Android: Make MotionEventSynthesizer a public interface

MotionEventSynthesizer class is used by Chrome (VR) and content
internally. This CL splits it into public interface with create
method and implementation class. Helps remove the exception rule
in DEPS.

Bug: 617324
Change-Id: I99fa8c01089ede078a7c2b2929897fdbbd7b40aa
Reviewed-on: https://chromium-review.googlesource.com/1058873
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561360}

chrome/android/java/DEPS

@@ -23,7 +23,6 @@ include_rules = [
   "!content/public/android/java/src/org/chromium/content/browser/BrowserStartupController.java",
   "!content/public/android/java/src/org/chromium/content/browser/ChildProcessCreationParams.java",
   "!content/public/android/java/src/org/chromium/content/browser/ChildProcessLauncherHelper.java",
-  "!content/public/android/java/src/org/chromium/content/browser/MotionEventSynthesizer.java",
   "!content/public/android/java/src/org/chromium/content/browser/ScreenOrientationProvider.java",
 
   "+device/gamepad/android/java",

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/AndroidUiGestureTarget.java

@@ -9,7 +9,7 @@ import android.view.View;
 
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
-import org.chromium.content.browser.MotionEventSynthesizer;
+import org.chromium.content_public.browser.MotionEventSynthesizer;
 
 /**
  * Forwards events for Java native UI pages to MotionEventSynthesizer.
@@ -21,7 +21,7 @@ public class AndroidUiGestureTarget {
 
     public AndroidUiGestureTarget(
             View target, float scaleFactor, float scrollRatio, int touchSlop) {
-        mMotionEventSynthesizer = new MotionEventSynthesizer(target);
+        mMotionEventSynthesizer = MotionEventSynthesizer.create(target);
         mNativePointer = nativeInit(scaleFactor, scrollRatio, touchSlop);
     }
 

content/public/android/BUILD.gn

@@ -133,7 +133,7 @@ android_library("content_java") {
     "java/src/org/chromium/content/browser/LauncherThread.java",
     "java/src/org/chromium/content/browser/MediaSessionImpl.java",
     "java/src/org/chromium/content/browser/MemoryMonitorAndroid.java",
-    "java/src/org/chromium/content/browser/MotionEventSynthesizer.java",
+    "java/src/org/chromium/content/browser/MotionEventSynthesizerImpl.java",
     "java/src/org/chromium/content/browser/NfcHost.java",
     "java/src/org/chromium/content/browser/PepperPluginManager.java",
     "java/src/org/chromium/content/browser/PopupController.java",
@@ -246,6 +246,7 @@ android_library("content_java") {
     "java/src/org/chromium/content_public/browser/MediaSession.java",
     "java/src/org/chromium/content_public/browser/MediaSessionObserver.java",
     "java/src/org/chromium/content_public/browser/MessagePort.java",
+    "java/src/org/chromium/content_public/browser/MotionEventSynthesizer.java",
     "java/src/org/chromium/content_public/browser/NavigationController.java",
     "java/src/org/chromium/content_public/browser/NavigationEntry.java",
     "java/src/org/chromium/content_public/browser/NavigationHistory.java",

content/public/android/java/src/org/chromium/content/browser/MotionEventSynthesizer.java → content/public/android/java/src/org/chromium/content/browser/MotionEventSynthesizerImpl.java

@@ -10,10 +10,12 @@ import android.view.MotionEvent.PointerCoords;
 import android.view.MotionEvent.PointerProperties;
 import android.view.View;
 
+import org.chromium.content_public.browser.MotionEventSynthesizer;
+
 /**
  * Injects synthetic touch events. All the coordinates are of physical unit.
  */
-public class MotionEventSynthesizer {
+public class MotionEventSynthesizerImpl implements MotionEventSynthesizer {
     private static final int MAX_NUM_POINTERS = 16;
 
     private final PointerProperties[] mPointerProperties;
@@ -21,7 +23,11 @@ public class MotionEventSynthesizer {
     private final View mTarget;
     private long mDownTimeInMs;
 
-    public MotionEventSynthesizer(View target) {
+    public static MotionEventSynthesizerImpl create(View target) {
+        return new MotionEventSynthesizerImpl(target);
+    }
+
+    private MotionEventSynthesizerImpl(View target) {
         assert target != null;
         mTarget = target;
         mPointerProperties = new PointerProperties[MAX_NUM_POINTERS];
@@ -37,6 +43,7 @@ public class MotionEventSynthesizer {
      * @param id Id property of the point.
      * @param toolType ToolType property of the point.
      */
+    @Override
     public void setPointer(int index, int x, int y, int id, int toolType) {
         assert (0 <= index && index < MAX_NUM_POINTERS);
 
@@ -85,6 +92,7 @@ public class MotionEventSynthesizer {
      * @param pointerCount The number of points associated with the event.
      * @param timeInMs Timestamp for the event.
      */
+    @Override
     public void inject(int action, int pointerCount, long timeInMs) {
         switch (action) {
             case MotionEventAction.START: {

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

@@ -14,7 +14,7 @@ import org.chromium.base.annotations.JNINamespace;
  */
 @JNINamespace("content")
 public class SyntheticGestureTarget {
-    private final MotionEventSynthesizer mMotionEventSynthesizer;
+    private final MotionEventSynthesizerImpl mMotionEventSynthesizer;
 
     @CalledByNative
     private static SyntheticGestureTarget create(View target) {
@@ -22,7 +22,7 @@ public class SyntheticGestureTarget {
     }
 
     private SyntheticGestureTarget(View target) {
-        mMotionEventSynthesizer = new MotionEventSynthesizer(target);
+        mMotionEventSynthesizer = MotionEventSynthesizerImpl.create(target);
     }
 
     @CalledByNative

content/public/android/java/src/org/chromium/content_public/browser/MotionEventSynthesizer.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.content_public.browser;
+
+import android.view.View;
+
+import org.chromium.content.browser.MotionEventSynthesizerImpl;
+
+/**
+ * Injects synthetic touch events. All the coordinates are of physical unit.
+ */
+public interface MotionEventSynthesizer {
+    public static MotionEventSynthesizer create(View target) {
+        return MotionEventSynthesizerImpl.create(target);
+    }
+
+    /**
+     * Sets the coordinate of the point at which a touch event takes place.
+     *
+     * @param index Index of the point when there are multiple points.
+     * @param x X coordinate of the point.
+     * @param x Y coordinate of the point.
+     * @param id Id property of the point.
+     * @param toolType ToolType property of the point.
+     */
+    void setPointer(int index, int x, int y, int id, int toolType);
+
+    /**
+     * Injects a synthetic action with the preset points and delta.
+     *
+     * @param action Type of the action to inject.
+     * @param pointerCount The number of points associated with the event.
+     * @param timeInMs Timestamp for the event.
+     */
+    void inject(int action, int pointerCount, long timeInMs);
+}