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 27 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:
+      return Shadow::STYLE_ACTIVE;

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

This still concerns me. You're relying on the fact that no one happens to turn
on shadows for popup windows right now.

How does the code work today? Visually in ToT it looks to me like system tray
bubbles have the same big shadows as active windows.

[Evan Stade, 2016/12/12 17:51:20]

I don't think that's an unreasonable assumption. It wouldn't make sense to just
flip them on for popups with or without this patch. You're right, we need to
eventually address it (as per the TODO), but as a part of future work.
yes, that is accurate. Spec[1]. This is category 5 (it's ambiguous whether that
applies to just the system menu or all tray bubbles but I assume the latter as
interaction patterns are the same), and it matches category 1 (active
application frame).

[1]
https://folio.googleplex.com/andromeda/Chrome%20OS/System%20Components/Specs%...

[James Cook, 2016/12/12 18:33:07]

I meant, how does the code work today to paint the system tray bubbles with
large shadows? Apparently they are not active, otherwise you wouldn't need this
line and could rely on 61 below.

[sky, 2016/12/12 19:16:53]

Bubbles are mapped to ui::wm::WINDOW_TYPE_POPUP, which by default shouldn't have
a shadow. Is someone explicitly calling SetShadowType()?

[Evan Stade, 2016/12/12 21:28:40]

They don't get wm shadows at all currently. With this patch they do because of
changes in TrayBubbleView.

+
     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) {
       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