Fixed: getDecor() NullPointeExceptions.

Bug 17481173

Change-Id: Ie6e1710cadb7d1e52515c2927dce733b3ec3eabb

3 files changed, 140 insertions, 98 deletions

diff --git a/core/java/android/app/ActivityTransitionCoordinator.java b/core/java/android/app/ActivityTransitionCoordinator.java
index 43fa3f0..e819a6d 100644
--- a/core/java/android/app/ActivityTransitionCoordinator.java
+++ b/core/java/android/app/ActivityTransitionCoordinator.java
@@ -223,7 +223,10 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
         mSharedElementNames.addAll(sharedElements.keySet());
         mSharedElements.addAll(sharedElements.values());
         if (getViewsTransition() != null) {
-            getDecor().captureTransitioningViews(mTransitioningViews);
+            ViewGroup decorView = getDecor();
+            if (decorView != null) {
+                decorView.captureTransitioningViews(mTransitioningViews);
+            }
             mTransitioningViews.removeAll(mSharedElements);
         }
         setEpicenter();
@@ -350,7 +353,10 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
                 sharedElements.put(accepted.get(i), localViews.get(i));
             }
         } else {
-            getDecor().findNamedViews(sharedElements);
+            ViewGroup decorView = getDecor();
+            if (decorView != null) {
+                decorView.findNamedViews(sharedElements);
+            }
         }
         return sharedElements;
     }
@@ -471,16 +477,18 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
 
     protected void scheduleSetSharedElementEnd(final ArrayList<View> snapshots) {
         final View decorView = getDecor();
-        decorView.getViewTreeObserver().addOnPreDrawListener(
-                new ViewTreeObserver.OnPreDrawListener() {
-                    @Override
-                    public boolean onPreDraw() {
-                        decorView.getViewTreeObserver().removeOnPreDrawListener(this);
-                        notifySharedElementEnd(snapshots);
-                        return true;
+        if (decorView != null) {
+            decorView.getViewTreeObserver().addOnPreDrawListener(
+                    new ViewTreeObserver.OnPreDrawListener() {
+                        @Override
+                        public boolean onPreDraw() {
+                            decorView.getViewTreeObserver().removeOnPreDrawListener(this);
+                            notifySharedElementEnd(snapshots);
+                            return true;
+                        }
                     }
-                }
-        );
+            );
+        }
     }
 
     private static SharedElementOriginalState getOldSharedElementState(View view, String name,
@@ -523,7 +531,10 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
         ArrayList<View> snapshots = new ArrayList<View>(numSharedElements);
         Context context = getWindow().getContext();
         int[] decorLoc = new int[2];
-        getDecor().getLocationOnScreen(decorLoc);
+        ViewGroup decorView = getDecor();
+        if (decorView != null) {
+            decorView.getLocationOnScreen(decorLoc);
+        }
         for (String name: names) {
             Bundle sharedElementBundle = state.getBundle(name);
             if (sharedElementBundle != null) {
@@ -746,15 +757,17 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
 
     protected void scheduleGhostVisibilityChange(final int visibility) {
         final View decorView = getDecor();
-        decorView.getViewTreeObserver()
-                .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
-                    @Override
-                    public boolean onPreDraw() {
-                        decorView.getViewTreeObserver().removeOnPreDrawListener(this);
-                        setGhostVisibility(visibility);
-                        return true;
-                    }
-                });
+        if (decorView != null) {
+            decorView.getViewTreeObserver()
+                    .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+                        @Override
+                        public boolean onPreDraw() {
+                            decorView.getViewTreeObserver().removeOnPreDrawListener(this);
+                            setGhostVisibility(visibility);
+                            return true;
+                        }
+                    });
+        }
     }
 
     protected class ContinueTransitionListener extends Transition.TransitionListenerAdapter {
diff --git a/core/java/android/app/EnterTransitionCoordinator.java b/core/java/android/app/EnterTransitionCoordinator.java
index 9ca150d..bfdb0eb 100644
--- a/core/java/android/app/EnterTransitionCoordinator.java
+++ b/core/java/android/app/EnterTransitionCoordinator.java
@@ -70,16 +70,18 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         resultReceiverBundle.putParcelable(KEY_REMOTE_RECEIVER, this);
         mResultReceiver.send(MSG_SET_REMOTE_RECEIVER, resultReceiverBundle);
         final View decorView = getDecor();
-        decorView.getViewTreeObserver().addOnPreDrawListener(
-                new ViewTreeObserver.OnPreDrawListener() {
-                    @Override
-                    public boolean onPreDraw() {
-                        if (mIsReadyForTransition) {
-                            decorView.getViewTreeObserver().removeOnPreDrawListener(this);
+        if (decorView != null) {
+            decorView.getViewTreeObserver().addOnPreDrawListener(
+                    new ViewTreeObserver.OnPreDrawListener() {
+                        @Override
+                        public boolean onPreDraw() {
+                            if (mIsReadyForTransition) {
+                                decorView.getViewTreeObserver().removeOnPreDrawListener(this);
+                            }
+                            return mIsReadyForTransition;
                         }
-                        return mIsReadyForTransition;
-                    }
-                });
+                    });
+        }
     }
 
     public void viewInstancesReady(ArrayList<String> accepted, ArrayList<String> localNames,
@@ -152,7 +154,10 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
     private ArrayMap<String, View> mapNamedElements(ArrayList<String> accepted,
             ArrayList<String> localNames) {
         ArrayMap<String, View> sharedElements = new ArrayMap<String, View>();
-        getDecor().findNamedViews(sharedElements);
+        ViewGroup decorView = getDecor();
+        if (decorView != null) {
+            decorView.findNamedViews(sharedElements);
+        }
         if (accepted != null) {
             for (int i = 0; i < localNames.size(); i++) {
                 String localName = localNames.get(i);
@@ -170,10 +175,13 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
 
     private void sendSharedElementDestination() {
         boolean allReady;
+        final View decorView = getDecor();
         if (allowOverlappingTransitions() && getEnterViewsTransition() != null) {
             allReady = false;
+        } else if (decorView == null) {
+            allReady = true;
         } else {
-            allReady = !getDecor().isLayoutRequested();
+            allReady = !decorView.isLayoutRequested();
             if (allReady) {
                 for (int i = 0; i < mSharedElements.size(); i++) {
                     if (mSharedElements.get(i).isLayoutRequested()) {
@@ -188,8 +196,7 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
             setSharedElementMatrices();
             moveSharedElementsToOverlay();
             mResultReceiver.send(MSG_SHARED_ELEMENT_DESTINATION, state);
-        } else {
-            final View decorView = getDecor();
+        } else if (decorView != null) {
             decorView.getViewTreeObserver()
                     .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
                         @Override
@@ -291,6 +298,10 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
     }
 
     private void startSharedElementTransition(Bundle sharedElementState) {
+        ViewGroup decorView = getDecor();
+        if (decorView == null) {
+            return;
+        }
         // Remove rejected shared elements
         ArrayList<String> rejectedNames = new ArrayList<String>(mAllSharedElementNames);
         rejectedNames.removeAll(mSharedElementNames);
@@ -311,7 +322,8 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         boolean startSharedElementTransition = true;
         setGhostVisibility(View.INVISIBLE);
         scheduleGhostVisibilityChange(View.INVISIBLE);
-        Transition transition = beginTransition(startEnterTransition, startSharedElementTransition);
+        Transition transition = beginTransition(decorView, startEnterTransition,
+                startSharedElementTransition);
         scheduleGhostVisibilityChange(View.VISIBLE);
         setGhostVisibility(View.VISIBLE);
 
@@ -324,8 +336,9 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         if (mResultReceiver != null) {
             // We can't trust that the view will disappear on the same frame that the shared
             // element appears here. Assure that we get at least 2 frames for double-buffering.
-            getDecor().postOnAnimation(new Runnable() {
+            decorView.postOnAnimation(new Runnable() {
                 int mAnimations;
+
                 @Override
                 public void run() {
                     if (mAnimations++ < MIN_ANIMATION_FRAMES) {
@@ -349,21 +362,23 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         final Bundle sharedElementState = mSharedElementsBundle;
         mSharedElementsBundle = null;
         final View decorView = getDecor();
-        decorView.getViewTreeObserver()
-                .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
-                    @Override
-                    public boolean onPreDraw() {
-                        decorView.getViewTreeObserver().removeOnPreDrawListener(this);
-                        startTransition(new Runnable() {
-                            @Override
-                            public void run() {
-                                startSharedElementTransition(sharedElementState);
-                            }
-                        });
-                        return false;
-                    }
-                });
-        decorView.invalidate();
+        if (decorView != null) {
+            decorView.getViewTreeObserver()
+                    .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+                        @Override
+                        public boolean onPreDraw() {
+                            decorView.getViewTreeObserver().removeOnPreDrawListener(this);
+                            startTransition(new Runnable() {
+                                @Override
+                                public void run() {
+                                    startSharedElementTransition(sharedElementState);
+                                }
+                            });
+                            return false;
+                        }
+                    });
+            decorView.invalidate();
+        }
     }
 
     private void requestLayoutForSharedElements() {
@@ -373,7 +388,7 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         }
     }
 
-    private Transition beginTransition(boolean startEnterTransition,
+    private Transition beginTransition(ViewGroup decorView, boolean startEnterTransition,
             boolean startSharedElementTransition) {
         Transition sharedElementTransition = null;
         if (startSharedElementTransition) {
@@ -433,7 +448,7 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         Transition transition = mergeTransitions(sharedElementTransition, viewsTransition);
         if (transition != null) {
             transition.addListener(new ContinueTransitionListener());
-            TransitionManager.beginDelayedTransition(getDecor(), transition);
+            TransitionManager.beginDelayedTransition(decorView, transition);
             if (startSharedElementTransition && !mSharedElementNames.isEmpty()) {
                 mSharedElements.get(0).invalidate();
             } else if (startEnterTransition && !mTransitioningViews.isEmpty()) {
@@ -467,8 +482,9 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
     }
 
     private void startEnterTransition(Transition transition) {
-        if (!mIsReturning) {
-            Drawable background = getDecor().getBackground();
+        ViewGroup decorView = getDecor();
+        if (!mIsReturning && decorView != null) {
+            Drawable background = decorView.getBackground();
             if (background != null) {
                 background = background.mutate();
                 getWindow().setBackgroundDrawable(background);
@@ -539,25 +555,28 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         if (rejectedSnapshots == null || rejectedSnapshots.isEmpty()) {
             return;
         }
-        ViewGroupOverlay overlay = getDecor().getOverlay();
-        ObjectAnimator animator = null;
-        int numRejected = rejectedSnapshots.size();
-        for (int i = 0; i < numRejected; i++) {
-            View snapshot = rejectedSnapshots.get(i);
-            overlay.add(snapshot);
-            animator = ObjectAnimator.ofFloat(snapshot, View.ALPHA, 1, 0);
-            animator.start();
-        }
-        animator.addListener(new AnimatorListenerAdapter() {
-            @Override
-            public void onAnimationEnd(Animator animation) {
-                ViewGroupOverlay overlay = getDecor().getOverlay();
-                int numRejected = rejectedSnapshots.size();
-                for (int i = 0; i < numRejected; i++) {
-                    overlay.remove(rejectedSnapshots.get(i));
-                }
+        final ViewGroup decorView = getDecor();
+        if (decorView != null) {
+            ViewGroupOverlay overlay = decorView.getOverlay();
+            ObjectAnimator animator = null;
+            int numRejected = rejectedSnapshots.size();
+            for (int i = 0; i < numRejected; i++) {
+                View snapshot = rejectedSnapshots.get(i);
+                overlay.add(snapshot);
+                animator = ObjectAnimator.ofFloat(snapshot, View.ALPHA, 1, 0);
+                animator.start();
             }
-        });
+            animator.addListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    ViewGroupOverlay overlay = decorView.getOverlay();
+                    int numRejected = rejectedSnapshots.size();
+                    for (int i = 0; i < numRejected; i++) {
+                        overlay.remove(rejectedSnapshots.get(i));
+                    }
+                }
+            });
+        }
     }
 
     protected void onRemoteExitTransitionComplete() {
@@ -572,9 +591,12 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
             public void run() {
                 boolean startEnterTransition = true;
                 boolean startSharedElementTransition = false;
-                Transition transition = beginTransition(startEnterTransition,
-                        startSharedElementTransition);
-                startEnterTransition(transition);
+                ViewGroup decorView = getDecor();
+                if (decorView != null) {
+                    Transition transition = beginTransition(decorView, startEnterTransition,
+                            startSharedElementTransition);
+                    startEnterTransition(transition);
+                }
             }
         });
     }
diff --git a/core/java/android/app/ExitTransitionCoordinator.java b/core/java/android/app/ExitTransitionCoordinator.java
index e85ec63..41b0db6 100644
--- a/core/java/android/app/ExitTransitionCoordinator.java
+++ b/core/java/android/app/ExitTransitionCoordinator.java
@@ -129,22 +129,25 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         showViews(mTransitioningViews, true);
         showViews(mSharedElements, true);
         mIsHidden = true;
-        if (!mIsReturning && getDecor() != null) {
-            getDecor().suppressLayout(false);
+        ViewGroup decorView = getDecor();
+        if (!mIsReturning && decorView != null) {
+            decorView.suppressLayout(false);
         }
         moveSharedElementsFromOverlay();
         clearState();
     }
 
     private void sharedElementExitBack() {
-        if (getDecor() != null) {
-            getDecor().suppressLayout(true);
+        final ViewGroup decorView = getDecor();
+        if (decorView != null) {
+            decorView.suppressLayout(true);
         }
-        if (mExitSharedElementBundle != null && !mExitSharedElementBundle.isEmpty() &&
+        if (decorView != null && mExitSharedElementBundle != null &&
+                !mExitSharedElementBundle.isEmpty() &&
                 !mSharedElements.isEmpty() && getSharedElementTransition() != null) {
             startTransition(new Runnable() {
                 public void run() {
-                    startSharedElementExit();
+                    startSharedElementExit(decorView);
                 }
             });
         } else {
@@ -152,7 +155,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         }
     }
 
-    private void startSharedElementExit() {
+    private void startSharedElementExit(final ViewGroup decorView) {
         Transition transition = getSharedElementExitTransition();
         transition.addListener(new Transition.TransitionListenerAdapter() {
             @Override
@@ -165,7 +168,6 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         });
         final ArrayList<View> sharedElementSnapshots = createSnapshots(mExitSharedElementBundle,
                 mSharedElementNames);
-        final View decorView = getDecor();
         decorView.getViewTreeObserver()
                 .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
                     @Override
@@ -178,10 +180,10 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         setGhostVisibility(View.INVISIBLE);
         scheduleGhostVisibilityChange(View.INVISIBLE);
         mListener.onSharedElementEnd(mSharedElementNames, mSharedElements, sharedElementSnapshots);
-        TransitionManager.beginDelayedTransition(getDecor(), transition);
+        TransitionManager.beginDelayedTransition(decorView, transition);
         scheduleGhostVisibilityChange(View.VISIBLE);
         setGhostVisibility(View.VISIBLE);
-        getDecor().invalidate();
+        decorView.invalidate();
     }
 
     private void hideSharedElements() {
@@ -196,8 +198,9 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
     public void startExit() {
         if (!mIsExitStarted) {
             mIsExitStarted = true;
-            if (getDecor() != null) {
-                getDecor().suppressLayout(true);
+            ViewGroup decorView = getDecor();
+            if (decorView != null) {
+                decorView.suppressLayout(true);
             }
             moveSharedElementsToOverlay();
             startTransition(new Runnable() {
@@ -212,8 +215,9 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
     public void startExit(int resultCode, Intent data) {
         if (!mIsExitStarted) {
             mIsExitStarted = true;
-            if (getDecor() != null) {
-                getDecor().suppressLayout(true);
+            ViewGroup decorView = getDecor();
+            if (decorView != null) {
+                decorView.suppressLayout(true);
             }
             mHandler = new Handler() {
                 @Override
@@ -224,7 +228,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
             };
             delayCancel();
             moveSharedElementsToOverlay();
-            if (getDecor().getBackground() == null) {
+            if (decorView != null && decorView.getBackground() == null) {
                 getWindow().setBackgroundDrawable(new ColorDrawable(Color.BLACK));
             }
             ActivityOptions options = ActivityOptions.makeSceneTransitionAnimation(mActivity, this,
@@ -248,8 +252,9 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
 
     private void startExitTransition() {
         Transition transition = getExitTransition();
-        if (transition != null) {
-            TransitionManager.beginDelayedTransition(getDecor(), transition);
+        ViewGroup decorView = getDecor();
+        if (transition != null && decorView != null) {
+            TransitionManager.beginDelayedTransition(decorView, transition);
             mTransitioningViews.get(0).invalidate();
         } else {
             transitionStarted();
@@ -337,13 +342,14 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         Transition viewsTransition = getExitTransition();
 
         Transition transition = mergeTransitions(sharedElementTransition, viewsTransition);
-        if (transition != null) {
+        ViewGroup decorView = getDecor();
+        if (transition != null && decorView != null) {
             setGhostVisibility(View.INVISIBLE);
             scheduleGhostVisibilityChange(View.INVISIBLE);
-            TransitionManager.beginDelayedTransition(getDecor(), transition);
+            TransitionManager.beginDelayedTransition(decorView, transition);
             scheduleGhostVisibilityChange(View.VISIBLE);
             setGhostVisibility(View.VISIBLE);
-            getDecor().invalidate();
+            decorView.invalidate();
         } else {
             transitionStarted();
         }
@@ -392,8 +398,9 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
                 mExitNotified = true;
                 mResultReceiver.send(MSG_EXIT_TRANSITION_COMPLETE, null);
                 mResultReceiver = null; // done talking
-                if (!mIsReturning && getDecor() != null) {
-                    getDecor().suppressLayout(false);
+                ViewGroup decorView = getDecor();
+                if (!mIsReturning && decorView != null) {
+                    decorView.suppressLayout(false);
                 }
                 finishIfNecessary();
             }