ui/views/widget/desktop_aura/desktop_drop_target_win.cc

   1 // Copyright (c) 2011 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/widget/desktop_aura/desktop_drop_target_win.h"
   6
   7 #include "base/metrics/histogram.h"
   8 #include "base/win/win_util.h"
   9 #include "ui/aura/window.h"
  10 #include "ui/aura/window_tree_host.h"
  11 #include "ui/base/dragdrop/drag_drop_types.h"
  12 #include "ui/base/dragdrop/drop_target_event.h"
  13 #include "ui/base/dragdrop/os_exchange_data_provider_win.h"
  14 #include "ui/events/event_constants.h"
  15 #include "ui/wm/public/drag_drop_client.h"
  16 #include "ui/wm/public/drag_drop_delegate.h"
  17
  18 using aura::client::DragDropClient;
  19 using aura::client::DragDropDelegate;
  20 using ui::OSExchangeData;
  21 using ui::OSExchangeDataProviderWin;
  22
  23 namespace views {
  24
  25 DesktopDropTargetWin::DesktopDropTargetWin(aura::Window* root_window,
  26                                            HWND window)
  27     : ui::DropTargetWin(window),
  28       root_window_(root_window),
  29       target_window_(NULL) {
  30 }
  31
  32 DesktopDropTargetWin::~DesktopDropTargetWin() {
  33   if (target_window_)
  34     target_window_->RemoveObserver(this);
  35 }
  36
  37 DWORD DesktopDropTargetWin::OnDragEnter(IDataObject* data_object,
  38                                         DWORD key_state,
  39                                         POINT position,
  40                                         DWORD effect) {
  41   scoped_ptr<OSExchangeData> data;
  42   scoped_ptr<ui::DropTargetEvent> event;
  43   DragDropDelegate* delegate;
  44   // Translate will call OnDragEntered.
  45   Translate(data_object, key_state, position, effect, &data, &event, &delegate);
  46   return ui::DragDropTypes::DragOperationToDropEffect(
  47       ui::DragDropTypes::DRAG_NONE);
  48 }
  49
  50 DWORD DesktopDropTargetWin::OnDragOver(IDataObject* data_object,
  51                                        DWORD key_state,
  52                                        POINT position,
  53                                        DWORD effect) {
  54   int drag_operation = ui::DragDropTypes::DRAG_NONE;
  55   scoped_ptr<OSExchangeData> data;
  56   scoped_ptr<ui::DropTargetEvent> event;
  57   DragDropDelegate* delegate;
  58   Translate(data_object, key_state, position, effect, &data, &event, &delegate);
  59   if (delegate)
  60     drag_operation = delegate->OnDragUpdated(*event);
  61   return ui::DragDropTypes::DragOperationToDropEffect(drag_operation);
  62 }
  63
  64 void DesktopDropTargetWin::OnDragLeave(IDataObject* data_object) {
  65   NotifyDragLeave();
  66 }
  67
  68 DWORD DesktopDropTargetWin::OnDrop(IDataObject* data_object,
  69                                    DWORD key_state,
  70                                    POINT position,
  71                                    DWORD effect) {
  72   int drag_operation = ui::DragDropTypes::DRAG_NONE;
  73   scoped_ptr<OSExchangeData> data;
  74   scoped_ptr<ui::DropTargetEvent> event;
  75   DragDropDelegate* delegate;
  76   Translate(data_object, key_state, position, effect, &data, &event, &delegate);
  77   if (delegate) {
  78     drag_operation = delegate->OnPerformDrop(*event);
  79     DragDropClient* client = aura::client::GetDragDropClient(root_window_);
  80     if (client && !client->IsDragDropInProgress() &&
  81         drag_operation != ui::DragDropTypes::DRAG_NONE) {
  82       UMA_HISTOGRAM_COUNTS("Event.DragDrop.ExternalOriginDrop", 1);
  83     }
  84   }
  85   if (target_window_) {
  86     target_window_->RemoveObserver(this);
  87     target_window_ = NULL;
  88   }
  89   return ui::DragDropTypes::DragOperationToDropEffect(drag_operation);
  90 }
  91
  92 void DesktopDropTargetWin::OnWindowDestroyed(aura::Window* window) {
  93   DCHECK(window == target_window_);
  94   target_window_ = NULL;
  95 }
  96
  97 void DesktopDropTargetWin::Translate(
  98     IDataObject* data_object,
  99     DWORD key_state,
 100     POINT position,
 101     DWORD effect,
 102     scoped_ptr<OSExchangeData>* data,
 103     scoped_ptr<ui::DropTargetEvent>* event,
 104     DragDropDelegate** delegate) {
 105   gfx::Point location(position.x, position.y);
 106   gfx::Point root_location = location;
 107   root_window_->GetHost()->ConvertPointFromNativeScreen(
 108       &root_location);
 109   aura::Window* target_window =
 110       root_window_->GetEventHandlerForPoint(root_location);
 111   bool target_window_changed = false;
 112   if (target_window != target_window_) {
 113     if (target_window_)
 114       NotifyDragLeave();
 115     target_window_ = target_window;
 116     if (target_window_)
 117       target_window_->AddObserver(this);
 118     target_window_changed = true;
 119   }
 120   *delegate = NULL;
 121   if (!target_window_)
 122     return;
 123   *delegate = aura::client::GetDragDropDelegate(target_window_);
 124   if (!*delegate)
 125     return;
 126
 127   data->reset(new OSExchangeData(new OSExchangeDataProviderWin(data_object)));
 128   location = root_location;
 129   aura::Window::ConvertPointToTarget(root_window_, target_window_, &location);
 130   event->reset(new ui::DropTargetEvent(
 131       *(data->get()),
 132       location,
 133       root_location,
 134       ui::DragDropTypes::DropEffectToDragOperation(effect)));
 135   int flags = 0;
 136   flags |= base::win::IsAltPressed() ? ui::EF_ALT_DOWN : ui::EF_NONE;
 137   flags |= base::win::IsShiftPressed() ? ui::EF_SHIFT_DOWN : ui::EF_NONE;
 138   flags |= base::win::IsCtrlPressed() ? ui::EF_CONTROL_DOWN : ui::EF_NONE;
 139   (*event)->set_flags(flags);
 140   if (target_window_changed)
 141     (*delegate)->OnDragEntered(*event->get());
 142 }
 143
 144 void DesktopDropTargetWin::NotifyDragLeave() {
 145   if (!target_window_)
 146     return;
 147   DragDropDelegate* delegate =
 148       aura::client::GetDragDropDelegate(target_window_);
 149   if (delegate)
 150     delegate->OnDragExited();
 151   target_window_->RemoveObserver(this);
 152   target_window_ = NULL;
 153 }
 154
 155 }  // namespace views