Implementing accelerators for Linux toolkit_views

base/message_pump_glib.h

 // Copyright (c) 2008 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_GLIB_H_
 #define BASE_MESSAGE_PUMP_GLIB_H_
 
 #include <gtk/gtk.h>
 #include <glib.h>
 
@@ skipping 13 matching lines @@
    public:
     virtual ~Observer() {}
 
     // This method is called before processing a message.
     virtual void WillProcessEvent(GdkEvent* event) = 0;
 
     // This method is called after processing a message.
     virtual void DidProcessEvent(GdkEvent* event) = 0;
   };
 
+  // Dispatcher is used during a nested invocation of Run to dispatch events.
+  // If Run is invoked with a non-NULL Dispatcher, MessageLoop does not
+  // dispatch events (or invoke gtk_main_do_event), rather every event is
+  // passed to Dispatcher's Dispatch method for dispatch. It is up to the
+  // Dispatcher to dispatch, or not, the event.
+  //
+  // The nested loop is exited by either posting a quit, or returning false
+  // from Dispatch.
+  class Dispatcher {
+   public:
+    virtual ~Dispatcher() {}
+    // Dispatches the event. If true is returned processing continues as
+    // normal. If false is returned, the nested loop exits immediately.
+    virtual bool Dispatch(GdkEvent* event) = 0;
+  };
+
   MessagePumpForUI();
-  ~MessagePumpForUI();
+  virtual ~MessagePumpForUI();
 
-  virtual void Run(Delegate* delegate);
+  // Like MessagePump::Run, but GdkEvent objects are routed through dispatcher.
+  virtual void RunWithDispatcher(Delegate* delegate, Dispatcher* dispatcher);
+
+  virtual void Run(Delegate* delegate) { RunWithDispatcher(delegate, NULL); }
   virtual void Quit();
   virtual void ScheduleWork();
   virtual void ScheduleDelayedWork(const Time& delayed_work_time);
 
   // Internal methods used for processing the pump callbacks.  They are
   // public for simplicity but should not be used directly.  HandlePrepare
   // is called during the prepare step of glib, and returns a timeout that
   // will be passed to the poll. HandleCheck is called after the poll
   // has completed, and returns whether or not HandleDispatch should be called.
   // HandleDispatch is called if HandleCheck returned true.
   int HandlePrepare();
   bool HandleCheck();
   void HandleDispatch();
 
-  // Add an Observer, which will start receiving notifications immediately.
+  // Adds an Observer, which will start receiving notifications immediately.
   void AddObserver(Observer* observer);
 
-  // Remove an Observer.  It is safe to call this method while an Observer is
+  // Removes an Observer.  It is safe to call this method while an Observer is
   // receiving a notification callback.
   void RemoveObserver(Observer* observer);
 
  private:
   // We may make recursive calls to Run, so we save state that needs to be
   // separate between them in this structure type.
   struct RunState {
     Delegate* delegate;
+    Dispatcher* dispatcher;
 
     // Used to flag that the current Run() invocation should return ASAP.
     bool should_quit;
 
     // Used to count how many Run() invocations are on the stack.
     int run_depth;
 
     // This keeps the state of whether the pump got signaled that there was new
     // work to be done. Since we eat the message on the wake up pipe as soon as
     // we get it, we keep that state here to stay consistent.
@@ skipping 35 matching lines @@
 
   // List of observers.
   ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpForUI);
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_PUMP_GLIB_H_