Draggable peeking/fullscreen launcher with transparent background.

ui/app_list/presenter/app_list_presenter_impl.cc

 // Copyright 2016 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 "ui/app_list/presenter/app_list_presenter_impl.h"
 
 #include "base/metrics/user_metrics.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/pagination_model.h"
@@ skipping 41 matching lines @@
 
 aura::Window* AppListPresenterImpl::GetWindow() {
   return is_visible_ && view_ ? view_->GetWidget()->GetNativeWindow() : nullptr;
 }
 
 void AppListPresenterImpl::Show(int64_t display_id) {
   if (is_visible_)
     return;
 
   is_visible_ = true;
-  if (app_list_)
+  if (app_list_) {
     app_list_->OnTargetVisibilityChanged(GetTargetVisibility());
+    app_list_->OnVisibilityChanged(GetTargetVisibility(), display_id);
+  }
 
   if (view_) {
     ScheduleAnimation();
   } else {
     presenter_delegate_ = factory_->GetDelegate(this);
     AppListViewDelegate* view_delegate = presenter_delegate_->GetViewDelegate();
     DCHECK(view_delegate);
     // Note the AppListViewDelegate outlives the AppListView. For Ash, the view
     // is destroyed when dismissed.
     AppListView* view = new AppListView(view_delegate);
     presenter_delegate_->Init(view, display_id, current_apps_page_);
     SetView(view);
   }
   presenter_delegate_->OnShown(display_id);
   base::RecordAction(base::UserMetricsAction("Launcher_Show"));
 }
 
 void AppListPresenterImpl::Dismiss() {
   if (!is_visible_)
     return;
 
   // If the app list is currently visible, there should be an existing view.
   DCHECK(view_);
 
   is_visible_ = false;
-  if (app_list_)
+  if (app_list_) {
     app_list_->OnTargetVisibilityChanged(GetTargetVisibility());
-
+    app_list_->OnVisibilityChanged(GetTargetVisibility(), GetDisplayId());
+  }
   // The dismissal may have occurred in response to the app list losing
   // activation. Otherwise, our widget is currently active. When the animation
   // completes we'll hide the widget, changing activation. If a menu is shown
   // before the animation completes then the activation change triggers the menu
   // to close. By deactivating now we ensure there is no activation change when
   // the animation completes and any menus stay open.
   if (view_->GetWidget()->IsActive())
     view_->GetWidget()->Deactivate();
 
   presenter_delegate_->OnDismissed();
@@ skipping 194 matching lines @@
   } else if (should_snap_back_) {
     should_snap_back_ = false;
     ui::ScopedLayerAnimationSettings animation(widget_animator);
     animation.SetTransitionDuration(
         base::TimeDelta::FromMilliseconds(kOverscrollPageTransitionDurationMs));
     widget->SetBounds(view_bounds_);
   }
 }
 
 }  // namespace app_list