Desktop Aura: Allow tab drags out of window.

base/message_pump_aurax11.h

 // 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.
 
 #ifndef BASE_MESSAGE_PUMP_AURAX11_H
 #define BASE_MESSAGE_PUMP_AURAX11_H
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_pump.h"
 #include "base/message_pump_glib.h"
 #include "base/message_pump_dispatcher.h"
 #include "base/message_pump_observer.h"
 
 #include <bitset>
 
+// It would be nice to include the X11 headers here so that we use Window
+// instead of its typedef of unsigned long, but we can't because everything in
+// chrome includes us through base/message_loop.h, and X11's crappy #define
+// heavy headers muck up half of chrome.
+
 typedef struct _GPollFD GPollFD;
 typedef struct _GSource GSource;
 typedef struct _XDisplay Display;
 
 namespace base {
 
 // This class implements a message-pump for dispatching X events.
 class BASE_EXPORT MessagePumpAuraX11 : public MessagePumpGlib {
  public:
   MessagePumpAuraX11();
 
   // Returns default X Display.
   static Display* GetDefaultXDisplay();
 
   // Returns true if the system supports XINPUT2.
   static bool HasXInput2();
 
   // Sets the default dispatcher to process native events.
   static void SetDefaultDispatcher(MessagePumpDispatcher* dispatcher);
 
+  // Returns the UI message pump.
+  static MessagePumpAuraX11* Current();
+
   // Internal function. Called by the glib source dispatch function. Processes
   // all available X events.
   bool DispatchXEvents();
 
+  // Blocks on the X11 event queue until we receive notification from the
+  // xserver that |w| has been mapped; StructureNotifyMask events on |w| are
+  // pulled out from the queue and dispatched out of order.
+  //
+  // For those that know X11, this is really a wrapper around XWindowEvent
+  // which still makes sure the preempted event is dispatched instead of
+  // dropped on the floor. This method exists because mapping a window is
+  // asynchronous (and we receive an XEvent when mapped), while there are also
+  // functions which require a mapped window.
+  void BlockUntilWindowMapped(unsigned long window);
+
  protected:
   virtual ~MessagePumpAuraX11();
 
  private:
   // Initializes the glib event source for X.
   void InitXSource();
 
   // Dispatches the XEvent and returns true if we should exit the current loop
   // of message processing.
   bool ProcessXEvent(MessagePumpDispatcher* dispatcher, XEvent* event);
@@ skipping 11 matching lines @@
   scoped_ptr<GPollFD> x_poll_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpAuraX11);
 };
 
 typedef MessagePumpAuraX11 MessagePumpForUI;
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_PUMP_AURAX11_H