private Window mWindow;
    private View mDecor;
    private WindowManager.LayoutParams mDecorLayoutParams;
    private SeekBar mProgress;
    private TextView mEndTime, mCurrentTime;
    private boolean mShowing;
    private boolean mDragging;
    private static final int sDefaultTimeout = 3000;
    private final boolean mUseFastForward;
    private boolean mFromXml;
    private boolean mListenersSet;
    private View.OnClickListener mNextListener, mPrevListener;
    StringBuilder mFormatBuilder;
    Formatter mFormatter;
    private ImageButton mBackButton;
    private ImageButton mPauseButton;
    private ImageButton mFfwdButton;
    private ImageButton mRewButton;
    private ImageButton mNextButton;
    private ImageButton mPrevButton;
    private CharSequence mPlayDescription;
    private CharSequence mPauseDescription;
    private final AccessibilityManager mAccessibilityManager;

    public MediaController(Context context, AttributeSet attrs) {
        super(context, attrs);
        mRoot = this;
        mContext = context;
        mUseFastForward = true;
        mFromXml = true;
        mAccessibilityManager = (AccessibilityManager) mContext
                .getSystemService(Context.ACCESSIBILITY_SERVICE);
    }

    @Override
    public void onFinishInflate() {
        super.onFinishInflate();
        if (mRoot != null)
            initControllerView(mRoot);
    }

    public MediaController(Context context, boolean useFastForward) {
        super(context);
        mContext = context;
        mUseFastForward = useFastForward;
        initFloatingWindowLayout();
        initFloatingWindow();
        mAccessibilityManager = (AccessibilityManager) mContext
                .getSystemService(Context.ACCESSIBILITY_SERVICE);
    }

    public MediaController(Context context) {
        this(context, true);
    }

    private void initFloatingWindow() {
        mWindowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
        mWindow = PolicyCompat.createWindow(mContext);
        mWindow.setWindowManager(mWindowManager, null, null);
        mWindow.requestFeature(Window.FEATURE_NO_TITLE);
        mDecor = mWindow.getDecorView();
        mDecor.setOnTouchListener(mTouchListener);
        mWindow.setContentView(this);
        mWindow.setBackgroundDrawableResource(android.R.color.transparent);

        // While the media controller is up, the volume control keys should
        // affect the media stream type
        mWindow.setVolumeControlStream(AudioManager.STREAM_MUSIC);

        setFocusable(true);
        setFocusableInTouchMode(true);
        setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
        requestFocus();
    }

    // Allocate and initialize the static parts of mDecorLayoutParams. Must
    // also call updateFloatingWindowLayout() to fill in the dynamic parts
    // (y and width) before mDecorLayoutParams can be used.
    private void initFloatingWindowLayout() {
        mDecorLayoutParams = new WindowManager.LayoutParams();
        WindowManager.LayoutParams p = mDecorLayoutParams;
        p.gravity = Gravity.TOP | Gravity.LEFT;
        p.height = LayoutParams.WRAP_CONTENT;
        p.x = 0;
        p.format = PixelFormat.TRANSLUCENT;
        p.type = WindowManager.LayoutParams.TYPE_APPLICATION_PANEL;
        p.flags |= WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM
                | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                | WindowManager.LayoutParams.FLAG_SPLIT_TOUCH;
        p.token = null;
        p.windowAnimations = 0; // android.R.style.DropDownAnimationDown;
    }

    // Update the dynamic parts of mDecorLayoutParams
    // Must be called with mAnchor != NULL.
    private void updateFloatingWindowLayout() {
        int[] anchorPos = new int[2];
        mAnchor.getLocationOnScreen(anchorPos);

        // we need to know the size of the controller so we can properly position it
        // within its space
        mDecor.measure(MeasureSpec.makeMeasureSpec(mAnchor.getWidth(), MeasureSpec.AT_MOST),
                MeasureSpec.makeMeasureSpec(mAnchor.getHeight(), MeasureSpec.AT_MOST));

        WindowManager.LayoutParams p = mDecorLayoutParams;
        p.width = mAnchor.getWidth();
        p.x = anchorPos[0] + (mAnchor.getWidth() - p.width) / 2;
        p.y = anchorPos[1] + mAnchor.getHeight() - mDecor.getMeasuredHeight();
    }

    // This is called whenever mAnchor's layout bound changes
    private final OnLayoutChangeListener mLayoutChangeListener =
            new OnLayoutChangeListener() {
                @Override
                public void onLayoutChange(View v, int left, int top, int right,
                                           int bottom, int oldLeft, int oldTop, int oldRight,
                                           int oldBottom) {
                    updateFloatingWindowLayout();
                    if (mShowing) {
                        mWindowManager.updateViewLayout(mDecor, mDecorLayoutParams);
                    }
                }
            };

    private final OnTouchListener mTouchListener = new OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_DOWN) {
                if (mShowing) {
                    hide();
                }
            }
            return false;
        }
    };

    public void setMediaPlayer(MediaPlayerControl player) {
        mPlayer = player;
        updatePausePlay();
    }

    /**
     * Set the view that acts as the anchor for the control view.
     * This can for example be a VideoView, or your Activity's main view.
     * When VideoView calls this method, it will use the VideoView's parent
     * as the anchor.
     *
     * @param view The view to which to anchor the controller when it is visible.
     */
    public void setAnchorView(View view) {
        if (mAnchor != null) {
            mAnchor.removeOnLayoutChangeListener(mLayoutChangeListener);
        }
        mAnchor = view;
        if (mAnchor != null) {
            mAnchor.addOnLayoutChangeListener(mLayoutChangeListener);
        }

        FrameLayout.LayoutParams frameParams = new FrameLayout.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.MATCH_PARENT
        );

        removeAllViews();
        View v = makeControllerView();
        addView(v, frameParams);
    }

    /**
     * Create the view that holds the widgets that control playback.
     * Derived classes can override this to create their own.
     *
     * @return The controller view.
     */
    protected View makeControllerView() {
        LayoutInflater inflate = LayoutInflater.from(getContext());
        mRoot = inflate.inflate(R.layout.media_controller, null);

        initControllerView(mRoot);

        return mRoot;
    }

    private void initControllerView(View v) {
        Resources res = mContext.getResources();
        mPlayDescription = res
                .getText(R.string.lockscreen_transport_play_description);
        mPauseDescription = res
                .getText(R.string.lockscreen_transport_pause_description);
        mBackButton = (ImageButton) v.findViewById(R.id.back);
        if (mBackButton != null) {
            mBackButton.setOnClickListener(mBackListener);
        }
        mPauseButton = (ImageButton) v.findViewById(R.id.pause);
        if (mPauseButton != null) {
            mPauseButton.requestFocus();
            mPauseButton.setOnClickListener(mPauseListener);
        }

        mFfwdButton = (ImageButton) v.findViewById(R.id.ffwd);
        if (mFfwdButton != null) {
            mFfwdButton.setOnClickListener(mFfwdListener);
            if (!mFromXml) {
                mFfwdButton.setVisibility(mUseFastForward ? View.VISIBLE : View.GONE);
            }
        }

        mRewButton = (ImageButton) v.findViewById(R.id.rew);
        if (mRewButton != null) {
            mRewButton.setOnClickListener(mRewListener);
            if (!mFromXml) {
                mRewButton.setVisibility(mUseFastForward ? View.VISIBLE : View.GONE);
            }
        }

        // By default these are hidden. They will be enabled when setPrevNextListeners() is called
        mNextButton = (ImageButton) v.findViewById(R.id.next);
        if (mNextButton != null && !mFromXml && !mListenersSet) {
            mNextButton.setVisibility(View.GONE);
        }
        mPrevButton = (ImageButton) v.findViewById(R.id.prev);
        if (mPrevButton != null && !mFromXml && !mListenersSet) {
            mPrevButton.setVisibility(View.GONE);
        }

        mProgress = (SeekBar) v.findViewById(R.id.mediacontroller_progress);
        if (mProgress != null) {
            mProgress.setOnSeekBarChangeListener(mSeekListener);
            mProgress.setMax(1000);
        }

        mEndTime = (TextView) v.findViewById(R.id.time);
        mCurrentTime = (TextView) v.findViewById(R.id.time_current);
        mFormatBuilder = new StringBuilder();
        mFormatter = new Formatter(mFormatBuilder, Locale.getDefault());

        installPrevNextListeners();
    }

    /**
     * Show the controller on screen. It will go away
     * automatically after 3 seconds of inactivity.
     */
    public void show() {
        show(sDefaultTimeout);
    }

    /**
     * Disable pause or seek buttons if the stream cannot be paused or seeked.
     * This requires the control interface to be a MediaPlayerControlExt
     */
    private void disableUnsupportedButtons() {
        try {
            if (mPauseButton != null && !mPlayer.canPause()) {
                mPauseButton.setEnabled(false);
            }
            if (mRewButton != null && !mPlayer.canSeekBackward()) {
                mRewButton.setEnabled(false);
            }
            if (mFfwdButton != null && !mPlayer.canSeekForward()) {
                mFfwdButton.setEnabled(false);
            }
            // TODO What we really should do is add a canSeek to the MediaPlayerControl interface;
            // this scheme can break the case when applications want to allow seek through the
            // progress bar but disable forward/backward buttons.
            //
            // However, currently the flags SEEK_BACKWARD_AVAILABLE, SEEK_FORWARD_AVAILABLE,
            // and SEEK_AVAILABLE are all (un)set together; as such the aforementioned issue
            // shouldn't arise in existing applications.
            if (mProgress != null && !mPlayer.canSeekBackward() && !mPlayer.canSeekForward()) {
                mProgress.setEnabled(false);
            }
        } catch (IncompatibleClassChangeError ex) {
            // We were given an old version of the interface, that doesn't have
            // the canPause/canSeekXYZ methods. This is OK, it just means we
            // assume the media can be paused and seeked, and so we don't disable
            // the buttons.
        }
    }

    /**
     * Show the controller on screen. It will go away
     * automatically after 'timeout' milliseconds of inactivity.
     *
     * @param timeout The timeout in milliseconds. Use 0 to show
     *                the controller until hide() is called.
     */
    public void show(int timeout) {
        if (!mShowing && mAnchor != null) {
            setProgress();
            if (mPauseButton != null) {
                mPauseButton.requestFocus();
            }
            disableUnsupportedButtons();
            updateFloatingWindowLayout();
            mWindowManager.addView(mDecor, mDecorLayoutParams);
            mShowing = true;
        }
        updatePausePlay();

        // cause the progress bar to be updated even if mShowing
        // was already true.  This happens, for example, if we're
        // paused with the progress bar showing the user hits play.
        post(mShowProgress);

        if (timeout != 0 && !mAccessibilityManager.isTouchExplorationEnabled()) {
            removeCallbacks(mFadeOut);
            postDelayed(mFadeOut, timeout);
        }
    }

    public boolean isShowing() {
        return mShowing;
    }

    /**
     * Remove the controller from the screen.
     */
    public void hide() {
        if (mAnchor == null)
            return;

        if (mShowing) {
            try {
                removeCallbacks(mShowProgress);
                mWindowManager.removeView(mDecor);
            } catch (IllegalArgumentException ex) {
                Log.w("MediaController", "already removed");
            }
            mShowing = false;
        }
    }

    private final Runnable mFadeOut = new Runnable() {
        @Override
        public void run() {
            hide();
        }
    };

    private final Runnable mShowProgress = new Runnable() {
        @Override
        public void run() {
            int pos = setProgress();
            if (!mDragging && mShowing && mPlayer.isPlaying()) {
                postDelayed(mShowProgress, 1000 - (pos % 1000));
            }
        }
    };

    private String stringForTime(int timeMs) {
        int totalSeconds = timeMs / 1000;

        int seconds = totalSeconds % 60;
        int minutes = (totalSeconds / 60) % 60;
        int hours = totalSeconds / 3600;

        mFormatBuilder.setLength(0);
        if (hours > 0) {
            return mFormatter.format("%d:%02d:%02d", hours, minutes, seconds).toString();
        } else {
            return mFormatter.format("%02d:%02d", minutes, seconds).toString();
        }
    }

    private int setProgress() {
        if (mPlayer == null || mDragging) {
            return 0;
        }
        int position = mPlayer.getCurrentPosition();
        int duration = mPlayer.getDuration();
        if (mProgress != null) {
            if (duration > 0) {
                // use long to avoid overflow
                long pos = 1000L * position / duration;
                mProgress.setProgress((int) pos);
            }
            int percent = mPlayer.getBufferPercentage();
            mProgress.setSecondaryProgress(percent * 10);
        }

        if (mEndTime != null)
            mEndTime.setText(stringForTime(duration));
        if (mCurrentTime != null)
            mCurrentTime.setText(stringForTime(position));

        return position;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                show(0); // show until hide is called
                break;
            case MotionEvent.ACTION_UP:
                show(sDefaultTimeout); // start timeout
                break;
            case MotionEvent.ACTION_CANCEL:
                hide();
                break;
            default:
                break;
        }
        return true;
    }

    @Override
    public boolean onTrackballEvent(MotionEvent ev) {
        show(sDefaultTimeout);
        return false;
    }

    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        int keyCode = event.getKeyCode();
        final boolean uniqueDown = event.getRepeatCount() == 0
                && event.getAction() == KeyEvent.ACTION_DOWN;
        if (keyCode == KeyEvent.KEYCODE_HEADSETHOOK
                || keyCode == KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE
                || keyCode == KeyEvent.KEYCODE_SPACE) {
            if (uniqueDown) {
                doPauseResume();
                show(sDefaultTimeout);
                if (mPauseButton != null) {
                    mPauseButton.requestFocus();
                }
            }
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_MEDIA_PLAY) {
            if (uniqueDown && !mPlayer.isPlaying()) {
                mPlayer.start();
                updatePausePlay();
                show(sDefaultTimeout);
            }
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_MEDIA_STOP
                || keyCode == KeyEvent.KEYCODE_MEDIA_PAUSE) {
            if (uniqueDown && mPlayer.isPlaying()) {
                mPlayer.pause();
                updatePausePlay();
                show(sDefaultTimeout);
            }
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN
                || keyCode == KeyEvent.KEYCODE_VOLUME_UP
                || keyCode == KeyEvent.KEYCODE_VOLUME_MUTE
                || keyCode == KeyEvent.KEYCODE_CAMERA) {
            // don't show the controls for volume adjustment
            return super.dispatchKeyEvent(event);
        } else if (keyCode == KeyEvent.KEYCODE_BACK || keyCode == KeyEvent.KEYCODE_MENU) {
            if (uniqueDown) {
                hide();
            }
            return true;
        }

        show(sDefaultTimeout);
        return super.dispatchKeyEvent(event);
    }

    private final View.OnClickListener mBackListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            hide();
            mPlayer.stop();
        }
    };

    private final View.OnClickListener mPauseListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            doPauseResume();
            show(sDefaultTimeout);
        }
    };

    private void updatePausePlay() {
        if (mRoot == null || mPauseButton == null)
            return;

        if (mPlayer.isPlaying()) {
            mPauseButton.setImageResource(R.drawable.ic_media_pause);
            mPauseButton.setContentDescription(mPauseDescription);
        } else {
            mPauseButton.setImageResource(R.drawable.ic_media_play);
            mPauseButton.setContentDescription(mPlayDescription);
        }
    }

    private void doPauseResume() {
        if (mPlayer.isPlaying()) {
            mPlayer.pause();
        } else {
            mPlayer.start();
        }
        updatePausePlay();
    }

    // There are two scenarios that can trigger the seekbar listener to trigger:
    //
    // The first is the user using the touchpad to adjust the posititon of the
    // seekbar's thumb. In this case onStartTrackingTouch is called followed by
    // a number of onProgressChanged notifications, concluded by onStopTrackingTouch.
    // We're setting the field "mDragging" to true for the duration of the dragging
    // session to avoid jumps in the position in case of ongoing playback.
    //
    // The second scenario involves the user operating the scroll ball, in this
    // case there WON'T BE onStartTrackingTouch/onStopTrackingTouch notifications,
    // we will simply apply the updated position without suspending regular updates.
    private final OnSeekBarChangeListener mSeekListener = new OnSeekBarChangeListener() {
        @Override
        public void onStartTrackingTouch(SeekBar bar) {
            show(3600000);

            mDragging = true;

            // By removing these pending progress messages we make sure
            // that a) we won't update the progress while the user adjusts
            // the seekbar and b) once the user is done dragging the thumb
            // we will post one of these messages to the queue again and
            // this ensures that there will be exactly one message queued up.
            removeCallbacks(mShowProgress);
        }

        @Override
        public void onProgressChanged(SeekBar bar, int progress, boolean fromuser) {
            if (!fromuser) {
                // We're not interested in programmatically generated changes to
                // the progress bar's position.
                return;
            }

            long duration = mPlayer.getDuration();
            long newposition = (duration * progress) / 1000L;
            mPlayer.seekTo((int) newposition);
            if (mCurrentTime != null)
                mCurrentTime.setText(stringForTime((int) newposition));
        }

        @Override
        public void onStopTrackingTouch(SeekBar bar) {
            mDragging = false;
            setProgress();
            updatePausePlay();
            show(sDefaultTimeout);

            // Ensure that progress is properly updated in the future,
            // the call to show() does not guarantee this because it is a
            // no-op if we are already showing.
            post(mShowProgress);
        }
    };

    @Override
    public void setEnabled(boolean enabled) {
        if (mBackButton != null) {
            mBackButton.setEnabled(enabled);
        }
        if (mPauseButton != null) {
            mPauseButton.setEnabled(enabled);
        }
        if (mFfwdButton != null) {
            mFfwdButton.setEnabled(enabled);
        }
        if (mRewButton != null) {
            mRewButton.setEnabled(enabled);
        }
        if (mNextButton != null) {
            mNextButton.setEnabled(enabled && mNextListener != null);
        }
        if (mPrevButton != null) {
            mPrevButton.setEnabled(enabled && mPrevListener != null);
        }
        if (mProgress != null) {
            mProgress.setEnabled(enabled);
        }
        disableUnsupportedButtons();
        super.setEnabled(enabled);
    }

    @Override
    public CharSequence getAccessibilityClassName() {
        return MediaController.class.getName();
    }

    private final View.OnClickListener mRewListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int pos = mPlayer.getCurrentPosition();
            pos -= 5000; // milliseconds
            mPlayer.seekTo(pos);
            setProgress();

            show(sDefaultTimeout);
        }
    };

    private final View.OnClickListener mFfwdListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int pos = mPlayer.getCurrentPosition();
            pos += 15000; // milliseconds
            mPlayer.seekTo(pos);
            setProgress();

            show(sDefaultTimeout);
        }
    };

    private void installPrevNextListeners() {
        if (mNextButton != null) {
            mNextButton.setOnClickListener(mNextListener);
            mNextButton.setEnabled(mNextListener != null);
        }

        if (mPrevButton != null) {
            mPrevButton.setOnClickListener(mPrevListener);
            mPrevButton.setEnabled(mPrevListener != null);
        }
    }

    public void setPrevNextListeners(View.OnClickListener next, View.OnClickListener prev) {
        mNextListener = next;
        mPrevListener = prev;
        mListenersSet = true;

        if (mRoot != null) {
            installPrevNextListeners();

            if (mNextButton != null && !mFromXml) {
                mNextButton.setVisibility(View.VISIBLE);
            }
            if (mPrevButton != null && !mFromXml) {
                mPrevButton.setVisibility(View.VISIBLE);
            }
        }
    }

    public interface MediaPlayerControl {
        void start();

        void pause();

        void stop();

        int getDuration();

        int getCurrentPosition();

        void seekTo(int pos);

        boolean isPlaying();

        int getBufferPercentage();

        boolean canPause();

        boolean canSeekBackward();

        boolean canSeekForward();

        /**
         * Get the audio session id for the player used by this VideoView. This can be used to
         * apply audio effects to the audio track of a video.
         *
         * @return The audio session, or 0 if there was an error.
         */
        int getAudioSessionId();
    }
}

PolicyCompat.java

package com.kuoruan.videoview.internal;

import android.content.Context;
import android.media.MediaPlayer;
import android.os.Build;
import android.os.Handler;
import android.view.Window;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class PolicyCompat {
    /*
     * Private constants
     */
    private static final String PHONE_WINDOW_CLASS_NAME = "com.android.internal.policy.PhoneWindow";
    private static final String POLICY_MANAGER_CLASS_NAME = "com.android.internal.policy.PolicyManager";


    private PolicyCompat() {
    }


    /*
     * Private methods
     */
    private static Window createPhoneWindow(Context context) {
        try {
            /* Find class */
            Class<?> cls = Class.forName(PHONE_WINDOW_CLASS_NAME);

            /* Get constructor */
            Constructor c = cls.getConstructor(Context.class);

            /* Create instance */
            return (Window) c.newInstance(context);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(PHONE_WINDOW_CLASS_NAME + " could not be loaded", e);
        } catch (Exception e) {
            throw new RuntimeException(PHONE_WINDOW_CLASS_NAME + " class could not be instantiated", e);
        }
    }

    private static Window makeNewWindow(Context context) {
        try {
            /* Find class */
            Class<?> cls = Class.forName(POLICY_MANAGER_CLASS_NAME);

            /* Find method */
            Method m = cls.getMethod("makeNewWindow", Context.class);

            /* Invoke method */
            return (Window) m.invoke(null, context);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(POLICY_MANAGER_CLASS_NAME + " could not be loaded", e);
        } catch (Exception e) {
            throw new RuntimeException(POLICY_MANAGER_CLASS_NAME + ".makeNewWindow could not be invoked", e);
        }
    }

    /*
     * Public methods
     */
    public static Window createWindow(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
            return createPhoneWindow(context);
        else
            return makeNewWindow(context);
    }

    public static MediaPlayer getMediaPlayer(Context context) {

        MediaPlayer mediaplayer = new MediaPlayer();

        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.KITKAT) {
            return mediaplayer;
        }

        try {
            Class<?> cMediaTimeProvider = Class.forName("android.media.MediaTimeProvider");
            Class<?> cSubtitleController = Class.forName("android.media.SubtitleController");
            Class<?> iSubtitleControllerAnchor = Class.forName("android.media.SubtitleController$Anchor");
            Class<?> iSubtitleControllerListener = Class.forName("android.media.SubtitleController$Listener");

            Constructor constructor = cSubtitleController.getConstructor(Context.class,
                    cMediaTimeProvider, iSubtitleControllerListener);

            Object subtitleInstance = constructor.newInstance(context, null, null);

            Field f = cSubtitleController.getDeclaredField("mHandler");

            f.setAccessible(true);
            try {
                f.set(subtitleInstance, new Handler());
            } catch (IllegalAccessException e) {return mediaplayer;} finally {
                f.setAccessible(false);
            }

            Method setSubtitleAnchor = mediaplayer.getClass().getMethod("setSubtitleAnchor", cSubtitleController,
                    iSubtitleControllerAnchor);

            setSubtitleAnchor.invoke(mediaplayer, subtitleInstance, null);
            //Log.e("", "subtitle is setted :p");
        } catch (Exception ignored) {}

        return mediaplayer;
    }
}

VideoView.java

/*
 * Copyright (C) 2006 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 com.kuoruan.videoview.view;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.util.AttributeSet;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;

import com.kuoruan.videoview.R;
import com.kuoruan.videoview.internal.PolicyCompat;

import java.io.IOException;
import java.util.Map;

/**
 * Displays a video file.  The VideoView class
 * can load images from various sources (such as resources or content
 * providers), takes care of computing its measurement from the video so that
 * it can be used in any layout manager, and provides various display options
 * such as scaling and tinting.<p>
 * <em>Note: VideoView does not retain its full state when going into the
 * background.</em>  In particular, it does not restore the current play state,
 * play position, selected tracks. Applications should
 * save and restore these on their own in
 * {@link android.app.Activity#onSaveInstanceState} and
 * {@link android.app.Activity#onRestoreInstanceState}.<p>
 * Also note that the audio session id (from {@link #getAudioSessionId}) may
 * change from its previously returned value when the VideoView is restored.
 */
public class VideoView extends SurfaceView implements MediaController.MediaPlayerControl {
    private static final String TAG = "VideoView";

    // all possible internal states
    private static final int STATE_ERROR = -1;
    private static final int STATE_IDLE = 0;
    private static final int STATE_PREPARING = 1;
    private static final int STATE_PREPARED = 2;
    private static final int STATE_PLAYING = 3;
    private static final int STATE_PAUSED = 4;
    private static final int STATE_PLAYBACK_COMPLETED = 5;

    // settable by the client
    private Uri mUri;
    private Map<String, String> mHeaders;

    // mCurrentState is a VideoView object's current state.
    // mTargetState is the state that a method caller intends to reach.
    // For instance, regardless the VideoView object's current state,
    // calling pause() intends to bring the object to a target state
    // of STATE_PAUSED.
    private int mCurrentState = STATE_IDLE;
    private int mTargetState = STATE_IDLE;

    // All the stuff we need for playing and showing a video
    private SurfaceHolder mSurfaceHolder = null;
    private MediaPlayer mMediaPlayer = null;
    private int mAudioSession;
    private int mVideoWidth;
    private int mVideoHeight;
    private int mSurfaceWidth;
    private int mSurfaceHeight;
    private MediaController mMediaController;
    private int mCurrentBufferPercentage;
    private MediaPlayListener mMediaPlayListener;
    private int mSeekWhenPrepared;  // recording the seek position while preparing
    private boolean mCanPause;
    private boolean mCanSeekBack;
    private boolean mCanSeekForward;

    public VideoView(Context context) {
        super(context);
        initVideoView();
    }

    public VideoView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initVideoView();
    }

    public VideoView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initVideoView();
    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public VideoView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        initVideoView();
    }

    private void initVideoView() {
        mVideoWidth = 0;
        mVideoHeight = 0;

        getHolder().addCallback(mSHCallback);
        getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        setFocusable(true);
        setFocusableInTouchMode(true);
        requestFocus();

        mCurrentState = STATE_IDLE;
        mTargetState = STATE_IDLE;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
        int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
        if (mVideoWidth > 0 && mVideoHeight > 0) {

            int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
            int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
            int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
            int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);

            if (widthSpecMode == MeasureSpec.EXACTLY && heightSpecMode == MeasureSpec.EXACTLY) {
                // the size is fixed
                width = widthSpecSize;
                height = heightSpecSize;

                // for compatibility, we adjust size based on aspect ratio
                if (mVideoWidth * height < width * mVideoHeight) {
                    //Log.i("@@@", "image too wide, correcting");
                    width = height * mVideoWidth / mVideoHeight;
                } else if (mVideoWidth * height > width * mVideoHeight) {
                    //Log.i("@@@", "image too tall, correcting");
                    height = width * mVideoHeight / mVideoWidth;
                }
            } else if (widthSpecMode == MeasureSpec.EXACTLY) {
                // only the width is fixed, adjust the height to match aspect ratio if possible
                width = widthSpecSize;
                height = width * mVideoHeight / mVideoWidth;
                if (heightSpecMode == MeasureSpec.AT_MOST && height > heightSpecSize) {
                    // couldn't match aspect ratio within the constraints
                    height = heightSpecSize;
                }
            } else if (heightSpecMode == MeasureSpec.EXACTLY) {
                // only the height is fixed, adjust the width to match aspect ratio if possible
                height = heightSpecSize;
                width = height * mVideoWidth / mVideoHeight;
                if (widthSpecMode == MeasureSpec.AT_MOST && width > widthSpecSize) {
                    // couldn't match aspect ratio within the constraints
                    width = widthSpecSize;
                }
            } else {
                // neither the width nor the height are fixed, try to use actual video size
                width = mVideoWidth;
                height = mVideoHeight;
                if (heightSpecMode == MeasureSpec.AT_MOST && height > heightSpecSize) {
                    // too tall, decrease both width and height
                    height = heightSpecSize;
                    width = height * mVideoWidth / mVideoHeight;
                }
                if (widthSpecMode == MeasureSpec.AT_MOST && width > widthSpecSize) {
                    // too wide, decrease both width and height
                    width = widthSpecSize;
                    height = width * mVideoHeight / mVideoWidth;
                }
            }
        } else {
            // no size yet, just adopt the given spec sizes
        }
        setMeasuredDimension(width, height);
    }

    @Override
    public CharSequence getAccessibilityClassName() {
        return VideoView.class.getName();
    }

    public int resolveAdjustedSize(int desiredSize, int measureSpec) {
        return getDefaultSize(desiredSize, measureSpec);
    }

    /**
     * Sets video path.
     *
     * @param path the path of the video.
     */
    public void setVideoPath(String path) {
        setVideoURI(Uri.parse(path));
    }

    /**
     * Sets video URI.
     *
     * @param uri the URI of the video.
     */
    public void setVideoURI(Uri uri) {
        setVideoURI(uri, null);
    }

    /**
     * Sets video URI using specific headers.
     *
     * @param uri     the URI of the video.
     * @param headers the headers for the URI request.
     *                Note that the cross domain redirection is allowed by default, but that can be
     *                changed with key/value pairs through the headers parameter with
     *                "android-allow-cross-domain-redirect" as the key and "0" or "1" as the value
     *                to disallow or allow cross domain redirection.
     */
    public void setVideoURI(Uri uri, Map<String, String> headers) {
        mUri = uri;
        mHeaders = headers;
        mSeekWhenPrepared = 0;
        openVideo();
        requestLayout();
        invalidate();
    }

    public void stopPlayback() {
        if (mMediaPlayer != null) {
            mMediaPlayer.stop();
            mMediaPlayer.release();
            mMediaPlayer = null;
            mCurrentState = STATE_IDLE;
            mTargetState = STATE_IDLE;
            AudioManager am = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
            am.abandonAudioFocus(null);
        }
    }

    private void openVideo() {
        if (mUri == null || mSurfaceHolder == null) {
            // not ready for playback just yet, will try again later
            return;
        }
        // we shouldn't clear the target state, because somebody might have
        // called start() previously
        release(false);

        AudioManager am = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
        am.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);

        try {
            mMediaPlayer = PolicyCompat.getMediaPlayer(getContext());

            if (mAudioSession != 0) {
                mMediaPlayer.setAudioSessionId(mAudioSession);
            } else {
                mAudioSession = mMediaPlayer.getAudioSessionId();
            }
            mMediaPlayer.setOnPreparedListener(mPreparedListener);
            mMediaPlayer.setOnVideoSizeChangedListener(mSizeChangedListener);
            mMediaPlayer.setOnCompletionListener(mCompletionListener);
            mMediaPlayer.setOnErrorListener(mErrorListener);
            mMediaPlayer.setOnInfoListener(mInfoListener);
            mMediaPlayer.setOnBufferingUpdateListener(mBufferingUpdateListener);
            mCurrentBufferPercentage = 0;
            mMediaPlayer.setDataSource(getContext(), mUri, mHeaders);
            mMediaPlayer.setDisplay(mSurfaceHolder);
            mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
            mMediaPlayer.setScreenOnWhilePlaying(true);
            mMediaPlayer.prepareAsync();

            // we don't set the target state here either, but preserve the
            // target state that was there before.
            mCurrentState = STATE_PREPARING;
            attachMediaController();
        } catch (IOException | IllegalArgumentException ex) {
            Log.w(TAG, "Unable to open content: " + mUri, ex);
            mCurrentState = STATE_ERROR;
            mTargetState = STATE_ERROR;
            mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);
        }
    }

    public void setMediaController(MediaController controller) {
        if (mMediaController != null) {
            mMediaController.hide();
        }
        mMediaController = controller;
        attachMediaController();
    }

    private void attachMediaController() {
        if (mMediaPlayer != null && mMediaController != null) {
            mMediaController.setMediaPlayer(this);
            View anchorView = this.getParent() instanceof View ?
                    (View) this.getParent() : this;
            mMediaController.setAnchorView(anchorView);
            mMediaController.setEnabled(isInPlaybackState());
        }
    }

    MediaPlayer.OnVideoSizeChangedListener mSizeChangedListener =
            new MediaPlayer.OnVideoSizeChangedListener() {
                public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
                    mVideoWidth = mp.getVideoWidth();
                    mVideoHeight = mp.getVideoHeight();
                    if (mVideoWidth != 0 && mVideoHeight != 0) {
                        getHolder().setFixedSize(mVideoWidth, mVideoHeight);
                        requestLayout();
                    }
                }
            };

    MediaPlayer.OnPreparedListener mPreparedListener = new MediaPlayer.OnPreparedListener() {
        public void onPrepared(MediaPlayer mp) {
            mCurrentState = STATE_PREPARED;

            mCanPause = mCanSeekBack = mCanSeekForward = true;

            if (mMediaPlayListener != null) {
                mMediaPlayListener.onPrepared(mMediaPlayer);
            }
            if (mMediaController != null) {
                mMediaController.setEnabled(true);
            }
            mVideoWidth = mp.getVideoWidth();
            mVideoHeight = mp.getVideoHeight();

            int seekToPosition = mSeekWhenPrepared;  // mSeekWhenPrepared may be changed after seekTo() call
            if (seekToPosition != 0) {
                seekTo(seekToPosition);
            }
            if (mVideoWidth != 0 && mVideoHeight != 0) {
                //Log.i("@@@@", "video size: " + mVideoWidth +"/"+ mVideoHeight);
                getHolder().setFixedSize(mVideoWidth, mVideoHeight);
                if (mSurfaceWidth == mVideoWidth && mSurfaceHeight == mVideoHeight) {
                    // We didn't actually change the size (it was already at the size
                    // we need), so we won't get a "surface changed" callback, so
                    // start the video here instead of in the callback.
                    if (mTargetState == STATE_PLAYING) {
                        start();
                        if (mMediaController != null) {
                            mMediaController.show();
                        }
                    } else if (!isPlaying() &&
                            (seekToPosition != 0 || getCurrentPosition() > 0)) {
                        if (mMediaController != null) {
                            // Show the media controls when we're paused into a video and make 'em stick.
                            mMediaController.show(0);
                        }
                    }
                }
            } else {
                // We don't know the video size yet, but should start anyway.
                // The video size might be reported to us later.
                if (mTargetState == STATE_PLAYING) {
                    start();
                }
            }
        }
    };

    private MediaPlayer.OnCompletionListener mCompletionListener =
            new MediaPlayer.OnCompletionListener() {
                public void onCompletion(MediaPlayer mp) {
                    mCurrentState = STATE_PLAYBACK_COMPLETED;
                    mTargetState = STATE_PLAYBACK_COMPLETED;
                    if (mMediaController != null) {
                        mMediaController.hide();
                    }
                    if (mMediaPlayListener != null) {
                        mMediaPlayListener.onCompletion(mMediaPlayer);
                    }
                }
            };

    private MediaPlayer.OnInfoListener mInfoListener =
            new MediaPlayer.OnInfoListener() {
                public boolean onInfo(MediaPlayer mp, int arg1, int arg2) {
                    if (mMediaPlayListener != null) {
                        mMediaPlayListener.onInfo(mp, arg1, arg2);
                    }
                    return true;
                }
            };

    private MediaPlayer.OnErrorListener mErrorListener =
            new MediaPlayer.OnErrorListener() {
                public boolean onError(MediaPlayer mp, int framework_err, int impl_err) {
                    Log.d(TAG, "Error: " + framework_err + "," + impl_err);
                    mCurrentState = STATE_ERROR;
                    mTargetState = STATE_ERROR;
                    if (mMediaController != null) {
                        mMediaController.hide();
                    }

            /* If an error handler has been supplied, use it and finish. */
                    if (mMediaPlayListener != null) {
                        if (mMediaPlayListener.onError(mMediaPlayer, framework_err, impl_err)) {
                            return true;
                        }
                    }

            /* Otherwise, pop up an error dialog so the user knows that
             * something bad has happened. Only try and pop up the dialog
             * if we're attached to a window. When we're going away and no
             * longer have a window, don't bother showing the user an error.
             */
                    if (getWindowToken() != null) {
                        int messageId;

                        if (framework_err == MediaPlayer.MEDIA_ERROR_NOT_VALID_FOR_PROGRESSIVE_PLAYBACK) {
                            messageId = R.string.VideoView_error_text_invalid_progressive_playback;
                        } else {
                            messageId = R.string.VideoView_error_text_unknown;
                        }

                        new AlertDialog.Builder(getContext())
                                .setMessage(messageId)
                                .setPositiveButton(R.string.VideoView_error_button,
                                        new DialogInterface.OnClickListener() {
                                            public void onClick(DialogInterface dialog, int whichButton) {
                                        /* If we get here, there is no onError listener, so
                                         * at least inform them that the video is over.
                                         */
                                                if (mMediaPlayListener != null) {
                                                    mMediaPlayListener.onCompletion(mMediaPlayer);
                                                }
                                            }
                                        })
                                .setCancelable(false)
                                .show();
                    }
                    return true;
                }
            };

    private MediaPlayer.OnBufferingUpdateListener mBufferingUpdateListener =
            new MediaPlayer.OnBufferingUpdateListener() {
                public void onBufferingUpdate(MediaPlayer mp, int percent) {
                    mCurrentBufferPercentage = percent;
                }
            };

    /**
     * Register a callback to be invoked when player status change
     * @param l
     */
    public void setMediaPlayListener(MediaPlayListener l) {
        mMediaPlayListener = l;
    }

    SurfaceHolder.Callback mSHCallback = new SurfaceHolder.Callback() {
        public void surfaceChanged(SurfaceHolder holder, int format,
                                   int w, int h) {
            mSurfaceWidth = w;
            mSurfaceHeight = h;
            boolean isValidState = (mTargetState == STATE_PLAYING);
            boolean hasValidSize = (mVideoWidth == w && mVideoHeight == h);
            if (mMediaPlayer != null && isValidState && hasValidSize) {
                if (mSeekWhenPrepared != 0) {
                    seekTo(mSeekWhenPrepared);
                }
                start();
            }
        }

        public void surfaceCreated(SurfaceHolder holder) {
            mSurfaceHolder = holder;
            openVideo();
        }

        public void surfaceDestroyed(SurfaceHolder holder) {
            // after we return from this we can't use the surface any more
            mSurfaceHolder = null;
            if (mMediaController != null) mMediaController.hide();
            release(true);
        }
    };

    /*
     * release the media player in any state
     */
    private void release(boolean cleartargetstate) {
        if (mMediaPlayer != null) {
            mMediaPlayer.reset();
            mMediaPlayer.release();
            mMediaPlayer = null;
            mCurrentState = STATE_IDLE;
            if (cleartargetstate) {
                mTargetState = STATE_IDLE;
            }
            AudioManager am = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
            am.abandonAudioFocus(null);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (isInPlaybackState() && mMediaController != null) {
            toggleMediaControlsVisiblity();
        }
        return false;
    }

    @Override
    public boolean onTrackballEvent(MotionEvent ev) {
        if (isInPlaybackState() && mMediaController != null) {
            toggleMediaControlsVisiblity();
        }
        return false;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        boolean isKeyCodeSupported = keyCode != KeyEvent.KEYCODE_BACK &&
                keyCode != KeyEvent.KEYCODE_VOLUME_UP &&
                keyCode != KeyEvent.KEYCODE_VOLUME_DOWN &&
                keyCode != KeyEvent.KEYCODE_VOLUME_MUTE &&
                keyCode != KeyEvent.KEYCODE_MENU &&
                keyCode != KeyEvent.KEYCODE_CALL &&
                keyCode != KeyEvent.KEYCODE_ENDCALL;
        if (isInPlaybackState() && isKeyCodeSupported && mMediaController != null) {
            if (keyCode == KeyEvent.KEYCODE_HEADSETHOOK ||
                    keyCode == KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE) {
                if (mMediaPlayer.isPlaying()) {
                    pause();
                    mMediaController.show();
                } else {
                    start();
                    mMediaController.hide();
                }
                return true;
            } else if (keyCode == KeyEvent.KEYCODE_MEDIA_PLAY) {
                if (!mMediaPlayer.isPlaying()) {
                    start();
                    mMediaController.hide();
                }
                return true;
            } else if (keyCode == KeyEvent.KEYCODE_MEDIA_STOP
                    || keyCode == KeyEvent.KEYCODE_MEDIA_PAUSE) {
                if (mMediaPlayer.isPlaying()) {
                    pause();
                    mMediaController.show();
                }
                return true;
            } else {
                toggleMediaControlsVisiblity();
            }
        }

        return super.onKeyDown(keyCode, event);
    }

    private void toggleMediaControlsVisiblity() {
        if (mMediaController.isShowing()) {
            mMediaController.hide();
        } else {
            mMediaController.show();
        }
    }

    @Override
    public void start() {
        if (isInPlaybackState()) {
            mMediaPlayer.start();
            mCurrentState = STATE_PLAYING;
        }
        mTargetState = STATE_PLAYING;
        if (mMediaController != null) {
            mMediaController.show();
        }
    }

    @Override
    public void pause() {
        if (isInPlaybackState()) {
            if (mMediaPlayer.isPlaying()) {
                mMediaPlayer.pause();
                mCurrentState = STATE_PAUSED;
            }
        }
        mTargetState = STATE_PAUSED;
    }

    public void suspend() {
        release(false);
    }

    public void resume() {
        openVideo();
    }

    @Override
    public int getDuration() {
        if (isInPlaybackState()) {
            return mMediaPlayer.getDuration();
        }

        return -1;
    }

    @Override
    public int getCurrentPosition() {
        if (isInPlaybackState()) {
            return mMediaPlayer.getCurrentPosition();
        }
        return 0;
    }

    @Override
    public void seekTo(int msec) {
        if (isInPlaybackState()) {
            mMediaPlayer.seekTo(msec);
            mSeekWhenPrepared = 0;
        } else {
            mSeekWhenPrepared = msec;
        }
    }

    @Override
    public boolean isPlaying() {
        return isInPlaybackState() && mMediaPlayer.isPlaying();
    }

    @Override
    public int getBufferPercentage() {
        if (mMediaPlayer != null) {
            return mCurrentBufferPercentage;
        }
        return 0;
    }

    private boolean isInPlaybackState() {
        return (mMediaPlayer != null &&
                mCurrentState != STATE_ERROR &&
                mCurrentState != STATE_IDLE &&
                mCurrentState != STATE_PREPARING);
    }

    @Override
    public boolean canPause() {
        return mCanPause;
    }

    @Override
    public boolean canSeekBackward() {
        return mCanSeekBack;
    }

    @Override
    public boolean canSeekForward() {
        return mCanSeekForward;
    }

    @Override
    public int getAudioSessionId() {
        if (mAudioSession == 0) {
            MediaPlayer foo = new MediaPlayer();
            mAudioSession = foo.getAudioSessionId();
            foo.release();
        }
        return mAudioSession;
    }

    @Override
    public void stop() {
        stopPlayback();
        if (mMediaPlayListener != null) {
            mMediaPlayListener.onStop();
        }
    }

    public interface MediaPlayListener {
        /**
         * Called when the media file is ready for playback.
         *
         * @param mp the MediaPlayer that is ready for playback
         */
        void onPrepared(MediaPlayer mp);

        /**
         * Called when the end of a media source is reached during playback.
         *
         * @param mp the MediaPlayer that reached the end of the file
         */
        void onCompletion(MediaPlayer mp);

        /**
         * Called to indicate an error.
         *
         * @param mp      the MediaPlayer the error pertains to
         * @param what    the type of error that has occurred:
         * <ul>
         * <li>{@link MediaPlayer#MEDIA_ERROR_UNKNOWN}
         * <li>{@link MediaPlayer#MEDIA_ERROR_SERVER_DIED}
         * </ul>
         * @param extra an extra code, specific to the error. Typically
         * implementation dependent.
         * <ul>
         * <li>{@link MediaPlayer#MEDIA_ERROR_IO}
         * <li>{@link MediaPlayer#MEDIA_ERROR_MALFORMED}
         * <li>{@link MediaPlayer#MEDIA_ERROR_UNSUPPORTED}
         * <li>{@link MediaPlayer#MEDIA_ERROR_TIMED_OUT}
         * <li><code>MEDIA_ERROR_SYSTEM (-2147483648)</code> - low-level system error.
         * </ul>
         * @return True if the method handled the error, false if it didn't.
         * Returning false, or not having an OnErrorListener at all, will
         * cause the OnCompletionListener to be called.
         */
        boolean onError(MediaPlayer mp, int what, int extra);

        /**
         * Called to indicate an info or a warning.
         *
         * @param mp      the MediaPlayer the info pertains to.
         * @param what    the type of info or warning.
         * <ul>
         * <li>{@link MediaPlayer#MEDIA_INFO_UNKNOWN}
         * <li>{@link MediaPlayer#MEDIA_INFO_VIDEO_TRACK_LAGGING}
         * <li>{@link MediaPlayer#MEDIA_INFO_VIDEO_RENDERING_START}
         * <li>{@link MediaPlayer#MEDIA_INFO_BUFFERING_START}
         * <li>{@link MediaPlayer#MEDIA_INFO_BUFFERING_END}
         * <li><code>MEDIA_INFO_NETWORK_BANDWIDTH (703)</code> -
         *     bandwidth information is available (as <code>extra</code> kbps)
         * <li>{@link MediaPlayer#MEDIA_INFO_BAD_INTERLEAVING}
         * <li>{@link MediaPlayer#MEDIA_INFO_NOT_SEEKABLE}
         * <li>{@link MediaPlayer#MEDIA_INFO_METADATA_UPDATE}
         * <li>{@link MediaPlayer#MEDIA_INFO_UNSUPPORTED_SUBTITLE}
         * <li>{@link MediaPlayer#MEDIA_INFO_SUBTITLE_TIMED_OUT}
         * </ul>
         * @param extra an extra code, specific to the info. Typically
         * implementation dependent.
         * @return True if the method handled the info, false if it didn't.
         * Returning false, or not having an OnInfoListener at all, will
         * cause the info to be discarded.
         */
        boolean onInfo(MediaPlayer mp, int what, int extra);

        /**
         * Called when media player stop.
         */
        void onStop();
    }
}

can you please add a screenshot of this player