Rename TranslucencyType -> BackdropType. Rename BackdropType consts. Add documentation for this option.

v2/internal/frontend/desktop/windows/win32/theme.go

@@ -17,14 +17,9 @@ 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
 
-const DwmsbtAuto BackdropType = 0
-const DwmsbtDisable = 1         // None
-const DwmsbtMainWindow = 2      // Mica
-const DwmsbtTransientWindow = 3 // Acrylic
-const DwmsbtTabbedWindow = 4    // Tabbed
-
 func dwmSetWindowAttribute(hwnd uintptr, dwAttribute DWMWINDOWATTRIBUTE, pvAttribute unsafe.Pointer, cbAttribute uintptr) {
 	ret, _, err := procDwmSetWindowAttribute.Call(
 		hwnd,
@@ -46,10 +41,18 @@ 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 uintptr, useDarkMode bool) {
-	if IsWindowsVersionAtLeast(10, 0, 17763) {
+	if SupportsThemes() {
 		attr := DwmwaUseImmersiveDarkModeBefore20h1
-		if IsWindowsVersionAtLeast(10, 0, 18985) {
+		if SupportsImmersiveDarkMode() {
 			attr = DwmwaUseImmersiveDarkMode
 		}
 		var winDark int32
@@ -61,10 +64,10 @@ func SetTheme(hwnd uintptr, useDarkMode bool) {
 }
 
 func EnableTranslucency(hwnd uintptr, backdrop BackdropType) {
-	if IsWindowsVersionAtLeast(10, 0, 22579) {
+	if SupportsBackdropTypes() {
 		dwmSetWindowAttribute(hwnd, DwmwaSystemBackdropType, unsafe.Pointer(&backdrop), unsafe.Sizeof(backdrop))
 	} else {
-		println("Warning: Translucency unavailable on Windows < 22579")
+		println("Warning: Translucency type unavailable on Windows < 22621")
 	}
 }
 

v2/internal/frontend/desktop/windows/window.go

@@ -105,11 +105,10 @@ func NewWindow(parent winc.Controller, appoptions *options.App, versionInfo *ope
 		result.OnSuspend = appoptions.Windows.OnSuspend
 		result.OnResume = appoptions.Windows.OnResume
 		if appoptions.Windows.WindowIsTranslucent {
-			// TODO: Migrate to win32 package
-			if !win32.IsWindowsVersionAtLeast(10, 0, 22579) {
+			if !win32.SupportsBackdropTypes() {
 				result.SetTranslucentBackground()
 			} else {
-				win32.EnableTranslucency(result.Handle(), win32.BackdropType(appoptions.Windows.TranslucencyType))
+				win32.EnableTranslucency(result.Handle(), win32.BackdropType(appoptions.Windows.BackdropType))
 			}
 		}
 

v2/pkg/options/windows/windows.go

@@ -27,11 +27,11 @@ const (
 type BackdropType int32
 
 const (
-	Auto            BackdropType = 0
-	Disable         BackdropType = 1 // None
-	MainWindow      BackdropType = 2 // Mica
-	TransientWindow BackdropType = 3 // Acrylic
-	TabbedWindow    BackdropType = 4 // Tabbed
+	Auto    BackdropType = 0
+	None    BackdropType = 1
+	Mica    BackdropType = 2
+	Acrylic BackdropType = 3
+	Tabbed  BackdropType = 4
 )
 
 func RGB(r, g, b uint8) int32 {
@@ -81,8 +81,8 @@ type Options struct {
 	// Custom settings for dark/light mode
 	CustomTheme *ThemeSettings
 
-	// Windows 11 22579 minimum
-	TranslucencyType BackdropType
+	// Select the type of translucent backdrop. Requires Windows 11 22621 or later.
+	BackdropType BackdropType
 
 	// User messages that can be customised
 	Messages *Messages

website/docs/reference/options.mdx

@@ -48,6 +48,7 @@ func main() {
         Windows: &windows.Options{
             WebviewIsTransparent:              false,
             WindowIsTranslucent:               false,
+            BackdropType:                      windows.Mica,
             DisableWindowIcon:                 false,
             DisableFramelessWindowDecorations: false,
             WebviewUserDataPath:               "",
@@ -381,11 +382,39 @@ Type: `bool`
 #### WindowIsTranslucent
 
 Setting this to `true` will make the window background translucent. Often combined
-with [WebviewIsTransparent](#WebviewIsTransparent) to make frosty-looking applications.
+with [WebviewIsTransparent](#WebviewIsTransparent).
+
+For Windows 11 versions before build 22621, this will use the [BlurBehind](https://learn.microsoft.com/en-us/windows/win32/dwm/blur-ovw)
+method for translucency, which can be slow. For Windows 11 versions after build 22621, this will enable the
+newer translucency types that are much faster. By default, the type of translucency used will be determined
+by Windows. To configure this, use the [BackdropType](#BackdropType) option.
 
 Name: WindowIsTranslucent<br/>
 Type: `bool`
 
+#### BackdropType 
+
+:::note
+
+Requires Windows 11 build 22621 or later.
+
+:::
+
+Sets the translucency type of the window. This is only applicable if [WindowIsTranslucent](#WindowIsTranslucent) is set to `true`.
+
+Name: BackdropType
+Type `windows.BackdropType`
+
+The Type can be one of the following:
+
+| Value   | Description                                                                               |
+|---------|-------------------------------------------------------------------------------------------|
+| Auto    | Let Windows decide which backdrop to use                                                  |
+| None    | Do not use translucency                                                                   |
+| Acrylic | Use [Acrylic](https://learn.microsoft.com/en-us/windows/apps/design/style/acrylic) effect |
+| Mica    | Use [Mica](https://learn.microsoft.com/en-us/windows/apps/design/style/mica) effect       |
+| Tabbed  | Use Tabbed. This is a backdrop that is similar to Mica.                                   |         
+
 #### DisableWindowIcon
 
 Setting this to `true` will remove the icon in the top left corner of the title bar.