feat(window): add Platform and PlatformWindow interfaces

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

pkg/window/mock_test.go

@@ -0,0 +1,66 @@
+// pkg/window/mock_test.go
+package window
+
+type mockPlatform struct {
+	windows []*mockWindow
+}
+
+func newMockPlatform() *mockPlatform {
+	return &mockPlatform{}
+}
+
+func (m *mockPlatform) CreateWindow(opts PlatformWindowOptions) PlatformWindow {
+	w := &mockWindow{
+		name: opts.Name, title: opts.Title, url: opts.URL,
+		width: opts.Width, height: opts.Height,
+		x: opts.X, y: opts.Y,
+	}
+	m.windows = append(m.windows, w)
+	return w
+}
+
+func (m *mockPlatform) GetWindows() []PlatformWindow {
+	out := make([]PlatformWindow, len(m.windows))
+	for i, w := range m.windows {
+		out[i] = w
+	}
+	return out
+}
+
+type mockWindow struct {
+	name, title, url     string
+	width, height, x, y  int
+	maximised, focused   bool
+	visible, alwaysOnTop bool
+	closed               bool
+	eventHandlers        []func(WindowEvent)
+}
+
+func (w *mockWindow) Name() string                            { return w.name }
+func (w *mockWindow) Position() (int, int)                    { return w.x, w.y }
+func (w *mockWindow) Size() (int, int)                        { return w.width, w.height }
+func (w *mockWindow) IsMaximised() bool                       { return w.maximised }
+func (w *mockWindow) IsFocused() bool                         { return w.focused }
+func (w *mockWindow) SetTitle(title string)                   { w.title = title }
+func (w *mockWindow) SetPosition(x, y int)                    { w.x = x; w.y = y }
+func (w *mockWindow) SetSize(width, height int)               { w.width = width; w.height = height }
+func (w *mockWindow) SetBackgroundColour(r, g, b, a uint8)    {}
+func (w *mockWindow) SetVisibility(visible bool)              { w.visible = visible }
+func (w *mockWindow) SetAlwaysOnTop(alwaysOnTop bool)         { w.alwaysOnTop = alwaysOnTop }
+func (w *mockWindow) Maximise()                               { w.maximised = true }
+func (w *mockWindow) Restore()                                { w.maximised = false }
+func (w *mockWindow) Minimise()                               {}
+func (w *mockWindow) Focus()                                  { w.focused = true }
+func (w *mockWindow) Close()                                  { w.closed = true }
+func (w *mockWindow) Show()                                   { w.visible = true }
+func (w *mockWindow) Hide()                                   { w.visible = false }
+func (w *mockWindow) Fullscreen()                             {}
+func (w *mockWindow) UnFullscreen()                           {}
+func (w *mockWindow) OnWindowEvent(handler func(WindowEvent)) { w.eventHandlers = append(w.eventHandlers, handler) }
+
+// emit fires a test event to all registered handlers.
+func (w *mockWindow) emit(e WindowEvent) {
+	for _, h := range w.eventHandlers {
+		h(e)
+	}
+}

pkg/window/platform.go

@@ -0,0 +1,67 @@
+// pkg/window/platform.go
+package window
+
+// Platform abstracts the windowing backend (Wails v3).
+type Platform interface {
+	CreateWindow(opts PlatformWindowOptions) PlatformWindow
+	GetWindows() []PlatformWindow
+}
+
+// PlatformWindowOptions are the backend-specific options passed to CreateWindow.
+type PlatformWindowOptions struct {
+	Name                  string
+	Title                 string
+	URL                   string
+	Width, Height         int
+	X, Y                  int
+	MinWidth, MinHeight   int
+	MaxWidth, MaxHeight   int
+	Frameless             bool
+	Hidden                bool
+	AlwaysOnTop           bool
+	BackgroundColour      [4]uint8 // RGBA
+	DisableResize         bool
+	EnableDragAndDrop     bool
+	Centered              bool
+}
+
+// PlatformWindow is a live window handle from the backend.
+type PlatformWindow interface {
+	// Identity
+	Name() string
+
+	// Queries
+	Position() (int, int)
+	Size() (int, int)
+	IsMaximised() bool
+	IsFocused() bool
+
+	// Mutations
+	SetTitle(title string)
+	SetPosition(x, y int)
+	SetSize(width, height int)
+	SetBackgroundColour(r, g, b, a uint8)
+	SetVisibility(visible bool)
+	SetAlwaysOnTop(alwaysOnTop bool)
+
+	// Window state
+	Maximise()
+	Restore()
+	Minimise()
+	Focus()
+	Close()
+	Show()
+	Hide()
+	Fullscreen()
+	UnFullscreen()
+
+	// Events
+	OnWindowEvent(handler func(event WindowEvent))
+}
+
+// WindowEvent is emitted by the backend for window state changes.
+type WindowEvent struct {
+	Type string // "focus", "blur", "move", "resize", "close"
+	Name string // window name
+	Data map[string]any
+}