/*
* 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 android.widget;
import android.content.Context;
import android.graphics.PixelFormat;
import android.media.AudioManager;
import android.os.Handler;
import android.os.Message;
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.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.SeekBar.OnSeekBarChangeListener;
import com.android.internal.policy.PolicyManager;
import java.util.Formatter;
import java.util.Locale;
/**
* 一个包含媒体播放器控件的视图.包含了一些典型的按钮，像“播放/暂停”、
* “倒退”、“快进”与进度条.它保持媒体播放器与控件的状态同步.
* <p>
* 要使用该类，需要通过编程来实例化.媒体控制器会创建默认的控件集合，
* 并把它们放到浮在你的应用程序上方的窗口中.具体来说，
* 就是这些控件浮在通过 setAnchorView() 方法指定的视图的上方.
* 如果这个窗口空闲3秒那么它将消失，直到用户再次触摸该宿主视图时重现.
* <p>
* 如果媒体控制器是在 XML 布局文件中创建的，则像 show() 和 hide()
* 这些函数对其没有影响.
*
* 媒体播放器将根据如下规则来显示和隐藏其按钮：
* <ul>
* <li> 在调用 setPrevNextListeners() 函数之前，
* “上一首”和“下一首”按钮都是隐藏的.
* <li> 如果调用 setPrevNextListeners() 函数时监听器参数为空，
* 则“上一首”和“下一首”按钮可见，但处于不可用状态.
* <li> “后退”和“快进”按钮是一直显示的，如果不需要可以在调用构造函数
* MediaController(Context, boolean) 时将布尔值设置为假.
* </ul>
*/
public class MediaController extends FrameLayout {
private MediaPlayerControl mPlayer;
private Context mContext;
private View mAnchor;
private View mRoot;
private WindowManager mWindowManager;
private Window mWindow;
private View mDecor;
private WindowManager.LayoutParams mDecorLayoutParams;
private ProgressBar mProgress;
private TextView mEndTime, mCurrentTime;
private boolean mShowing;
private boolean mDragging;
private static final int sDefaultTimeout = 3000;
private static final int FADE_OUT = 1;
private static final int SHOW_PROGRESS = 2;
private boolean mUseFastForward;
private boolean mFromXml;
private boolean mListenersSet;
private View.OnClickListener mNextListener, mPrevListener;
StringBuilder mFormatBuilder;
Formatter mFormatter;
private ImageButton mPauseButton;
private ImageButton mFfwdButton;
private ImageButton mRewButton;
private ImageButton mNextButton;
private ImageButton mPrevButton;
public MediaController(Context context, AttributeSet attrs) {
super(context, attrs);
mRoot = this;
mContext = context;
mUseFastForward = true;
mFromXml = true;
}
@Override
public void onFinishInflate() {
if (mRoot != null)
initControllerView(mRoot);
}
public MediaController(Context context, boolean useFastForward) {
super(context);
mContext = context;
mUseFastForward = useFastForward;
initFloatingWindowLayout();
initFloatingWindow();
}
public MediaController(Context context) {
this(context, true);
}
private void initFloatingWindow() {
mWindowManager = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);
mWindow = PolicyManager.makeNewWindow(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;
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);
WindowManager.LayoutParams p = mDecorLayoutParams;
p.width = mAnchor.getWidth();
p.y = anchorPos[1] + mAnchor.getHeight();
}
// This is called whenever mAnchor's layout bound changes
private OnLayoutChangeListener mLayoutChangeListener =
new OnLayoutChangeListener() {
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 OnTouchListener mTouchListener = new OnTouchListener() {
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();
}
/**
* 设置绑定媒体控制器视图的视图.该视图可以是 VideoView，或者是你的活动的主视图.
* @param view 控制器可见时绑定的视图.
*/
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);
}
/**
* 创建用于放置控制播放的小部件的视图.派生的类可以使用自己的实现覆盖该方法.
* @return 控制器视图.
* @hide This doesn't work as advertised
*/
protected View makeControllerView() {
LayoutInflater inflate = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mRoot = inflate.inflate(com.android.internal.R.layout.media_controller, null);
initControllerView(mRoot);
return mRoot;
}
private void initControllerView(View v) {
mPauseButton = (ImageButton) v.findViewById(com.android.internal.R.id.pause);
if (mPauseButton != null) {
mPauseButton.requestFocus();
mPauseButton.setOnClickListener(mPauseListener);
}
mFfwdButton = (ImageButton) v.findViewById(com.android.internal.R.id.ffwd);
if (mFfwdButton != null) {
mFfwdButton.setOnClickListener(mFfwdListener);
if (!mFromXml) {
mFfwdButton.setVisibility(mUseFastForward ? View.VISIBLE : View.GONE);
}
}
mRewButton = (ImageButton) v.findViewById(com.android.internal.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(com.android.internal.R.id.next);
if (mNextButton != null && !mFromXml && !mListenersSet) {
mNextButton.setVisibility(View.GONE);
}
mPrevButton = (ImageButton) v.findViewById(com.android.internal.R.id.prev);
if (mPrevButton != null && !mFromXml && !mListenersSet) {
mPrevButton.setVisibility(View.GONE);
}
mProgress = (ProgressBar) v.findViewById(com.android.internal.R.id.mediacontroller_progress);
if (mProgress != null) {
if (mProgress instanceof SeekBar) {
SeekBar seeker = (SeekBar) mProgress;
seeker.setOnSeekBarChangeListener(mSeekListener);
}
mProgress.setMax(1000);
}
mEndTime = (TextView) v.findViewById(com.android.internal.R.id.time);
mCurrentTime = (TextView) v.findViewById(com.android.internal.R.id.time_current);
mFormatBuilder = new StringBuilder();
mFormatter = new Formatter(mFormatBuilder, Locale.getDefault());
installPrevNextListeners();
}
/**
* 在屏幕上显示控制器.它将在空闲超过 3 秒后自动隐藏.
*/
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);
}
} 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.
}
}
/**
* 在屏幕上显示控制器.它将在空闲超过 “timeout” 毫秒后自动隐藏.
* @param timeout 以毫秒为单位的超时时间.设置为0时，在调用 hide()函数之前控件一直可见.
*/
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.
mHandler.sendEmptyMessage(SHOW_PROGRESS);
Message msg = mHandler.obtainMessage(FADE_OUT);
if (timeout != 0) {
mHandler.removeMessages(FADE_OUT);
mHandler.sendMessageDelayed(msg, timeout);
}
}
public boolean isShowing() {
return mShowing;
}
/**
* 隐藏屏幕上显示的控件.
*/
public void hide() {
if (mAnchor == null)
return;
if (mShowing) {
try {
mHandler.removeMessages(SHOW_PROGRESS);
mWindowManager.removeView(mDecor);
} catch (IllegalArgumentException ex) {
Log.w("MediaController", "already removed");
}
mShowing = false;
}
}
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
int pos;
switch (msg.what) {
case FADE_OUT:
hide();
break;
case SHOW_PROGRESS:
pos = setProgress();
if (!mDragging && mShowing && mPlayer.isPlaying()) {
msg = obtainMessage(SHOW_PROGRESS);
sendMessageDelayed(msg, 1000 - (pos % 1000));
}
break;
}
}
};
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) {
show(sDefaultTimeout);
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 View.OnClickListener mPauseListener = new View.OnClickListener() {
public void onClick(View v) {
doPauseResume();
show(sDefaultTimeout);
}
};
private void updatePausePlay() {
if (mRoot == null || mPauseButton == null)
return;
if (mPlayer.isPlaying()) {
mPauseButton.setImageResource(com.android.internal.R.drawable.ic_media_pause);
} else {
mPauseButton.setImageResource(com.android.internal.R.drawable.ic_media_play);
}
}
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 OnSeekBarChangeListener mSeekListener = new OnSeekBarChangeListener() {
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.
mHandler.removeMessages(SHOW_PROGRESS);
}
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));
}
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.
mHandler.sendEmptyMessage(SHOW_PROGRESS);
}
};
@Override
public void setEnabled(boolean 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 void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(MediaController.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(MediaController.class.getName());
}
private View.OnClickListener mRewListener = new View.OnClickListener() {
public void onClick(View v) {
int pos = mPlayer.getCurrentPosition();
pos -= 5000; // milliseconds
mPlayer.seekTo(pos);
setProgress();
show(sDefaultTimeout);
}
};
private View.OnClickListener mFfwdListener = new View.OnClickListener() {
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();
int getDuration();
int getCurrentPosition();
void seekTo(int pos);
boolean isPlaying();
int getBufferPercentage();
boolean canPause();
boolean canSeekBackward();
boolean canSeekForward();
}
}