Add NewDialogWithFlags

gir/cmd/gir_generate/gendata/gendata.go

@@ -667,13 +667,54 @@ func GtkTextBufferInsert(nsgen *girgen.NamespaceGenerator) error {
 	return nil
 }
 
+const cGTKDialogNew2 = `
+	GtkWidget* _gotk4_gtk_dialog_new2(const gchar* title, GtkWindow* parent, GtkDialogFlags flags) {
+		return gtk_dialog_new_with_buttons(title, parent, flags, NULL, NULL);
+	}
+`
+
+func GtkNewDialog(nsgen *girgen.NamespaceGenerator) error {
+	fg, ok := nsgen.Files["gtkdialog.go"]
+	if !ok {
+		return nil
+	}
+
+	h := fg.Header()
+	h.Import("runtime")
+	h.AddCBlock(cGTKDialogNew2)
+
+	p := fg.Pen()
+	p.Line(`
+		// NewDialogWithFlags is a slightly more advanced version of NewDialog,
+		// allowing the user to construct a new dialog with the given
+		// constructor-only dialog flags.
+		//
+		// It is a wrapper around Gtk.Dialog.new_with_buttons in C.
+		func NewDialogWithFlags(title string, parent *gtk.Window, flags gtk.DialogFlags) *gtk.Dialog {
+			ctitle := C.CString(title)
+			defer C.free(unsafe.Pointer(ctitle))
+
+			w := C._gotk4_gtk_dialog_new2(
+				(*C.gchar)(ctitle),
+				(*C.GtkWindow)(parent.Native()),
+				(C.GtkDialogFlags)(flags),
+			)
+			runtime.KeepAlive(parent)
+
+			return wrapDialog(externglib.Take(unsafe.Pointer(c)))
+		}
+	`)
+
+	return nil
+}
+
 // Postprocessors is similar to Append, except the caller can mutate the package
 // in a more flexible manner.
 var Postprocessors = map[string][]girgen.Postprocessor{
-	"GLib-2": {GioArrayUseBytes, GLibAliases, GLibLogs, GLibDateTime},
+	"GLib-2": {ImportGError, GioArrayUseBytes, GLibAliases, GLibLogs, GLibDateTime},
 	"Gio-2":  {ImportGError},
-	"Gtk-3":  {ImportGError},
-	"Gtk-4":  {ImportGError}, // for the marshaler
+	"Gtk-3":  {ImportGError, GtkNewDialog},
+	"Gtk-4":  {ImportGError, GtkNewDialog},
 }
 
 // Appends contains the contents of files that are appended into generated

gir/girgen/file.go

@@ -132,7 +132,7 @@ func (f *FileGenerator) Generate() ([]byte, error) {
 
 	if len(f.header.Callbacks) > 0 {
 		for _, callback := range f.header.SortedCallbackHeaders() {
-			fpen.Words("//", callback)
+			fpen.Words(makeComment(callback))
 		}
 	}
 
@@ -160,6 +160,14 @@ func (f *FileGenerator) Generate() ([]byte, error) {
 	return b, nil
 }
 
+func makeComment(block string) string {
+	lines := strings.Split(block, "\n")
+	for i := range lines {
+		lines[i] = "// " + lines[i]
+	}
+	return strings.Join(lines, "\n")
+}
+
 func makeImport(importPath, alias string) string {
 	pathBase := path.Base(importPath)
 

gir/girgen/file/file.go

@@ -215,6 +215,36 @@ func CallbackCHeader(source *gir.NamespaceFindResult, callback *gir.Callback) st
 	)
 }
 
+// AddCBlock adds a block of C code into the Cgo preamble.
+func (h *Header) AddCBlock(block string) {
+	if block == "" {
+		// Bound check to prevent panic in line logic.
+		return
+	}
+
+	block = strings.TrimSpace(block)
+
+	// Guess the indentation: grab the last line and count its leading tabs.
+	lines := strings.Split(block, "\n")
+	lastLine := lines[len(lines)-1]
+
+	var tabs int
+	for tabs < len(lastLine) && lastLine[tabs] == '\t' {
+		tabs++
+	}
+
+	// Trim all lines except for the first, since TrimSpace will take care of
+	// that.
+	indent := strings.Repeat("\t", tabs)
+	for i := 1; i < len(lines); i++ {
+		lines[i] = strings.TrimPrefix(lines[i], indent)
+	}
+
+	// Rejoin and add.
+	block = strings.Join(lines, "\n")
+	h.AddCallbackHeader(block)
+}
+
 // AddCallbackHeader adds a callback header raw.
 func (h *Header) AddCallbackHeader(header string) {
 	if h.stop {