ui/events/event_processor.cc

   1 // Copyright 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 #include "ui/events/event_processor.h"
   6
   7 #include "ui/events/event_target.h"
   8 #include "ui/events/event_targeter.h"
   9
  10 namespace ui {
  11
  12 EventDispatchDetails EventProcessor::OnEventFromSource(Event* event) {
  13   EventTarget* root = GetRootTarget();
  14   CHECK(root);
  15   EventTargeter* targeter = root->GetEventTargeter();
  16   CHECK(targeter);
  17
  18   // If |event| is in the process of being dispatched or has already been
  19   // dispatched, then dispatch a copy of the event instead.
  20   bool dispatch_original_event = event->phase() == EP_PREDISPATCH;
  21   Event* event_to_dispatch = event;
  22   scoped_ptr<Event> event_copy;
  23   if (!dispatch_original_event) {
  24     event_copy = Event::Clone(*event);
  25     event_to_dispatch = event_copy.get();
  26   }
  27
  28   OnEventProcessingStarted(event_to_dispatch);
  29   EventTarget* target = NULL;
  30   if (!event_to_dispatch->handled())
  31     target = targeter->FindTargetForEvent(root, event_to_dispatch);
  32
  33   EventDispatchDetails details;
  34   while (target) {
  35     details = DispatchEvent(target, event_to_dispatch);
  36
  37     if (!dispatch_original_event) {
  38       if (event_to_dispatch->stopped_propagation())
  39         event->StopPropagation();
  40       else if (event_to_dispatch->handled())
  41         event->SetHandled();
  42     }
  43
  44     if (details.dispatcher_destroyed)
  45       return details;
  46
  47     if (details.target_destroyed || event->handled())
  48       break;
  49
  50     target = targeter->FindNextBestTarget(target, event_to_dispatch);
  51   }
  52
  53   OnEventProcessingFinished(event);
  54   return details;
  55 }
  56
  57 void EventProcessor::OnEventProcessingStarted(Event* event) {
  58 }
  59
  60 void EventProcessor::OnEventProcessingFinished(Event* event) {
  61 }
  62
  63 }  // namespace ui