Merge pull request #7518 from electron/inverted-color-scheme

Support detecting inverted color scheme on Windows

atom/browser/api/atom_api_system_preferences.cc

@@ -8,16 +8,21 @@
 #include "atom/common/native_mate_converters/value_converter.h"
 #include "atom/common/node_includes.h"
 #include "native_mate/dictionary.h"
+#include "ui/gfx/color_utils.h"
 
 namespace atom {
 
 namespace api {
 
-SystemPreferences::SystemPreferences(v8::Isolate* isolate) {
+SystemPreferences::SystemPreferences(v8::Isolate* isolate)
+#if defined(OS_WIN)
+    : color_change_listener_(this)
+#endif
+    {
   Init(isolate);
-  #if defined(OS_WIN)
+#if defined(OS_WIN)
   InitializeWindow();
-  #endif
+#endif
 }
 
 SystemPreferences::~SystemPreferences() {
@@ -29,6 +34,10 @@ bool SystemPreferences::IsDarkMode() {
 }
 #endif
 
+bool SystemPreferences::IsInvertedColorScheme() {
+  return color_utils::IsInvertedColorScheme();
+}
+
 // static
 mate::Handle<SystemPreferences> SystemPreferences::Create(
     v8::Isolate* isolate) {
@@ -60,6 +69,8 @@ void SystemPreferences::BuildPrototype(
       .SetMethod("isSwipeTrackingFromScrollEventsEnabled",
                  &SystemPreferences::IsSwipeTrackingFromScrollEventsEnabled)
 #endif
+      .SetMethod("isInvertedColorScheme",
+                 &SystemPreferences::IsInvertedColorScheme)
       .SetMethod("isDarkMode", &SystemPreferences::IsDarkMode);
 }
 

atom/browser/api/atom_api_system_preferences.h

@@ -12,6 +12,10 @@
 #include "base/values.h"
 #include "native_mate/handle.h"
 
+#if defined(OS_WIN)
+#include "ui/gfx/sys_color_change_listener.h"
+#endif
+
 namespace base {
 class DictionaryValue;
 }
@@ -20,7 +24,11 @@ namespace atom {
 
 namespace api {
 
-class SystemPreferences : public mate::EventEmitter<SystemPreferences> {
+class SystemPreferences : public mate::EventEmitter<SystemPreferences>
+#if defined(OS_WIN)
+    , public gfx::SysColorChangeListener
+#endif
+  {
  public:
   static mate::Handle<SystemPreferences> Create(v8::Isolate* isolate);
 
@@ -39,6 +47,8 @@ class SystemPreferences : public mate::EventEmitter<SystemPreferences> {
 
   void InitializeWindow();
 
+  // gfx::SysColorChangeListener:
+  void OnSysColorChange() override;
 
 #elif defined(OS_MACOSX)
   using NotificationCallback = base::Callback<
@@ -59,6 +69,7 @@ class SystemPreferences : public mate::EventEmitter<SystemPreferences> {
   bool IsSwipeTrackingFromScrollEventsEnabled();
 #endif
   bool IsDarkMode();
+  bool IsInvertedColorScheme();
 
  protected:
   explicit SystemPreferences(v8::Isolate* isolate);
@@ -93,6 +104,10 @@ class SystemPreferences : public mate::EventEmitter<SystemPreferences> {
   HWND window_;
 
   std::string current_color_;
+
+  bool invertered_color_scheme_;
+
+  gfx::ScopedSysColorChangeListener color_change_listener_;
 #endif
   DISALLOW_COPY_AND_ASSIGN(SystemPreferences);
 };

atom/browser/api/atom_api_system_preferences_win.cc

@@ -42,6 +42,8 @@ std::string SystemPreferences::GetAccentColor() {
 }
 
 void SystemPreferences::InitializeWindow() {
+  invertered_color_scheme_ = IsInvertedColorScheme();
+
   WNDCLASSEX window_class;
   base::win::InitializeWindowClass(
       kSystemPreferencesWindowClass,
@@ -88,6 +90,14 @@ LRESULT CALLBACK SystemPreferences::WndProc(HWND hwnd,
   return ::DefWindowProc(hwnd, message, wparam, lparam);
 }
 
+void SystemPreferences::OnSysColorChange() {
+  bool new_invertered_color_scheme = IsInvertedColorScheme();
+  if (new_invertered_color_scheme != invertered_color_scheme_) {
+    invertered_color_scheme_ = new_invertered_color_scheme;
+    Emit("inverted-color-scheme-changed", new_invertered_color_scheme);
+  }
+}
+
 }  // namespace api
 
 }  // namespace atom

docs/api/system-preferences.md

@@ -17,8 +17,15 @@ Returns:
 
 * `event` Event
 * `newColor` String - The new RGBA color the user assigned to be there system
-accent color.
+  accent color.
 
+### Event: 'inverted-color-scheme-changed' _Windows_
+
+Returns:
+
+* `event` Event
+* `invertedColorScheme` Boolean - `true` if an inverted color scheme, such as
+  a high contrast theme, is being used, `false` otherwise.
 
 ## Methods
 
@@ -150,3 +157,8 @@ const green = color.substr(2, 2) // "bb"
 const blue = color.substr(4, 2) // "cc"
 const alpha = color.substr(6, 2) // "dd"
 ```
+
+### `systemPreferences.isInvertedColorScheme()` _Windows_
+
+Returns `Boolean` - `true` if an inverted color scheme, such as a high contrast
+theme, is active, `false` otherwise.

spec/api-system-preferences-spec.js

@@ -30,4 +30,10 @@ describe('systemPreferences module', function () {
       assert(languages.length > 0)
     })
   })
+
+  describe('systemPreferences.isInvertedColorScheme()', function () {
+    it('returns a boolean', function () {
+      assert.equal(typeof systemPreferences.isInvertedColorScheme(), 'boolean')
+    })
+  })
 })