MacViews: Style BUTTON_STYLE buttons using the "modern" UI

ui/native_theme/native_theme_mac.mm

 // Copyright (c) 2013 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/native_theme/native_theme_mac.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
 #include "base/mac/mac_util.h"
@@ skipping 24 matching lines @@
 const SkColor kMenuSeparatorColorMavericks = SkColorSetARGB(243, 228, 228, 228);
 
 // Hardcoded color used for some existing dialogs in Chrome's Cocoa UI.
 const SkColor kDialogBackgroundColor = SkColorSetRGB(251, 251, 251);
 
 // Color for the highlighted text in a control when that control doesn't have
 // keyboard focus.
 const SkColor kUnfocusedSelectedTextBackgroundColor =
     SkColorSetRGB(220, 220, 220);
 
+// Helper to make indexing an array by an enum class easier.
+template <class KEY, class VALUE>
+struct EnumArray {
+  VALUE& operator[](const KEY& key) { return array[static_cast<size_t>(key)]; }
+  VALUE array[static_cast<size_t>(KEY::COUNT)];
+};
+
 // On 10.6 and 10.7 there is no way to get components from system colors. Here,
 // system colors are just opaque objects that can paint themselves and otherwise
 // tell you nothing. In 10.8, some of the system color classes have incomplete
 // implementations and throw exceptions even attempting to convert using
 // -[NSColor colorUsingColorSpace:], so don't bother there either.
 // This function paints a single pixel to a 1x1 swatch and reads it back.
 SkColor GetSystemColorUsingSwatch(NSColor* color) {
   SkColor swatch;
   base::ScopedCFTypeRef<CGColorSpaceRef> color_space(
       CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB));
@@ skipping 94 matching lines @@
     case kColorId_LabelBackgroundColor:
       return NSSystemColorToSkColor([NSColor controlBackgroundColor]);
     case kColorId_ButtonEnabledColor:
     case kColorId_EnabledMenuButtonBorderColor:
     case kColorId_LabelEnabledColor:
       return NSSystemColorToSkColor([NSColor controlTextColor]);
     case kColorId_ButtonDisabledColor:
     case kColorId_LabelDisabledColor:
       return NSSystemColorToSkColor([NSColor disabledControlTextColor]);
     case kColorId_ButtonHighlightColor:
+      // Although the NSColor documentation names "selectedControlTextColor" as
+      // the color for a "text in a .. control being clicked or dragged", it
+      // remains black, and text on Yosemite-style pressed buttons is white.
+      return SK_ColorWHITE;
     case kColorId_ButtonHoverColor:
       return NSSystemColorToSkColor([NSColor selectedControlTextColor]);
 
     // Menus.
     case kColorId_EnabledMenuItemForegroundColor:
       return NSSystemColorToSkColor([NSColor controlTextColor]);
     case kColorId_DisabledMenuItemForegroundColor:
     case kColorId_DisabledEmphasizedMenuItemForegroundColor:
       return NSSystemColorToSkColor([NSColor disabledControlTextColor]);
     case kColorId_SelectedMenuItemForegroundColor:
@@ skipping 95 matching lines @@
       canvas->drawRect(gfx::RectToSkRect(rect), paint);
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 // static
 sk_sp<SkShader> NativeThemeMac::GetButtonBackgroundShader(
-    NativeTheme::State state, int height) {
-  typedef SkColor ColorByState[NativeTheme::State::kNumStates];
+    ButtonBackgroundType type,
+    int height) {
+  using ColorByState = EnumArray<ButtonBackgroundType, SkColor>;
   SkPoint gradient_points[2];
   gradient_points[0].iset(0, 0);
   gradient_points[1].iset(0, height);
 
   SkScalar gradient_positions[] = { 0.0, 0.38, 1.0 };
 
   ColorByState start_colors;
-  start_colors[NativeTheme::State::kDisabled] = gfx::kMaterialGrey300;
-  start_colors[NativeTheme::State::kHovered] = gfx::kMaterialBlue300;
-  start_colors[NativeTheme::State::kNormal] = gfx::kMaterialBlue300;
-  start_colors[NativeTheme::State::kPressed] = gfx::kMaterialBlue300;
+  start_colors[ButtonBackgroundType::DISABLED] = gfx::kMaterialGrey300;
+  start_colors[ButtonBackgroundType::HIGHLIGHTED] = gfx::kMaterialBlue300;
+  start_colors[ButtonBackgroundType::NORMAL] = SK_ColorWHITE;
+  start_colors[ButtonBackgroundType::PRESSED] = gfx::kMaterialBlue300;
   ColorByState end_colors;
-  end_colors[NativeTheme::State::kDisabled] = gfx::kMaterialGrey300;
-  end_colors[NativeTheme::State::kHovered] = gfx::kMaterialBlue700;
-  end_colors[NativeTheme::State::kNormal] = gfx::kMaterialBlue700;
-  end_colors[NativeTheme::State::kPressed] = gfx::kMaterialBlue700;
+  end_colors[ButtonBackgroundType::DISABLED] = gfx::kMaterialGrey300;
+  end_colors[ButtonBackgroundType::HIGHLIGHTED] = gfx::kMaterialBlue700;
+  end_colors[ButtonBackgroundType::NORMAL] = SK_ColorWHITE;
+  end_colors[ButtonBackgroundType::PRESSED] = gfx::kMaterialBlue700;
 
-  SkColor gradient_colors[] = {
-    start_colors[state], start_colors[state], end_colors[state]
-  };
+  SkColor gradient_colors[] = {start_colors[type], start_colors[type],
+                               end_colors[type]};
 
   return SkGradientShader::MakeLinear(
       gradient_points, gradient_colors, gradient_positions, 3,
       SkShader::kClamp_TileMode);
 }
 
 NativeThemeMac::NativeThemeMac() {
 }
 
 NativeThemeMac::~NativeThemeMac() {
 }
 
 }  // namespace ui