Added the ability to make different window types

backend.go

@@ -21,9 +21,9 @@ type Backend interface {
 	Do (callback func ())
 
 	// NewWindow creates a new window with the specified width and height,
-	// and returns a struct representing it that fulfills the Window
+	// and returns a struct representing it that fulfills the MainWindow
 	// interface.
-	NewWindow (width, height int) (window elements.Window, err error)
+	NewWindow (width, height int) (window elements.MainWindow, err error)
 
 	// Copy puts data into the clipboard.
 	Copy (data.Data)

backends/x/window.go

@@ -14,6 +14,7 @@ import "git.tebibyte.media/sashakoshka/tomo/canvas"
 import "git.tebibyte.media/sashakoshka/tomo/elements"
 // import "runtime/debug"
 
+type mainWindow struct { *window }
 type window struct {
 	backend *Backend
 	xWindow *xwindow.Window
@@ -35,11 +36,21 @@ type window struct {
 func (backend *Backend) NewWindow (
 	width, height int,
 ) (
-	output elements.Window,
+	output elements.MainWindow,
 	err error,
 ) {
 	if backend == nil { panic("nil backend") }
+	window, err := backend.newWindow(width, height)
+	output = mainWindow { window }
+	return output, err
+}
 
+func (backend *Backend) newWindow (
+	width, height int,
+) (
+	output *window,
+	err error,
+) {
 	window := &window { backend: backend }
 
 	window.xWindow, err = xwindow.Generate(backend.connection)
@@ -86,6 +97,7 @@ func (backend *Backend) NewWindow (
 	window.reallocateCanvas()
 
 	backend.windows[window.xWindow.Id] = window
+
 	output = window
 	return
 }
@@ -195,6 +207,30 @@ func (window *window) SetIcon (sizes []image.Image) {
 		wmIcons)
 }
 
+func (window *window) NewModal (width, height int) (elements.Window, error) {
+	modal, err := window.backend.newWindow(width, height)
+	icccm.WmTransientForSet (
+		window.backend.connection,
+		modal.xWindow.Id,
+		window.xWindow.Id)
+	ewmh.WmStateSet (
+		window.backend.connection,
+		modal.xWindow.Id,
+		[]string { "_NET_WM_STATE_MODAL" })
+	return modal, err
+}
+
+func (window mainWindow) NewPanel (width, height int) (elements.Window, error) {
+	panel, err := window.backend.newWindow(width, height)
+	hints, _ := icccm.WmHintsGet(window.backend.connection, panel.xWindow.Id)
+	hints.WindowGroup = window.xWindow.Id
+	icccm.WmHintsSet (
+		window.backend.connection,
+		panel.xWindow.Id,
+		hints)
+	return panel, err
+}
+
 func (window *window) Show () {
 	if window.child == nil {
 		window.xCanvas.For (func (x, y int) xgraphics.BGRA {

elements/window.go

@@ -25,6 +25,9 @@ type Window interface {
 	// for some backends.
 	SetIcon (sizes []image.Image)
 
+	// NewModal creates a new modal dialog window.
+	NewModal (width, height int) (window Window, err error)
+
 	// Show shows the window. The window starts off hidden, so this must be
 	// called after initial setup to make sure it is visible.
 	Show ()
@@ -38,3 +41,13 @@ type Window interface {
 	// OnClose specifies a function to be called when the window is closed.
 	OnClose (func ())
 }
+
+// MainWindow is a window capable of owning multiple sub-windows.
+type MainWindow interface {
+	Window
+
+	// NewPanel creates a panel window that is semantically tied to this
+	// window. This is intended to be used for utility windows, tool bars,
+	// torn-off menus, etc.
+	NewPanel (width, height int) (window Window, err error)
+}