Disable input during Activity Transition.

Bug 19437530

While the actual Activity Transitions are running,
input is stopped, except for the "back" button.

Change-Id: I112e6252b9de05ece10a6267681fee5487e5ef6b

3 files changed, 32 insertions, 10 deletions

diff --git a/core/java/android/view/AccessibilityInteractionController.java b/core/java/android/view/AccessibilityInteractionController.java
index 68ad782..3781d40 100644
--- a/core/java/android/view/AccessibilityInteractionController.java
+++ b/core/java/android/view/AccessibilityInteractionController.java
@@ -586,7 +586,7 @@ final class AccessibilityInteractionController {
         }
     }
 
-    private void perfromAccessibilityActionUiThread(Message message) {
+    private void performAccessibilityActionUiThread(Message message) {
         final int flags = message.arg1;
         final int accessibilityViewId = message.arg2;
 
@@ -602,7 +602,8 @@ final class AccessibilityInteractionController {
 
         boolean succeeded = false;
         try {
-            if (mViewRootImpl.mView == null || mViewRootImpl.mAttachInfo == null) {
+            if (mViewRootImpl.mView == null || mViewRootImpl.mAttachInfo == null ||
+                    mViewRootImpl.mStopped || mViewRootImpl.mPausedForTransition) {
                 return;
             }
             mViewRootImpl.mAttachInfo.mAccessibilityFetchFlags = flags;
@@ -1146,7 +1147,7 @@ final class AccessibilityInteractionController {
                     findAccessibilityNodeInfoByAccessibilityIdUiThread(message);
                 } break;
                 case MSG_PERFORM_ACCESSIBILITY_ACTION: {
-                    perfromAccessibilityActionUiThread(message);
+                    performAccessibilityActionUiThread(message);
                 } break;
                 case MSG_FIND_ACCESSIBILITY_NODE_INFOS_BY_VIEW_ID: {
                     findAccessibilityNodeInfosByViewIdUiThread(message);
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index fda6e63..8421e6962 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -173,6 +173,9 @@ public final class ViewRootImpl implements ViewParent,
     // so the window should no longer be active.
     boolean mStopped = false;
 
+    // Set to true to stop input during an Activity Transition.
+    boolean mPausedForTransition = false;
+
     boolean mLastInCompatMode = false;
 
     SurfaceHolder.Callback2 mSurfaceHolderCallback;
@@ -977,15 +980,25 @@ public final class ViewRootImpl implements ViewParent,
         return null;
     }
 
-    void setStopped(boolean stopped) {
+    void setWindowStopped(boolean stopped) {
         if (mStopped != stopped) {
             mStopped = stopped;
-            if (!stopped) {
+            if (!mStopped) {
                 scheduleTraversals();
             }
         }
     }
 
+    /**
+     * Block the input events during an Activity Transition. The KEYCODE_BACK event is allowed
+     * through to allow quick reversal of the Activity Transition.
+     *
+     * @param paused true to pause, false to resume.
+     */
+    public void setPausedForTransition(boolean paused) {
+        mPausedForTransition = paused;
+    }
+
     @Override
     public ViewParent getParent() {
         return null;
@@ -3632,8 +3645,9 @@ public final class ViewRootImpl implements ViewParent,
             if (mView == null || !mAdded) {
                 Slog.w(TAG, "Dropping event due to root view being removed: " + q.mEvent);
                 return true;
-            } else if ((!mAttachInfo.mHasWindowFocus || mStopped)
-                    && !q.mEvent.isFromSource(InputDevice.SOURCE_CLASS_POINTER)) {
+            } else if ((!mAttachInfo.mHasWindowFocus
+                    && !q.mEvent.isFromSource(InputDevice.SOURCE_CLASS_POINTER)) || mStopped
+                    || (mPausedForTransition && !isBack(q.mEvent))) {
                 // This is a focus event and the window doesn't currently have input focus or
                 // has stopped. This could be an event that came back from the previous stage
                 // but the window has lost focus or stopped in the meantime.
@@ -3656,6 +3670,14 @@ public final class ViewRootImpl implements ViewParent,
                 mNext.dump(prefix, writer);
             }
         }
+
+        private boolean isBack(InputEvent event) {
+            if (event instanceof KeyEvent) {
+                return ((KeyEvent) event).getKeyCode() == KeyEvent.KEYCODE_BACK;
+            } else {
+                return false;
+            }
+        }
     }
 
     /**
@@ -6223,7 +6245,7 @@ public final class ViewRootImpl implements ViewParent,
 
     @Override
     public boolean requestSendAccessibilityEvent(View child, AccessibilityEvent event) {
-        if (mView == null) {
+        if (mView == null || mStopped || mPausedForTransition) {
             return false;
         }
         // Intercept accessibility focus events fired by virtual nodes to keep
diff --git a/core/java/android/view/WindowManagerGlobal.java b/core/java/android/view/WindowManagerGlobal.java
index 57558ff..e7a7ba8 100644
--- a/core/java/android/view/WindowManagerGlobal.java
+++ b/core/java/android/view/WindowManagerGlobal.java
@@ -21,7 +21,6 @@ import android.app.ActivityManager;
 import android.content.ComponentCallbacks2;
 import android.content.Context;
 import android.content.res.Configuration;
-import android.os.Build;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.ServiceManager;
@@ -552,7 +551,7 @@ public final class WindowManagerGlobal {
             for (int i = 0; i < count; i++) {
                 if (token == null || mParams.get(i).token == token) {
                     ViewRootImpl root = mRoots.get(i);
-                    root.setStopped(stopped);
+                    root.setWindowStopped(stopped);
                 }
             }
         }