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 96 matching lines @@
         WmWindow::Get(root_window), GetMinimumBoundsHeightForAppList(view)));
   }
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)
     keyboard_controller->AddObserver(this);
   Shell::Get()->AddPreTargetHandler(this);
   WmShelf* shelf = WmShelf::ForWindow(root_window);
   shelf->AddObserver(this);
 
+  // Notify the shelf that the app list is active so the backgrounds do not
+  // overlap.
+  if (app_list::features::IsFullscreenAppListEnabled())
+    shelf->AppListIsActive(true);
+
   // By setting us as DnD recipient, the app list knows that we can
   // handle items.
   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 =
       WmShelf::ForWindow(root_window)->shelf_widget()->GetAppListButton();
   if (app_list_button)
     app_list_button->OnAppListShown();
 }
 
 void AppListPresenterDelegate::OnDismissed() {
   DCHECK(is_visible_);
   DCHECK(view_);
 
   is_visible_ = false;
 
   // Update applist button status when app list visibility is changed.
   WmShelf* shelf = WmShelf::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->AppListIsActive(false);

[vadimt, 2017/05/22 23:36:56]

Just asking: isn't OnShown a counterpart of OnDismissed, and should we move the
AppListIsActive(true) to OnShown?

[newcomer, 2017/05/25 23:10:50]

You're correct! I put it in OnShown.

 }
 
 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, WmShelfObserver implementation:
 
 void AppListPresenterDelegate::OnShelfIconPositionsChanged() {
   UpdateBounds();
 }
 
 }  // namespace ash