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// Copyright 2013 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.
#include "ui/events/event_processor.h"
#include "ui/events/event_target.h"
#include "ui/events/event_targeter.h"
namespace ui {
EventProcessor::EventProcessor() : weak_ptr_factory_(this) {}
EventProcessor::~EventProcessor() {}
EventDispatchDetails EventProcessor::OnEventFromSource(Event* event) {
base::WeakPtr<EventProcessor> weak_this = weak_ptr_factory_.GetWeakPtr();
// If |event| is in the process of being dispatched or has already been
// dispatched, then dispatch a copy of the event instead. We expect event
// target to be already set if event phase is after EP_PREDISPATCH.
bool dispatch_original_event = event->phase() == EP_PREDISPATCH;
DCHECK(dispatch_original_event || event->target());
Event* event_to_dispatch = event;
std::unique_ptr<Event> event_copy;
if (!dispatch_original_event) {
event_copy = Event::Clone(*event);
event_to_dispatch = event_copy.get();
}
EventDispatchDetails details;
OnEventProcessingStarted(event_to_dispatch);
// GetInitialEventTarget() may handle the event.
EventTarget* initial_target = event_to_dispatch->handled()
? nullptr
: GetInitialEventTarget(event_to_dispatch);
if (!event_to_dispatch->handled()) {
EventTarget* target = initial_target;
EventTargeter* targeter = nullptr;
if (!target) {
EventTarget* root = GetRootForEvent(event_to_dispatch);
DCHECK(root);
targeter = root->GetEventTargeter();
if (targeter) {
target = targeter->FindTargetForEvent(root, event_to_dispatch);
} else {
targeter = GetDefaultEventTargeter();
if (event_to_dispatch->target())
target = root;
else
target = targeter->FindTargetForEvent(root, event_to_dispatch);
}
DCHECK(targeter);
}
while (target) {
details = DispatchEvent(target, event_to_dispatch);
if (!dispatch_original_event) {
if (event_to_dispatch->stopped_propagation())
event->StopPropagation();
else if (event_to_dispatch->handled())
event->SetHandled();
}
if (details.dispatcher_destroyed)
return details;
if (!weak_this) {
details.dispatcher_destroyed = true;
return details;
}
if (details.target_destroyed || event->handled() ||
target == initial_target) {
break;
}
DCHECK(targeter);
target = targeter->FindNextBestTarget(target, event_to_dispatch);
}
}
OnEventProcessingFinished(event);
return details;
}
void EventProcessor::OnEventProcessingStarted(Event* event) {
}
void EventProcessor::OnEventProcessingFinished(Event* event) {
}
} // namespace ui
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