Ensure on Windows AURA that the cursor stays within the bounds of the window during a LockMouse ope…

content/browser/renderer_host/render_widget_host_view_aura.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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
@@ skipping 53 matching lines @@
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/compositor/layer.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/gestures/gesture_recognizer.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/display.h"
+#include "ui/gfx/rect.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/skia_util.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #include "content/browser/accessibility/browser_accessibility_manager_win.h"
 #include "content/browser/accessibility/browser_accessibility_win.h"
 #include "ui/base/win/hidden_window.h"
@@ skipping 2103 matching lines @@
     cursor_client->HideCursor();
     cursor_client->LockCursor();
   }
 
   if (ShouldMoveToCenter()) {
     synthetic_move_sent_ = true;
     window_->MoveCursorTo(gfx::Rect(window_->bounds().size()).CenterPoint());
   }
   if (aura::client::GetTooltipClient(root_window))
     aura::client::GetTooltipClient(root_window)->SetTooltipsEnabled(false);
+#if defined(OS_WIN)
+  RECT window_rect = window_->GetBoundsInScreen().ToRECT();
+  ::ClipCursor(&window_rect);

[scheib, 2013/10/30 18:16:45]

Yes, clipping to the window is necessary. It's also necessary on window
resizing. See render_widget_host_view_win [1]. I'm unsure about a platform
#ifdef here though? I don't know aura, but is clipping not already abstracted,
or if not shouldn't it be?

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/re...

[ananta, 2013/10/30 20:47:29]

Good point. We have the ConfineCursorToWindow and UnConfineCursor functions on
the RootWindowHost interface. Moved this logic there.

+#endif
   return true;
 }
 
 void RenderWidgetHostViewAura::UnlockMouse() {
   aura::Window* root_window = window_->GetRootWindow();
   if (!mouse_locked_ || !root_window)
     return;
 
   mouse_locked_ = false;
 
 #if !defined(OS_WIN)
   window_->ReleaseCapture();
 #endif
   window_->MoveCursorTo(unlocked_mouse_position_);
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(root_window);
   if (cursor_client) {
     cursor_client->UnlockCursor();
     cursor_client->ShowCursor();
   }
 
   if (aura::client::GetTooltipClient(root_window))
     aura::client::GetTooltipClient(root_window)->SetTooltipsEnabled(true);
 
+#if defined(OS_WIN)
+  ::ClipCursor(NULL);
+#endif
   host_->LostMouseLock();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewAura, ui::TextInputClient implementation:
 void RenderWidgetHostViewAura::SetCompositionText(
     const ui::CompositionText& composition) {
   if (!host_)
     return;
 
@@ skipping 492 matching lines @@
     DCHECK(!cursor_client || !cursor_client->IsCursorVisible());
 
     if (event->type() == ui::ET_MOUSEWHEEL) {
       WebKit::WebMouseWheelEvent mouse_wheel_event =
           MakeWebMouseWheelEvent(static_cast<ui::MouseWheelEvent*>(event));
       if (mouse_wheel_event.deltaX != 0 || mouse_wheel_event.deltaY != 0)
         host_->ForwardWheelEvent(mouse_wheel_event);
       return;
     }
 
+    gfx::Point center(gfx::Rect(window_->bounds().size()).CenterPoint());
+
+    // If we receive non client mouse messages while we are in the locked state
+    // it probably means that the mouse left the borders of our window and
+    // needs to be moved back to the center.
+    if (event->flags() & ui::EF_IS_NON_CLIENT) {

[scheib, 2013/10/30 18:16:45]

I can't comment here because I don't understand NON CLIENT. The enum is not
documented, and its name+context alone isn't descriptive enough for me to
understand.

+      synthetic_move_sent_ = true;
+      window_->MoveCursorTo(center);
+      return;
+    }
+
     WebKit::WebMouseEvent mouse_event = MakeWebMouseEvent(event);
-    gfx::Point center(gfx::Rect(window_->bounds().size()).CenterPoint());
 
     bool is_move_to_center_event = (event->type() == ui::ET_MOUSE_MOVED ||
         event->type() == ui::ET_MOUSE_DRAGGED) &&
         mouse_event.x == center.x() && mouse_event.y == center.y();
 
     ModifyEventMovementAndCoords(&mouse_event);
 
     bool should_not_forward = is_move_to_center_event && synthetic_move_sent_;
     if (should_not_forward) {
       synthetic_move_sent_ = false;
@@ skipping 680 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content