Added support of relative mouse motion in Chromoting.

remoting/host/input_injector_win.cc

 // Copyright (c) 2012 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.
 
 #include "remoting/host/input_injector.h"
 
 #include <windows.h>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 201 matching lines @@
     input.ki.dwFlags |= KEYEVENTF_EXTENDEDKEY;
 
   if (SendInput(1, &input, sizeof(INPUT)) == 0)
     LOG_GETLASTERROR(ERROR) << "Failed to inject a key event";
 }
 
 void InputInjectorWin::Core::HandleMouse(const MouseEvent& event) {
   // Reset the system idle suspend timeout.
   SetThreadExecutionState(ES_SYSTEM_REQUIRED);
 
-  // TODO(garykac) Collapse mouse (x,y) and button events into a single
+  // TODO(garykac) Collapse mouse movement and button events into a single
   // input event when possible.
-  if (event.has_x() && event.has_y()) {
-    int x = event.x();
-    int y = event.y();
-
+  if (event.has_delta_x() && event.has_delta_y()) {
+    INPUT input;
+    input.type = INPUT_MOUSE;
+    input.mi.time = 0;
+    input.mi.dx = event.delta_x();
+    input.mi.dy = event.delta_y();
+    input.mi.dwFlags = MOUSEEVENTF_MOVE | MOUSEEVENTF_VIRTUALDESK;
+    if (SendInput(1, &input, sizeof(INPUT)) == 0)

[Wez, 2013/09/05 20:24:45]

How does this interact with mouse acceleration?

[alexeypa (please no reviews), 2013/09/06 20:00:17]

MSDN:

Relative mouse motion is subject to the effects of the mouse speed and the
two-mouse threshold values. A user sets these three values with the Pointer
Speed slider of the Control Panel's Mouse Properties sheet. You can obtain and
set these values using the SystemParametersInfo function.

+      LOG_GETLASTERROR(ERROR) << "Failed to inject a mouse move event";
+  } else if (event.has_x() && event.has_y()) {
     INPUT input;
     input.type = INPUT_MOUSE;
     input.mi.time = 0;
     SkISize screen_size(SkISize::Make(GetSystemMetrics(SM_CXVIRTUALSCREEN),
                                       GetSystemMetrics(SM_CYVIRTUALSCREEN)));
     if ((screen_size.width() > 1) && (screen_size.height() > 1)) {
-      x = std::max(0, std::min(screen_size.width(), x));
-      y = std::max(0, std::min(screen_size.height(), y));
+      int x = std::max(0, std::min(screen_size.width(), event.x()));
+      int y = std::max(0, std::min(screen_size.height(), event.y()));
       input.mi.dx = static_cast<int>((x * 65535) / (screen_size.width() - 1));
       input.mi.dy = static_cast<int>((y * 65535) / (screen_size.height() - 1));
       input.mi.dwFlags =
           MOUSEEVENTF_MOVE | MOUSEEVENTF_ABSOLUTE | MOUSEEVENTF_VIRTUALDESK;
       if (SendInput(1, &input, sizeof(INPUT)) == 0)
         LOG_GETLASTERROR(ERROR) << "Failed to inject a mouse move event";
     }
   }
 
   int wheel_delta_x = 0;
@@ skipping 64 matching lines @@
 }  // namespace
 
 scoped_ptr<InputInjector> InputInjector::Create(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
   return scoped_ptr<InputInjector>(
       new InputInjectorWin(main_task_runner, ui_task_runner));
 }
 
 }  // namespace remoting