Cancel drag if display configuration changes.

ash/wm/toplevel_window_event_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/toplevel_window_event_handler.h"
 
 #include "ash/shell.h"
 #include "ash/wm/default_window_resizer.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/resize_shadow_controller.h"
@@ skipping 78 matching lines @@
   DCHECK(resizer_.get());
   DCHECK_EQ(resizer_->GetTarget(), window);
   handler_->ResizerWindowDestroyed();
 }
 
 
 // ToplevelWindowEventHandler --------------------------------------------------
 
 ToplevelWindowEventHandler::ToplevelWindowEventHandler(aura::Window* owner)
     : in_move_loop_(false),
-      in_gesture_resize_(false) {
+      move_cancelled_(false) {
   aura::client::SetWindowMoveClient(owner, this);
+  Shell::GetInstance()->display_controller()->AddObserver(this);
 }
 
 ToplevelWindowEventHandler::~ToplevelWindowEventHandler() {
+  Shell::GetInstance()->display_controller()->RemoveObserver(this);
 }
 
 ui::EventResult ToplevelWindowEventHandler::OnKeyEvent(ui::KeyEvent* event) {
   if (window_resizer_.get() && event->type() == ui::ET_KEY_PRESSED &&
       event->key_code() == ui::VKEY_ESCAPE) {
     CompleteDrag(DRAG_REVERT, event->flags());
   }
   return ui::ER_UNHANDLED;
 }
 
@@ skipping 133 matching lines @@
       }
       break;
     }
     default:
       return ui::ER_UNHANDLED;
   }
 
   return ui::ER_CONSUMED;
 }
 
-void ToplevelWindowEventHandler::RunMoveLoop(aura::Window* source,
-                                             const gfx::Point& drag_offset) {
+aura::client::WindowMoveResult ToplevelWindowEventHandler::RunMoveLoop(
+    aura::Window* source,
+    const gfx::Point& drag_offset) {
   DCHECK(!in_move_loop_);  // Can only handle one nested loop at a time.
   in_move_loop_ = true;
+  move_cancelled_ = false;
   aura::RootWindow* root_window = source->GetRootWindow();
   DCHECK(root_window);
   gfx::Point drag_location;
   if (aura::Env::GetInstance()->is_touch_down()) {
     in_gesture_resize_ = true;
     bool has_point = root_window->gesture_recognizer()->
         GetLastTouchPointForTarget(source, &drag_location);
     DCHECK(has_point);
   } else {
     drag_location = root_window->GetLastMouseLocationInRoot();
     aura::Window::ConvertPointToTarget(
         root_window, source->parent(), &drag_location);
   }
   CreateScopedWindowResizer(source, drag_location, HTCAPTION);
   source->GetRootWindow()->SetCursor(ui::kCursorPointer);
 #if !defined(OS_MACOSX)
   MessageLoopForUI* loop = MessageLoopForUI::current();
   MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
   base::RunLoop run_loop(aura::Env::GetInstance()->GetDispatcher());
   quit_closure_ = run_loop.QuitClosure();
   run_loop.Run();
 #endif  // !defined(OS_MACOSX)
   in_gesture_resize_ = in_move_loop_ = false;
+  return move_cancelled_ ? aura::client::MOVE_CANCELED :
+      aura::client::MOVE_SUCCESSFUL;
 }
 
 void ToplevelWindowEventHandler::EndMoveLoop() {
   if (!in_move_loop_)
     return;
 
   in_move_loop_ = false;
   if (window_resizer_.get()) {
     window_resizer_->resizer()->RevertDrag();
     window_resizer_.reset();
   }
   quit_closure_.Run();
 }
 
+void ToplevelWindowEventHandler::OnDisplayConfigurationChanging() {
+  if (in_move_loop_) {
+    move_cancelled_ = true;
+    EndMoveLoop();
+  } else if (window_resizer_.get()) {
+    window_resizer_->resizer()->RevertDrag();
+    window_resizer_.reset();
+  }
+}
+
 // static
 WindowResizer* ToplevelWindowEventHandler::CreateWindowResizer(
     aura::Window* window,
     const gfx::Point& point_in_parent,
     int window_component) {
   if (!wm::IsWindowNormal(window))
     return NULL;  // Don't allow resizing/dragging maximized/fullscreen windows.
   return DefaultWindowResizer::Create(
       window, point_in_parent, window_component);
 }
@@ skipping 66 matching lines @@
 void ToplevelWindowEventHandler::ResizerWindowDestroyed() {
   // We explicitly don't invoke RevertDrag() since that may do things to window.
   // Instead we destroy the resizer.
   window_resizer_.reset();
 
   // End the move loop. This does nothing if we're not in a move loop.
   EndMoveLoop();
 }
 
 }  // namespace ash