Rework thumbnail API to not suffer from IPC failures.

Thumbnails are now requested separately, so we don't exceed the
IPC buffer size limit.

Also implement issue #3349553: Please provide a hook to intercept
fragment-breadcrumb clicks

And maybe fix issue #3439199: Music Notification does not turn on
when app switching out of Music app

Change-Id: Ie939e78cc8ded07b18112760e053185947549f61

7 files changed, 185 insertions, 38 deletions

diff --git a/api/current.xml b/api/current.xml
index 1ce49d4d7964..2c7229063a38 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -25064,6 +25064,17 @@
 <parameter name="packageName" type="java.lang.String">
 </parameter>
 </method>
+<field name="MOVE_TASK_NO_USER_ACTION"
+ type="int"
+ transient="false"
+ volatile="false"
+ value="2"
+ static="true"
+ final="true"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</field>
 <field name="MOVE_TASK_WITH_HOME"
  type="int"
  transient="false"
@@ -25495,6 +25506,16 @@
  visibility="public"
 >
 </field>
+<field name="persistentId"
+ type="int"
+ transient="false"
+ volatile="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</field>
 </class>
 <class name="ActivityManager.RunningAppProcessInfo"
  extends="java.lang.Object"
@@ -30692,6 +30713,19 @@
 <parameter name="visibleCrumbs" type="int">
 </parameter>
 </method>
+<method name="setOnBreadCrumbClickListener"
+ return="void"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="listener" type="android.app.FragmentBreadCrumbs.OnBreadCrumbClickListener">
+</parameter>
+</method>
 <method name="setParentTitle"
  return="void"
  abstract="false"
@@ -30725,6 +30759,29 @@
 </parameter>
 </method>
 </class>
+<interface name="FragmentBreadCrumbs.OnBreadCrumbClickListener"
+ abstract="true"
+ static="true"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<method name="onBreadCrumbClick"
+ return="boolean"
+ abstract="true"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="backStack" type="android.app.FragmentManager.BackStackEntry">
+</parameter>
+<parameter name="flags" type="int">
+</parameter>
+</method>
+</interface>
 <class name="FragmentManager"
  extends="java.lang.Object"
  abstract="true"
@@ -265799,7 +265856,7 @@
  deprecated="not deprecated"
  visibility="public"
 >
-<parameter name="t" type="T">
+<parameter name="arg0" type="T">
 </parameter>
 </method>
 </interface>
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index d76b67d3ef2a..a660076b4b03 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -112,6 +112,11 @@ public class ActivityManager {
         public int id;
 
         /**
+         * The true identifier of this task, valid even if it is not running.
+         */
+        public int persistentId;
+        
+        /**
          * The original Intent used to launch the task.  You can use this
          * Intent to re-launch the task (if it is no longer running) or bring
          * the current task to the front.
@@ -127,14 +132,6 @@ public class ActivityManager {
         public ComponentName origActivity;
 
         /**
-         * Thumbnail representation of the task's last state.  Must
-         * use {@link ActivityManager#TASKS_GET_THUMBNAILS} to have this set.
-         * @hide -- this is not scalable, need to have a separate API to get
-         * the bitmap.
-         */
-        public Bitmap thumbnail;
-
-        /**
          * Description of the task's last state.
          */
         public CharSequence description;
@@ -148,6 +145,7 @@ public class ActivityManager {
 
         public void writeToParcel(Parcel dest, int flags) {
             dest.writeInt(id);
+            dest.writeInt(persistentId);
             if (baseIntent != null) {
                 dest.writeInt(1);
                 baseIntent.writeToParcel(dest, 0);
@@ -155,29 +153,19 @@ public class ActivityManager {
                 dest.writeInt(0);
             }
             ComponentName.writeToParcel(origActivity, dest);
-            if (thumbnail != null) {
-                dest.writeInt(1);
-                thumbnail.writeToParcel(dest, 0);
-            } else {
-                dest.writeInt(0);
-            }
             TextUtils.writeToParcel(description, dest,
                     Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
         }
 
         public void readFromParcel(Parcel source) {
             id = source.readInt();
+            persistentId = source.readInt();
             if (source.readInt() != 0) {
                 baseIntent = Intent.CREATOR.createFromParcel(source);
             } else {
                 baseIntent = null;
             }
             origActivity = ComponentName.readFromParcel(source);
-            if (source.readInt() != 0) {
-                thumbnail = Bitmap.CREATOR.createFromParcel(source);
-            } else {
-                thumbnail = null;
-            }
             description = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(source);
         }
         
@@ -401,6 +389,16 @@ public class ActivityManager {
         return getRunningTasks(maxNum, 0, null);
     }
 
+    /** @hide */
+    public Bitmap getTaskThumbnail(int id) throws SecurityException {
+        try {
+            return ActivityManagerNative.getDefault().getTaskThumbnail(id);
+        } catch (RemoteException e) {
+            // System dead, we will be dead too soon!
+            return null;
+        }
+    }
+    
     /**
      * Flag for {@link #moveTaskToFront(int, int)}: also move the "home"
      * activity along with the task, so it is positioned immediately behind
@@ -409,6 +407,13 @@ public class ActivityManager {
     public static final int MOVE_TASK_WITH_HOME = 0x00000001;
 
     /**
+     * Flag for {@link #moveTaskToFront(int, int)}: don't count this as a
+     * user-instigated action, so the current activity will not receive a
+     * hint that the user is leaving.
+     */
+    public static final int MOVE_TASK_NO_USER_ACTION = 0x00000002;
+
+    /**
      * Ask that the task associated with a given task ID be moved to the
      * front of the stack, so it is now visible to the user.  Requires that
      * the caller hold permission {@link android.Manifest.permission#REORDER_TASKS}
diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index c095c069918b..d3d379294789 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -442,6 +442,20 @@ public abstract class ActivityManagerNative extends Binder implements IActivityM
             return true;
         }
         
+        case GET_TASK_THUMBNAIL_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            int id = data.readInt();
+            Bitmap bm = getTaskThumbnail(id);
+            reply.writeNoException();
+            if (bm != null) {
+                reply.writeInt(1);
+                bm.writeToParcel(reply, 0);
+            } else {
+                reply.writeInt(0);
+            }
+            return true;
+        }
+        
         case GET_SERVICES_TRANSACTION: {
             data.enforceInterface(IActivityManager.descriptor);
             int maxNum = data.readInt();
@@ -1816,6 +1830,21 @@ class ActivityManagerProxy implements IActivityManager
         reply.recycle();
         return list;
     }
+    public Bitmap getTaskThumbnail(int id) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeInt(id);
+        mRemote.transact(GET_TASK_THUMBNAIL_TRANSACTION, data, reply, 0);
+        reply.readException();
+        Bitmap bm = null;
+        if (reply.readInt() != 0) {
+            bm = Bitmap.CREATOR.createFromParcel(reply);
+        }
+        data.recycle();
+        reply.recycle();
+        return bm;
+    }
     public List getServices(int maxNum, int flags) throws RemoteException {
         Parcel data = Parcel.obtain();
         Parcel reply = Parcel.obtain();
diff --git a/core/java/android/app/FragmentBreadCrumbs.java b/core/java/android/app/FragmentBreadCrumbs.java
index 3f045ac288f9..df64035b4be9 100644
--- a/core/java/android/app/FragmentBreadCrumbs.java
+++ b/core/java/android/app/FragmentBreadCrumbs.java
@@ -50,6 +50,26 @@ public class FragmentBreadCrumbs extends ViewGroup
     /** Listener to inform when a parent entry is clicked */
     private OnClickListener mParentClickListener;
 
+    private OnBreadCrumbClickListener mOnBreadCrumbClickListener;
+    
+    /**
+     * Interface to intercept clicks on the bread crumbs.
+     */
+    public interface OnBreadCrumbClickListener {
+        /**
+         * Called when a bread crumb is clicked.
+         * 
+         * @param backStack The BackStackEntry whose bread crumb was clicked.
+         * May be null, if this bread crumb is for the root of the back stack.
+         * @param flags Additional information about the entry.  Currently
+         * always 0.
+         * 
+         * @return Return true to consume this click.  Return to false to allow
+         * the default action (popping back stack to this entry) to occur.
+         */
+        public boolean onBreadCrumbClick(BackStackEntry backStack, int flags);
+    }
+    
     public FragmentBreadCrumbs(Context context) {
         this(context, null);
     }
@@ -107,6 +127,16 @@ public class FragmentBreadCrumbs extends ViewGroup
         updateCrumbs();
     }
 
+    /**
+     * Sets a listener for clicks on the bread crumbs.  This will be called before
+     * the default click action is performed.
+     * 
+     * @param listener The new listener to set.  Replaces any existing listener.
+     */
+    public void setOnBreadCrumbClickListener(OnBreadCrumbClickListener listener) {
+        mOnBreadCrumbClickListener = listener;
+    }
+    
     private BackStackRecord createBackStackEntry(CharSequence title, CharSequence shortTitle) {
         if (title == null) return null;
 
@@ -266,8 +296,18 @@ public class FragmentBreadCrumbs extends ViewGroup
                         mParentClickListener.onClick(v);
                     }
                 } else {
-                    mActivity.getFragmentManager().popBackStack(bse.getId(),
-                            bse == mTopEntry? FragmentManager.POP_BACK_STACK_INCLUSIVE : 0);
+                    if (mOnBreadCrumbClickListener != null) {
+                        if (mOnBreadCrumbClickListener.onBreadCrumbClick(
+                                bse == mTopEntry ? null : bse, 0)) {
+                            return;
+                        }
+                    }
+                    if (bse == mTopEntry) {
+                        // Pop everything off the back stack.
+                        mActivity.getFragmentManager().popBackStack();
+                    } else {
+                        mActivity.getFragmentManager().popBackStack(bse.getId(), 0);
+                    }
                 }
             }
         }
diff --git a/core/java/android/app/IActivityManager.java b/core/java/android/app/IActivityManager.java
index 5d4380b3c18c..f42e8fb73e86 100644
--- a/core/java/android/app/IActivityManager.java
+++ b/core/java/android/app/IActivityManager.java
@@ -133,6 +133,7 @@ public interface IActivityManager extends IInterface {
                          IThumbnailReceiver receiver) throws RemoteException;
     public List<ActivityManager.RecentTaskInfo> getRecentTasks(int maxNum,
             int flags) throws RemoteException;
+    public Bitmap getTaskThumbnail(int taskId) throws RemoteException;
     public List getServices(int maxNum, int flags) throws RemoteException;
     public List<ActivityManager.ProcessErrorStateInfo> getProcessesInErrorState()
             throws RemoteException;
@@ -514,7 +515,7 @@ public interface IActivityManager extends IInterface {
     int FORCE_STOP_PACKAGE_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+78;
     int KILL_PIDS_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+79;
     int GET_SERVICES_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+80;
-
+    int GET_TASK_THUMBNAIL_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+81;
     int GET_RUNNING_APP_PROCESSES_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+82;
     int GET_DEVICE_CONFIGURATION_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+83;
     int PEEK_SERVICE_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+84;
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java b/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java
index 86c3e7597884..e0d558f2580d 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java
@@ -374,8 +374,9 @@ public class RecentAppsPanel extends RelativeLayout implements StatusBarPanel, O
                 if (title != null && title.length() > 0 && icon != null) {
                     if (DEBUG) Log.v(TAG, "creating activity desc for id=" + id + ", label=" + title);
                     ActivityDescription item = new ActivityDescription(
-                            recentInfo.thumbnail, icon, title,
-                            recentInfo.description, intent, id, index, info.packageName);
+                            am.getTaskThumbnail(recentInfo.persistentId),
+                            icon, title, recentInfo.description, intent, id,
+                            index, info.packageName);
                     activityDescriptions.add(item);
                     ++index;
                 } else {
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 9e3b9c6dd62a..f3ccd3860b5b 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -4969,11 +4969,6 @@ public final class ActivityManagerService extends ActivityManagerNative
             enforceCallingPermission(android.Manifest.permission.GET_TASKS,
                     "getRecentTasks()");
 
-            final boolean canReadFb = (flags&ActivityManager.TASKS_GET_THUMBNAILS) != 0
-                    && checkCallingPermission(
-                            android.Manifest.permission.READ_FRAME_BUFFER)
-                            == PackageManager.PERMISSION_GRANTED;
-            
             IPackageManager pm = AppGlobals.getPackageManager();
             
             ActivityRecord resumed = mMainStack.mResumedActivity;
@@ -4991,17 +4986,10 @@ public final class ActivityManagerService extends ActivityManagerNative
                     ActivityManager.RecentTaskInfo rti
                             = new ActivityManager.RecentTaskInfo();
                     rti.id = tr.numActivities > 0 ? tr.taskId : -1;
+                    rti.persistentId = tr.taskId;
                     rti.baseIntent = new Intent(
                             tr.intent != null ? tr.intent : tr.affinityIntent);
                     rti.origActivity = tr.origActivity;
-                    
-                    if (canReadFb) {
-                        if (resumed != null && resumed.task == tr) {
-                            rti.thumbnail = resumed.stack.screenshotActivities(resumed);
-                        } else {
-                            rti.thumbnail = tr.lastThumbnail;
-                        }
-                    }
                     rti.description = tr.lastDescription;
                     
                     if ((flags&ActivityManager.RECENT_IGNORE_UNAVAILABLE) != 0) {
@@ -5030,6 +5018,26 @@ public final class ActivityManagerService extends ActivityManagerNative
         }
     }
 
+    public Bitmap getTaskThumbnail(int id) {
+        synchronized (this) {
+            enforceCallingPermission(android.Manifest.permission.READ_FRAME_BUFFER,
+                    "getTaskThumbnail()");
+            ActivityRecord resumed = mMainStack.mResumedActivity;
+            final int N = mRecentTasks.size();
+            for (int i=0; i<N; i++) {
+                TaskRecord tr = mRecentTasks.get(i);
+                if (tr.taskId == id) {
+                    if (resumed != null && resumed.task == tr) {
+                        return resumed.stack.screenshotActivities(resumed);
+                    } else {
+                        return tr.lastThumbnail;
+                    }
+                }
+            }
+        }
+        return null;
+    }
+    
     private final int findAffinityTaskTopLocked(int startIndex, String affinity) {
         int j;
         TaskRecord startTask = ((ActivityRecord)mMainStack.mHistory.get(startIndex)).task; 
@@ -5085,6 +5093,9 @@ public final class ActivityManagerService extends ActivityManagerNative
                 for (int i=0; i<N; i++) {
                     TaskRecord tr = mRecentTasks.get(i);
                     if (tr.taskId == task) {
+                        if ((flags&ActivityManager.MOVE_TASK_NO_USER_ACTION) == 0) {
+                            mMainStack.mUserLeaving = true;
+                        }
                         if ((flags&ActivityManager.MOVE_TASK_WITH_HOME) != 0) {
                             // Caller wants the home activity moved with it.  To accomplish this,
                             // we'll just move the home task to the top first.
@@ -5097,6 +5108,9 @@ public final class ActivityManagerService extends ActivityManagerNative
                 for (int i=mMainStack.mHistory.size()-1; i>=0; i--) {
                     ActivityRecord hr = (ActivityRecord)mMainStack.mHistory.get(i);
                     if (hr.task.taskId == task) {
+                        if ((flags&ActivityManager.MOVE_TASK_NO_USER_ACTION) == 0) {
+                            mMainStack.mUserLeaving = true;
+                        }
                         if ((flags&ActivityManager.MOVE_TASK_WITH_HOME) != 0) {
                             // Caller wants the home activity moved with it.  To accomplish this,
                             // we'll just move the home task to the top first.