1// Copyright 2014 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/views/widget/root_view_targeter.h" 6 7#include "ui/views/view.h" 8#include "ui/views/view_targeter_delegate.h" 9#include "ui/views/views_switches.h" 10#include "ui/views/widget/root_view.h" 11#include "ui/views/widget/widget.h" 12 13namespace views { 14 15RootViewTargeter::RootViewTargeter(ViewTargeterDelegate* delegate, 16 internal::RootView* root_view) 17 : ViewTargeter(delegate), root_view_(root_view) { 18} 19 20RootViewTargeter::~RootViewTargeter() { 21} 22 23View* RootViewTargeter::FindTargetForGestureEvent( 24 View* root, 25 const ui::GestureEvent& gesture) { 26 CHECK_EQ(root, root_view_); 27 28 // Return the default gesture handler if one is already set. 29 if (root_view_->gesture_handler_) { 30 CHECK(root_view_->gesture_handler_set_before_processing_); 31 return root_view_->gesture_handler_; 32 } 33 34 // If no default gesture handler has already been set, do not perform any 35 // targeting for a ET_GESTURE_END event. 36 if (gesture.type() == ui::ET_GESTURE_END) 37 return NULL; 38 39 // If rect-based targeting is enabled, use the gesture's bounding box to 40 // determine the target. Otherwise use the center point of the gesture's 41 // bounding box to determine the target. 42 gfx::Rect rect(gesture.location(), gfx::Size(1, 1)); 43 if (views::switches::IsRectBasedTargetingEnabled() && 44 !gesture.details().bounding_box().IsEmpty()) { 45 // TODO(tdanderson): Pass in the bounding box to GetEventHandlerForRect() 46 // once crbug.com/313392 is resolved. 47 rect.set_size(gesture.details().bounding_box().size()); 48 rect.Offset(-rect.width() / 2, -rect.height() / 2); 49 } 50 51 return root->GetEffectiveViewTargeter()->TargetForRect(root, rect); 52} 53 54ui::EventTarget* RootViewTargeter::FindNextBestTargetForGestureEvent( 55 ui::EventTarget* previous_target, 56 const ui::GestureEvent& gesture) { 57 // ET_GESTURE_END events should only ever be targeted to the default 58 // gesture handler set by a previous gesture, if one exists. Thus we do not 59 // permit any re-targeting of ET_GESTURE_END events. 60 if (gesture.type() == ui::ET_GESTURE_END) 61 return NULL; 62 63 // Prohibit re-targeting of gesture events (except for GESTURE_SCROLL_BEGIN 64 // events) if the default gesture handler was set by the dispatch of a 65 // previous gesture event. 66 if (root_view_->gesture_handler_set_before_processing_ && 67 gesture.type() != ui::ET_GESTURE_SCROLL_BEGIN) { 68 return NULL; 69 } 70 71 // If |gesture_handler_| is NULL, it is either because the view was removed 72 // from the tree by the previous dispatch of |gesture| or because |gesture| is 73 // the GESTURE_END event corresponding to the removal of the last touch 74 // point. In either case, no further re-targeting of |gesture| should be 75 // permitted. 76 if (!root_view_->gesture_handler_) 77 return NULL; 78 79 return previous_target->GetParentTarget(); 80} 81 82} // namespace views 83