Apply new MD shadows to CrOS tray bubbles.

ui/wm/core/shadow_controller.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 "ui/wm/core/shadow_controller.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 28 matching lines @@
     case ui::wm::WINDOW_TYPE_PANEL:
     case ui::wm::WINDOW_TYPE_MENU:
     case ui::wm::WINDOW_TYPE_TOOLTIP:
       return SHADOW_TYPE_RECTANGULAR;
     default:
       break;
   }
   return SHADOW_TYPE_NONE;
 }
 
-bool ShouldUseSmallShadowForWindow(aura::Window* window) {
+Shadow::Style GetShadowStyleForWindow(aura::Window* window) {
   switch (window->type()) {
     case ui::wm::WINDOW_TYPE_MENU:
     case ui::wm::WINDOW_TYPE_TOOLTIP:
-      return true;
+      return Shadow::STYLE_SMALL;
+
+    // System tray bubbles render like active windows. TODO(estade): this
+    // mechanism will need to be revisited for applying WM shadows to other
+    // types of bubbles which don't want to render such large shadows.
+    case ui::wm::WINDOW_TYPE_POPUP:

[James Cook, 2016/12/09 19:40:13]

From the code this looks like it will apply large shadows to non-bubble windows
(like any Widget of type frameless, and drag widgets too:

https://cs.chromium.org/chromium/src/ui/views/widget/widget_aura_utils.cc?l=2...

That seems undesirable to me, even in the short term.

[Evan Stade, 2016/12/09 21:09:18]

I'll look into it. I had hoped that other popups weren't getting WM shadows.

[Evan Stade, 2016/12/09 21:20:32]

Do you have an example of a drag widget? When I drag a bookmark bar button or
something inside a webpage, I don't see a shadow of any kind. When I drag a
window around, I assume that's still using the same window, which is active.

+      return Shadow::STYLE_ACTIVE;
+
     default:
-      break;
+      return IsActiveWindow(window) ? Shadow::STYLE_ACTIVE
+                                    : Shadow::STYLE_INACTIVE;
   }
-  return false;
-}
-
-Shadow::Style GetShadowStyleForWindow(aura::Window* window) {
-  return ShouldUseSmallShadowForWindow(window) ? Shadow::STYLE_SMALL :
-      (IsActiveWindow(window) ? Shadow::STYLE_ACTIVE : Shadow::STYLE_INACTIVE);
 }
 
 // Returns the shadow style to be applied to |losing_active| when it is losing
 // active to |gaining_active|. |gaining_active| may be of a type that hides when
 // inactive, and as such we do not want to render |losing_active| as inactive.
 Shadow::Style GetShadowStyleForWindowLosingActive(
     aura::Window* losing_active,
     aura::Window* gaining_active) {
   if (gaining_active && aura::client::GetHideOnDeactivate(gaining_active)) {
     aura::Window::Windows::const_iterator it =
@@ skipping 114 matching lines @@
 void ShadowController::Impl::OnWindowDestroyed(aura::Window* window) {
   window->ClearProperty(kShadowLayerKey);
   observer_manager_.Remove(window);
 }
 
 void ShadowController::Impl::OnWindowActivated(ActivationReason reason,
                                                aura::Window* gained_active,
                                                aura::Window* lost_active) {
   if (gained_active) {
     Shadow* shadow = GetShadowForWindow(gained_active);
-    if (shadow && !ShouldUseSmallShadowForWindow(gained_active))
-      shadow->SetStyle(Shadow::STYLE_ACTIVE);
+    if (shadow)
+      shadow->SetStyle(GetShadowStyleForWindow(gained_active));
   }
   if (lost_active) {
     Shadow* shadow = GetShadowForWindow(lost_active);
-    if (shadow && !ShouldUseSmallShadowForWindow(lost_active)) {
+    if (shadow &&
+        GetShadowStyleForWindow(lost_active) == Shadow::STYLE_INACTIVE) {

[James Cook, 2016/12/09 19:40:13]

Shouldn't you be checking if the window that lost activation was previously
active? Or always updating the style?

[Evan Stade, 2016/12/09 21:09:18]

I don't think this change affects the behavior at all, does it? 

[James Cook, 2016/12/10 00:19:16]

What if |lost_active| had shadow style Shadow::STYLE_ACTIVE? You should reset
the shadow style to inactive, right?

       shadow->SetStyle(GetShadowStyleForWindowLosingActive(lost_active,
                                                            gained_active));
     }
   }
 }
 
 bool ShadowController::Impl::ShouldShowShadowForWindow(
     aura::Window* window) const {
   ui::WindowShowState show_state =
       window->GetProperty(aura::client::kShowStateKey);
@@ skipping 64 matching lines @@
   activation_client_->RemoveObserver(this);
 }
 
 void ShadowController::OnWindowActivated(ActivationReason reason,
                                          aura::Window* gained_active,
                                          aura::Window* lost_active) {
   impl_->OnWindowActivated(reason, gained_active, lost_active);
 }
 
 }  // namespace wm