src/ash/drag_drop/drag_drop_tracker.cc

   1 // Copyright (c) 2012 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 "ash/drag_drop/drag_drop_tracker.h"
   6
   7 #include "ash/shell.h"
   8 #include "ash/shell_window_ids.h"
   9 #include "ash/wm/coordinate_conversion.h"
  10 #include "ui/aura/client/activation_delegate.h"
  11 #include "ui/aura/client/window_tree_client.h"
  12 #include "ui/aura/root_window.h"
  13 #include "ui/aura/window.h"
  14 #include "ui/events/event.h"
  15 #include "ui/gfx/screen.h"
  16
  17 namespace ash {
  18 namespace internal {
  19
  20 namespace {
  21
  22 // An activation delegate which disables activating the drag and drop window.
  23 class CaptureWindowActivationDelegate
  24     : public aura::client::ActivationDelegate {
  25  public:
  26   CaptureWindowActivationDelegate() {}
  27   virtual ~CaptureWindowActivationDelegate() {}
  28
  29   // aura::client::ActivationDelegate overrides:
  30   virtual bool ShouldActivate() const OVERRIDE {
  31     return false;
  32   }
  33
  34  private:
  35
  36   DISALLOW_COPY_AND_ASSIGN(CaptureWindowActivationDelegate);
  37 };
  38
  39 // Creates a window for capturing drag events.
  40 aura::Window* CreateCaptureWindow(aura::Window* context_root,
  41                                   aura::WindowDelegate* delegate) {
  42   static CaptureWindowActivationDelegate* activation_delegate_instance = NULL;
  43   if (!activation_delegate_instance)
  44     activation_delegate_instance = new CaptureWindowActivationDelegate;
  45   aura::Window* window = new aura::Window(delegate);
  46   window->SetType(ui::wm::WINDOW_TYPE_NORMAL);
  47   window->Init(aura::WINDOW_LAYER_NOT_DRAWN);
  48   aura::client::ParentWindowWithContext(window, context_root, gfx::Rect());
  49   aura::client::SetActivationDelegate(window, activation_delegate_instance);
  50   window->Show();
  51   DCHECK(window->bounds().size().IsEmpty());
  52   return window;
  53 }
  54
  55 }  // namespace
  56
  57 DragDropTracker::DragDropTracker(aura::Window* context_root,
  58                                  aura::WindowDelegate* delegate)
  59     : capture_window_(CreateCaptureWindow(context_root, delegate)) {
  60 }
  61
  62 DragDropTracker::~DragDropTracker()  {
  63   capture_window_->ReleaseCapture();
  64 }
  65
  66 void DragDropTracker::TakeCapture() {
  67   capture_window_->SetCapture();
  68 }
  69
  70 aura::Window* DragDropTracker::GetTarget(const ui::LocatedEvent& event) {
  71   DCHECK(capture_window_.get());
  72   gfx::Point location_in_screen = event.location();
  73   wm::ConvertPointToScreen(capture_window_.get(),
  74                            &location_in_screen);
  75   aura::Window* root_window_at_point =
  76       wm::GetRootWindowAt(location_in_screen);
  77   gfx::Point location_in_root = location_in_screen;
  78   wm::ConvertPointFromScreen(root_window_at_point, &location_in_root);
  79   return root_window_at_point->GetEventHandlerForPoint(location_in_root);
  80 }
  81
  82 ui::LocatedEvent* DragDropTracker::ConvertEvent(
  83     aura::Window* target,
  84     const ui::LocatedEvent& event) {
  85   DCHECK(capture_window_.get());
  86   gfx::Point target_location = event.location();
  87   aura::Window::ConvertPointToTarget(capture_window_.get(), target,
  88                                      &target_location);
  89   gfx::Point location_in_screen = event.location();
  90   ash::wm::ConvertPointToScreen(capture_window_.get(), &location_in_screen);
  91   gfx::Point target_root_location = event.root_location();
  92   aura::Window::ConvertPointToTarget(
  93       capture_window_->GetRootWindow(),
  94       ash::wm::GetRootWindowAt(location_in_screen),
  95       &target_root_location);
  96   return new ui::MouseEvent(event.type(),
  97                             target_location,
  98                             target_root_location,
  99                             event.flags(),
 100                             static_cast<const ui::MouseEvent&>(event).
 101                                 changed_button_flags());
 102 }
 103
 104 }  // namespace internal
 105 }  // namespace ash