Draggable peeking/fullscreen launcher with transparent background.

ash/app_list/app_list_presenter_delegate.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/app_list/app_list_presenter_delegate.h"
 
 #include "ash/ash_switches.h"
 #include "ash/public/cpp/shelf_types.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/app_list_button.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
+#include "ash/shell_observer.h"
 #include "ash/shell_port.h"
 #include "ash/wm/maximize_mode/maximize_mode_controller.h"
 #include "base/command_line.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_features.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/presenter/app_list_presenter_impl.h"
 #include "ui/app_list/presenter/app_list_view_delegate_factory.h"
 #include "ui/app_list/views/app_list_view.h"
 #include "ui/aura/window.h"
@@ skipping 85 matching lines @@
 
   // By setting us as DnD recipient, the app list knows that we can
   // handle items.
   Shelf* shelf = Shelf::ForWindow(root_window);
   view->SetDragAndDropHostOfCurrentAppList(
       shelf->shelf_widget()->GetDragAndDropHostForAppList());
 }
 
 void AppListPresenterDelegate::OnShown(int64_t display_id) {
   is_visible_ = true;
-  // Update applist button status when app list visibility is changed.
   aura::Window* root_window =
       ShellPort::Get()->GetRootWindowForDisplayId(display_id);
-  AppListButton* app_list_button =
-      Shelf::ForWindow(root_window)->shelf_widget()->GetAppListButton();
-  if (app_list_button)
-    app_list_button->OnAppListShown();
+  Shell::Get()->NotifyAppListShownOrDismissed(is_visible_, root_window);

[xiyuan, 2017/06/06 15:51:04]

Think we can remove this code block from Line 123-125 and also line 133-135
since AppListPresenterImpl would call Shell's app_list() instance via mojo to
notify the visiblity change [1].

[1]:
https://cs.chromium.org/chromium/src/ui/app_list/presenter/app_list_presenter...

[newcomer, 2017/06/06 16:42:29]

Done.

 }
 
 void AppListPresenterDelegate::OnDismissed() {
   DCHECK(is_visible_);
   DCHECK(view_);
-
   is_visible_ = false;
 
-  // Update applist button status when app list visibility is changed.
-  Shelf* shelf = Shelf::ForWindow(view_->GetWidget()->GetNativeWindow());
-  AppListButton* app_list_button = shelf->shelf_widget()->GetAppListButton();
-  if (app_list_button)
-    app_list_button->OnAppListDismissed();
+  aura::Window* root_window =
+      RootWindowController::ForTargetRootWindow()->GetRootWindow();
+  Shell::Get()->NotifyAppListShownOrDismissed(is_visible_, root_window);
 }
 
 void AppListPresenterDelegate::UpdateBounds() {
   if (!view_ || !is_visible_)
     return;
 
   view_->UpdateBounds();
   view_->MaybeSetAnchorPoint(
       GetCenterOfDisplayForWindow(view_->GetWidget()->GetNativeWindow(),
                                   GetMinimumBoundsHeightForAppList(view_)));
@@ skipping 78 matching lines @@
 void AppListPresenterDelegate::OnKeyboardClosed() {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListPresenterDelegate, ShellObserver implementation:
 void AppListPresenterDelegate::OnOverviewModeStarting() {
   if (is_visible_)
     presenter_->Dismiss();
 }
 
 }  // namespace ash