Attach panel while dragging to bring it in front of other panels.

ash/wm/panels/panel_window_resizer.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/panels/panel_window_resizer.h"
 
 #include "ash/launcher/launcher.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_types.h"
 #include "ash/shelf/shelf_widget.h"
@@ skipping 18 matching lines @@
 const int kPanelSnapToLauncherDistance = 30;
 }  // namespace
 
 PanelWindowResizer::~PanelWindowResizer() {
   ash::Shell::GetInstance()->cursor_manager()->UnlockCursor();
 }
 
 // static
 PanelWindowResizer*
 PanelWindowResizer::Create(aura::Window* window,
-                             const gfx::Point& location,
-                             int window_component) {
+                           const gfx::Point& location,
+                           int window_component) {
   Details details(window, location, window_component);
   return details.is_resizable ? new PanelWindowResizer(details) : NULL;
 }
 
 void PanelWindowResizer::Drag(const gfx::Point& location, int event_flags) {
   gfx::Rect bounds(CalculateBoundsForDrag(details_, location));
   if (bounds != details_.window->bounds()) {
     if (!did_move_or_resize_) {
       if (!details_.restore_bounds.IsEmpty())
         ClearRestoreBounds(details_.window);
       StartedDragging();
     }
     did_move_or_resize_ = true;
     should_attach_ = AttachToLauncher(&bounds);
     details_.window->SetBounds(bounds);
   }
 }
 
 void PanelWindowResizer::CompleteDrag(int event_flags) {
-  if (should_attach_ != was_attached_) {
+  if (details_.window->GetProperty(internal::kPanelAttachedKey) !=
+      should_attach_) {
     details_.window->SetProperty(internal::kPanelAttachedKey, should_attach_);
     details_.window->SetDefaultParentByRootWindow(
             details_.window->GetRootWindow(),
             details_.window->bounds());
   }
   FinishDragging();
 }
 
 void PanelWindowResizer::RevertDrag() {
   if (!did_move_or_resize_)
@@ skipping 62 matching lines @@
           should_attach = true;
           bounds->set_y(launcher_bounds.bottom());
         }
         break;
     }
   }
   return should_attach;
 }
 
 void PanelWindowResizer::StartedDragging() {
-  if (was_attached_)
-    panel_layout_manager_->StartDragging(details_.window);
+  // Tell the panel layout manager that we are dragging this panel before
+  // attaching it so that it does not get repositioned.
+  panel_layout_manager_->StartDragging(details_.window);
+  if (!was_attached_) {
+    // Attach the panel while dragging placing it in front of other panels.
+    details_.window->SetProperty(internal::kContinueDragAfterReparent, true);
+    details_.window->SetProperty(internal::kPanelAttachedKey, true);
+    details_.window->SetDefaultParentByRootWindow(
+            details_.window->GetRootWindow(),
+            details_.window->bounds());
+  }
 }
 
 void PanelWindowResizer::FinishDragging() {
-  if (was_attached_)
-    panel_layout_manager_->FinishDragging();
+  panel_layout_manager_->FinishDragging();
 }
 
 }  // namespace aura