Merge pull request #4646 from phamdaniel/dark-mode

Add API to check OSX's Dark theme

atom/browser/api/atom_api_app.cc

@@ -283,6 +283,12 @@ void App::OnGpuProcessCrashed(base::TerminationStatus exit_code) {
   Emit("gpu-process-crashed");
 }
 
+#if defined(OS_MACOSX)
+void App::OnPlatformThemeChanged() {
+  Emit("platform-theme-changed");
+}
+#endif
+
 base::FilePath App::GetPath(mate::Arguments* args, const std::string& name) {
   bool succeed = false;
   base::FilePath path;
@@ -371,6 +377,8 @@ mate::ObjectTemplateBuilder App::GetObjectTemplateBuilder(
 #if defined(OS_MACOSX)
       .SetMethod("hide", base::Bind(&Browser::Hide, browser))
       .SetMethod("show", base::Bind(&Browser::Show, browser))
+      .SetMethod("isDarkMode",
+                 base::Bind(&Browser::IsDarkMode, browser))
 #endif
 #if defined(OS_WIN)
       .SetMethod("setUserTasks",

atom/browser/api/atom_api_app.h

@@ -71,6 +71,10 @@ class App : public AtomBrowserClient::Delegate,
   // content::GpuDataManagerObserver:
   void OnGpuProcessCrashed(base::TerminationStatus exit_code) override;
 
+#if defined(OS_MACOSX)
+  void OnPlatformThemeChanged() override;
+#endif
+
   // mate::Wrappable:
   mate::ObjectTemplateBuilder GetObjectTemplateBuilder(
       v8::Isolate* isolate) override;

atom/browser/browser.cc

@@ -181,4 +181,8 @@ void Browser::OnWindowAllClosed() {
     FOR_EACH_OBSERVER(BrowserObserver, observers_, OnWindowAllClosed());
 }
 
+void Browser::PlatformThemeChanged() {
+  FOR_EACH_OBSERVER(BrowserObserver, observers_, OnPlatformThemeChanged());
+}
+
 }  // namespace atom

atom/browser/browser.h

@@ -83,6 +83,9 @@ class Browser : public WindowListObserver {
   // Show the application.
   void Show();
 
+  // Check if the system is in Dark Mode.
+  bool IsDarkMode();
+
   // Bounce the dock icon.
   enum BounceType {
     BOUNCE_CRITICAL = 0,
@@ -142,6 +145,9 @@ class Browser : public WindowListObserver {
   // Request basic auth login.
   void RequestLogin(LoginHandler* login_handler);
 
+  // Tell the application that plaform's theme changed.
+  void PlatformThemeChanged();
+
   void AddObserver(BrowserObserver* obs) {
     observers_.AddObserver(obs);
   }

atom/browser/browser_mac.mm

@@ -26,6 +26,11 @@ void Browser::Show() {
   [[AtomApplication sharedApplication] unhide:nil];
 }
 
+bool Browser::IsDarkMode() {
+  NSString *mode = [[NSUserDefaults standardUserDefaults] stringForKey:@"AppleInterfaceStyle"];
+  return [mode isEqualToString: @"Dark"];
+}
+
 void Browser::AddRecentDocument(const base::FilePath& path) {
   NSString* path_string = base::mac::FilePathToNSString(path);
   if (!path_string)

atom/browser/browser_observer.h

@@ -45,6 +45,8 @@ class BrowserObserver {
   // The browser requests HTTP login.
   virtual void OnLogin(LoginHandler* login_handler) {}
 
+  virtual void OnPlatformThemeChanged() {}
+
  protected:
   virtual ~BrowserObserver() {}
 };

atom/browser/mac/atom_application_delegate.mm

@@ -24,6 +24,9 @@
   // Don't add the "Enter Full Screen" menu item automatically.
   [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"NSFullScreenMenuItemEverywhere"];
 
+  // Add observer to monitor the system's Dark Mode theme.
+  [[NSDistributedNotificationCenter defaultCenter] addObserver:self selector:@selector(platformThemeChanged:) name:@"AppleInterfaceThemeChangedNotification" object:nil];
+
   atom::Browser::Get()->WillFinishLaunching();
 }
 
@@ -59,4 +62,8 @@
   return flag;
 }
 
+- (void)platformThemeChanged:(NSNotification *)notify {
+  atom::Browser::Get()->PlatformThemeChanged();
+}
+
 @end

docs/api/app.md

@@ -228,6 +228,10 @@ app.on('login', function(event, webContents, request, authInfo, callback) {
 
 Emitted when the gpu process crashes.
 
+### Event: 'platform-theme-changed' _OS X_
+
+Emitted when the system's Dark Mode theme is toggled.
+
 ## Methods
 
 The `app` object has the following methods:
@@ -461,6 +465,10 @@ if (browserOptions.transparent) {
 }
 ```
 
+### `app.isDarkMode()` _OS X_
+
+This method returns `true` if the system is in Dark Mode, and `false` otherwise.
+
 ### `app.commandLine.appendSwitch(switch[, value])`
 
 Append a switch (with optional `value`) to Chromium's command line.