MenuButton: support Mac look & feel

ui/views/style/platform_style.cc

 // Copyright 2015 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/style/platform_style.h"
 
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 38 matching lines @@
 std::unique_ptr<FocusableBorder> PlatformStyle::CreateComboboxBorder() {
   return base::WrapUnique(new FocusableBorder());
 }
 
 // static
 std::unique_ptr<Background> PlatformStyle::CreateComboboxBackground() {
   return nullptr;
 }
 
 // static
+std::unique_ptr<Background> PlatformStyle::CreateMenuButtonBackground() {
+  return nullptr;
+}
+
+// static
+std::unique_ptr<FocusableBorder> PlatformStyle::CreateMenuButtonBorder() {
+  return base::WrapUnique(new FocusableBorder());
+}
+
+// static
 std::unique_ptr<LabelButtonBorder> PlatformStyle::CreateLabelButtonBorder(
     Button::ButtonStyle style) {
   if (!ui::MaterialDesignController::IsModeMaterial() ||
       style != Button::STYLE_TEXTBUTTON) {
     return base::WrapUnique(new LabelButtonAssetBorder(style));
   }
 
   std::unique_ptr<LabelButtonBorder> border(new views::LabelButtonBorder());
   border->set_insets(views::LabelButtonAssetBorder::GetDefaultInsetsForStyle(
       Button::STYLE_TEXTBUTTON));
   return border;
 }
 
 // static
+gfx::ImageSkia PlatformStyle::CreateMenuButtonArrow(bool is_enabled) {
+  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
+  return *rb.GetImageSkiaNamed(IDR_MENU_DROPARROW);
+}
+
+// static
 std::unique_ptr<ScrollBar> PlatformStyle::CreateScrollBar(bool is_horizontal) {
   return base::WrapUnique(new NativeScrollBar(is_horizontal));
 }
 
 // static
 SkColor PlatformStyle::TextColorForButton(
     const ButtonColorByState& color_by_state,
     const LabelButton& button) {
   return color_by_state[button.state()];
 }
 
 #endif  // OS_MACOSX
 
+// This definition is used even on Mac, but Mac has its own
+// CreateComboboxArrow() so it will return something different on Mac.
+// static
+int PlatformStyle::GetComboboxArrowWidth(Combobox::Style style) {
+  const int kNormalLeftPadding = 7;
+  const int kNormalRightPadding = 7;

[tapted, 2016/04/21 06:06:46]

I think we can collapse the left/right and just call it kNormalPadding. Same for
Action. Then multiply by 2. Same below.

[Elly Fong-Jones, 2016/04/21 15:30:27]

Done.

+  const int kActionLeftPadding = 11;
+  const int kActionRightPadding = 12;
+  int padding = style == Combobox::STYLE_NORMAL
+                    ? kNormalLeftPadding + kNormalRightPadding
+                    : kActionLeftPadding + kActionRightPadding;
+  int image_width = CreateComboboxArrow(true, style).size().width();
+  return padding + image_width;
+}
+
+// static
+int PlatformStyle::GetMenuButtonArrowWidth() {
+  const int kLeftPadding = 7;
+  const int kRightPadding = 7;
+  return kLeftPadding + kRightPadding +
+         CreateMenuButtonArrow(true).size().width();
+}
+
 #if !defined(DESKTOP_LINUX) && !defined(OS_MACOSX)
 // static
 void PlatformStyle::ApplyLabelButtonTextStyle(
     Label* label,
     ButtonColorByState* color_by_state) {
   ButtonColorByState& colors = *color_by_state;
   colors[Button::STATE_NORMAL] = kStyleButtonTextColor;
   colors[Button::STATE_HOVERED] = kStyleButtonTextColor;
   colors[Button::STATE_PRESSED] = kStyleButtonTextColor;
 
   const ui::NativeTheme* theme = label->GetNativeTheme();
   label->SetBackgroundColor(
       theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonBackgroundColor));
   label->SetAutoColorReadabilityEnabled(false);
   label->SetShadows(gfx::ShadowValues(
       1, gfx::ShadowValue(gfx::Vector2d(0, 1), 0, kStyleButtonShadowColor)));
 }
 #endif
 
 #if !defined(DESKTOP_LINUX)
 // static
 std::unique_ptr<Border> PlatformStyle::CreateThemedLabelButtonBorder(
     LabelButton* button) {
   return button->CreateDefaultBorder();
 }
 #endif
 
 }  // namespace views