Match window border color to app theme rather than OS theme (#958)

* MacOS: match window chrome to app light/dark mode when app setting is different from OS

* match window border to app theme on Windows

main.go

@@ -16,6 +16,8 @@ import (
 	"github.com/dweymouth/supersonic/res"
 	"github.com/dweymouth/supersonic/res/wintaskbarthumbs"
 	"github.com/dweymouth/supersonic/ui"
+	"github.com/dweymouth/supersonic/ui/controller"
+	myTheme "github.com/dweymouth/supersonic/ui/theme"
 	"github.com/dweymouth/supersonic/ui/util"
 	"golang.org/x/term"
 
@@ -133,6 +135,9 @@ func main() {
 		fyneApp.Run()
 	} else {
 		fyneApp.Lifecycle().SetOnStarted(func() {
+			if mode := fyne.CurrentApp().Settings().Theme().(*myTheme.MyTheme).AppearanceMode(); mode != myTheme.AppearanceAuto {
+				controller.SetWindowThemeMode(mainWindow.Window, mode)
+			}
 			defaultServer := myApp.ServerManager.GetDefaultServer()
 			if defaultServer == nil {
 				mainWindow.Controller.PromptForFirstServer()

ui/controller/controller.go

@@ -10,6 +10,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"runtime"
 	"time"
 
 	fynetooltip "github.com/dweymouth/fyne-tooltip"
@@ -26,6 +27,7 @@ import (
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/container"
 	"fyne.io/fyne/v2/dialog"
+	"fyne.io/fyne/v2/driver"
 	"fyne.io/fyne/v2/lang"
 	"fyne.io/fyne/v2/layout"
 	"fyne.io/fyne/v2/theme"
@@ -655,3 +657,22 @@ func (c *Controller) GetSongRadioTracks(sourceTrack *mediaprovider.Track) ([]*me
 	tracks = append(tracks, filteredTracks...)
 	return tracks, nil
 }
+
+func SetWindowThemeMode(win fyne.Window, mode myTheme.AppearanceMode) {
+	arg := 0
+	switch fyne.CurrentApp().Settings().Theme().(*myTheme.MyTheme).AppearanceMode() {
+	case myTheme.AppearanceDark:
+		arg = 1
+	case myTheme.AppearanceLight:
+		arg = 2
+	}
+	win.(driver.NativeWindow).RunNative(func(ctx any) {
+		switch runtime.GOOS {
+		case "darwin":
+			// ensure dark mode setting is applied to window controls in title bar on Mac
+			setWindowDarkTheme(ctx.(driver.MacWindowContext).NSWindow, arg)
+		case "windows":
+			setWindowDarkTheme(ctx.(driver.WindowsWindowContext).HWND, arg)
+		}
+	})
+}

ui/controller/visualizations.go

@@ -9,6 +9,7 @@ import (
 	"github.com/dweymouth/supersonic/backend/player"
 	"github.com/dweymouth/supersonic/backend/player/mpv"
 	"github.com/dweymouth/supersonic/ui/shortcuts"
+	myTheme "github.com/dweymouth/supersonic/ui/theme"
 	"github.com/dweymouth/supersonic/ui/util"
 	"github.com/dweymouth/supersonic/ui/visualizations"
 )
@@ -68,6 +69,7 @@ func (c *Controller) ShowPeakMeter() {
 		c.peakMeter.Refresh()
 	}
 	c.peakMeterWin.Show()
+	SetWindowThemeMode(c.peakMeterWin, fyne.CurrentApp().Settings().Theme().(*myTheme.MyTheme).AppearanceMode())
 }
 
 func (c *Controller) stopVisualizationAnim() {

ui/controller/windowtheme.m

@@ -0,0 +1,20 @@
+//go:build darwin
+
+#import <AppKit/AppKit.h>
+
+void setWindowDarkMode(void* windowPtr, int mode) {
+    if (windowPtr == NULL) return;
+
+    NSWindow* window = (__bridge NSWindow*)windowPtr;
+
+    if (mode == 1) {
+        // Forces the window chrome and borders into Dark Mode
+        window.appearance = [NSAppearance appearanceNamed:NSAppearanceNameVibrantDark];
+    } else if (mode == 2) {
+        // Forces the window chrome and borders into Light Mode
+        window.appearance = [NSAppearance appearanceNamed:NSAppearanceNameVibrantLight];
+    } else {
+        // Reverts the window back to standard/system default behavior
+        window.appearance = nil; // Fallback to inherited system style
+    }
+}

ui/controller/windowtheme_darwin.go

@@ -0,0 +1,16 @@
+//go:build darwin
+
+package controller
+
+/*
+void setWindowDarkMode(void* windowPtr, int useDarkMode);
+*/
+import "C"
+import "unsafe"
+
+// setWindowDarkTheme takes an unsafe.Pointer referencing the macOS NSWindow
+// and explicitly applies or clears the dark mode appearance.
+// Mode arg: 0 = auto, 1 = dark, 2 = light
+func setWindowDarkTheme(nsWindowPtr uintptr, mode int) {
+	C.setWindowDarkMode(unsafe.Pointer(nsWindowPtr), C.int(mode))
+}

ui/controller/windowtheme_other.go

@@ -0,0 +1,5 @@
+//go:build !darwin && !windows
+
+package controller
+
+func setWindowDarkTheme(ptr uintptr, mode int) {}

ui/controller/windowtheme_windows.go

@@ -0,0 +1,57 @@
+//go:build windows
+
+package controller
+
+import (
+	"runtime"
+	"syscall"
+	"unsafe"
+
+	"fyne.io/fyne/v2"
+	"golang.org/x/sys/windows/registry"
+)
+
+var (
+	dwm    = syscall.NewLazyDLL("dwmapi.dll")
+	setAtt = dwm.NewProc("DwmSetWindowAttribute")
+)
+
+func setWindowDarkTheme(hwnd uintptr, mode int) {
+	if runtime.GOOS != "windows" {
+		return
+	}
+	arg := 0
+	switch mode {
+	case 0: /*auto*/
+		if isDark() {
+			arg = 1
+		}
+	case 1: /*dark*/
+		arg = 1
+	}
+
+	// copied from Fyne internals
+	ret, _, err := setAtt.Call(uintptr(unsafe.Pointer(hwnd)), // window handle
+		20,                            // DWMWA_USE_IMMERSIVE_DARK_MODE
+		uintptr(unsafe.Pointer(&arg)), // on or off
+		4)                             // sizeof(bool for windows))
+	if ret != 0 && ret != 0x80070057 { // err is always non-nil, we check return value (except erroneous code)
+		fyne.LogError("Failed to set dark mode", err)
+	}
+}
+
+// copied from Fyne internals
+func isDark() bool {
+	k, err := registry.OpenKey(registry.CURRENT_USER, `SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize`, registry.QUERY_VALUE)
+	if err != nil { // older version of Windows will not have this key
+		return false
+	}
+	defer k.Close()
+
+	useLight, _, err := k.GetIntegerValue("AppsUseLightTheme")
+	if err != nil { // older version of Windows will not have this value
+		return false
+	}
+
+	return useLight == 0
+}

ui/mainwindow.go

@@ -557,6 +557,9 @@ func (m *MainWindow) addShortcuts() {
 func (m *MainWindow) showSettingsDialog() {
 	m.Controller.ShowSettingsDialog(func() {
 		fyne.CurrentApp().Settings().SetTheme(m.theme)
+		for _, w := range fyne.CurrentApp().Driver().AllWindows() {
+			controller.SetWindowThemeMode(w, m.theme.AppearanceMode())
+		}
 	}, m.theme.ListThemeFiles())
 }
 

ui/theme/theme.go

@@ -115,6 +115,16 @@ func (m *MyTheme) ReloadThemeFile() {
 	m.loadedThemeFile = nil
 }
 
+func (m *MyTheme) AppearanceMode() AppearanceMode {
+	v := DefaultAppearance // default if config has invalid or missing setting
+	if slices.Contains(
+		[]string{string(AppearanceLight), string(AppearanceDark), string(AppearanceAuto)},
+		m.config.Appearance) {
+		v = AppearanceMode(m.config.Appearance)
+	}
+	return v
+}
+
 func (m *MyTheme) Color(name fyne.ThemeColorName, defVariant fyne.ThemeVariant) color.Color {
 	// load theme file if necessary
 	if m.loadedThemeFile == nil || m.config.ThemeFile != m.loadedThemeFilename {