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/window_tree_client.h"
  11 #include "ui/aura/window.h"
  12 #include "ui/aura/window_event_dispatcher.h"
  13 #include "ui/events/event.h"
  14 #include "ui/events/event_utils.h"
  15 #include "ui/gfx/screen.h"
  16 #include "ui/wm/core/coordinate_conversion.h"
  17 #include "ui/wm/public/activation_delegate.h"
  18
  19 namespace ash {
  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   ~CaptureWindowActivationDelegate() override {}
  28
  29   // aura::client::ActivationDelegate overrides:
  30   bool ShouldActivate() const override { return false; }
  31
  32  private:
  33
  34   DISALLOW_COPY_AND_ASSIGN(CaptureWindowActivationDelegate);
  35 };
  36
  37 // Creates a window for capturing drag events.
  38 aura::Window* CreateCaptureWindow(aura::Window* context_root,
  39                                   aura::WindowDelegate* delegate) {
  40   static CaptureWindowActivationDelegate* activation_delegate_instance = NULL;
  41   if (!activation_delegate_instance)
  42     activation_delegate_instance = new CaptureWindowActivationDelegate;
  43   aura::Window* window = new aura::Window(delegate);
  44   // Set type of window as popup to prevent different window manager codes
  45   // trying to manage this window.
  46   window->SetType(ui::wm::WINDOW_TYPE_POPUP);
  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(), &location_in_screen);
  74   aura::Window* root_window_at_point =
  75       wm::GetRootWindowAt(location_in_screen);
  76   gfx::Point location_in_root = location_in_screen;
  77   ::wm::ConvertPointFromScreen(root_window_at_point, &location_in_root);
  78   return root_window_at_point->GetEventHandlerForPoint(location_in_root);
  79 }
  80
  81 ui::LocatedEvent* DragDropTracker::ConvertEvent(
  82     aura::Window* target,
  83     const ui::LocatedEvent& event) {
  84   DCHECK(capture_window_.get());
  85   gfx::Point target_location = event.location();
  86   aura::Window::ConvertPointToTarget(capture_window_.get(), target,
  87                                      &target_location);
  88   gfx::Point location_in_screen = event.location();
  89   ::wm::ConvertPointToScreen(capture_window_.get(), &location_in_screen);
  90   gfx::Point target_root_location = event.root_location();
  91   aura::Window::ConvertPointToTarget(
  92       capture_window_->GetRootWindow(),
  93       ash::wm::GetRootWindowAt(location_in_screen),
  94       &target_root_location);
  95   return new ui::MouseEvent(
  96       event.type(), target_location, target_root_location,
  97       ui::EventTimeForNow(), event.flags(),
  98       static_cast<const ui::MouseEvent&>(event).changed_button_flags());
  99 }
 100
 101 }  // namespace ash