aura: No shadow for transparent window.

ash/wm/shadow_controller.cc

 // Copyright (c) 2011 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/wm/shadow_controller.h"
 
 #include <utility>
 
 #include "ash/ash_switches.h"
 #include "ash/wm/shadow.h"
 #include "ash/wm/shadow_types.h"
 #include "ash/wm/window_properties.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 
 using std::make_pair;
 
 namespace ash {
 namespace internal {
 
 namespace {
 
-ShadowType GetShadowTypeFromWindowType(aura::Window* window) {
+ShadowType GetShadowTypeFromWindow(aura::Window* window) {
   switch (window->type()) {

[Ben Goodger (Google), 2012/01/25 23:02:36]

I think as a general rule transparent windows shouldn't have shadows... so
perhaps rather than putting the condition in each branch below you can just do a
test at the beginning and return early.

[xiyuan, 2012/01/25 23:33:14]

Done.

     case aura::client::WINDOW_TYPE_NORMAL:
     case aura::client::WINDOW_TYPE_PANEL:
       return CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kAuraTranslucentFrames) ?
+          switches::kAuraTranslucentFrames) || window->transparent() ?
               SHADOW_TYPE_NONE : SHADOW_TYPE_RECTANGULAR;
     case aura::client::WINDOW_TYPE_MENU:
     case aura::client::WINDOW_TYPE_TOOLTIP:
-      return SHADOW_TYPE_RECTANGULAR;
+      return window->transparent() ? SHADOW_TYPE_NONE :
+                                     SHADOW_TYPE_RECTANGULAR;
     default:
       break;
   }
   return SHADOW_TYPE_NONE;
 }
 
 }  // namespace
 
 ShadowController::ShadowController() {
   aura::RootWindow::GetInstance()->AddRootWindowObserver(this);
 }
 
 ShadowController::~ShadowController() {
   for (WindowShadowMap::const_iterator it = window_shadows_.begin();
        it != window_shadows_.end(); ++it) {
     it->first->RemoveObserver(this);
   }
   aura::RootWindow::GetInstance()->RemoveRootWindowObserver(this);
 }
 
 void ShadowController::OnWindowInitialized(aura::Window* window) {
   window->AddObserver(this);
-  SetShadowType(window, GetShadowTypeFromWindowType(window));
+  SetShadowType(window, GetShadowTypeFromWindow(window));
   HandlePossibleShadowVisibilityChange(window);
 }
 
 void ShadowController::OnWindowPropertyChanged(aura::Window* window,
                                                const char* name,
                                                void* old) {
   if (name == kShadowTypeKey)
     HandlePossibleShadowVisibilityChange(window);
 }
 
@@ skipping 41 matching lines @@
   window_shadows_.insert(make_pair(window, shadow));
 
   shadow->Init();
   shadow->SetContentBounds(gfx::Rect(window->bounds().size()));
   shadow->layer()->SetVisible(ShouldShowShadowForWindow(window));
   window->layer()->Add(shadow->layer());
 }
 
 }  // namespace internal
 }  // namespace ash