Keep activities stopped while the lock screen is up.

Tell the activity manager when the lock screen is shown, so it
can keep itself (mostly) in sleep mode during this time, having
the foreground actvities remain in their stopped state.

Change-Id: I71c86d3298f23a98014d7ae36fd540c9df9a64e6

Author: Dianne Hackborn

core/java/android/app/ActivityManagerNative.java

@@ -1000,7 +1000,7 @@ public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
             }
             return true;
         }
-        
+
         case GOING_TO_SLEEP_TRANSACTION: {
             data.enforceInterface(IActivityManager.descriptor);
             goingToSleep();
@@ -1015,6 +1015,13 @@ public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
             return true;
         }
 
+        case SET_LOCK_SCREEN_SHOWN_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            setLockScreenShown(data.readInt() != 0);
+            reply.writeNoException();
+            return true;
+        }
+
         case SET_DEBUG_APP_TRANSACTION: {
             data.enforceInterface(IActivityManager.descriptor);
             String pn = data.readString();
@@ -2912,6 +2919,17 @@ public void wakingUp() throws RemoteException
         data.recycle();
         reply.recycle();
     }
+    public void setLockScreenShown(boolean shown) throws RemoteException
+    {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeInt(shown ? 1 : 0);
+        mRemote.transact(SET_LOCK_SCREEN_SHOWN_TRANSACTION, data, reply, 0);
+        reply.readException();
+        data.recycle();
+        reply.recycle();
+    }
     public void setDebugApp(
         String packageName, boolean waitForDebugger, boolean persistent)
         throws RemoteException

core/java/android/app/IActivityManager.java

@@ -205,7 +205,8 @@ public void showWaitingForDebugger(IApplicationThread who, boolean waiting)
     // Note: probably don't want to allow applications access to these.
     public void goingToSleep() throws RemoteException;
     public void wakingUp() throws RemoteException;
-    
+    public void setLockScreenShown(boolean shown) throws RemoteException;
+
     public void unhandledBack() throws RemoteException;
     public ParcelFileDescriptor openContentUri(Uri uri) throws RemoteException;
     public void setDebugApp(
@@ -588,4 +589,5 @@ private WaitResult(Parcel source) {
     int GET_CURRENT_USER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+144;
     int TARGET_TASK_AFFINITY_MATCHES_ACTIVITY_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+145;
     int NAVIGATE_UP_TO_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+146;
+    int SET_LOCK_SCREEN_SHOWN_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+147;
 }

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

@@ -567,6 +567,7 @@ private void handleSetHidden(boolean isHidden) {
         synchronized (KeyguardViewMediator.this) {
             if (mHidden != isHidden) {
                 mHidden = isHidden;
+                updateActivityLockScreenState();
                 adjustUserActivityLocked();
                 adjustStatusBarLocked();
             }
@@ -1162,6 +1163,14 @@ private void playSounds(boolean locked) {
         }
     }
 
+    private void updateActivityLockScreenState() {
+        try {
+            ActivityManagerNative.getDefault().setLockScreenShown(
+                    mShowing && !mHidden);
+        } catch (RemoteException e) {
+        }
+    }
+
     /**
      * Handle message sent by {@link #showLocked}.
      * @see #SHOW
@@ -1173,6 +1182,7 @@ private void handleShow() {
 
             mKeyguardViewManager.show();
             mShowing = true;
+            updateActivityLockScreenState();
             adjustUserActivityLocked();
             adjustStatusBarLocked();
             try {
@@ -1207,6 +1217,7 @@ private void handleHide() {
 
             mKeyguardViewManager.hide();
             mShowing = false;
+            updateActivityLockScreenState();
             adjustUserActivityLocked();
             adjustStatusBarLocked();
         }
@@ -1324,6 +1335,7 @@ private void handleVerifyUnlock() {
             if (DEBUG) Log.d(TAG, "handleVerifyUnlock");
             mKeyguardViewManager.verifyUnlock();
             mShowing = true;
+            updateActivityLockScreenState();
         }
     }
 

services/java/com/android/server/am/ActivityManagerService.java

@@ -696,6 +696,16 @@ private class Identity {
      */
     boolean mSleeping = false;
 
+    /**
+     * State of external calls telling us if the device is asleep.
+     */
+    boolean mWentToSleep = false;
+
+    /**
+     * State of external call telling us if the lock screen is shown.
+     */
+    boolean mLockScreenShown = false;
+
     /**
      * Set if we are shutting down the system, similar to sleeping.
      */
@@ -6656,17 +6666,26 @@ public boolean isSleeping() {
     }
 
     public void goingToSleep() {
+        if (checkCallingPermission(android.Manifest.permission.DEVICE_POWER)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires permission "
+                    + android.Manifest.permission.DEVICE_POWER);
+        }
+
         synchronized(this) {
-            mSleeping = true;
+            mWentToSleep = true;
             mWindowManager.setEventDispatching(false);
 
-            mMainStack.stopIfSleepingLocked();
+            if (!mSleeping) {
+                mSleeping = true;
+                mMainStack.stopIfSleepingLocked();
 
-            // Initialize the wake times of all processes.
-            checkExcessivePowerUsageLocked(false);
-            mHandler.removeMessages(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
-            Message nmsg = mHandler.obtainMessage(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
-            mHandler.sendMessageDelayed(nmsg, POWER_CHECK_DELAY);
+                // Initialize the wake times of all processes.
+                checkExcessivePowerUsageLocked(false);
+                mHandler.removeMessages(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
+                Message nmsg = mHandler.obtainMessage(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
+                mHandler.sendMessageDelayed(nmsg, POWER_CHECK_DELAY);
+            }
         }
     }
 
@@ -6726,12 +6745,40 @@ public final void activitySlept(IBinder token) {
         Binder.restoreCallingIdentity(origId);
     }
 
+    private void comeOutOfSleepIfNeededLocked() {
+        if (!mWentToSleep && !mLockScreenShown) {
+            if (mSleeping) {
+                mSleeping = false;
+                mMainStack.awakeFromSleepingLocked();
+                mMainStack.resumeTopActivityLocked(null);
+            }
+        }
+    }
+
     public void wakingUp() {
+        if (checkCallingPermission(android.Manifest.permission.DEVICE_POWER)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires permission "
+                    + android.Manifest.permission.DEVICE_POWER);
+        }
+
         synchronized(this) {
+            mWentToSleep = false;
             mWindowManager.setEventDispatching(true);
-            mSleeping = false;
-            mMainStack.awakeFromSleepingLocked();
-            mMainStack.resumeTopActivityLocked(null);
+            comeOutOfSleepIfNeededLocked();
+        }
+    }
+
+    public void setLockScreenShown(boolean shown) {
+        if (checkCallingPermission(android.Manifest.permission.DEVICE_POWER)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires permission "
+                    + android.Manifest.permission.DEVICE_POWER);
+        }
+
+        synchronized(this) {
+            mLockScreenShown = shown;
+            comeOutOfSleepIfNeededLocked();
         }
     }
 
@@ -8815,7 +8862,13 @@ boolean dumpProcessesLocked(FileDescriptor fd, PrintWriter pw, String[] args,
                 }
             }
         }
-        pw.println("  mSleeping=" + mSleeping + " mShuttingDown=" + mShuttingDown);
+        if (mSleeping || mWentToSleep || mLockScreenShown) {
+            pw.println("  mSleeping=" + mSleeping + " mWentToSleep=" + mWentToSleep
+                    + " mLockScreenShown " + mLockScreenShown);
+        }
+        if (mShuttingDown) {
+            pw.println("  mShuttingDown=" + mShuttingDown);
+        }
         if (mDebugApp != null || mOrigDebugApp != null || mDebugTransient
                 || mOrigWaitForDebugger) {
             pw.println("  mDebugApp=" + mDebugApp + "/orig=" + mOrigDebugApp