Block internal PlatformEvents before they are dispatched in touchview.

ui/events/platform/platform_event_source.h

 // Copyright 2014 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 UI_EVENTS_PLATFORM_PLATFORM_EVENT_SOURCE_H_
 #define UI_EVENTS_PLATFORM_PLATFORM_EVENT_SOURCE_H_
 
 #include <map>
 #include <vector>
 
 #include "base/auto_reset.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "ui/events/events_export.h"
 #include "ui/events/platform/platform_event_types.h"
 
 namespace ui {
 
 class Event;
 class PlatformEventDispatcher;
+class PlatformEventFilter;
 class PlatformEventObserver;
 class ScopedEventDispatcher;
 
 // PlatformEventSource receives events from a source and dispatches the events
 // to the appropriate dispatchers.
 class EVENTS_EXPORT PlatformEventSource {
  public:
   virtual ~PlatformEventSource();
 
   static PlatformEventSource* GetInstance();
@@ skipping 15 matching lines @@
   // The returned |ScopedEventDispatcher| object is a handler for the overridden
   // dispatcher. When this handler is destroyed, it removes the overridden
   // dispatcher, and restores the previous override-dispatcher (or NULL if there
   // wasn't any).
   scoped_ptr<ScopedEventDispatcher> OverrideDispatcher(
       PlatformEventDispatcher* dispatcher);
 
   void AddPlatformEventObserver(PlatformEventObserver* observer);
   void RemovePlatformEventObserver(PlatformEventObserver* observer);
 
+  void AddPlatformEventFilter(PlatformEventFilter* filter);
+  void RemovePlatformEventFilter(PlatformEventFilter* filter);
+
   static scoped_ptr<PlatformEventSource> CreateDefault();
 
  protected:
   PlatformEventSource();
 
   // Dispatches |platform_event| to the dispatchers. If there is an override
   // dispatcher installed using |OverrideDispatcher()|, then that dispatcher
   // receives the event first. |POST_DISPATCH_QUIT_LOOP| flag is set in the
   // returned value if the event-source should stop dispatching events at the
   // current message-loop iteration.
@@ skipping 18 matching lines @@
   // dispatchers, so that adding/removing dispatchers during an event dispatch
   // is well-defined.
   typedef ObserverList<PlatformEventDispatcher> PlatformEventDispatcherList;
   PlatformEventDispatcherList dispatchers_;
   PlatformEventDispatcher* overridden_dispatcher_;
 
   // Used to keep track of whether the current override-dispatcher has been
   // reset and a previous override-dispatcher has been restored.
   bool overridden_dispatcher_restored_;
 
+  // Use an ObserverList<> instead of an std::vector<> to store the list of
+  // filters as well, so that adding/removing filters during event filtering
+  // is well-defined.
+  typedef ObserverList<PlatformEventFilter> PlatformEventFilterList;
+  PlatformEventFilterList filters_;
+
   ObserverList<PlatformEventObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformEventSource);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_PLATFORM_PLATFORM_EVENT_SOURCE_H_