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

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
===================================================================
--- content/browser/renderer_host/render_widget_host_view_aura.cc	(revision 231601)
+++ content/browser/renderer_host/render_widget_host_view_aura.cc	(working copy)
@@ -71,6 +71,7 @@
 #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"
@@ -2194,6 +2195,10 @@
   }
   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;
 }
 
@@ -2218,6 +2223,9 @@
   if (aura::client::GetTooltipClient(root_window))
     aura::client::GetTooltipClient(root_window)->SetTooltipsEnabled(true);
 
+#if defined(OS_WIN)
+  ::ClipCursor(NULL);
+#endif
   host_->LostMouseLock();
 }
 
@@ -2730,9 +2738,19 @@
       return;
     }
 
-    WebKit::WebMouseEvent mouse_event = MakeWebMouseEvent(event);
     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);
+
     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();