ui/events/ozone/event_factory_ozone.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_EVENTS_OZONE_EVENT_FACTORY_OZONE_H_
   6 #define UI_EVENTS_OZONE_EVENT_FACTORY_OZONE_H_
   7
   8 #include <map>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/message_loop/message_pump_libevent.h"
  12 #include "base/task_runner.h"
  13 #include "ui/events/events_export.h"
  14
  15 namespace ui {
  16
  17 class Event;
  18
  19 // Creates and dispatches |ui.Event|'s. Ozone assumes that events arrive on file
  20 // descriptors with one  |EventConverterOzone| instance for each descriptor.
  21 // Ozone presumes that the set of file desctiprtors can vary at runtime so this
  22 // class supports dynamically adding and removing |EventConverterOzone|
  23 // instances as necessary.
  24 class EVENTS_EXPORT EventFactoryOzone {
  25  public:
  26   EventFactoryOzone();
  27   virtual ~EventFactoryOzone();
  28
  29   // Called from WindowTreeHostOzone to initialize and start processing events.
  30   // This should create the initial set of converters, and potentially arrange
  31   // for more converters to be created as new event sources become available.
  32   // No events processing should happen until this is called. All processes have
  33   // an EventFactoryOzone but not all of them should process events. In chrome,
  34   // events are dispatched in the browser process on the UI thread.
  35   virtual void StartProcessingEvents();
  36
  37   // Sets the TaskRunner to use for file I/O. The thread that calls
  38   // StartProcessingEvents() should only be used for I/O that is critical
  39   // to event dispatching.
  40   virtual void SetFileTaskRunner(scoped_refptr<base::TaskRunner> task_runner);
  41
  42   // Returns the static instance last set using SetInstance().
  43   static EventFactoryOzone* GetInstance();
  44
  45   // Sets the implementation delegate. Ownership is retained by the caller.
  46   static void SetInstance(EventFactoryOzone*);
  47
  48   // Subclasses should use this method to post a task that will dispatch
  49   // |event| from the UI message loop. This method takes ownership of
  50   // |event|. |event| will be deleted at the end of the posted task.
  51   static void DispatchEvent(scoped_ptr<ui::Event> event);
  52
  53  private:
  54   static EventFactoryOzone* impl_;  // not owned
  55
  56   DISALLOW_COPY_AND_ASSIGN(EventFactoryOzone);
  57 };
  58
  59 }  // namespace ui
  60
  61 #endif  // UI_EVENTS_OZONE_EVENT_FACTORY_OZONE_H_