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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ui/views/widget/root_view_targeter.h"
#include "ui/views/view.h"
#include "ui/views/view_targeter_delegate.h"
#include "ui/views/views_switches.h"
#include "ui/views/widget/root_view.h"
#include "ui/views/widget/widget.h"
namespace views {
RootViewTargeter::RootViewTargeter(ViewTargeterDelegate* delegate,
internal::RootView* root_view)
: ViewTargeter(delegate), root_view_(root_view) {}
RootViewTargeter::~RootViewTargeter() = default;
View* RootViewTargeter::FindTargetForGestureEvent(
View* root,
const ui::GestureEvent& gesture) {
CHECK_EQ(root, root_view_);
// Return the default gesture handler if one is already set.
if (root_view_->gesture_handler_) {
CHECK(root_view_->gesture_handler_set_before_processing_);
return root_view_->gesture_handler_;
}
// If non-empty, use the gesture's bounding box to determine the target.
// Otherwise use the center point of the gesture's bounding box.
gfx::Rect rect(gesture.location(), gfx::Size(1, 1));
if (!gesture.details().bounding_box().IsEmpty()) {
// TODO(tdanderson): Pass in the bounding box to GetEventHandlerForRect()
// once crbug.com/313392 is resolved.
rect.set_size(gesture.details().bounding_box().size());
rect.Offset(-rect.width() / 2, -rect.height() / 2);
}
return root->GetEffectiveViewTargeter()->TargetForRect(root, rect);
}
ui::EventTarget* RootViewTargeter::FindNextBestTargetForGestureEvent(
ui::EventTarget* previous_target,
const ui::GestureEvent& gesture) {
// EventType::kGestureEnd events should only ever be targeted to the default
// gesture handler set by a previous gesture, if one exists. Thus we do not
// permit any re-targeting of EventType::kGestureEnd events.
if (gesture.type() == ui::EventType::kGestureEnd) {
return nullptr;
}
// Prohibit re-targeting of gesture events (except for GESTURE_SCROLL_BEGIN
// events) if the default gesture handler was set by the dispatch of a
// previous gesture event.
if (root_view_->gesture_handler_set_before_processing_ &&
gesture.type() != ui::EventType::kGestureScrollBegin) {
return nullptr;
}
// If |gesture_handler_| is NULL, it is either because the view was removed
// from the tree by the previous dispatch of |gesture| or because |gesture| is
// the GESTURE_END event corresponding to the removal of the last touch
// point. In either case, no further re-targeting of |gesture| should be
// permitted.
if (!root_view_->gesture_handler_) {
return nullptr;
}
return previous_target->GetParentTarget();
}
} // namespace views
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