Allow a root activity to relinquish task identity

If a an acitivty with attribute android:relinquishTaskIdentity true
is the root activity of a task then the intent of that task will
be that of the first activity in the stack with
android:relinquishTaskIdentity set false.

The ability to set intent also includes the ability to set the
TaskDescription of the task.

Fixes bug 15675610.
Fixes bug 10428661.

Change-Id: Ib28a9eae3b9832eeeef9106adbebe344184ee5ae

9 files changed, 91 insertions, 56 deletions

diff --git a/api/current.txt b/api/current.txt
index 3b311e31ca0f..03b301335ac8 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -957,6 +957,7 @@ package android {
     field public static final int ratingBarStyleIndicator = 16843280; // 0x1010210
     field public static final int ratingBarStyleSmall = 16842877; // 0x101007d
     field public static final int readPermission = 16842759; // 0x1010007
+    field public static final int relinquishTaskIdentity = 16843893; // 0x1010475
     field public static final int repeatCount = 16843199; // 0x10101bf
     field public static final int repeatMode = 16843200; // 0x10101c0
     field public static final int reqFiveWayNav = 16843314; // 0x1010232
@@ -8085,6 +8086,7 @@ package android.content.pm {
     field public static final int FLAG_IMMERSIVE = 2048; // 0x800
     field public static final int FLAG_MULTIPROCESS = 1; // 0x1
     field public static final int FLAG_NO_HISTORY = 128; // 0x80
+    field public static final int FLAG_RELINQUISH_TASK_IDENTITY = 4096; // 0x1000
     field public static final int FLAG_SINGLE_USER = 1073741824; // 0x40000000
     field public static final int FLAG_STATE_NOT_NEEDED = 16; // 0x10
     field public static final int LAUNCH_MULTIPLE = 0; // 0x0
diff --git a/core/java/android/content/pm/ActivityInfo.java b/core/java/android/content/pm/ActivityInfo.java
index abc8cde2c9eb..bcf1e8760e75 100644
--- a/core/java/android/content/pm/ActivityInfo.java
+++ b/core/java/android/content/pm/ActivityInfo.java
@@ -252,6 +252,13 @@ public class ActivityInfo extends ComponentInfo
      */
     public static final int FLAG_IMMERSIVE = 0x0800;
     /**
+     * Bit in {@link #flags}: If set, a task rooted at this activity will have its
+     * baseIntent replaced by the activity immediately above this. Each activity may further
+     * relinquish its identity to the activity above it using this flag. Set from the
+     * android.R.attr#relinquishTaskIdentity attribute.
+     */
+    public static final int FLAG_RELINQUISH_TASK_IDENTITY = 0x1000;
+    /**
      * Bit in {@link #flags} indicating that tasks started with this activity are to be
      * removed from the recent list of tasks when the last activity in the task is finished.
      * {@link android.R.attr#autoRemoveFromRecents}
diff --git a/core/java/android/content/pm/PackageParser.java b/core/java/android/content/pm/PackageParser.java
index 0b336d011692..b40a441a88d6 100644
--- a/core/java/android/content/pm/PackageParser.java
+++ b/core/java/android/content/pm/PackageParser.java
@@ -2629,6 +2629,12 @@ public class PackageParser {
                     false)) {
                 a.info.flags |= ActivityInfo.FLAG_AUTO_REMOVE_FROM_RECENTS;
             }
+
+            if (sa.getBoolean(
+                    com.android.internal.R.styleable.AndroidManifestActivity_relinquishTaskIdentity,
+                    false)) {
+                a.info.flags |= ActivityInfo.FLAG_RELINQUISH_TASK_IDENTITY;
+            }
         } else {
             a.info.launchMode = ActivityInfo.LAUNCH_MULTIPLE;
             a.info.configChanges = 0;
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 8b5dff014e19..fa1a563e43b9 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2742,7 +2742,8 @@
                 android:finishOnCloseSystemDialogs="true"
                 android:excludeFromRecents="true"
                 android:multiprocess="true"
-                android:documentLaunchMode="never">
+                android:documentLaunchMode="never"
+                android:relinquishTaskIdentity="true">
             <intent-filter>
                 <action android:name="android.intent.action.CHOOSER" />
                 <category android:name="android.intent.category.DEFAULT" />
diff --git a/core/res/res/values/attrs_manifest.xml b/core/res/res/values/attrs_manifest.xml
index 4e06d9a03c5e..fc1d0df86f46 100644
--- a/core/res/res/values/attrs_manifest.xml
+++ b/core/res/res/values/attrs_manifest.xml
@@ -985,6 +985,14 @@
          Intent.FLAG_ACTIVITY_AUTO_REMOVE_FROM_RECENTS} -->
     <attr name="autoRemoveFromRecents" format="boolean" />
 
+    <!-- Tasks whose root has this attribute set to true will replace baseIntent with that of the
+         next activity in the task. If the next activity also has this attribute set to true then
+         it will yield the baseIntent to any activity that it launches in the same task. This
+         continues until an activity is encountered which has this attribute set to false. False
+         is the default. This attribute set to true also permits activity's use of the
+         TaskDescription to change labels, colors and icons in the recent task list. -->
+    <attr name="relinquishTaskIdentity" format="boolean" />
+
     <!-- The <code>manifest</code> tag is the root of an
          <code>AndroidManifest.xml</code> file,
          describing the contents of an Android package (.apk) file.  One
@@ -1653,6 +1661,7 @@
         <attr name="documentLaunchMode" />
         <attr name="maxRecents" />
         <attr name="autoRemoveFromRecents" />
+        <attr name="relinquishTaskIdentity" />
     </declare-styleable>
     
     <!-- The <code>activity-alias</code> tag declares a new
diff --git a/core/res/res/values/public.xml b/core/res/res/values/public.xml
index f73c9586788f..07a1e5159fdf 100644
--- a/core/res/res/values/public.xml
+++ b/core/res/res/values/public.xml
@@ -2209,6 +2209,7 @@
   <public type="attr" name="fullBackupOnly" />
   <public type="attr" name="propertyXName" />
   <public type="attr" name="propertyYName" />
+  <public type="attr" name="relinquishTaskIdentity" />
 
   <public-padding type="dimen" name="l_resource_pad" end="0x01050010" />
 
diff --git a/services/core/java/com/android/server/am/ActivityRecord.java b/services/core/java/com/android/server/am/ActivityRecord.java
index dd9cae90dd00..0825f2e75554 100755
--- a/services/core/java/com/android/server/am/ActivityRecord.java
+++ b/services/core/java/com/android/server/am/ActivityRecord.java
@@ -582,11 +582,6 @@ final class ActivityRecord {
         }
     }
 
-    boolean isRootActivity() {
-        final ArrayList<ActivityRecord> activities = task.mActivities;
-        return activities.size() == 0 || this == activities.get(0);
-    }
-
     UriPermissionOwner getUriPermissionsLocked() {
         if (uriPermissions == null) {
             uriPermissions = new UriPermissionOwner(service, this);
@@ -1035,11 +1030,11 @@ final class ActivityRecord {
             return -1;
         }
         final TaskRecord task = r.task;
-        switch (task.mActivities.indexOf(r)) {
-            case -1: return -1;
-            case 0: return task.taskId;
-            default: return onlyRoot ? -1 : task.taskId;
+        final int activityNdx = task.mActivities.indexOf(r);
+        if (activityNdx < 0 || (onlyRoot && activityNdx > task.findEffectiveRootIndex())) {
+            return -1;
         }
+        return task.taskId;
     }
 
     static ActivityRecord isInStackLocked(IBinder token) {
diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 03ce5300e863..fe2a473e3173 100755
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -1066,40 +1066,6 @@ final class ActivityStack {
         }
     }
 
-    /**
-     * Determine if home should be visible below the passed record.
-     * @param record activity we are querying for.
-     * @return true if home is visible below the passed activity, false otherwise.
-     */
-    boolean isActivityOverHome(ActivityRecord record) {
-        // Start at record and go down, look for either home or a visible fullscreen activity.
-        final TaskRecord recordTask = record.task;
-        for (int taskNdx = mTaskHistory.indexOf(recordTask); taskNdx >= 0; --taskNdx) {
-            TaskRecord task = mTaskHistory.get(taskNdx);
-            final ArrayList<ActivityRecord> activities = task.mActivities;
-            final int startNdx =
-                    task == recordTask ? activities.indexOf(record) : activities.size() - 1;
-            for (int activityNdx = startNdx; activityNdx >= 0; --activityNdx) {
-                final ActivityRecord r = activities.get(activityNdx);
-                if (r.isHomeActivity()) {
-                    return true;
-                }
-                if (!r.finishing && r.fullscreen) {
-                    // Passed activity is over a fullscreen activity.
-                    return false;
-                }
-            }
-            if (task.mOnTopOfHome) {
-                // Got to the bottom of a task on top of home without finding a visible fullscreen
-                // activity. Home is visible.
-                return true;
-            }
-        }
-        // Got to the bottom of this stack and still don't know. If this is over the home stack
-        // then record is over home. May not work if we ever get more than two layers.
-        return mStackSupervisor.isFrontStack(this);
-    }
-
     private void setVisibile(ActivityRecord r, boolean visible) {
         r.visible = visible;
         mWindowManager.setAppVisibility(r.appToken, visible);
@@ -1954,8 +1920,7 @@ final class ActivityStack {
                 // existing activities from other tasks in to it.
                 // If the caller has requested that the target task be
                 // reset, then do so.
-                if ((r.intent.getFlags()
-                        & Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED) != 0) {
+                if ((r.intent.getFlags() & Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED) != 0) {
                     resetTaskIfNeededLocked(r, r);
                     doShow = topRunningNonDelayedActivityLocked(null) == r;
                 }
@@ -2048,7 +2013,8 @@ final class ActivityStack {
         // the root, we may no longer have the task!).
         final ArrayList<ActivityRecord> activities = task.mActivities;
         final int numActivities = activities.size();
-        for (int i = numActivities - 1; i > 0; --i ) {
+        final int rootActivityNdx = task.findEffectiveRootIndex();
+        for (int i = numActivities - 1; i > rootActivityNdx; --i ) {
             ActivityRecord target = activities.get(i);
 
             final int flags = target.info.flags;
@@ -2207,8 +2173,10 @@ final class ActivityStack {
 
         final ArrayList<ActivityRecord> activities = affinityTask.mActivities;
         final int numActivities = activities.size();
-        // Do not operate on the root Activity.
-        for (int i = numActivities - 1; i > 0; --i) {
+        final int rootActivityNdx = affinityTask.findEffectiveRootIndex();
+
+        // Do not operate on or below the effective root Activity.
+        for (int i = numActivities - 1; i > rootActivityNdx; --i) {
             ActivityRecord target = activities.get(i);
 
             final int flags = target.info.flags;
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 1cde41fb92ad..9fff329b7bca 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -27,7 +27,6 @@ import android.content.ComponentName;
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
 import android.graphics.Bitmap;
-import android.os.SystemClock;
 import android.os.UserHandle;
 import android.service.voice.IVoiceInteractionSession;
 import android.util.Slog;
@@ -57,11 +56,12 @@ final class TaskRecord extends ThumbnailHolder {
     private static final String ATTR_ONTOPOFHOME = "on_top_of_home";
     private static final String ATTR_LASTDESCRIPTION = "last_description";
     private static final String ATTR_LASTTIMEMOVED = "last_time_moved";
+    private static final String ATTR_NEVERRELINQUISH = "never_relinquish_identity";
 
     private static final String TASK_THUMBNAIL_SUFFIX = "_task_thumbnail";
 
     final int taskId;       // Unique identifier for this task.
-    final String affinity;  // The affinity name for this task, or null.
+    String affinity;        // The affinity name for this task, or null.
     final IVoiceInteractionSession voiceSession;    // Voice interaction session driving task
     final IVoiceInteractor voiceInteractor;         // Associated interactor to provide to app
     Intent intent;          // The original intent that started the task.
@@ -111,13 +111,15 @@ final class TaskRecord extends ThumbnailHolder {
      * Display.DEFAULT_DISPLAY. */
     boolean mOnTopOfHome = false;
 
+    /** If original intent did not allow relinquishing task identity, save that information */
+    boolean mNeverRelinquishIdentity = true;
+
     final ActivityManagerService mService;
 
     TaskRecord(ActivityManagerService service, int _taskId, ActivityInfo info, Intent _intent,
             IVoiceInteractionSession _voiceSession, IVoiceInteractor _voiceInteractor) {
         mService = service;
         taskId = _taskId;
-        affinity = info.taskAffinity;
         voiceSession = _voiceSession;
         voiceInteractor = _voiceInteractor;
         setIntent(_intent, info);
@@ -128,7 +130,7 @@ final class TaskRecord extends ThumbnailHolder {
             String _affinity, ComponentName _realActivity, ComponentName _origActivity,
             boolean _rootWasReset, boolean _askedCompatMode, int _taskType, boolean _onTopOfHome,
             int _userId, String _lastDescription, ArrayList<ActivityRecord> activities,
-            long lastTimeMoved) {
+            long lastTimeMoved, boolean neverRelinquishIdentity) {
         mService = service;
         taskId = _taskId;
         intent = _intent;
@@ -146,6 +148,7 @@ final class TaskRecord extends ThumbnailHolder {
         lastDescription = _lastDescription;
         mActivities = activities;
         mLastTimeMoved = lastTimeMoved;
+        mNeverRelinquishIdentity = neverRelinquishIdentity;
     }
 
     void touchActiveTime() {
@@ -157,6 +160,14 @@ final class TaskRecord extends ThumbnailHolder {
     }
 
     void setIntent(Intent _intent, ActivityInfo info) {
+        if (intent == null) {
+            mNeverRelinquishIdentity =
+                    (info.flags & ActivityInfo.FLAG_RELINQUISH_TASK_IDENTITY) == 0;
+        } else if (mNeverRelinquishIdentity) {
+            return;
+        }
+
+        affinity = info.taskAffinity;
         stringName = null;
 
         if (info.targetActivity == null) {
@@ -282,6 +293,7 @@ final class TaskRecord extends ThumbnailHolder {
 
         mActivities.remove(newTop);
         mActivities.add(newTop);
+        updateEffectiveIntent();
 
         setFrontOfTask();
     }
@@ -311,6 +323,7 @@ final class TaskRecord extends ThumbnailHolder {
             r.mActivityType = taskType;
         }
         mActivities.add(index, r);
+        updateEffectiveIntent();
         if (r.isPersistable()) {
             mService.notifyTaskPersisterLocked(this, false);
         }
@@ -322,6 +335,7 @@ final class TaskRecord extends ThumbnailHolder {
             // Was previously in list.
             numFullscreen--;
         }
+        updateEffectiveIntent();
         if (r.isPersistable()) {
             mService.notifyTaskPersisterLocked(this, false);
         }
@@ -579,12 +593,19 @@ final class TaskRecord extends ThumbnailHolder {
         // utility activities.
         int activityNdx;
         final int numActivities = mActivities.size();
+        final boolean relinquish = numActivities == 0 ? false :
+                (mActivities.get(0).info.flags & ActivityInfo.FLAG_RELINQUISH_TASK_IDENTITY) != 0;
         for (activityNdx = Math.min(numActivities, 1); activityNdx < numActivities;
                 ++activityNdx) {
             final ActivityRecord r = mActivities.get(activityNdx);
+            if (relinquish && (r.info.flags & ActivityInfo.FLAG_RELINQUISH_TASK_IDENTITY) == 0) {
+                // This will be the top activity for determining taskDescription. Pre-inc to
+                // overcome initial decrement below.
+                ++activityNdx;
+                break;
+            }
             if (r.intent != null &&
-                    (r.intent.getFlags() & Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET)
-                            != 0) {
+                    (r.intent.getFlags() & Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET) != 0) {
                 break;
             }
         }
@@ -615,6 +636,27 @@ final class TaskRecord extends ThumbnailHolder {
         }
     }
 
+    int findEffectiveRootIndex() {
+        int activityNdx;
+        final int topActivityNdx = mActivities.size() - 1;
+        for (activityNdx = 0; activityNdx < topActivityNdx; ++activityNdx) {
+            final ActivityRecord r = mActivities.get(activityNdx);
+            if (r.finishing) {
+                continue;
+            }
+            if ((r.info.flags & ActivityInfo.FLAG_RELINQUISH_TASK_IDENTITY) == 0) {
+                break;
+            }
+        }
+        return activityNdx;
+    }
+
+    void updateEffectiveIntent() {
+        final int effectiveRootIndex = findEffectiveRootIndex();
+        final ActivityRecord r = mActivities.get(effectiveRootIndex);
+        setIntent(r.intent, r.info);
+    }
+
     void saveToXml(XmlSerializer out) throws IOException, XmlPullParserException {
         Slog.i(TAG, "Saving task=" + this);
 
@@ -634,6 +676,7 @@ final class TaskRecord extends ThumbnailHolder {
         out.attribute(null, ATTR_TASKTYPE, String.valueOf(taskType));
         out.attribute(null, ATTR_ONTOPOFHOME, String.valueOf(mOnTopOfHome));
         out.attribute(null, ATTR_LASTTIMEMOVED, String.valueOf(mLastTimeMoved));
+        out.attribute(null, ATTR_NEVERRELINQUISH, String.valueOf(mNeverRelinquishIdentity));
         if (lastDescription != null) {
             out.attribute(null, ATTR_LASTDESCRIPTION, lastDescription.toString());
         }
@@ -684,6 +727,7 @@ final class TaskRecord extends ThumbnailHolder {
         int userId = 0;
         String lastDescription = null;
         long lastTimeOnTop = 0;
+        boolean neverRelinquishIdentity = true;
         int taskId = -1;
         final int outerDepth = in.getDepth();
 
@@ -714,6 +758,8 @@ final class TaskRecord extends ThumbnailHolder {
                 lastDescription = attrValue;
             } else if (ATTR_LASTTIMEMOVED.equals(attrName)) {
                 lastTimeOnTop = Long.valueOf(attrValue);
+            } else if (ATTR_NEVERRELINQUISH.equals(attrName)) {
+                neverRelinquishIdentity = Boolean.valueOf(attrValue);
             } else {
                 Slog.w(TAG, "TaskRecord: Unknown attribute=" + attrName);
             }
@@ -748,7 +794,7 @@ final class TaskRecord extends ThumbnailHolder {
         final TaskRecord task = new TaskRecord(stackSupervisor.mService, taskId, intent,
                 affinityIntent, affinity, realActivity, origActivity, rootHasReset,
                 askedCompatMode, taskType, onTopOfHome, userId, lastDescription, activities,
-                lastTimeOnTop);
+                lastTimeOnTop, neverRelinquishIdentity);
 
         for (int activityNdx = activities.size() - 1; activityNdx >=0; --activityNdx) {
             final ActivityRecord r = activities.get(activityNdx);