feat(window): add Wails v3 adapter

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/window/options.go

@@ -62,6 +62,6 @@ func WithBackgroundColour(r, g, b, a uint8) WindowOption {
 	return func(w *Window) error { w.BackgroundColour = [4]uint8{r, g, b, a}; return nil }
 }
 
-func WithCentered(centered bool) WindowOption {
-	return func(w *Window) error { w.Centered = centered; return nil }
+func WithFileDrop(enabled bool) WindowOption {
+	return func(w *Window) error { w.EnableFileDrop = enabled; return nil }
 }

pkg/window/platform.go

@@ -21,8 +21,7 @@ type PlatformWindowOptions struct {
 	AlwaysOnTop           bool
 	BackgroundColour      [4]uint8 // RGBA
 	DisableResize         bool
-	EnableDragAndDrop     bool
-	Centered              bool
+	EnableFileDrop        bool
 }
 
 // PlatformWindow is a live window handle from the backend.

pkg/window/wails.go

@@ -0,0 +1,128 @@
+// pkg/window/wails.go
+package window
+
+import (
+	"github.com/wailsapp/wails/v3/pkg/application"
+	"github.com/wailsapp/wails/v3/pkg/events"
+)
+
+// WailsPlatform implements Platform using Wails v3.
+type WailsPlatform struct {
+	app *application.App
+}
+
+// NewWailsPlatform creates a Wails-backed Platform.
+func NewWailsPlatform(app *application.App) *WailsPlatform {
+	return &WailsPlatform{app: app}
+}
+
+func (wp *WailsPlatform) CreateWindow(opts PlatformWindowOptions) PlatformWindow {
+	wOpts := application.WebviewWindowOptions{
+		Name:              opts.Name,
+		Title:             opts.Title,
+		URL:               opts.URL,
+		Width:             opts.Width,
+		Height:            opts.Height,
+		X:                 opts.X,
+		Y:                 opts.Y,
+		MinWidth:          opts.MinWidth,
+		MinHeight:         opts.MinHeight,
+		MaxWidth:          opts.MaxWidth,
+		MaxHeight:         opts.MaxHeight,
+		Frameless:         opts.Frameless,
+		Hidden:            opts.Hidden,
+		AlwaysOnTop:       opts.AlwaysOnTop,
+		DisableResize:  opts.DisableResize,
+		EnableFileDrop: opts.EnableFileDrop,
+		BackgroundColour:  application.NewRGBA(opts.BackgroundColour[0], opts.BackgroundColour[1], opts.BackgroundColour[2], opts.BackgroundColour[3]),
+	}
+	w := wp.app.Window.NewWithOptions(wOpts)
+	return &wailsWindow{w: w}
+}
+
+func (wp *WailsPlatform) GetWindows() []PlatformWindow {
+	all := wp.app.Window.GetAll()
+	out := make([]PlatformWindow, 0, len(all))
+	for _, w := range all {
+		if wv, ok := w.(*application.WebviewWindow); ok {
+			out = append(out, &wailsWindow{w: wv})
+		}
+	}
+	return out
+}
+
+// wailsWindow wraps *application.WebviewWindow to implement PlatformWindow.
+type wailsWindow struct {
+	w *application.WebviewWindow
+}
+
+func (ww *wailsWindow) Name() string             { return ww.w.Name() }
+func (ww *wailsWindow) Position() (int, int)     { return ww.w.Position() }
+func (ww *wailsWindow) Size() (int, int)         { return ww.w.Size() }
+func (ww *wailsWindow) IsMaximised() bool        { return ww.w.IsMaximised() }
+func (ww *wailsWindow) IsFocused() bool          { return ww.w.IsFocused() }
+func (ww *wailsWindow) SetTitle(title string)    { ww.w.SetTitle(title) }
+func (ww *wailsWindow) SetPosition(x, y int)     { ww.w.SetPosition(x, y) }
+func (ww *wailsWindow) SetSize(width, height int) { ww.w.SetSize(width, height) }
+func (ww *wailsWindow) SetBackgroundColour(r, g, b, a uint8) {
+	ww.w.SetBackgroundColour(application.NewRGBA(r, g, b, a))
+}
+func (ww *wailsWindow) SetVisibility(visible bool) {
+	if visible {
+		ww.w.Show()
+	} else {
+		ww.w.Hide()
+	}
+}
+func (ww *wailsWindow) SetAlwaysOnTop(alwaysOnTop bool) { ww.w.SetAlwaysOnTop(alwaysOnTop) }
+func (ww *wailsWindow) Maximise()                       { ww.w.Maximise() }
+func (ww *wailsWindow) Restore()                        { ww.w.Restore() }
+func (ww *wailsWindow) Minimise()                       { ww.w.Minimise() }
+func (ww *wailsWindow) Focus()                          { ww.w.Focus() }
+func (ww *wailsWindow) Close()                          { ww.w.Close() }
+func (ww *wailsWindow) Show()                           { ww.w.Show() }
+func (ww *wailsWindow) Hide()                           { ww.w.Hide() }
+func (ww *wailsWindow) Fullscreen()                     { ww.w.Fullscreen() }
+func (ww *wailsWindow) UnFullscreen()                   { ww.w.UnFullscreen() }
+
+func (ww *wailsWindow) OnWindowEvent(handler func(event WindowEvent)) {
+	name := ww.w.Name()
+
+	// Map common Wails window events to our WindowEvent type.
+	eventMap := map[events.WindowEventType]string{
+		events.Common.WindowFocus:     "focus",
+		events.Common.WindowLostFocus: "blur",
+		events.Common.WindowDidMove:   "move",
+		events.Common.WindowDidResize: "resize",
+		events.Common.WindowClosing:   "close",
+	}
+
+	for eventType, eventName := range eventMap {
+		typeName := eventName // capture for closure
+		ww.w.OnWindowEvent(eventType, func(event *application.WindowEvent) {
+			data := make(map[string]any)
+			switch typeName {
+			case "move":
+				x, y := ww.w.Position()
+				data["x"] = x
+				data["y"] = y
+			case "resize":
+				w, h := ww.w.Size()
+				data["width"] = w
+				data["height"] = h
+			}
+			handler(WindowEvent{
+				Type: typeName,
+				Name: name,
+				Data: data,
+			})
+		})
+	}
+}
+
+// Ensure wailsWindow satisfies PlatformWindow at compile time.
+var _ PlatformWindow = (*wailsWindow)(nil)
+
+// Ensure WailsPlatform satisfies Platform at compile time.
+var _ Platform = (*WailsPlatform)(nil)
+

pkg/window/window.go

@@ -20,8 +20,7 @@ type Window struct {
 	AlwaysOnTop       bool
 	BackgroundColour  [4]uint8
 	DisableResize     bool
-	EnableDragAndDrop bool
-	Centered          bool
+	EnableFileDrop    bool
 }
 
 // ToPlatformOptions converts a Window to PlatformWindowOptions for the backend.
@@ -33,8 +32,7 @@ func (w *Window) ToPlatformOptions() PlatformWindowOptions {
 		MaxWidth: w.MaxWidth, MaxHeight: w.MaxHeight,
 		Frameless: w.Frameless, Hidden: w.Hidden,
 		AlwaysOnTop: w.AlwaysOnTop, BackgroundColour: w.BackgroundColour,
-		DisableResize: w.DisableResize, EnableDragAndDrop: w.EnableDragAndDrop,
-		Centered: w.Centered,
+		DisableResize: w.DisableResize, EnableFileDrop: w.EnableFileDrop,
 	}
 }