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