[Chromoting] Add InputInjector and InputInjectorWrapper for easy unittesting

remoting/android/java/src/org/chromium/chromoting/InputStub.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 InputEventSender} 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 InputStub {
+    // These constants must match those in the generated struct protocol::MouseEvent_MouseButton.
+    public static final int BUTTON_UNDEFINED = 0;
+    public static final int BUTTON_LEFT = 1;
+    public static final int BUTTON_MIDDLE = 2;
+    public static final int BUTTON_RIGHT = 3;
+
+    /** 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);
+}