From dc30b8637748e431583c65fd89f1793f031d0beb Mon Sep 17 00:00:00 2001
From: Micha Hanselmann <DeerMichel@github.com>
Date: Fri, 19 Jul 2019 16:04:42 -0700
Subject: [PATCH] feat: support `isHighContrastColorScheme()` on macOS (#19331)

* change docs

* use NativeTheme to check high contrast scheme
---
 docs/api/system-preferences.md                |  2 +-
 .../api/atom_api_system_preferences.cc        |  4 +---
 .../api/atom_api_system_preferences_win.cc    | 21 -------------------
 3 files changed, 2 insertions(+), 25 deletions(-)

diff --git a/docs/api/system-preferences.md b/docs/api/system-preferences.md
index e4753eff35d1..f6dc2af28ffd 100644
--- a/docs/api/system-preferences.md
+++ b/docs/api/system-preferences.md
@@ -344,7 +344,7 @@ Returns one of several standard system colors that automatically adapt to vibran
 
 Returns `Boolean` - `true` if an inverted color scheme (a high contrast color scheme with light text and dark backgrounds) is active, `false` otherwise.
 
-### `systemPreferences.isHighContrastColorScheme()` _Windows_
+### `systemPreferences.isHighContrastColorScheme()` _macOS_ _Windows_
 
 Returns `Boolean` - `true` if a high contrast theme is active, `false` otherwise.
 
diff --git a/shell/browser/api/atom_api_system_preferences.cc b/shell/browser/api/atom_api_system_preferences.cc
index 0f51e6036295..b5d32871e33f 100644
--- a/shell/browser/api/atom_api_system_preferences.cc
+++ b/shell/browser/api/atom_api_system_preferences.cc
@@ -39,11 +39,9 @@ bool SystemPreferences::IsInvertedColorScheme() {
   return color_utils::IsInvertedColorScheme();
 }
 
-#if !defined(OS_WIN)
 bool SystemPreferences::IsHighContrastColorScheme() {
-  return false;
+  return ui::NativeTheme::GetInstanceForNativeUi()->UsesHighContrastColors();
 }
-#endif  // !defined(OS_WIN)
 
 v8::Local<v8::Value> SystemPreferences::GetAnimationSettings(
     v8::Isolate* isolate) {
diff --git a/shell/browser/api/atom_api_system_preferences_win.cc b/shell/browser/api/atom_api_system_preferences_win.cc
index d83de630bff9..2f0faea03628 100644
--- a/shell/browser/api/atom_api_system_preferences_win.cc
+++ b/shell/browser/api/atom_api_system_preferences_win.cc
@@ -20,18 +20,6 @@ namespace {
 const wchar_t kSystemPreferencesWindowClass[] =
     L"Electron_SystemPreferencesHostWindow";
 
-bool g_is_high_contract_color_scheme = false;
-bool g_is_high_contract_color_scheme_initialized = false;
-
-void UpdateHighContrastColorScheme() {
-  HIGHCONTRAST high_contrast = {0};
-  high_contrast.cbSize = sizeof(HIGHCONTRAST);
-  g_is_high_contract_color_scheme =
-      SystemParametersInfo(SPI_GETHIGHCONTRAST, 0, &high_contrast, 0) &&
-      ((high_contrast.dwFlags & HCF_HIGHCONTRASTON) != 0);
-  g_is_high_contract_color_scheme_initialized = true;
-}
-
 }  // namespace
 
 namespace api {
@@ -40,12 +28,6 @@ bool SystemPreferences::IsAeroGlassEnabled() {
   return ui::win::IsAeroGlassEnabled();
 }
 
-bool SystemPreferences::IsHighContrastColorScheme() {
-  if (!g_is_high_contract_color_scheme_initialized)
-    UpdateHighContrastColorScheme();
-  return g_is_high_contract_color_scheme;
-}
-
 std::string hexColorDWORDToRGBA(DWORD color) {
   DWORD rgba = color << 8 | color >> 24;
   std::ostringstream stream;
@@ -188,9 +170,6 @@ LRESULT CALLBACK SystemPreferences::WndProc(HWND hwnd,
       Emit("accent-color-changed", hexColorDWORDToRGBA(new_color));
       current_color_ = new_color_string;
     }
-  } else if (message == WM_SYSCOLORCHANGE ||
-             (message == WM_SETTINGCHANGE && wparam == SPI_SETHIGHCONTRAST)) {
-    UpdateHighContrastColorScheme();
   }
   return ::DefWindowProc(hwnd, message, wparam, lparam);
 }