Excluded Views don't go through Transition.

Bug 35832096

When entering or exiting Views were excluded, they were still
being set to INVISIBLE during the exit transition. This made
them disappear instantly. Instead, I've reverted back to the
original implementation by not affecting excluded Views during
the transition.

This CL walks the transition and removes excluded Views from
the enter/exit from being affected.

Test: I5b1b75dd12a3914e35c1d0fb641850981a19f9c3
Change-Id: I2b00ba95575420bae690b1cd8d4894c98401da79

core/java/android/app/ActivityTransitionCoordinator.java

@@ -28,6 +28,7 @@ import android.transition.TransitionListenerAdapter;
 import android.transition.TransitionSet;
 import android.transition.Visibility;
 import android.util.ArrayMap;
+import android.util.ArraySet;
 import android.view.GhostView;
 import android.view.View;
 import android.view.ViewGroup;
@@ -394,6 +395,60 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
         return transition;
     }
 
+    /**
+     * Looks through the transition to see which Views have been included and which have been
+     * excluded. {@code views} will be modified to contain only those Views that are included
+     * in the transition. If {@code transition} is a TransitionSet, it will search through all
+     * contained Transitions to find targeted Views.
+     *
+     * @param transition The transition to look through for inclusion of Views
+     * @param views The list of Views that are to be checked for inclusion. Will be modified
+     *              to remove all excluded Views, possibly leaving an empty list.
+     */
+    protected static void removeExcludedViews(Transition transition, ArrayList<View> views) {
+        ArraySet<View> included = new ArraySet<>();
+        findIncludedViews(transition, views, included);
+        views.clear();
+        views.addAll(included);
+    }
+
+    /**
+     * Looks through the transition to see which Views have been included. Only {@code views}
+     * will be examined for inclusion. If {@code transition} is a TransitionSet, it will search
+     * through all contained Transitions to find targeted Views.
+     *
+     * @param transition The transition to look through for inclusion of Views
+     * @param views The list of Views that are to be checked for inclusion.
+     * @param included Modified to contain all Views in views that have at least one Transition
+     *                 that affects it.
+     */
+    private static void findIncludedViews(Transition transition, ArrayList<View> views,
+            ArraySet<View> included) {
+        if (transition instanceof TransitionSet) {
+            TransitionSet set = (TransitionSet) transition;
+            ArrayList<View> includedViews = new ArrayList<>();
+            final int numViews = views.size();
+            for (int i = 0; i < numViews; i++) {
+                final View view = views.get(i);
+                if (transition.isValidTarget(view)) {
+                    includedViews.add(view);
+                }
+            }
+            final int count = set.getTransitionCount();
+            for (int i = 0; i < count; i++) {
+                findIncludedViews(set.getTransitionAt(i), includedViews, included);
+            }
+        } else {
+            final int numViews = views.size();
+            for (int i = 0; i < numViews; i++) {
+                final View view = views.get(i);
+                if (transition.isValidTarget(view)) {
+                    included.add(view);
+                }
+            }
+        }
+    }
+
     protected static Transition mergeTransitions(Transition transition1, Transition transition2) {
         if (transition1 == null) {
             return transition2;

core/java/android/app/EnterTransitionCoordinator.java

@@ -132,7 +132,9 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         super.viewsReady(sharedElements);
         mIsReadyForTransition = true;
         hideViews(mSharedElements);
-        if (getViewsTransition() != null && mTransitioningViews != null) {
+        Transition viewsTransition = getViewsTransition();
+        if (viewsTransition != null && mTransitioningViews != null) {
+            removeExcludedViews(viewsTransition, mTransitioningViews);
             stripOffscreenViews();
             hideViews(mTransitioningViews);
         }

core/java/android/app/ExitTransitionCoordinator.java

@@ -321,6 +321,10 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         Transition viewsTransition = null;
         if (mTransitioningViews != null && !mTransitioningViews.isEmpty()) {
             viewsTransition = configureTransition(getViewsTransition(), true);
+            removeExcludedViews(viewsTransition, mTransitioningViews);
+            if (mTransitioningViews.isEmpty()) {
+                viewsTransition = null;
+            }
         }
         if (viewsTransition == null) {
             viewsTransitionComplete();

core/java/android/transition/Transition.java

@@ -799,8 +799,10 @@ public abstract class Transition implements Cloneable {
      * targetId list. If the target parameter is null, then the target list
      * is not checked (this is in the case of ListView items, where the
      * views are ignored and only the ids are used).
+     *
+     * @hide
      */
-    boolean isValidTarget(View target) {
+    public boolean isValidTarget(View target) {
         if (target == null) {
             return false;
         }