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"
@@ skipping 108 matching lines @@
   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();

[sky, 2017/05/31 15:04:17]

I prefer minimizing direct dependencies between classes and using observers. How
about adding ShellObserver::OnAppListShown()? This code would call to Shell to
notify observers and shelf could observe said function. Shelf would use this
function to both update the applistbutton (as done on 131) as well as the new
functionality you are adding.

[newcomer, 2017/06/01 01:42:54]

Done.

   if (app_list_button)
     app_list_button->OnAppListShown();
+
+  if (app_list::features::IsFullscreenAppListEnabled()) {
+    // Notify the shelf that the app list is active so the backgrounds do not
+    // overlap.
+    Shelf* shelf = Shelf::ForWindow(root_window);
+    shelf->OnAppListIsActive(true);

[xiyuan, 2017/05/30 22:18:50]

nit: Get rid of |shelf| and use Shelf::ForWindow in-place.

[newcomer, 2017/06/01 01:42:53]

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();
+  if (app_list::features::IsFullscreenAppListEnabled()) {
+    // Notify the shelf that the app list is being dismissed so it can
+    // re-enable its transparent background.
+    shelf->OnAppListIsActive(false);
+  }
 }
 
 void AppListPresenterDelegate::UpdateBounds() {
   if (!view_ || !is_visible_)
     return;
 
   view_->UpdateBounds();
   view_->MaybeSetAnchorPoint(GetCenterOfDisplayForWindow(
       WmWindow::Get(view_->GetWidget()->GetNativeWindow()),
       GetMinimumBoundsHeightForAppList(view_)));
@@ skipping 85 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListPresenterDelegate, ShelfObserver implementation:
 
 void AppListPresenterDelegate::OnShelfIconPositionsChanged() {
   UpdateBounds();
 }
 
 }  // namespace ash