Adding a gray semi transparent backdrop behind the topmost window within the default container

ash/wm/workspace/workspace_layout_manager.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/workspace/workspace_layout_manager.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_util.h"
 #include "ash/session_state_delegate.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shell.h"
 #include "ash/wm/always_on_top_controller.h"
 #include "ash/wm/window_animations.h"
 #include "ash/wm/window_positioner.h"
 #include "ash/wm/window_properties.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/wm_event.h"
+#include "ash/wm/workspace/workspace_layout_manager_delegate.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/compositor/layer.h"
 #include "ui/events/event.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/corewm/window_util.h"
 
@@ skipping 13 matching lines @@
       is_fullscreen_(GetRootWindowController(
           window->GetRootWindow())->GetWindowForFullscreenMode() != NULL) {
   Shell::GetInstance()->activation_client()->AddObserver(this);
   Shell::GetInstance()->AddShellObserver(this);
   root_window_->AddObserver(this);
 }
 
 WorkspaceLayoutManager::~WorkspaceLayoutManager() {
   if (root_window_)
     root_window_->RemoveObserver(this);
-  for (WindowSet::const_iterator i = windows_.begin();
-       i != windows_.end();
-       ++i) {
+  for (WindowSet::const_iterator i = windows_.begin(); i != windows_.end(); ++i)
     (*i)->RemoveObserver(this);
-    wm::GetWindowState(*i)->RemoveObserver(this);
-  }
   Shell::GetInstance()->RemoveShellObserver(this);
   Shell::GetInstance()->activation_client()->RemoveObserver(this);
 }
 
 void WorkspaceLayoutManager::SetShelf(internal::ShelfLayoutManager* shelf) {
   shelf_ = shelf;
 }
 
+void WorkspaceLayoutManager::SetMaximizeBackdropDelegate(
+    scoped_ptr<WorkspaceLayoutManagerDelegate> delegate) {
+  backdrop_delegate_.reset(delegate.release());
+}
+
 //////////////////////////////////////////////////////////////////////////////
 // WorkspaceLayoutManager, aura::LayoutManager implementation:
 
 void WorkspaceLayoutManager::OnWindowAddedToLayout(Window* child) {
   wm::WindowState* window_state = wm::GetWindowState(child);
   wm::WMEvent event(wm::WM_EVENT_ADDED_TO_WORKSPACE);
   window_state->OnWMEvent(&event);
   windows_.insert(child);
   child->AddObserver(this);
   window_state->AddObserver(this);
   UpdateShelfVisibility();
   UpdateFullscreenState();
+  if (backdrop_delegate_)
+    backdrop_delegate_->OnWindowAddedToLayout(child);
   WindowPositioner::RearrangeVisibleWindowOnShow(child);
 }
 
 void WorkspaceLayoutManager::OnWillRemoveWindowFromLayout(Window* child) {
   windows_.erase(child);
   child->RemoveObserver(this);
   wm::GetWindowState(child)->RemoveObserver(this);
 
   if (child->TargetVisibility())
     WindowPositioner::RearrangeVisibleWindowOnHideOrRemove(child);
 }
 
 void WorkspaceLayoutManager::OnWindowRemovedFromLayout(Window* child) {
   UpdateShelfVisibility();
   UpdateFullscreenState();
+  if (backdrop_delegate_)
+    backdrop_delegate_->OnWindowRemovedFromLayout(child);
 }
 
 void WorkspaceLayoutManager::OnChildWindowVisibilityChanged(Window* child,
                                                             bool visible) {
   wm::WindowState* window_state = wm::GetWindowState(child);
   // Attempting to show a minimized window. Unminimize it.
   if (visible && window_state->IsMinimized())
     window_state->Unminimize();
 
   if (child->TargetVisibility())
     WindowPositioner::RearrangeVisibleWindowOnShow(child);
   else
     WindowPositioner::RearrangeVisibleWindowOnHideOrRemove(child);
   UpdateFullscreenState();
   UpdateShelfVisibility();
+  if (backdrop_delegate_)
+    backdrop_delegate_->OnChildWindowVisibilityChanged(child, visible);
 }
 
 void WorkspaceLayoutManager::SetChildBounds(
     Window* child,
     const gfx::Rect& requested_bounds) {
   wm::WindowState* window_state = wm::GetWindowState(child);
   wm::SetBoundsEvent event(wm::WM_EVENT_SET_BOUNDS, requested_bounds);
   window_state->OnWMEvent(&event);
   UpdateShelfVisibility();
 }
@@ skipping 40 matching lines @@
   if (key == aura::client::kAlwaysOnTopKey &&
       window->GetProperty(aura::client::kAlwaysOnTopKey)) {
     GetRootWindowController(window->GetRootWindow())->
         always_on_top_controller()->GetContainer(window)->AddChild(window);
   }
 }
 
 void WorkspaceLayoutManager::OnWindowStackingChanged(aura::Window* window) {
   UpdateShelfVisibility();
   UpdateFullscreenState();
+  if (backdrop_delegate_)
+    backdrop_delegate_->OnWindowStackingChanged(window);
 }
 
 void WorkspaceLayoutManager::OnWindowDestroying(aura::Window* window) {
   if (root_window_ == window) {
     root_window_->RemoveObserver(this);
     root_window_ = NULL;
   }
 }
 
 void WorkspaceLayoutManager::OnWindowBoundsChanged(aura::Window* window,
@@ skipping 28 matching lines @@
     wm::WindowState* window_state,
     wm::WindowStateType old_type) {
 
   // Notify observers that fullscreen state may be changing.
   if (window_state->IsFullscreen() ||
       old_type == wm::WINDOW_STATE_TYPE_FULLSCREEN) {
     UpdateFullscreenState();
   }
 
   UpdateShelfVisibility();
+  if (backdrop_delegate_)
+    backdrop_delegate_->OnPostWindowStateTypeChange(window_state, old_type);
 }
 
 //////////////////////////////////////////////////////////////////////////////
 // WorkspaceLayoutManager, private:
 
 void WorkspaceLayoutManager::AdjustAllWindowsBoundsForWorkAreaChange(
     const wm::WMEvent* event) {
   DCHECK(event->type() == wm::WM_EVENT_DISPLAY_BOUNDS_CHANGED ||
          event->type() == wm::WM_EVENT_WORKAREA_BOUNDS_CHANGED);
 
@@ skipping 37 matching lines @@
       window_->GetRootWindow())->GetWindowForFullscreenMode() != NULL;
   if (is_fullscreen != is_fullscreen_) {
     ash::Shell::GetInstance()->NotifyFullscreenStateChange(
         is_fullscreen, window_->GetRootWindow());
     is_fullscreen_ = is_fullscreen;
   }
 }
 
 }  // namespace internal
 }  // namespace ash