Move cursor when it's hidden so that UX can update correctly

ui/aura/env.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 "ui/aura/env.h"
 
 #include "base/command_line.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env_observer.h"
 #include "ui/aura/event_filter.h"
@@ skipping 10 matching lines @@
 namespace aura {
 
 // static
 Env* Env::instance_ = NULL;
 
 ////////////////////////////////////////////////////////////////////////////////
 // Env, public:
 
 Env::Env()
     : mouse_button_flags_(0),
+      is_cursor_hidden_(false),
       is_touch_down_(false),
       render_white_bg_(true),
       stacking_client_(NULL) {
 }
 
 Env::~Env() {
   ui::Compositor::Terminate();
 }
 
 // static
@@ skipping 21 matching lines @@
 
 void Env::SetLastMouseLocation(const Window& window,
                                const gfx::Point& location_in_root) {
   last_mouse_location_ = location_in_root;
   client::ScreenPositionClient* client =
       client::GetScreenPositionClient(window.GetRootWindow());
   if (client)
     client->ConvertPointToScreen(&window, &last_mouse_location_);
 }
 
+void Env::SetCursorShown(bool cursor_shown) {
+  if (cursor_shown) {
+    // Protect against restoring a position that hadn't been saved.
+    if (is_cursor_hidden_)
+      last_mouse_location_ = hidden_cursor_location_;
+    is_cursor_hidden_ = false;
+  } else {
+    hidden_cursor_location_ = last_mouse_location_;
+    last_mouse_location_ = gfx::Point(-10000, -10000);

[sky, 2012/08/14 16:01:00]

Won't this cause all sorts of weirdness if the hide occurs during a mouse drag
or something?

+    is_cursor_hidden_ = true;
+  }
+}
+
 void Env::SetDisplayManager(DisplayManager* display_manager) {
   display_manager_.reset(display_manager);
 #if defined(USE_X11)
   // Update the display manager with latest info.
   display_change_observer_->NotifyDisplayChange();
 #endif
 }
 
 void Env::SetEventFilter(EventFilter* event_filter) {
   event_filter_.reset(event_filter);
@@ skipping 18 matching lines @@
   ui::Compositor::Initialize(
       CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kUIEnableThreadedCompositing));
 }
 
 void Env::NotifyWindowInitialized(Window* window) {
   FOR_EACH_OBSERVER(EnvObserver, observers_, OnWindowInitialized(window));
 }
 
 }  // namespace aura