From c818b141ee97a7a26fe069456d4b662d06c9eaea Mon Sep 17 00:00:00 2001
From: Marco Nelissen <marcone@google.com>
Date: Wed, 19 Aug 2009 08:32:21 -0700
Subject: [PATCH] Do not enable the rew/pause/ffwd buttons when the media being
 played does not support these functions. This extends the MediaPlayerControl
 interface with some new methods, and uses reflection to detect whether the
 old or new interface is used by an application.

---
 api/current.xml                               | 66 +++++++++++++++++++
 core/java/android/widget/MediaController.java | 41 +++++++++---
 core/java/android/widget/VideoView.java       | 30 ++++++++-
 3 files changed, 127 insertions(+), 10 deletions(-)

diff --git a/api/current.xml b/api/current.xml
index e9082bc5af253..ec76edb3ce8a4 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -175196,6 +175196,39 @@
  deprecated="not deprecated"
  visibility="public"
 >
+<method name="canPause"
+ return="boolean"
+ abstract="true"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
+<method name="canSeekBackward"
+ return="boolean"
+ abstract="true"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
+<method name="canSeekForward"
+ return="boolean"
+ abstract="true"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
 <method name="getBufferPercentage"
  return="int"
  abstract="true"
@@ -183524,6 +183557,39 @@
 <parameter name="defStyle" type="int">
 </parameter>
 </constructor>
+<method name="canPause"
+ return="boolean"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
+<method name="canSeekBackward"
+ return="boolean"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
+<method name="canSeekForward"
+ return="boolean"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
 <method name="getBufferPercentage"
  return="int"
  abstract="false"
diff --git a/core/java/android/widget/MediaController.java b/core/java/android/widget/MediaController.java
index 0c9d980488eaf..9910c3715df9f 100644
--- a/core/java/android/widget/MediaController.java
+++ b/core/java/android/widget/MediaController.java
@@ -249,6 +249,29 @@ public class MediaController extends FrameLayout {
         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.
+        }
+    }
+    
     /**
      * Show the controller on screen. It will go away
      * automatically after 'timeout' milliseconds of inactivity.
@@ -259,6 +282,7 @@ public class MediaController extends FrameLayout {
 
         if (!mShowing && mAnchor != null) {
             setProgress();
+            disableUnsupportedButtons();
 
             int [] anchorpos = new int[2];
             mAnchor.getLocationOnScreen(anchorpos);
@@ -421,17 +445,13 @@ public class MediaController extends FrameLayout {
     };
 
     private void updatePausePlay() {
-        if (mRoot == null)
-            return;
-
-        ImageButton button = (ImageButton) mRoot.findViewById(com.android.internal.R.id.pause);
-        if (button == null)
+        if (mRoot == null || mPauseButton == null)
             return;
 
         if (mPlayer.isPlaying()) {
-            button.setImageResource(com.android.internal.R.drawable.ic_media_pause);
+            mPauseButton.setImageResource(com.android.internal.R.drawable.ic_media_pause);
         } else {
-            button.setImageResource(com.android.internal.R.drawable.ic_media_play);
+            mPauseButton.setImageResource(com.android.internal.R.drawable.ic_media_play);
         }
     }
 
@@ -516,7 +536,7 @@ public class MediaController extends FrameLayout {
         if (mProgress != null) {
             mProgress.setEnabled(enabled);
         }
-
+        disableUnsupportedButtons();
         super.setEnabled(enabled);
     }
 
@@ -579,5 +599,8 @@ public class MediaController extends FrameLayout {
         void    seekTo(int pos);
         boolean isPlaying();
         int     getBufferPercentage();
-    };
+        boolean canPause();
+        boolean canSeekBackward();
+        boolean canSeekForward();
+    }
 }
diff --git a/core/java/android/widget/VideoView.java b/core/java/android/widget/VideoView.java
index 5bc25073f7740..e60ff25703f99 100644
--- a/core/java/android/widget/VideoView.java
+++ b/core/java/android/widget/VideoView.java
@@ -23,6 +23,7 @@ import android.content.Intent;
 import android.content.res.Resources;
 import android.media.AudioManager;
 import android.media.MediaPlayer;
+import android.media.Metadata;
 import android.media.MediaPlayer.OnCompletionListener;
 import android.media.MediaPlayer.OnErrorListener;
 import android.net.Uri;
@@ -34,7 +35,7 @@ import android.view.MotionEvent;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 import android.view.View;
-import android.widget.MediaController.MediaPlayerControl;
+import android.widget.MediaController.*;
 
 import java.io.IOException;
 
@@ -81,6 +82,9 @@ public class VideoView extends SurfaceView implements MediaPlayerControl {
     private int         mCurrentBufferPercentage;
     private OnErrorListener mOnErrorListener;
     private int         mSeekWhenPrepared;  // recording the seek position while preparing
+    private boolean     mCanPause;
+    private boolean     mCanSeekBack;
+    private boolean     mCanSeekForward;
 
     public VideoView(Context context) {
         super(context);
@@ -259,6 +263,17 @@ public class VideoView extends SurfaceView implements MediaPlayerControl {
     MediaPlayer.OnPreparedListener mPreparedListener = new MediaPlayer.OnPreparedListener() {
         public void onPrepared(MediaPlayer mp) {
             mCurrentState = STATE_PREPARED;
+
+            // Get the capabilities of the player for this stream
+            Metadata data = mp.getMetadata(MediaPlayer.METADATA_ALL,
+                                      MediaPlayer.BYPASS_METADATA_FILTER);
+            mCanPause = !data.has(Metadata.PAUSE_AVAILABLE)
+                    || data.getBoolean(Metadata.PAUSE_AVAILABLE);
+            mCanSeekBack = !data.has(Metadata.SEEK_BACKWARD_AVAILABLE)
+                    || data.getBoolean(Metadata.SEEK_BACKWARD_AVAILABLE);
+            mCanSeekForward = !data.has(Metadata.SEEK_FORWARD_AVAILABLE)
+                    || data.getBoolean(Metadata.SEEK_FORWARD_AVAILABLE);
+
             if (mOnPreparedListener != null) {
                 mOnPreparedListener.onPrepared(mMediaPlayer);
             }
@@ -267,6 +282,7 @@ public class VideoView extends SurfaceView implements MediaPlayerControl {
             }
             mVideoWidth = mp.getVideoWidth();
             mVideoHeight = mp.getVideoHeight();
+
             int seekToPosition = mSeekWhenPrepared;  // mSeekWhenPrepared may be changed after seekTo() call
             if (seekToPosition != 0) {
                 seekTo(seekToPosition);
@@ -580,4 +596,16 @@ public class VideoView extends SurfaceView implements MediaPlayerControl {
                 mCurrentState != STATE_IDLE &&
                 mCurrentState != STATE_PREPARING);
     }
+
+    public boolean canPause() {
+        return mCanPause;
+    }
+
+    public boolean canSeekBackward() {
+        return mCanSeekBack;
+    }
+
+    public boolean canSeekForward() {
+        return mCanSeekForward;
+    }
 }