Add distance change on gesture swipe listener

Add distance change between the current motion event and the last motion
event.

Bug: 1142475
Change-Id: I365fb9d37c2138ac42ce46a8cafe6b8adf554bf2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518995
Commit-Queue: Lijin Shen <lazzzis@google.com>
Reviewed-by: Jinsuk Kim <jinsukkim@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/master@{#824760}

components/browser_ui/widget/android/BUILD.gn

@@ -52,7 +52,6 @@ android_library("java") {
     "java/src/org/chromium/components/browser_ui/widget/displaystyle/ViewResizer.java",
     "java/src/org/chromium/components/browser_ui/widget/dragreorder/DragReorderableListAdapter.java",
     "java/src/org/chromium/components/browser_ui/widget/dragreorder/DragStateDelegate.java",
-    "java/src/org/chromium/components/browser_ui/widget/gesture/EmptySwipeHandler.java",
     "java/src/org/chromium/components/browser_ui/widget/gesture/SwipeGestureListener.java",
     "java/src/org/chromium/components/browser_ui/widget/highlight/PulseDrawable.java",
     "java/src/org/chromium/components/browser_ui/widget/highlight/PulseInterpolator.java",

components/browser_ui/widget/android/java/src/org/chromium/components/browser_ui/widget/gesture/EmptySwipeHandler.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.components.browser_ui.widget.gesture;
-
-import android.view.MotionEvent;
-
-import org.chromium.components.browser_ui.widget.gesture.SwipeGestureListener.SwipeHandler;
-
-/**
- * An empty implementation of {@link SwipeHandler}.
- */
-public class EmptySwipeHandler implements SwipeHandler {
-    @Override
-    public void onSwipeStarted(int direction, MotionEvent ev) {}
-
-    @Override
-    public void onSwipeUpdated(MotionEvent start, MotionEvent current) {}
-
-    @Override
-    public void onSwipeFinished(MotionEvent end) {}
-
-    @Override
-    public void onFling(int direction, MotionEvent start, MotionEvent end) {}
-
-    @Override
-    public boolean isSwipeEnabled(int direction) {
-        return true;
-    }
-}

components/browser_ui/widget/android/java/src/org/chromium/components/browser_ui/widget/gesture/SwipeGestureListener.java

@@ -5,6 +5,7 @@
 package org.chromium.components.browser_ui.widget.gesture;
 
 import android.content.Context;
+import android.graphics.PointF;
 import android.view.GestureDetector;
 import android.view.GestureDetector.SimpleOnGestureListener;
 import android.view.MotionEvent;
@@ -57,37 +58,52 @@ public class SwipeGestureListener extends SimpleOnGestureListener {
          * @param direction The {@link ScrollDirection} representing the swipe direction.
          * @param ev The first down motion event triggering the swipe.
          */
-        void onSwipeStarted(@ScrollDirection int direction, MotionEvent ev);
+        default void onSwipeStarted(@ScrollDirection int direction, MotionEvent ev) {}
 
         /**
-         * @param start The first down motion event triggering the swipe.
          * @param current The move motion event triggering the current swipe.
+         * @param tx The horizontal difference between the start and the current position in px.
+         * @param ty The vertical difference between the start and the current position in px.
+         * @param distanceX The distance along the X axis that has been scrolled since the last call
+         *         to onScroll.
+         * @param distanceY The distance along the Y axis that has been scrolled since the last call
+         *         to onScroll.
          */
-        void onSwipeUpdated(MotionEvent start, MotionEvent current);
+        default void onSwipeUpdated(
+                MotionEvent current, float tx, float ty, float distanceX, float distanceY) {}
 
         /**
          * @param end The last motion event canceling the swipe.
          */
-        void onSwipeFinished(MotionEvent end);
+        default void onSwipeFinished(MotionEvent end) {}
 
         /**
          * @param direction The {@link ScrollDirection} representing the swipe direction.
-         * @param start The first down motion event triggering the swipe.
-         * @param end The last motion event canceling the swipe.
+         * @param current The first down motion event triggering the swipe.
+         * @param tx The horizontal difference between the start and the current position in px.
+         * @param ty The vertical difference between the start and the current position in px.
+         * @param velocityX The velocity of this fling measured in pixels per second along the x
+         *         axis.
+         * @param velocityY The velocity of this fling measured in pixels per second along the y
+         *         axis.
          */
-        void onFling(@ScrollDirection int direction, MotionEvent start, MotionEvent end);
+        default void onFling(@ScrollDirection int direction, MotionEvent current, float tx,
+                float ty, float velocityX, float velocityY) {}
 
         /**
          * @param direction The direction of the on-going swipe.
          * @return False if this direction should be ignored.
          */
-        boolean isSwipeEnabled(@ScrollDirection int direction);
+        default boolean isSwipeEnabled(@ScrollDirection int direction) {
+            return true;
+        }
     }
 
     /**
      * The internal {@link GestureDetector} used to recognize swipe gestures.
      */
     private final GestureDetector mGestureDetector;
+    private final PointF mMotionStartPoint = new PointF();
     @ScrollDirection
     private int mDirection = ScrollDirection.UNKNOWN;
     private final SwipeHandler mHandler;
@@ -165,6 +181,11 @@ public class SwipeGestureListener extends SimpleOnGestureListener {
     // Swipe Recognition Helpers
     // ============================================================================================
 
+    @Override
+    public boolean onDown(MotionEvent e) {
+        return true;
+    }
+
     @Override
     public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
         if (mHandler == null || e1 == null || e2 == null) return false;
@@ -188,12 +209,14 @@ public class SwipeGestureListener extends SimpleOnGestureListener {
 
             if (direction != ScrollDirection.UNKNOWN && mHandler.isSwipeEnabled(direction)) {
                 mDirection = direction;
-                mHandler.onSwipeStarted(direction, e1);
+                mHandler.onSwipeStarted(direction, e2);
+                mMotionStartPoint.set(e2.getRawX(), e2.getRawY());
             }
         }
 
         if (mDirection != ScrollDirection.UNKNOWN) {
-            mHandler.onSwipeUpdated(e1, e2);
+            mHandler.onSwipeUpdated(e2, e2.getRawX() - mMotionStartPoint.x,
+                    e2.getRawY() - mMotionStartPoint.y, distanceX, distanceY);
             return true;
         }
 
@@ -205,7 +228,8 @@ public class SwipeGestureListener extends SimpleOnGestureListener {
         if (mHandler == null) return false;
 
         if (mDirection != ScrollDirection.UNKNOWN) {
-            mHandler.onFling(mDirection, e1, e2);
+            mHandler.onFling(mDirection, e2, e2.getRawX() - mMotionStartPoint.x,
+                    e2.getRawY() - mMotionStartPoint.y, velocityX, velocityY);
             return true;
         }
 

components/browser_ui/widget/android/java/src/org/chromium/components/browser_ui/widget/gesture/SwipeGestureListenerTest.java

@@ -22,6 +22,7 @@ import org.robolectric.annotation.Config;
 
 import org.chromium.base.test.BaseRobolectricTestRunner;
 import org.chromium.components.browser_ui.widget.gesture.SwipeGestureListener.ScrollDirection;
+import org.chromium.components.browser_ui.widget.gesture.SwipeGestureListener.SwipeHandler;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -35,7 +36,7 @@ public class SwipeGestureListenerTest {
     private SwipeGestureListener mListener;
 
     @Mock
-    private EmptySwipeHandler mHandler;
+    private SwipeHandler mHandler;
 
     @Before
     public void setUp() {
@@ -79,7 +80,14 @@ public class SwipeGestureListenerTest {
         ArgumentCaptor<MotionEvent> argumentCaptor = ArgumentCaptor.forClass(MotionEvent.class);
         Mockito.verify(mHandler).onSwipeStarted(
                 Mockito.eq(expectedDirection), argumentCaptor.capture());
-        Assert.assertEquals(argumentCaptor.getValue().getRawX(), eventStream.get(0).getRawX(), 0.1);
+        boolean found = false;
+        for (MotionEvent event : eventStream) {
+            if (Math.abs(event.getRawX() - argumentCaptor.getValue().getRawX()) < 0.1) {
+                found = true;
+                break;
+            }
+        }
+        Assert.assertTrue("Can not found the expected first move event", found);
 
         Mockito.verify(mHandler).onSwipeFinished(argumentCaptor.capture());
         Assert.assertEquals(argumentCaptor.getValue().getRawX(),