src/ui/views/view_targeter.cc

   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/view_targeter.h"
   6
   7 #include "ui/events/event_target.h"
   8 #include "ui/views/focus/focus_manager.h"
   9 #include "ui/views/view.h"
  10 #include "ui/views/view_targeter_delegate.h"
  11
  12 namespace views {
  13
  14 ViewTargeter::ViewTargeter(ViewTargeterDelegate* delegate)
  15     : delegate_(delegate) {
  16   DCHECK(delegate_);
  17 }
  18
  19 ViewTargeter::~ViewTargeter() {}
  20
  21 bool ViewTargeter::DoesIntersectRect(const View* target,
  22                                      const gfx::Rect& rect) const {
  23   return delegate_->DoesIntersectRect(target, rect);
  24 }
  25
  26 View* ViewTargeter::TargetForRect(View* root, const gfx::Rect& rect) const {
  27   return delegate_->TargetForRect(root, rect);
  28 }
  29
  30 ui::EventTarget* ViewTargeter::FindTargetForEvent(ui::EventTarget* root,
  31                                                   ui::Event* event) {
  32   View* view = static_cast<View*>(root);
  33
  34   if (event->IsKeyEvent())
  35     return FindTargetForKeyEvent(view, *static_cast<ui::KeyEvent*>(event));
  36
  37   if (event->IsScrollEvent()) {
  38     return FindTargetForScrollEvent(view,
  39                                     *static_cast<ui::ScrollEvent*>(event));
  40   }
  41
  42   if (event->IsGestureEvent()) {
  43     ui::GestureEvent* gesture = event->AsGestureEvent();
  44     View* gesture_target = FindTargetForGestureEvent(view, *gesture);
  45     root->ConvertEventToTarget(gesture_target, gesture);
  46     return gesture_target;
  47   }
  48
  49   NOTREACHED() << "ViewTargeter does not yet support this event type.";
  50   return NULL;
  51 }
  52
  53 ui::EventTarget* ViewTargeter::FindNextBestTarget(
  54     ui::EventTarget* previous_target,
  55     ui::Event* event) {
  56   if (!previous_target)
  57     return NULL;
  58
  59   if (event->IsGestureEvent()) {
  60     ui::GestureEvent* gesture = event->AsGestureEvent();
  61     ui::EventTarget* next_target =
  62         FindNextBestTargetForGestureEvent(previous_target, *gesture);
  63     previous_target->ConvertEventToTarget(next_target, gesture);
  64     return next_target;
  65   }
  66
  67   return previous_target->GetParentTarget();
  68 }
  69
  70 bool ViewTargeter::SubtreeCanAcceptEvent(
  71     ui::EventTarget* target,
  72     const ui::LocatedEvent& event) const {
  73   NOTREACHED();
  74   return false;
  75 }
  76
  77 bool ViewTargeter::EventLocationInsideBounds(
  78     ui::EventTarget* target,
  79     const ui::LocatedEvent& event) const {
  80   NOTREACHED();
  81   return false;
  82 }
  83
  84 View* ViewTargeter::FindTargetForKeyEvent(View* root, const ui::KeyEvent& key) {
  85   if (root->GetFocusManager())
  86     return root->GetFocusManager()->GetFocusedView();
  87   return NULL;
  88 }
  89
  90 View* ViewTargeter::FindTargetForScrollEvent(View* root,
  91                                              const ui::ScrollEvent& scroll) {
  92   gfx::Rect rect(scroll.location(), gfx::Size(1, 1));
  93   return root->GetEffectiveViewTargeter()->TargetForRect(root, rect);
  94 }
  95
  96 View* ViewTargeter::FindTargetForGestureEvent(View* root,
  97                                               const ui::GestureEvent& gesture) {
  98   // TODO(tdanderson): The only code path that performs targeting for gestures
  99   //                   uses the ViewTargeter installed on the RootView (i.e.,
 100   //                   a RootViewTargeter). Provide a default implementation
 101   //                   here if we need to be able to perform gesture targeting
 102   //                   starting at an arbitrary node in a Views tree.
 103   NOTREACHED();
 104   return NULL;
 105 }
 106
 107 ui::EventTarget* ViewTargeter::FindNextBestTargetForGestureEvent(
 108     ui::EventTarget* previous_target,
 109     const ui::GestureEvent& gesture) {
 110   NOTREACHED();
 111   return NULL;
 112 }
 113
 114 }  // namespace views