[v3 mac] Add IsDarkMode to application and JS runtime. Add Common.ThemeChanged event

v3/STATUS.md

@@ -136,6 +136,12 @@ explicitly set with `--default-contextmenu: show`.
 | GetPrimary | Y       | Y     | Y   |       |
 | GetCurrent | Y       | Y     | Y   |       |
 
+### System
+
+| Feature    | Windows | Linux | Mac | Notes |
+|------------|---------|-------|-----|-------|
+| IsDarkMode |         |       | Y   |       |
+
 ### Window
 
 Y = Supported

v3/examples/dev/go.mod

@@ -68,4 +68,5 @@ require (
 	mvdan.cc/sh/v3 v3.7.0 // indirect
 )
 
-replace github.com/wailsapp/wails/v3 => D:\GolandProjects\wails\v3
+replace github.com/wailsapp/wails/v3 => ../..
+

v3/examples/dev/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"embed"
 	_ "embed"
+	"github.com/wailsapp/wails/v3/pkg/events"
 	"log"
 
 	"github.com/wailsapp/wails/v3/pkg/application"
@@ -35,6 +36,14 @@ func main() {
 		URL: "/",
 	})
 
+	app.On(events.Common.ThemeChanged, func(e *application.Event) {
+		if app.IsDarkMode() {
+			log.Println("Dark mode!")
+		} else {
+			log.Println("Light mode!")
+		}
+	})
+
 	err := app.Run()
 
 	if err != nil {

v3/internal/runtime/desktop/api/event_types.js

@@ -43,6 +43,7 @@ export const EventTypes = {
 		ApplicationWillTerminate: "mac:ApplicationWillTerminate",
 		ApplicationWillUnhide: "mac:ApplicationWillUnhide",
 		ApplicationWillUpdate: "mac:ApplicationWillUpdate",
+		ApplicationDidChangeTheme: "mac:ApplicationDidChangeTheme!",
 		WindowDidBecomeKey: "mac:WindowDidBecomeKey",
 		WindowDidBecomeMain: "mac:WindowDidBecomeMain",
 		WindowDidBeginSheet: "mac:WindowDidBeginSheet",
@@ -165,5 +166,6 @@ export const EventTypes = {
 		WindowShow: "common:WindowShow",
 		WindowHide: "common:WindowHide",
 		WindowDPIChanged: "common:WindowDPIChanged",
+		ThemeChanged: "common:ThemeChanged",
 	},
 };

v3/internal/runtime/desktop/main.js

@@ -13,6 +13,7 @@ The electron alternative for Go
 import * as Clipboard from './clipboard';
 import * as Application from './application';
 import * as Screens from './screens';
+import * as System from './system';
 import {Plugin, Call, callErrorCallback, callCallback} from "./calls";
 import {newWindow} from "./window";
 import {dispatchWailsEvent, Emit, Off, OffAll, On, Once, OnMultiple} from "./events";
@@ -53,6 +54,7 @@ export function newRuntime(windowName) {
                 return newRuntime(windowName);
             }
         },
+        System,
         Screens,
         Call,
         Plugin,

v3/internal/runtime/desktop/system.js

@@ -0,0 +1,23 @@
+/*
+ _	   __	  _ __
+| |	 / /___ _(_) /____
+| | /| / / __ `/ / / ___/
+| |/ |/ / /_/ / / (__  )
+|__/|__/\__,_/_/_/____/
+The electron alternative for Go
+(c) Lea Anthony 2019-present
+*/
+
+/* jshint esversion: 9 */
+
+import {newRuntimeCaller} from "./runtime";
+
+let call = newRuntimeCaller("system");
+
+/**
+ * Determines if the system is currently using dark mode
+ * @returns {Promise<boolean>}
+ */
+export function IsDarkMode() {
+    return call("IsDarkMode");
+}

v3/pkg/application/application.go

@@ -132,6 +132,7 @@ type (
 		getScreens() ([]*Screen, error)
 		GetFlags(options Options) map[string]any
 		isOnMainThread() bool
+		isDarkMode() bool
 	}
 
 	runnable interface {
@@ -653,6 +654,13 @@ func (a *App) dispatchEventToWindows(event *WailsEvent) {
 	}
 }
 
+func (a *App) IsDarkMode() bool {
+	if a.impl == nil {
+		return false
+	}
+	return a.impl.isDarkMode()
+}
+
 func (a *App) Hide() {
 	if a.impl != nil {
 		a.impl.hide()

v3/pkg/application/application_darwin.go

@@ -52,6 +52,24 @@ static void init(void) {
 		}
 		return event;
 	}];
+
+	NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
+	[center addObserver:appDelegate selector:@selector(themeChanged:) name:@"AppleInterfaceThemeChangedNotification" object:nil];
+
+}
+
+static bool isDarkMode(void) {
+	NSUserDefaults* userDefaults = [NSUserDefaults standardUserDefaults];
+	if (userDefaults == nil) {
+		return false;
+	}
+
+	NSString *interfaceStyle = [userDefaults stringForKey:@"AppleInterfaceStyle"];
+	if (interfaceStyle == nil) {
+		return false;
+	}
+
+	return [interfaceStyle isEqualToString:@"Dark"];
 }
 
 static void setApplicationShouldTerminateAfterLastWindowClosed(bool shouldTerminate) {
@@ -138,6 +156,10 @@ type macosApp struct {
 	parent          *App
 }
 
+func (m *macosApp) isDarkMode() bool {
+	return bool(C.isDarkMode())
+}
+
 func getNativeApplication() *macosApp {
 	return globalApplication.impl.(*macosApp)
 }

v3/pkg/application/application_darwin_delegate.m

@@ -12,6 +12,11 @@ extern bool hasListeners(unsigned int);
 {
     return self.shouldTerminateWhenLastWindowClosed;
 }
+- (void)themeChanged:(NSNotification *)notification {
+    if( hasListeners(EventApplicationDidChangeTheme) ) {
+        processApplicationEvent(EventApplicationDidChangeTheme);
+    }
+}
 // GENERATED EVENTS START
 - (void)applicationDidBecomeActive:(NSNotification *)notification {
     if( hasListeners(EventApplicationDidBecomeActive) ) {

v3/pkg/application/events_common_darwin.go

@@ -6,6 +6,7 @@ import "github.com/wailsapp/wails/v3/pkg/events"
 
 var commonApplicationEventMap = map[events.ApplicationEventType]events.ApplicationEventType{
 	events.Mac.ApplicationDidFinishLaunching: events.Common.ApplicationStarted,
+	events.Mac.ApplicationDidChangeTheme:     events.Common.ThemeChanged,
 }
 
 func (m *macosApp) setupCommonEvents() {

v3/pkg/application/messageprocessor.go

@@ -94,6 +94,8 @@ func (m *MessageProcessor) HandleRuntimeCall(rw http.ResponseWriter, r *http.Req
 		m.processScreensMethod(method, rw, r, targetWindow, params)
 	case "call":
 		m.processCallMethod(method, rw, r, targetWindow, params)
+	case "system":
+		m.processSystemMethod(method, rw, r, targetWindow, params)
 	default:
 		m.httpError(rw, "Unknown runtime call: %s", object)
 	}

v3/pkg/application/messageprocessor_application.go

@@ -16,8 +16,10 @@ func (m *MessageProcessor) processApplicationMethod(method string, rw http.Respo
 	case "Show":
 		globalApplication.Show()
 		m.ok(rw)
+	case "IsDarkMode":
+		m.json(rw, globalApplication.IsDarkMode())
 	default:
-		m.httpError(rw, "Unknown event method: %s", method)
+		m.httpError(rw, "Unknown application method: %s", method)
 	}
 
 	m.Info("Runtime:", "method", "Application."+method)

v3/pkg/application/messageprocessor_call.go

@@ -63,7 +63,7 @@ func (m *MessageProcessor) processCallMethod(method string, rw http.ResponseWrit
 		}()
 		m.ok(rw)
 	default:
-		m.httpError(rw, "Unknown dialog method: %s", method)
+		m.httpError(rw, "Unknown call method: %s", method)
 	}
 
 }

v3/pkg/application/messageprocessor_contextmenu.go

@@ -24,7 +24,7 @@ func (m *MessageProcessor) processContextMenuMethod(method string, rw http.Respo
 		window.openContextMenu(&data)
 		m.ok(rw)
 	default:
-		m.httpError(rw, "Unknown clipboard method: %s", method)
+		m.httpError(rw, "Unknown contextmenu method: %s", method)
 	}
 
 	m.Info("Runtime:", "method", "ContextMenu."+method)