android: separates GestureStateListener into two interfaces

To fully support onScrollOffsetOrExtentChanged() comes at a performance
cost. As very few places actually need this, this creates a new interface
with onScrollOffsetOrExtentChanged() and converts the places that need it
to the new interface.

BUG=1087480
TEST=none

Change-Id: I1f54bdf74ee0b6006fc92284bc761ed6992a0d55
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2225548
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774422}

android_webview/java/src/org/chromium/android_webview/AwContents.java

@@ -801,11 +801,6 @@ public class AwContents implements SmartClipProvider {
         public void onScaleLimitsChanged(float minPageScaleFactor, float maxPageScaleFactor) {
             mZoomControls.updateZoomControls();
         }
-
-        @Override
-        public void onScrollOffsetOrExtentChanged(int scrollOffsetY, int scrollExtentY) {
-            mZoomControls.updateZoomControls();
-        }
     }
 
     //--------------------------------------------------------------------------------------------

android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java

@@ -25,7 +25,7 @@ import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.NativeMethods;
 import org.chromium.content_public.browser.GestureListenerManager;
-import org.chromium.content_public.browser.GestureStateListener;
+import org.chromium.content_public.browser.GestureStateListenerWithScroll;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.ui.base.WindowAndroid;
 import org.chromium.ui.display.DisplayAndroid.DisplayAndroidObserver;
@@ -90,7 +90,7 @@ public class PopupTouchHandleDrawable extends View implements DisplayAndroidObse
     private boolean mRotationChanged;
 
     // Gesture accounting for handle hiding while scrolling.
-    private final GestureStateListener mGestureStateListener;
+    private final GestureStateListenerWithScroll mGestureStateListener;
 
     // There are no guarantees that the side effects of setting the position of
     // the PopupWindow and the visibility of its content View will be realized
@@ -143,7 +143,7 @@ public class PopupTouchHandleDrawable extends View implements DisplayAndroidObse
 
         mParentPositionObserver = new ViewPositionObserver(containerView);
         mParentPositionListener = (x, y) -> updateParentPosition(x, y);
-        mGestureStateListener = new GestureStateListener() {
+        mGestureStateListener = new GestureStateListenerWithScroll() {
             @Override
             public void onScrollStarted(int scrollOffsetX, int scrollOffsetY) {
                 setIsScrolling(true);

chrome/android/java/src/org/chromium/chrome/browser/banners/SwipableOverlayView.java

@@ -21,7 +21,7 @@ import androidx.annotation.IntDef;
 
 import org.chromium.base.MathUtils;
 import org.chromium.content_public.browser.GestureListenerManager;
-import org.chromium.content_public.browser.GestureStateListener;
+import org.chromium.content_public.browser.GestureStateListenerWithScroll;
 import org.chromium.content_public.browser.WebContents;
 
 import java.lang.annotation.Retention;
@@ -58,7 +58,7 @@ public abstract class SwipableOverlayView extends FrameLayout {
     private static final long ANIMATION_DURATION_MS = 250;
 
     /** Detects when the user is dragging the WebContents. */
-    private final GestureStateListener mGestureStateListener;
+    private final GestureStateListenerWithScroll mGestureStateListener;
 
     /** Listens for changes in the layout. */
     private final View.OnLayoutChangeListener mLayoutChangeListener;
@@ -202,10 +202,10 @@ public abstract class SwipableOverlayView extends FrameLayout {
     /**
      * Creates a listener than monitors the WebContents for scrolls and flings.
      * The listener updates the location of this View to account for the user's gestures.
-     * @return GestureStateListener to send to the WebContents.
+     * @return GestureStateListenerWithScroll to send to the WebContents.
      */
-    private GestureStateListener createGestureStateListener() {
-        return new GestureStateListener() {
+    private GestureStateListenerWithScroll createGestureStateListener() {
+        return new GestureStateListenerWithScroll() {
             /** Tracks the previous event's scroll offset to determine if a scroll is up or down. */
             private int mLastScrollOffsetY;
 

content/public/android/BUILD.gn

@@ -282,6 +282,7 @@ android_library("content_java") {
     "java/src/org/chromium/content_public/browser/DeviceUtils.java",
     "java/src/org/chromium/content_public/browser/GestureListenerManager.java",
     "java/src/org/chromium/content_public/browser/GestureStateListener.java",
+    "java/src/org/chromium/content_public/browser/GestureStateListenerWithScroll.java",
     "java/src/org/chromium/content_public/browser/ImageDownloadCallback.java",
     "java/src/org/chromium/content_public/browser/ImeAdapter.java",
     "java/src/org/chromium/content_public/browser/ImeEventObserver.java",

content/public/android/java/src/org/chromium/content/browser/GestureListenerManagerImpl.java

@@ -21,6 +21,7 @@ import org.chromium.content.browser.webcontents.WebContentsImpl;
 import org.chromium.content.browser.webcontents.WebContentsImpl.UserDataFactory;
 import org.chromium.content_public.browser.GestureListenerManager;
 import org.chromium.content_public.browser.GestureStateListener;
+import org.chromium.content_public.browser.GestureStateListenerWithScroll;
 import org.chromium.content_public.browser.ViewEventSink.InternalAccessDelegate;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.ui.base.GestureEventType;
@@ -147,7 +148,11 @@ public class GestureListenerManagerImpl
      */
     public void updateOnScrollChanged(int offset, int extent) {
         for (mIterator.rewind(); mIterator.hasNext();) {
-            mIterator.next().onScrollOffsetOrExtentChanged(offset, extent);
+            GestureStateListener listener = mIterator.next();
+            if (listener instanceof GestureStateListenerWithScroll) {
+                ((GestureStateListenerWithScroll) listener)
+                        .onScrollOffsetOrExtentChanged(offset, extent);
+            }
         }
     }
 

content/public/android/java/src/org/chromium/content_public/browser/GestureStateListener.java

@@ -12,22 +12,22 @@ public interface GestureStateListener {
     /**
      * Called when the pinch gesture starts.
      */
-    default public void onPinchStarted() {}
+    public default void onPinchStarted() {}
 
     /**
      * Called when the pinch gesture ends.
      */
-    default public void onPinchEnded() {}
+    public default void onPinchEnded() {}
 
     /**
      * Called when a fling starts.
      */
-    default public void onFlingStartGesture(int scrollOffsetY, int scrollExtentY) {}
+    public default void onFlingStartGesture(int scrollOffsetY, int scrollExtentY) {}
 
     /**
      * Called when a fling has ended.
      */
-    default public void onFlingEndGesture(int scrollOffsetY, int scrollExtentY) {}
+    public default void onFlingEndGesture(int scrollOffsetY, int scrollExtentY) {}
 
     /**
      * Called to indicate that a scroll update gesture had been consumed by the page.
@@ -35,58 +35,53 @@ public interface GestureStateListener {
      * not called when a JS touch handler consumes the event (preventDefault), it is not called
      * for JS-initiated scrolling.
      */
-    default public void onScrollUpdateGestureConsumed() {}
+    public default void onScrollUpdateGestureConsumed() {}
 
     /**
      * Called when a scroll gesture has started.
      */
-    default public void onScrollStarted(int scrollOffsetY, int scrollExtentY) {}
+    public default void onScrollStarted(int scrollOffsetY, int scrollExtentY) {}
 
     /**
      * Called when a scroll gesture has stopped.
      */
-    default public void onScrollEnded(int scrollOffsetY, int scrollExtentY) {}
+    public default void onScrollEnded(int scrollOffsetY, int scrollExtentY) {}
 
     /**
      * Called when the min or max scale factor may have been changed.
      */
-    default public void onScaleLimitsChanged(float minPageScaleFactor, float maxPageScaleFactor) {}
-
-    /**
-     * Called when the scroll offsets or extents may have changed.
-     */
-    default public void onScrollOffsetOrExtentChanged(int scrollOffsetY, int scrollExtentY) {}
+    public default void onScaleLimitsChanged(float minPageScaleFactor, float maxPageScaleFactor) {}
 
     /**
      * Called at the beginning of any kind of touch event when the user's finger first touches down
      * onto the screen.  The resulting gesture may be a single tap, long-press, or scroll.
      */
-    default public void onTouchDown() {}
+    public default void onTouchDown() {}
 
     /**
      * Called after a single-tap gesture event was dispatched to the renderer,
      * indicating whether or not the gesture was consumed.
      */
-    default public void onSingleTap(boolean consumed) {}
+    public default void onSingleTap(boolean consumed) {}
 
     /**
      * Called after a single-tap gesture event was processed by the renderer,
      * but was not handled.
      */
-    default public void onShowUnhandledTapUIIfNeeded(int x, int y) {}
+    public default void onShowUnhandledTapUIIfNeeded(int x, int y) {}
 
     /**
      * Called when the gesture source loses window focus.
      */
-    default public void onWindowFocusChanged(boolean hasWindowFocus) {}
+    public default void onWindowFocusChanged(boolean hasWindowFocus) {}
 
     /**
      * Called when a long press gesture event was processed by the rendereer.
      */
-    default public void onLongPress() {}
+    public default void onLongPress() {}
 
     /**
      * Called when the gesture source is being destroyed.
      */
-    default public void onDestroyed() {}
+    public default void onDestroyed() {}
 }

content/public/android/java/src/org/chromium/content_public/browser/GestureStateListenerWithScroll.java

+// Copyright 2020 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.content_public.browser;
+
+/**
+ * Adds notification of changes in scroll offset/extent to GestureStateListener. Tracking changes to
+ * scroll offset/extent impacts performance, which is why it's separated in its own interface.
+ */
+public interface GestureStateListenerWithScroll extends GestureStateListener {
+    /**
+     * Called when the scroll offsets or extents may have changed.
+     */
+    public default void onScrollOffsetOrExtentChanged(int scrollOffsetY, int scrollExtentY) {}
+}