Fix 5358124: Better transport control visibility management in lock screen

This changes TransportControlView to be "sticky" on lockscreen.  Basically, once it
appears on lockscreen, it stays there until unlocked and then locked again in paused state.

Tested basic design goals (using Music2):
- play then lock -> shows
- pause then lock -> not shown
- toggle pause to play while locked and not shown -> shows
- pause after played once while locked -> stays until we unlock and lock again while paused
- remote control play while paused & sleeping -> resume lockscreen -> shows

Also tested:
- configuration changes (orientation) to ensure widget continues to show after it once appears
- remote events while lock screen on -> keeps lockscreen on.
- remote events while sleeping -> doesn't wake.

Change-Id: I23418c5f7dfd1457c0844d2683772e8a3ed0abd1

Author: Jim Miller

core/java/com/android/internal/widget/LockScreenWidgetCallback.java

@@ -29,6 +29,9 @@ public interface LockScreenWidgetCallback {
     // Sends a message to lock screen requesting the view to be hidden.
     public void requestHide(View self);
 
+    // Whether or not this view is currently visible on LockScreen
+    public boolean isVisible(View self);
+
     // Sends a message to lock screen that user has interacted with widget. This should be used
     // exclusively in response to user activity, i.e. user hits a button in the view.
     public void userActivity(View self);

core/java/com/android/internal/widget/TransportControlView.java

@@ -34,6 +34,8 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
+import android.os.Parcel;
+import android.os.Parcelable;
 import android.os.RemoteException;
 import android.os.SystemClock;
 import android.text.Spannable;
@@ -61,7 +63,7 @@ public class TransportControlView extends FrameLayout implements OnClickListener
     private static final int MSG_SET_GENERATION_ID = 104;
     private static final int MAXDIM = 512;
     private static final int DISPLAY_TIMEOUT_MS = 5000; // 5s
-    protected static final boolean DEBUG = true;
+    protected static final boolean DEBUG = false;
     protected static final String TAG = "TransportControlView";
 
     private ImageView mAlbumArt;
@@ -74,7 +76,7 @@ public class TransportControlView extends FrameLayout implements OnClickListener
     private boolean mAttached;
     private PendingIntent mClientIntent;
     private int mTransportControlFlags;
-    private int mPlayState;
+    private int mCurrentPlayState;
     private AudioManager mAudioManager;
     private LockScreenWidgetCallback mWidgetCallbacks;
     private IRemoteControlDisplayWeak mIRCD;
@@ -84,6 +86,11 @@ public class TransportControlView extends FrameLayout implements OnClickListener
      */
     private Bundle mPopulateMetadataWhenAttached = null;
 
+    /**
+     * Whether to clear the interface next time it is shown (i.e. the generation id changed)
+     */
+    private boolean mClearOnNextShow;
+
     // This handler is required to ensure messages from IRCD are handled in sequence and on
     // the UI thread.
     private Handler mHandler = new Handler() {
@@ -113,15 +120,10 @@ public void handleMessage(Message msg) {
                 break;
 
             case MSG_SET_GENERATION_ID:
-                if (mWidgetCallbacks != null) {
-                    boolean clearing = msg.arg2 != 0;
-                    if (DEBUG) Log.v(TAG, "New genId = " + msg.arg1 + ", clearing = " + clearing);
-                    if (!clearing) {
-                        mWidgetCallbacks.requestShow(TransportControlView.this);
-                    } else {
-                        mWidgetCallbacks.requestHide(TransportControlView.this);
-                    }
+                if (msg.arg2 != 0) {
+                    mClearOnNextShow = true; // TODO: handle this
                 }
+                if (DEBUG) Log.v(TAG, "New genId = " + msg.arg1 + ", clearing = " + msg.arg2);
                 mClientGeneration = msg.arg1;
                 mClientIntent = (PendingIntent) msg.obj;
                 break;
@@ -195,6 +197,7 @@ public TransportControlView(Context context, AttributeSet attrs) {
         super(context, attrs);
         Log.v(TAG, "Create TCV " + this);
         mAudioManager = new AudioManager(mContext);
+        mCurrentPlayState = RemoteControlClient.PLAYSTATE_NONE; // until we get a callback
         mIRCD = new IRemoteControlDisplayWeak(mHandler);
     }
 
@@ -319,7 +322,7 @@ private void populateMetadata() {
                 | RemoteControlClient.FLAG_KEY_MEDIA_PLAY_PAUSE
                 | RemoteControlClient.FLAG_KEY_MEDIA_STOP);
 
-        updatePlayPauseState(mPlayState);
+        updatePlayPauseState(mCurrentPlayState);
     }
 
     private static void setVisibilityBasedOnFlag(View view, int flags, int flag) {
@@ -332,32 +335,92 @@ private static void setVisibilityBasedOnFlag(View view, int flags, int flag) {
 
     private void updatePlayPauseState(int state) {
         if (DEBUG) Log.v(TAG,
-                "updatePlayPauseState(), old=" + mPlayState + ", state=" + state);
-        if (state == mPlayState) {
+                "updatePlayPauseState(), old=" + mCurrentPlayState + ", state=" + state);
+        if (state == mCurrentPlayState) {
             return;
         }
         final int imageResId;
         final int imageDescId;
+        final boolean showIfHidden;
         switch (state) {
             case RemoteControlClient.PLAYSTATE_PLAYING:
                 imageResId = com.android.internal.R.drawable.ic_media_pause;
                 imageDescId = com.android.internal.R.string.lockscreen_transport_pause_description;
+                showIfHidden = true;
                 break;
 
             case RemoteControlClient.PLAYSTATE_BUFFERING:
                 imageResId = com.android.internal.R.drawable.ic_media_stop;
                 imageDescId = com.android.internal.R.string.lockscreen_transport_stop_description;
+                showIfHidden = true;
                 break;
 
             case RemoteControlClient.PLAYSTATE_PAUSED:
             default:
                 imageResId = com.android.internal.R.drawable.ic_media_play;
                 imageDescId = com.android.internal.R.string.lockscreen_transport_play_description;
+                showIfHidden = false;
                 break;
         }
         mBtnPlay.setImageResource(imageResId);
         mBtnPlay.setContentDescription(getResources().getString(imageDescId));
-        mPlayState = state;
+        if (showIfHidden && mWidgetCallbacks != null && !mWidgetCallbacks.isVisible(this)) {
+            mWidgetCallbacks.requestShow(this);
+        }
+        mCurrentPlayState = state;
+    }
+
+    static class SavedState extends BaseSavedState {
+        boolean wasShowing;
+
+        SavedState(Parcelable superState) {
+            super(superState);
+        }
+
+        private SavedState(Parcel in) {
+            super(in);
+            this.wasShowing = in.readInt() != 0;
+        }
+
+        @Override
+        public void writeToParcel(Parcel out, int flags) {
+            super.writeToParcel(out, flags);
+            out.writeInt(this.wasShowing ? 1 : 0);
+        }
+
+        public static final Parcelable.Creator<SavedState> CREATOR
+                = new Parcelable.Creator<SavedState>() {
+            public SavedState createFromParcel(Parcel in) {
+                return new SavedState(in);
+            }
+
+            public SavedState[] newArray(int size) {
+                return new SavedState[size];
+            }
+        };
+    }
+
+    @Override
+    public Parcelable onSaveInstanceState() {
+        if (DEBUG) Log.v(TAG, "onSaveInstanceState()");
+        Parcelable superState = super.onSaveInstanceState();
+        SavedState ss = new SavedState(superState);
+        ss.wasShowing = mWidgetCallbacks.isVisible(this);
+        return ss;
+    }
+
+    @Override
+    public void onRestoreInstanceState(Parcelable state) {
+        if (DEBUG) Log.v(TAG, "onRestoreInstanceState()");
+        if (!(state instanceof SavedState)) {
+            super.onRestoreInstanceState(state);
+            return;
+        }
+        SavedState ss = (SavedState) state;
+        super.onRestoreInstanceState(ss.getSuperState());
+        if (ss.wasShowing) {
+            mWidgetCallbacks.requestShow(this);
+        }
     }
 
     public void onClick(View v) {

policy/src/com/android/internal/policy/impl/LockPatternKeyguardView.java

@@ -49,6 +49,7 @@
 import android.os.Handler;
 import android.os.Message;
 import android.os.IBinder;
+import android.os.Parcelable;
 import android.os.RemoteException;
 import android.os.SystemClock;
 import android.os.SystemProperties;
@@ -221,6 +222,7 @@ enum UnlockMode {
     private Runnable mRecreateRunnable = new Runnable() {
         public void run() {
             updateScreen(mMode, true);
+            restoreWidgetState();
         }
     };
 
@@ -244,8 +246,20 @@ public void requestHide(View view) {
             // TODO: examine all widgets to derive clock status
             mUpdateMonitor.reportClockVisible(true);
         }
+
+        public boolean isVisible(View self) {
+            // TODO: this should be up to the lockscreen to determine if the view
+            // is currently showing. The idea is it can be used for the widget to
+            // avoid doing work if it's not visible. For now just returns the view's
+            // actual visibility.
+            return self.getVisibility() == View.VISIBLE;
+        }
     };
 
+    private TransportControlView mTransportControlView;
+
+    private Parcelable mSavedState;
+
     /**
      * @return Whether we are stuck on the lock screen because the sim is
      *   missing.
@@ -365,6 +379,7 @@ public void pokeWakelock(int millis) {
 
             public void keyguardDone(boolean authenticated) {
                 getCallback().keyguardDone(authenticated);
+                mSavedState = null; // clear state so we re-establish when locked again
             }
 
             public void keyguardDoneDrawing() {
@@ -528,6 +543,8 @@ public void onScreenTurnedOff() {
             ((KeyguardScreen) mUnlockScreen).onPause();
         }
 
+        saveWidgetState();
+
         // When screen is turned off, need to unbind from FaceLock service if using FaceLock
         stopAndUnbindFromFaceLock();
     }
@@ -558,8 +575,28 @@ public void onScreenTurnedOn() {
             mScreenOn = true;
             runFaceLock = mWindowFocused;
         }
+
         show();
-        if(runFaceLock) activateFaceLockIfAble();
+
+        restoreWidgetState();
+
+        if (runFaceLock) activateFaceLockIfAble();
+    }
+
+    private void saveWidgetState() {
+        if (mTransportControlView != null) {
+            if (DEBUG) Log.v(TAG, "Saving widget state");
+            mSavedState = mTransportControlView.onSaveInstanceState();
+        }
+    }
+
+    private void restoreWidgetState() {
+        if (mTransportControlView != null) {
+            if (DEBUG) Log.v(TAG, "Restoring widget state");
+            if (mSavedState != null) {
+                mTransportControlView.onRestoreInstanceState(mSavedState);
+            }
+        }
     }
 
     /** Unbind from facelock if something covers this window (such as an alarm)
@@ -643,6 +680,7 @@ protected void onConfigurationChanged(Configuration newConfig) {
         mShowLockBeforeUnlock = resources.getBoolean(R.bool.config_enableLockBeforeUnlockScreen);
         mConfiguration = newConfig;
         if (DEBUG_CONFIGURATION) Log.v(TAG, "**** re-creating lock screen since config changed");
+        saveWidgetState();
         removeCallbacks(mRecreateRunnable);
         post(mRecreateRunnable);
     }
@@ -895,13 +933,13 @@ View createUnlockScreenFor(UnlockMode unlockMode) {
     }
 
     private void initializeTransportControlView(View view) {
-        TransportControlView tcv = (TransportControlView) view.findViewById(R.id.transport);
-        if (tcv == null) {
+        mTransportControlView = (TransportControlView) view.findViewById(R.id.transport);
+        if (mTransportControlView == null) {
             if (DEBUG) Log.w(TAG, "Couldn't find transport control widget");
         } else {
             mUpdateMonitor.reportClockVisible(true);
-            tcv.setVisibility(View.GONE); // hide until it requests being shown.
-            tcv.setCallback(mWidgetCallback);
+            mTransportControlView.setVisibility(View.GONE); // hide until it requests being shown.
+            mTransportControlView.setCallback(mWidgetCallback);
         }
     }