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 View* ViewTargeter::FindTargetForKeyEvent(View* root, const ui::KeyEvent& key) {
  71   if (root->GetFocusManager())
  72     return root->GetFocusManager()->GetFocusedView();
  73   return NULL;
  74 }
  75
  76 View* ViewTargeter::FindTargetForScrollEvent(View* root,
  77                                              const ui::ScrollEvent& scroll) {
  78   gfx::Rect rect(scroll.location(), gfx::Size(1, 1));
  79   return root->GetEffectiveViewTargeter()->TargetForRect(root, rect);
  80 }
  81
  82 View* ViewTargeter::FindTargetForGestureEvent(View* root,
  83                                               const ui::GestureEvent& gesture) {
  84   // TODO(tdanderson): The only code path that performs targeting for gestures
  85   //                   uses the ViewTargeter installed on the RootView (i.e.,
  86   //                   a RootViewTargeter). Provide a default implementation
  87   //                   here if we need to be able to perform gesture targeting
  88   //                   starting at an arbitrary node in a Views tree.
  89   NOTREACHED();
  90   return NULL;
  91 }
  92
  93 ui::EventTarget* ViewTargeter::FindNextBestTargetForGestureEvent(
  94     ui::EventTarget* previous_target,
  95     const ui::GestureEvent& gesture) {
  96   NOTREACHED();
  97   return NULL;
  98 }
  99
 100 }  // namespace views