Draggable peeking/fullscreen launcher with transparent background.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index c12b790bc3bec3a4db87f3b6667ff067f839f259..141f4be315064330ef1ccaa0901257d494e4a97d 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -14,7 +14,6 @@
 #include "ash/accelerators/magnifier_key_scroller.h"
 #include "ash/accelerators/spoken_feedback_toggler.h"
 #include "ash/accessibility_delegate.h"
-#include "ash/app_list/app_list_delegate_impl.h"
 #include "ash/ash_constants.h"
 #include "ash/ash_switches.h"
 #include "ash/aura/shell_port_classic.h"
@@ -486,6 +485,12 @@ void Shell::UpdateAfterLoginStatusChange(LoginStatus status) {
   }
 }
 
+void Shell::NotifyAppListVisibilityChanged(bool shown,
+                                           aura::Window* root_window) {
+  for (auto& observer : shell_observers_)
+    observer.OnAppListVisibilityChanged(shown, root_window);
+}
+
 void Shell::NotifyMaximizeModeStarted() {
   for (auto& observer : shell_observers_)
     observer.OnMaximizeModeStarted();
@@ -596,6 +601,7 @@ Shell::Shell(std::unique_ptr<ShellDelegate> shell_delegate,
     window_tree_host_manager_.reset(new WindowTreeHostManager);
     user_metrics_recorder_.reset(new UserMetricsRecorder);
   }
+  app_list()->set_delegate(this);
 
   PowerStatus::Initialize();
 
@@ -610,6 +616,8 @@ Shell::~Shell() {
   if (config != Config::MASH)
     user_metrics_recorder_->OnShellShuttingDown();
 
+  app_list()->set_delegate(nullptr);
+
   shell_delegate_->PreShutdown();
 
   // Remove the focus from any window. This will prevent overhead and side
@@ -726,9 +734,6 @@ Shell::~Shell() {
   ScreenAsh::CreateScreenForShutdown();
   display_configuration_controller_.reset();
 
-  // AppListDelegateImpl depends upon AppList.
-  app_list_delegate_impl_.reset();
-
   // These members access Shell in their destructors.
   wallpaper_controller_.reset();
   accessibility_delegate_.reset();
@@ -836,9 +841,6 @@ void Shell::Init(const ShellInitParams& init_params) {
     devtools_server_->AttachClient(std::move(devtools_client));
   }
 
-  if (config == Config::MASH)
-    app_list_delegate_impl_ = base::MakeUnique<AppListDelegateImpl>();
-
   // TODO(sky): move creation to ShellPort.
   if (config != Config::MASH)
     immersive_handler_factory_ = base::MakeUnique<ImmersiveHandlerFactoryAsh>();
@@ -1218,6 +1220,11 @@ void Shell::OnWindowActivated(
     root_window_for_new_windows_ = gained_active->GetRootWindow();
 }
 
+void Shell::OnAppListVisibilityChanged(bool visible, int64_t display_id) {
+  NotifyAppListVisibilityChanged(
+      visible, ShellPort::Get()->GetRootWindowForDisplayId(display_id));
+}
+
 void Shell::OnSessionStateChanged(session_manager::SessionState state) {
   // Initialize the shelf when a session becomes active. It's safe to do this
   // multiple times (e.g. initial login vs. multiprofile add session).