Add ability for Widgets to override the DefaultThemeProvider

ui/views/widget/widget.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/views/widget/widget.h"
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 105 matching lines @@
       mirror_origin_in_rtl(false),
       shadow_type(SHADOW_TYPE_DEFAULT),
       remove_standard_frame(false),
       use_system_default_icon(false),
       show_state(ui::SHOW_STATE_DEFAULT),
       parent(NULL),
       native_widget(NULL),
       desktop_window_tree_host(NULL),
       layer_type(ui::LAYER_TEXTURED),
       context(NULL),
-      force_show_in_taskbar(false) {
+      force_show_in_taskbar(false),
+      theme_provider(nullptr) {
 }
 
 Widget::InitParams::InitParams(Type type)
     : type(type),
       delegate(NULL),
       child(false),
       opacity(INFER_OPACITY),
       accept_events(true),
       activatable(ACTIVATABLE_DEFAULT),
       keep_on_top(type == TYPE_MENU || type == TYPE_DRAG),
       visible_on_all_workspaces(false),
       ownership(NATIVE_WIDGET_OWNS_WIDGET),
       mirror_origin_in_rtl(false),
       shadow_type(SHADOW_TYPE_DEFAULT),
       remove_standard_frame(false),
       use_system_default_icon(false),
       show_state(ui::SHOW_STATE_DEFAULT),
       parent(NULL),
       native_widget(NULL),
       desktop_window_tree_host(NULL),
       layer_type(ui::LAYER_TEXTURED),
       context(NULL),
-      force_show_in_taskbar(false) {
+      force_show_in_taskbar(false),
+      theme_provider(nullptr) {
 }
 
 Widget::InitParams::~InitParams() {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Widget, public:
 
 Widget::Widget()
     : native_widget_(NULL),
       widget_delegate_(NULL),
       non_client_view_(NULL),
+      theme_provider_(nullptr),
       dragged_view_(NULL),
       ownership_(InitParams::NATIVE_WIDGET_OWNS_WIDGET),
       is_secondary_widget_(true),
       frame_type_(FRAME_TYPE_DEFAULT),
       disable_inactive_rendering_(false),
       widget_closed_(false),
       saved_show_state_(ui::SHOW_STATE_DEFAULT),
       focus_on_creation_(true),
       is_top_level_(false),
       native_widget_initialized_(false),
@@ skipping 173 matching lines @@
   }
 
   widget_delegate_ = params.delegate ?
       params.delegate : new DefaultWidgetDelegate(this);
   widget_delegate_->set_can_activate(can_activate);
 
   ownership_ = params.ownership;
   native_widget_ = CreateNativeWidget(params.native_widget, this)->
                    AsNativeWidgetPrivate();
   root_view_.reset(CreateRootView());
-  default_theme_provider_.reset(new ui::DefaultThemeProvider);
+  if (in_params.theme_provider && GetTopLevelWidget() == this)
+    theme_provider_ = in_params.theme_provider;
+  else
+    default_theme_provider_.reset(new ui::DefaultThemeProvider);

[tdanderson, 2015/09/09 17:38:58]

nit: newline after line 361

[sadrul, 2015/09/09 17:56:57]

I was thinking this could be more like:

  theme_provider_ = in_params.theme_provider;
  if (theme_provider_) {
    DCHECK(is_toplevel_);
  } else {
    default_theme_provider_.reset(....);
  }

Because silently ignoring a custom theme_provider would make it difficult to
figure out what's going on when a developer adds one for a non-toplevel widget.

   if (params.type == InitParams::TYPE_MENU) {
     is_mouse_button_pressed_ =
         internal::NativeWidgetPrivate::IsMouseButtonDown();
   }
   native_widget_->InitNativeWidget(params);
   if (RequiresNonClientView(params.type)) {
     non_client_view_ = new NonClientView;
     non_client_view_->SetFrameView(CreateNonClientFrameView());
     // Create the ClientView, add it to the NonClientView and add the
     // NonClientView to the RootView. This will cause everything to be parented.
@@ skipping 371 matching lines @@
 const View* Widget::GetRootView() const {
   return root_view_.get();
 }
 
 bool Widget::IsVisible() const {
   return native_widget_->IsVisible();
 }
 
 ui::ThemeProvider* Widget::GetThemeProvider() const {
   const Widget* root_widget = GetTopLevelWidget();
-  if (root_widget && root_widget != this) {
-    // Attempt to get the theme provider, and fall back to the default theme
-    // provider if not found.
-    ui::ThemeProvider* provider = root_widget->GetThemeProvider();
-    if (provider)
-      return provider;
-
-    provider = root_widget->default_theme_provider_.get();
-    if (provider)
-      return provider;
-  }
-  return default_theme_provider_.get();
+  if (root_widget && root_widget != this)
+    return root_widget->GetThemeProvider();
+  return theme_provider_ ? theme_provider_ : default_theme_provider_.get();
 }
 
 const ui::NativeTheme* Widget::GetNativeTheme() const {
   return native_widget_->GetNativeTheme();
 }
 
 FocusManager* Widget::GetFocusManager() {
   Widget* toplevel_widget = GetTopLevelWidget();
   return toplevel_widget ? toplevel_widget->focus_manager_.get() : NULL;
 }
@@ skipping 722 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // internal::NativeWidgetPrivate, NativeWidget implementation:
 
 internal::NativeWidgetPrivate* NativeWidgetPrivate::AsNativeWidgetPrivate() {
   return this;
 }
 
 }  // namespace internal
 }  // namespace views