Menu to follow theme

v2/internal/platform/systray/windows.go

@@ -336,6 +336,10 @@ func (p *Systray) updateIcon() error {
 	return p.setIcon(newIcon)
 }
 
+func (p *Systray) updateTheme() {
+	//win32.SetTheme(p.hwnd, win32.IsCurrentlyDarkMode())
+}
+
 func RegisterWindow(name string, proc win32.WindowProc) (win32.HINSTANCE, error) {
 	instance, exists := windowClasses[name]
 	if exists {

v2/internal/platform/win32/consts.go

@@ -1,6 +1,8 @@
 package win32
 
 import (
+	"github.com/wailsapp/wails/v2/internal/system/operatingsystem"
+	"golang.org/x/sys/windows"
 	"syscall"
 	"unsafe"
 )
@@ -28,11 +30,79 @@ var (
 	procTranslateMessage         = moduser32.NewProc("TranslateMessage")
 	procDispatchMessage          = moduser32.NewProc("DispatchMessageW")
 	procPostQuitMessage          = moduser32.NewProc("PostQuitMessage")
+	procSystemParametersInfo     = moduser32.NewProc("SystemParametersInfoW")
 
 	modshell32          = syscall.NewLazyDLL("shell32.dll")
 	procShellNotifyIcon = modshell32.NewProc("Shell_NotifyIconW")
+
+	moddwmapi                 = syscall.NewLazyDLL("dwmapi.dll")
+	procDwmSetWindowAttribute = moddwmapi.NewProc("DwmSetWindowAttribute")
+
+	moduxtheme         = syscall.NewLazyDLL("uxtheme.dll")
+	procSetWindowTheme = moduxtheme.NewProc("SetWindowTheme")
+
+	AllowDarkModeForWindow func(HWND, bool) uintptr
+	SetPreferredAppMode    func(int32) uintptr
 )
 
+type PreferredAppMode = int32
+
+const (
+	PreferredAppModeDefault PreferredAppMode = iota
+	PreferredAppModeAllowDark
+	PreferredAppModeForceDark
+	PreferredAppModeForceLight
+	PreferredAppModeMax
+)
+
+/*
+RtlGetNtVersionNumbers = void (LPDWORD major, LPDWORD minor, LPDWORD build) // 1809 17763
+ShouldAppsUseDarkMode = bool () // ordinal 132
+AllowDarkModeForWindow = bool (HWND hWnd, bool allow) // ordinal 133
+AllowDarkModeForApp = bool (bool allow) // ordinal 135, removed since 18334
+FlushMenuThemes = void () // ordinal 136
+RefreshImmersiveColorPolicyState = void () // ordinal 104
+IsDarkModeAllowedForWindow = bool (HWND hWnd) // ordinal 137
+GetIsImmersiveColorUsingHighContrast = bool (IMMERSIVE_HC_CACHE_MODE mode) // ordinal 106
+OpenNcThemeData = HTHEME (HWND hWnd, LPCWSTR pszClassList) // ordinal 49
+// Insider 18290
+ShouldSystemUseDarkMode = bool () // ordinal 138
+// Insider 18334
+SetPreferredAppMode = PreferredAppMode (PreferredAppMode appMode) // ordinal 135, since 18334
+IsDarkModeAllowedForApp = bool () // ordinal 139
+*/
+func init() {
+	if IsWindowsVersionAtLeast(10, 0, 18334) {
+
+		// AllowDarkModeForWindow is only available on Windows 10+
+		uxtheme, err := windows.LoadLibrary("uxtheme.dll")
+		if err == nil {
+			procAllowDarkModeForWindow, err := windows.GetProcAddressByOrdinal(uxtheme, uintptr(133))
+			if err == nil {
+				AllowDarkModeForWindow = func(hwnd HWND, allow bool) uintptr {
+					var allowInt int32
+					if allow {
+						allowInt = 1
+					}
+					ret, _, _ := syscall.SyscallN(procAllowDarkModeForWindow, uintptr(hwnd), uintptr(allowInt))
+					return ret
+				}
+			}
+		}
+
+		// SetPreferredAppMode is only available on Windows 10+
+		procSetPreferredAppMode, err := windows.GetProcAddressByOrdinal(uxtheme, uintptr(135))
+		if err == nil {
+			SetPreferredAppMode = func(mode int32) uintptr {
+				ret, _, _ := syscall.SyscallN(procSetPreferredAppMode, uintptr(mode))
+				return ret
+			}
+			SetPreferredAppMode(PreferredAppModeAllowDark)
+		}
+	}
+
+}
+
 type HANDLE uintptr
 type HINSTANCE HANDLE
 type HICON HANDLE
@@ -117,6 +187,14 @@ const (
 	CS_HREDRAW = 0x0002
 )
 
+var windowsVersion, _ = operatingsystem.GetWindowsVersionInfo()
+
+func IsWindowsVersionAtLeast(major, minor, buildNumber int) bool {
+	return windowsVersion.Major >= major &&
+		windowsVersion.Minor >= minor &&
+		windowsVersion.Build >= buildNumber
+}
+
 type WindowProc func(hwnd HWND, msg uint32, wparam, lparam uintptr) uintptr
 
 func GetModuleHandle(value uintptr) uintptr {

v2/internal/platform/win32/theme.go

@@ -2,8 +2,100 @@ package win32
 
 import (
 	"golang.org/x/sys/windows/registry"
+	"unsafe"
 )
 
+type DWMWINDOWATTRIBUTE int32
+
+const DwmwaUseImmersiveDarkModeBefore20h1 DWMWINDOWATTRIBUTE = 19
+const DwmwaUseImmersiveDarkMode DWMWINDOWATTRIBUTE = 20
+const DwmwaBorderColor DWMWINDOWATTRIBUTE = 34
+const DwmwaCaptionColor DWMWINDOWATTRIBUTE = 35
+const DwmwaTextColor DWMWINDOWATTRIBUTE = 36
+const DwmwaSystemBackdropType DWMWINDOWATTRIBUTE = 38
+
+const SPI_GETHIGHCONTRAST = 0x0042
+const HCF_HIGHCONTRASTON = 0x00000001
+
+// BackdropType defines the type of translucency we wish to use
+type BackdropType int32
+
+func dwmSetWindowAttribute(hwnd HWND, dwAttribute DWMWINDOWATTRIBUTE, pvAttribute unsafe.Pointer, cbAttribute uintptr) {
+	ret, _, err := procDwmSetWindowAttribute.Call(
+		uintptr(hwnd),
+		uintptr(dwAttribute),
+		uintptr(pvAttribute),
+		cbAttribute)
+	if ret != 0 {
+		_ = err
+		// println(err.Error())
+	}
+}
+
+func SupportsThemes() bool {
+	// We can't support Windows versions before 17763
+	return IsWindowsVersionAtLeast(10, 0, 17763)
+}
+
+func SupportsCustomThemes() bool {
+	return IsWindowsVersionAtLeast(10, 0, 17763)
+}
+
+func SupportsBackdropTypes() bool {
+	return IsWindowsVersionAtLeast(10, 0, 22621)
+}
+
+func SupportsImmersiveDarkMode() bool {
+	return IsWindowsVersionAtLeast(10, 0, 18985)
+}
+
+func SetTheme(hwnd HWND, useDarkMode bool) {
+	if SupportsThemes() {
+		attr := DwmwaUseImmersiveDarkModeBefore20h1
+		if SupportsImmersiveDarkMode() {
+			attr = DwmwaUseImmersiveDarkMode
+		}
+		var winDark int32
+		if useDarkMode {
+			winDark = 1
+		}
+		dwmSetWindowAttribute(hwnd, attr, unsafe.Pointer(&winDark), unsafe.Sizeof(winDark))
+	}
+}
+
+func EnableTranslucency(hwnd HWND, backdrop BackdropType) {
+	if SupportsBackdropTypes() {
+		dwmSetWindowAttribute(hwnd, DwmwaSystemBackdropType, unsafe.Pointer(&backdrop), unsafe.Sizeof(backdrop))
+	} else {
+		println("Warning: Translucency type unavailable on Windows < 22621")
+	}
+}
+
+func SetTitleBarColour(hwnd HWND, titleBarColour int32) {
+	dwmSetWindowAttribute(hwnd, DwmwaCaptionColor, unsafe.Pointer(&titleBarColour), unsafe.Sizeof(titleBarColour))
+}
+
+func SetTitleTextColour(hwnd HWND, titleTextColour int32) {
+	dwmSetWindowAttribute(hwnd, DwmwaTextColor, unsafe.Pointer(&titleTextColour), unsafe.Sizeof(titleTextColour))
+}
+
+func SetBorderColour(hwnd HWND, titleBorderColour int32) {
+	dwmSetWindowAttribute(hwnd, DwmwaBorderColor, unsafe.Pointer(&titleBorderColour), unsafe.Sizeof(titleBorderColour))
+}
+
+func SetWindowTheme(hwnd HWND, appName string, subIdList string) uintptr {
+	var subID uintptr
+	if subIdList != "" {
+		subID = MustStringToUTF16uintptr(subIdList)
+	}
+	ret, _, _ := procSetWindowTheme.Call(
+		uintptr(hwnd),
+		MustStringToUTF16uintptr(appName),
+		subID,
+	)
+
+	return ret
+}
 func IsCurrentlyDarkMode() bool {
 	key, err := registry.OpenKey(registry.CURRENT_USER, `SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize`, registry.QUERY_VALUE)
 	if err != nil {
@@ -17,3 +109,21 @@ func IsCurrentlyDarkMode() bool {
 	}
 	return AppsUseLightTheme == 0
 }
+
+type highContrast struct {
+	CbSize            uint32
+	DwFlags           uint32
+	LpszDefaultScheme *int16
+}
+
+func IsCurrentlyHighContrastMode() bool {
+	var result highContrast
+	result.CbSize = uint32(unsafe.Sizeof(result))
+	res, _, err := procSystemParametersInfo.Call(SPI_GETHIGHCONTRAST, uintptr(result.CbSize), uintptr(unsafe.Pointer(&result)), 0)
+	if res == 0 {
+		_ = err
+		return false
+	}
+	r := result.DwFlags&HCF_HIGHCONTRASTON == HCF_HIGHCONTRASTON
+	return r
+}