client-side wheel mouse support

remoting/client/plugin/pepper_input_handler.cc

 // Copyright (c) 2011 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/client/plugin/pepper_input_handler.h"
 
 #include "ppapi/cpp/input_event.h"
 #include "ppapi/cpp/point.h"
 #include "remoting/client/plugin/pepper_view_proxy.h"
 
 namespace remoting {
 
-using pp::KeyboardInputEvent;
-using pp::MouseInputEvent;
-using protocol::KeyEvent;
 using protocol::MouseEvent;
 
 PepperInputHandler::PepperInputHandler(ClientContext* context,
                                        protocol::ConnectionToHost* connection,
                                        PepperViewProxy* view)
     : InputHandler(context, connection, view),
-      pepper_view_(view) {
+      pepper_view_(view),
+      wheel_ticks_x_(0),
+      wheel_ticks_y_(0) {
 }
 
 PepperInputHandler::~PepperInputHandler() {
 }
 
 void PepperInputHandler::Initialize() {
 }
 
 void PepperInputHandler::HandleKeyEvent(bool keydown,
                                         const pp::KeyboardInputEvent& event) {
@@ skipping 38 matching lines @@
     case PP_INPUTEVENT_MOUSEBUTTON_NONE:
       // Leave button undefined.
       break;
   }
 
   if (button != MouseEvent::BUTTON_UNDEFINED) {
     SendMouseButtonEvent(button_down, button);
   }
 }
 
+void PepperInputHandler::HandleMouseWheelEvent(
+    const pp::WheelInputEvent& event) {
+  pp::FloatPoint ticks = event.GetTicks();

[Lambros, 2011/10/14 21:00:25]

Can GetTicks() be negative?  You seem to have coded this as though it's always
non-negative.
If it can be negative, consider using trunc() from <math.h> or <cmath> which
guarantees to round towards zero (unlike static_cast<int>) but you'd probably
still need the static_cast<int> anyway since trunc() returns a double.

[Lambros, 2011/10/14 21:08:45]

Sorry, ignore my comment.  static_cast<int> does round toward zero, and your
code does works for -ve values :)

On 2011/10/14 21:00:25, Lambros wrote:

+  wheel_ticks_x_ += ticks.x();
+  wheel_ticks_y_ += ticks.y();
+  int ticks_x = static_cast<int>(wheel_ticks_x_);
+  int ticks_y = static_cast<int>(wheel_ticks_y_);
+  if (ticks_x != 0 || ticks_y != 0) {
+    wheel_ticks_x_ -= ticks_x;
+    wheel_ticks_y_ -= ticks_y;
+    SendMouseWheelEvent(ticks_x, ticks_y);
+  }
+}
+
 }  // namespace remoting