Bug 1100904 - Add TransitionsTracker API (r=mcomella)

mobile/android/base/animation/TransitionsTracker.java

@@ -0,0 +1,119 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.animation;
+
+import com.nineoldandroids.animation.Animator;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.mozilla.gecko.animation.PropertyAnimator;
+import org.mozilla.gecko.animation.PropertyAnimator.PropertyAnimationListener;
+import org.mozilla.gecko.util.ThreadUtils;
+
+
+/**
+ * {@link TransitionsTracker} provides a simple API to avoid running layout code
+ * during UI transitions. You should use it whenever you need to time-shift code
+ * that will likely trigger a layout traversal during an animation.
+ */
+public class TransitionsTracker {
+    private static final ArrayList<Runnable> pendingActions = new ArrayList<>();
+    private static int transitionCount;
+
+    private static final PropertyAnimationListener propertyAnimatorListener =
+            new PropertyAnimationListener() {
+        @Override
+        public void onPropertyAnimationStart() {
+            pushTransition();
+        }
+
+        @Override
+        public void onPropertyAnimationEnd() {
+            popTransition();
+        }
+    };
+
+    private static final Animator.AnimatorListener animatorListener =
+            new Animator.AnimatorListener() {
+        @Override
+        public void onAnimationStart(Animator animation) {
+            pushTransition();
+        }
+
+        @Override
+        public void onAnimationEnd(Animator animation) {
+            popTransition();
+        }
+
+        @Override
+        public void onAnimationCancel(Animator animation) {
+        }
+
+        @Override
+        public void onAnimationRepeat(Animator animation) {
+        }
+    };
+
+    private static void runPendingActions() {
+        ThreadUtils.assertOnUiThread();
+
+        final int size = pendingActions.size();
+        for (int i = 0; i < size; i++) {
+            pendingActions.get(i).run();
+        }
+
+        pendingActions.clear();
+    }
+
+    public static void pushTransition() {
+        ThreadUtils.assertOnUiThread();
+        transitionCount++;
+    }
+
+    public static void popTransition() {
+        ThreadUtils.assertOnUiThread();
+        transitionCount--;
+
+        if (transitionCount < 0) {
+            throw new IllegalStateException("Invalid transition stack update");
+        }
+
+        if (transitionCount == 0) {
+            runPendingActions();
+        }
+    }
+
+    public static boolean areTransitionsRunning() {
+        ThreadUtils.assertOnUiThread();
+        return (transitionCount > 0);
+    }
+
+    public static void track(PropertyAnimator animator) {
+        ThreadUtils.assertOnUiThread();
+        animator.addPropertyAnimationListener(propertyAnimatorListener);
+    }
+
+    public static void track(Animator animator) {
+        ThreadUtils.assertOnUiThread();
+        animator.addListener(animatorListener);
+    }
+
+    public static boolean cancelPendingAction(Runnable action) {
+        ThreadUtils.assertOnUiThread();
+        return pendingActions.removeAll(Collections.singleton(action));
+    }
+
+    public static void runAfterTransitions(Runnable action) {
+        ThreadUtils.assertOnUiThread();
+
+        if (transitionCount == 0) {
+            action.run();
+        } else {
+            pendingActions.add(action);
+        }
+    }
+}

mobile/android/base/moz.build

@@ -124,6 +124,7 @@ gbjar.sources += [
     'animation/HeightChangeAnimation.java',
     'animation/PropertyAnimator.java',
     'animation/Rotate3DAnimation.java',
+    'animation/TransitionsTracker.java',
     'animation/ViewHelper.java',
     'ANRReporter.java',
     'AppNotificationClient.java',