[Chromoting] Add InputInjector and InputInjectorWrapper for easy unittesting

remoting/android/java/src/org/chromium/chromoting/InputInjector.java

+// Copyright 2016 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.chromoting;
+
+import org.chromium.chromoting.jni.TouchEventData;
+
+/**
+ * A set of functions to send client users' activities to remote host machine. This interface
+ * represents low level functions without relationships with Android system. Consumers can use
+ * {@link InputInjectorWrapper} to avoid conversions between Android classes and JNI types. The
+ * implementations of this interface are not required to be thread-safe. All these functions should
+ * be called from Android UI thread.
+ */
+public interface InputInjector {

[Sergey Ulanov, 2016/06/22 06:39:01]

This name is confusing because this interface doesn't really inject's anything.
We call InputInjector an object on the host side that injects input events to
the OS. Here InputInjector doesn't really inject anything. Maybe call it
InputStub, which is what we call similar interface in C++? It's not the best
name, but at least it would be consistent. Or if you have another idea for a
better name please use it here.

[Hzj_jie, 2016/06/22 23:18:54]

Done.

+    /** Sends a mouse event. */
+    void sendMouseEvent(int x, int y, int whichButton, boolean buttonDown);
+
+    /** Sends a mouse wheel event. */
+    void sendMouseWheelEvent(int deltaX, int deltaY);
+
+    /**
+     * Sends a key event, and returns false if both scanCode and keyCode are not able to be
+     * converted to a known usb key code. Nothing will be sent to remote host, if this function
+     * returns false.
+     */
+    boolean sendKeyEvent(int scanCode, int keyCode, boolean keyDown);
+
+    /**
+     * Sends a string literal. This function is useful to handle outputs from Android input
+     * methods.
+     */
+    void sendTextEvent(String text);
+
+    /** Sends a set of {@link TouchEventData}. */
+    void sendTouchEvent(TouchEventData.EventType eventType, TouchEventData[] data);
+}