[Unity][Android] Extract AnimationLooper

This CL moves the code from SigninView startAnimations/stopAnimations
methods into separate AnimationLooper class that encapsulates animation
looping logic. This class is then used in ConsentBumpMoreOptionsFragment
to run the header animation.

Bug: 869426
Change-Id: Ie305e4535adf27662d7d6724afc419b7bcfd8084
Reviewed-on: https://chromium-review.googlesource.com/1172688Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584402}

chrome/android/java/src/org/chromium/chrome/browser/signin/ConsentBumpMoreOptionsFragment.java

@@ -11,10 +11,12 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
+import android.widget.ImageView;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.widget.RadioButtonWithDescription;
+import org.chromium.ui.drawable.AnimationLooper;
 
 /**
  * This fragment implements the advanced consent bump screen. This screen lets users to enable or
@@ -23,6 +25,8 @@ import org.chromium.chrome.browser.widget.RadioButtonWithDescription;
 public class ConsentBumpMoreOptionsFragment extends Fragment {
     private static final String TAG = "ConsentBumpMoreOptionsFragment";
 
+    private AnimationLooper mAnimationLooper;
+
     public ConsentBumpMoreOptionsFragment() {}
 
     @Override
@@ -30,6 +34,9 @@ public class ConsentBumpMoreOptionsFragment extends Fragment {
             LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View view = inflater.inflate(R.layout.consent_bump_more_options_view, container, false);
 
+        ImageView headerImage = view.findViewById(R.id.consent_bump_header_image);
+        mAnimationLooper = AnimationLooper.create(headerImage.getDrawable());
+
         RadioButtonWithDescription noChanges = view.findViewById(R.id.consent_bump_no_changes);
         noChanges.setDescriptionText(getText(R.string.consent_bump_no_changes_description));
         RadioButtonWithDescription turnOn = view.findViewById(R.id.consent_bump_turn_on);
@@ -43,4 +50,16 @@ public class ConsentBumpMoreOptionsFragment extends Fragment {
         });
         return view;
     }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        mAnimationLooper.start();
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        mAnimationLooper.stop();
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninView.java

@@ -4,15 +4,10 @@
 
 package org.chromium.chrome.browser.signin;
 
-import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.res.ColorStateList;
-import android.graphics.drawable.Animatable;
-import android.graphics.drawable.Animatable2;
 import android.graphics.drawable.Drawable;
-import android.os.Build;
 import android.support.annotation.Nullable;
-import android.support.graphics.drawable.Animatable2Compat;
 import android.support.v4.graphics.drawable.DrawableCompat;
 import android.support.v7.content.res.AppCompatResources;
 import android.util.AttributeSet;
@@ -22,8 +17,8 @@ import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;
 
-import org.chromium.base.ThreadUtils;
 import org.chromium.chrome.R;
+import org.chromium.ui.drawable.AnimationLooper;
 import org.chromium.ui.widget.ButtonCompat;
 
 /** View that wraps signin screen and caches references to UI elements. */
@@ -44,8 +39,7 @@ public class SigninView extends LinearLayout {
     private Button mRefuseButton;
     private Button mMoreButton;
     private View mAcceptButtonEndPadding;
-
-    private Runnable mStopAnimationsRunnable;
+    private AnimationLooper mAnimationLooper;
 
     public SigninView(Context context, @Nullable AttributeSet attrs) {
         super(context, attrs);
@@ -73,16 +67,14 @@ public class SigninView extends LinearLayout {
         mRefuseButton = (Button) findViewById(R.id.negative_button);
         mMoreButton = (Button) findViewById(R.id.more_button);
         mAcceptButtonEndPadding = findViewById(R.id.positive_button_end_padding);
+
+        mAnimationLooper = AnimationLooper.create(mHeaderImage.getDrawable());
     }
 
     SigninScrollView getScrollView() {
         return mScrollView;
     }
 
-    ImageView getHeaderImage() {
-        return mHeaderImage;
-    }
-
     TextView getTitleView() {
         return mTitle;
     }
@@ -140,59 +132,11 @@ public class SigninView extends LinearLayout {
     }
 
     void startAnimations() {
-        Drawable headerImage = getHeaderImage().getDrawable();
-        if (headerImage instanceof Animatable2Compat) {
-            Animatable2Compat animatable = (Animatable2Compat) headerImage;
-            Animatable2Compat.AnimationCallback animationCallback =
-                    new Animatable2Compat.AnimationCallback() {
-                        @Override
-                        public void onAnimationEnd(Drawable drawable) {
-                            restartAnimations(animatable);
-                        }
-                    };
-            mStopAnimationsRunnable = () -> {
-                animatable.unregisterAnimationCallback(animationCallback);
-                animatable.stop();
-            };
-            animatable.registerAnimationCallback(animationCallback);
-            animatable.start();
-            return;
-        }
-
-        // Animatable2 was added in API level 23 (Android M).
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) return;
-        if (headerImage instanceof Animatable2) {
-            Animatable2 animatable = (Animatable2) headerImage;
-            Animatable2.AnimationCallback animationCallback = new Animatable2.AnimationCallback() {
-                @Override
-                @TargetApi(Build.VERSION_CODES.M)
-                public void onAnimationEnd(Drawable drawable) {
-                    restartAnimations(animatable);
-                }
-            };
-            mStopAnimationsRunnable = () -> {
-                animatable.unregisterAnimationCallback(animationCallback);
-                animatable.stop();
-            };
-            animatable.registerAnimationCallback(animationCallback);
-            animatable.start();
-        }
+        mAnimationLooper.start();
     }
 
     void stopAnimations() {
-        if (mStopAnimationsRunnable == null) return;
-        mStopAnimationsRunnable.run();
-        mStopAnimationsRunnable = null;
-    }
-
-    private void restartAnimations(Animatable animatable) {
-        // In some cases (Animatable2Compat from Support Library, etc.), onAnimationEnd is invoked
-        // before the animation is marked as ended, so calls to start() here may be ignored.
-        // This issue is worked around by deferring the call to start().
-        ThreadUtils.postOnUiThread(() -> {
-            if (mStopAnimationsRunnable == null) return;
-            animatable.start();
-        });
+        mAnimationLooper.stop();
     }
 
     static Drawable getExpandArrowDrawable(Context context) {

ui/android/BUILD.gn

@@ -277,6 +277,7 @@ android_library("ui_full_java") {
     "java/src/org/chromium/ui/display/DisplayUtil.java",
     "java/src/org/chromium/ui/display/PhysicalDisplayAndroid.java",
     "java/src/org/chromium/ui/display/VirtualDisplayAndroid.java",
+    "java/src/org/chromium/ui/drawable/AnimationLooper.java",
     "java/src/org/chromium/ui/drawable/StateListDrawableBuilder.java",
     "java/src/org/chromium/ui/events/devices/InputDeviceObserver.java",
     "java/src/org/chromium/ui/gfx/BitmapHelper.java",

ui/android/java/src/org/chromium/ui/drawable/AnimationLooper.java

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.ui.drawable;
+
+import android.annotation.TargetApi;
+import android.graphics.drawable.Animatable2;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import android.support.graphics.drawable.Animatable2Compat;
+
+import org.chromium.base.ThreadUtils;
+
+/**
+ * Encapsulates the logic to loop animated drawables from both Android Framework (using Animatable2)
+ * and Support Library (using Animatable2Compat). Should be instantiated by {@link #create}. The
+ * animation should be started and stopped using {@link #start()} and {@link #stop()}.
+ */
+public interface AnimationLooper {
+    /** Starts the animation of the associated drawable. */
+    void start();
+
+    /** Stops the animation of the associated drawable. */
+    void stop();
+
+    /**
+     * Instantiates proper implementation of AnimationLooper for the drawable.
+     * @param drawable The drawable to be animated. Created AnimationLooper instance will be
+     *         associated with this drawable. The drawable should implement either
+     *         {@link Animatable2} or {@link Animatable2Compat}.
+     * @return The new AnimationLooper.
+     */
+    static AnimationLooper create(Drawable drawable) {
+        // Animatable2 was added in API level 23 (Android M).
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            return new Animatable2CompatImpl((Animatable2Compat) drawable);
+        }
+        if (drawable instanceof Animatable2Compat) {
+            return new Animatable2CompatImpl((Animatable2Compat) drawable);
+        }
+        return new Animatable2Impl((Animatable2) drawable);
+    }
+
+    /** Used with drawables that implement {@link Animatable2Compat}. */
+    class Animatable2CompatImpl implements AnimationLooper {
+        private final Animatable2Compat mAnimatable;
+        private final Animatable2Compat.AnimationCallback mAnimationCallback;
+        private boolean mRunning;
+
+        Animatable2CompatImpl(Animatable2Compat animatable) {
+            mAnimatable = animatable;
+            mAnimationCallback = new Animatable2Compat.AnimationCallback() {
+                @Override
+                public void onAnimationEnd(Drawable drawable) {
+                    restartAnimation(animatable);
+                }
+            };
+        }
+
+        @Override
+        public void start() {
+            assert !mRunning : "The animation is already running!";
+            mRunning = true;
+            mAnimatable.registerAnimationCallback(mAnimationCallback);
+            mAnimatable.start();
+        }
+
+        @Override
+        public void stop() {
+            assert mRunning : "The animation isn't running!";
+            mRunning = false;
+            mAnimatable.unregisterAnimationCallback(mAnimationCallback);
+            mAnimatable.stop();
+        }
+
+        private void restartAnimation(Animatable2Compat animatable) {
+            ThreadUtils.postOnUiThread(() -> {
+                if (mRunning) animatable.start();
+            });
+        }
+    }
+
+    /** Used with drawables that implement {@link Animatable2}. */
+    @TargetApi(Build.VERSION_CODES.M)
+    class Animatable2Impl implements AnimationLooper {
+        private final Animatable2 mAnimatable;
+        private final Animatable2.AnimationCallback mAnimationCallback;
+        private boolean mRunning;
+
+        Animatable2Impl(Animatable2 animatable) {
+            mAnimatable = animatable;
+            mAnimationCallback = new Animatable2.AnimationCallback() {
+                @Override
+                public void onAnimationEnd(Drawable drawable) {
+                    restartAnimation(animatable);
+                }
+            };
+        }
+
+        @Override
+        public void start() {
+            assert !mRunning : "The animation is already running!";
+            mRunning = true;
+            mAnimatable.registerAnimationCallback(mAnimationCallback);
+            mAnimatable.start();
+        }
+
+        @Override
+        public void stop() {
+            assert mRunning : "The animation isn't running!";
+            mRunning = false;
+            mAnimatable.unregisterAnimationCallback(mAnimationCallback);
+            mAnimatable.stop();
+        }
+
+        private void restartAnimation(Animatable2 animatable) {
+            ThreadUtils.postOnUiThread(() -> {
+                if (mRunning) animatable.start();
+            });
+        }
+    }
+}