Mouse lock implementation, including the renderer side and the Windows version of the browser side.

content/browser/renderer_host/render_widget_host_view_win.h

 // 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_WIN_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_WIN_H_
 #pragma once
 
 #include <atlbase.h>
 #include <atlapp.h>
@@ skipping 160 matching lines @@
       const WebKit::WebMouseWheelEvent& event) OVERRIDE;
   virtual void SetHasHorizontalScrollbar(
       bool has_horizontal_scrollbar) OVERRIDE;
   virtual void SetScrollOffsetPinning(
       bool is_pinned_to_left, bool is_pinned_to_right) OVERRIDE;
   virtual gfx::PluginWindowHandle GetCompositingSurface() OVERRIDE;
   virtual void ShowCompositorHostWindow(bool show) OVERRIDE;
   virtual void OnAccessibilityNotifications(
       const std::vector<ViewHostMsg_AccessibilityNotification_Params>& params
       ) OVERRIDE;
+  virtual bool LockMouse() OVERRIDE;
+  virtual void UnlockMouse() OVERRIDE;
 
   // Implementation of NotificationObserver:
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
   // Implementation of BrowserAccessibilityDelegate:
   virtual void SetAccessibilityFocus(int acc_obj_id) OVERRIDE;
   virtual void AccessibilityDoDefaultAction(int acc_obj_id) OVERRIDE;
 
@@ skipping 90 matching lines @@
   void CleanupCompositorWindow();
 
   // Whether the window should be activated.
   bool IsActivatable() const;
 
   // Do initialization needed by both InitAsPopup() and InitAsFullscreen().
   void DoPopupOrFullscreenInit(HWND parent_hwnd,
                                const gfx::Rect& pos,
                                DWORD ex_style);
 
+  CPoint GetClientCenter() const;
+  void MoveCursorToCenter() const;
+
+  void HandleLockedMouseEvent(UINT message, WPARAM wparam, LPARAM lparam);
+
   // The associated Model.  While |this| is being Destroyed,
   // |render_widget_host_| is NULL and the Windows message loop is run one last
   // time. Message handlers must check for a NULL |render_widget_host_|.
   RenderWidgetHost* render_widget_host_;
 
   // When we are doing accelerated compositing
   HWND compositor_host_window_;
 
   // true if the compositor host window must be hidden after the
   // software renderered view is updated.
@@ skipping 75 matching lines @@
 
   // Stores the current text input type received by ImeUpdateTextInputState()
   // method.
   ui::TextInputType text_input_type_;
 
   ScopedVector<ui::ViewProp> props_;
 
   // Is the widget fullscreen?
   bool is_fullscreen_;
 
+  // Used to record the last position of the mouse.
+  // While the mouse is locked, they store the last known position just as mouse
+  // lock was entered.
+  // Relative to the upper-left corner of the view.
+  int last_x_;

[brettw, 2011/09/14 22:17:58]

Can you use a gfx::Point for both of these cases? It will handle initialization
to 0 in the constructor and also remove one extra member variable. Maybe you
could even use end-of-line comments for the "Relative to..." comments and then
everything is only 2 lines.

[yzshen1, 2011/09/19 20:48:41]

Done. (Didn't use end-of-line comments because I cannot fit them in the same
line as the definitions now.)

+  int last_y_;
+  // Relative to the upper-left corner of the screen.
+  int last_global_x_;
+  int last_global_y_;
+
+  // In the case of the mouse being moved away from the view and then moved
+  // back, we regard the mouse movement as (0, 0).
+  bool ignore_mouse_movement_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewWin);
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_WIN_H_