added scale animation for context menu

chrome/android/java/src/org/chromium/chrome/browser/widget/ContextMenuDialog.java

+// Copyright 2017 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.chrome.browser.widget;
+
+import android.app.Activity;
+import android.support.v4.view.animation.LinearOutSlowInInterpolator;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.animation.Animation;
+import android.view.animation.Animation.AnimationListener;
+import android.view.animation.ScaleAnimation;
+
+/**
+ * AlwaysDismissedDialog that ensures that the dialog animates when it's being dismissed.
+ */
+public class ContextMenuDialog extends AlwaysDismissedDialog {
+    private View mPagerView;
+    private float mContextMenuSourceX;
+    private float mContextMenuSourceY;
+    private int mContextMenuYLocationOnScreen;
+
+    // Animation out duration should be set to 60% of the animation in duration found in
+    // TabularContextMenuUi.java

[Theresa, 2017/05/24 17:53:34]

Comments like this spread across files are likely to be missed if someone is
changing ANIMATION_IN_DURATION in the other file sometime in the future.

[Daniel Park, 2017/05/24 19:44:39]

Done.

+    private static final int ANIMATION_OUT_DURATION = 150;
+
+    public ContextMenuDialog(Activity ownerActivity, int theme) {
+        super(ownerActivity, theme);
+    }
+
+    public void setAnimationOutParameters(View pagerView, float contextMenuSourceX,
+            float contextMenuSourceY, int contextMenuYLocationOnScreen) {
+        mPagerView = pagerView;
+        mContextMenuSourceX = contextMenuSourceX;
+        mContextMenuSourceY = contextMenuSourceY;
+        mContextMenuYLocationOnScreen = contextMenuYLocationOnScreen;
+    }
+
+    @Override
+    public void dismiss() {
+        Animation exitAnimation = getAnimationOut();

[Theresa, 2017/05/24 17:53:34]

nit: rename method to getExitAnimation() for more consistency between variables
and method names. Similar, getScaleAnimationIn() and
initializeAnimationAndRevealView() and initAnimations() should be named
consistently with respect to each other and this file.

[Daniel Park, 2017/05/24 19:44:39]

Done.

+        exitAnimation.setAnimationListener(new AnimationListener() {
+
+            @Override
+            public void onAnimationStart(Animation animation) {}
+
+            @Override
+            public void onAnimationRepeat(Animation animation) {}
+
+            @Override
+            public void onAnimationEnd(Animation animation) {
+                ContextMenuDialog.super.dismiss();
+            }
+        });
+        mPagerView.startAnimation(exitAnimation);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        if (event.getAction() == MotionEvent.ACTION_DOWN) {
+            this.dismiss();
+        }
+        return true;
+    }
+
+    private Animation getAnimationOut() {
+        int[] outLocation = new int[2];
+        mPagerView.getLocationOnScreen(outLocation);
+        // Recalculate mContextMenuSourceY because the final tab shown may have caused the view
+        // height to change
+        mContextMenuSourceY =
+                mContextMenuSourceY + (mContextMenuYLocationOnScreen - outLocation[1]);
+        ScaleAnimation animation = new ScaleAnimation(1f, 0f, 1f, 0f, Animation.ABSOLUTE,
+                mContextMenuSourceX, Animation.ABSOLUTE, mContextMenuSourceY);
+
+        animation.setDuration(ANIMATION_OUT_DURATION);
+        animation.setInterpolator(new LinearOutSlowInInterpolator());
+        return animation;
+    }
+}