ui/wm/public/scoped_drag_drop_disabler.cc

   1 // Copyright 2015 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/wm/public/scoped_drag_drop_disabler.h"
   6
   7 #include "ui/aura/window.h"
   8 #include "ui/wm/public/drag_drop_client.h"
   9
  10 namespace aura {
  11 namespace client {
  12
  13 class NopDragDropClient : public DragDropClient {
  14  public:
  15   ~NopDragDropClient() override {}
  16   int StartDragAndDrop(const ui::OSExchangeData& data,
  17                        aura::Window* root_window,
  18                        aura::Window* source_window,
  19                        const gfx::Point& screen_location,
  20                        int operation,
  21                        ui::DragDropTypes::DragEventSource source) override {
  22     return 0;
  23   }
  24   void DragUpdate(aura::Window* target,
  25                   const ui::LocatedEvent& event) override {}
  26   void Drop(aura::Window* target, const ui::LocatedEvent& event) override {}
  27   void DragCancel() override {}
  28   bool IsDragDropInProgress() override {
  29     return false;
  30   }
  31 };
  32
  33 ScopedDragDropDisabler::ScopedDragDropDisabler(Window* window)
  34     : window_(window),
  35       old_client_(GetDragDropClient(window)),
  36       new_client_(new NopDragDropClient()) {
  37   SetDragDropClient(window_, new_client_.get());
  38   window_->AddObserver(this);
  39 }
  40
  41 ScopedDragDropDisabler::~ScopedDragDropDisabler() {
  42   if (window_) {
  43     window_->RemoveObserver(this);
  44     SetDragDropClient(window_, old_client_);
  45   }
  46 }
  47
  48 void ScopedDragDropDisabler::OnWindowDestroyed(Window* window) {
  49   CHECK_EQ(window_, window);
  50   window_ = NULL;
  51   new_client_.reset();
  52 }
  53
  54 }  // namespace client
  55 }  // namespace aura