#GIR GObject subclass generator

#Input

#gobject.subclass(name=CustomButton, parent="@gtk.Button", gtype_name="ExampleCustomButton")
struct CustomButtonState {
  mut count : Int
}

• name is the generated public MoonBit GObject class name.
• parent is the immediate external GObject class, written as a string containing its MoonBit import alias and type, such as "@gtk.Button".
• The annotated struct is the MoonBit state retained by the native instance.
• gtype_name is optional. It is the first argument to G_DEFINE_TYPE, so it must be a C identifier and becomes the process-global GType name. The default is MoonBit followed by name.

impl @gtk.VButtonClicked for CustomButtonState with clicked(self, button) {
  self.count = self.count + 1
  CustomButton::parent_clicked(button)
}

#Generate

moon runwasm gir/subclass -- \
  path/to/custom_button.mbt

moonx tonyfettes/gir/subclass@0.3.2 -- \
  path/to/custom_button.mbt

• the parent binding package from a qualified parent such as @gtk.Button;
• the canonical binding package path from the input package's moon.pkg imports, including custom aliases;
• gir.json from the binding checkout or the consuming module's .mooncakes;
• a C symbol prefix from the subclass GType name;
• the output directory from the input file; and
• the ordered GIR search path from GI_GIR_PATH, XDG_DATA_DIRS, Homebrew, MacPorts, or the standard Unix data directories.

rule(
  name: "generate-subclass",
  command: "moonx tonyfettes/gir/subclass@0.3.2 -- \"$mod_dir/$input\"",
)

• custom_button.generated.mbt: CustomButton, ICustomButton, parent I<Class> implementations, selected parent_<method> calls, and CustomButton::new(state).
• custom_button.generated.c: instance/class structs, G_DEFINE_TYPE, selected class-slot assignments, C-to-MoonBit callbacks, explicit parent calls, and retained-state disposal.

options(
  link: { "native": { "stub-cc-flags": "${build.MY_GTK_CC_FLAGS}" } },
  "native-stub": [ "custom_button.generated.c" ],
)

#Current ABI boundary

• GLib signed/unsigned integers, Bool, Float, and Double;
• selected non-bitfield GIR enums and selected primitive or record aliases;
• UTF-8 strings, including nullable strings represented as String?;
• selected GObject classes and interfaces; and
• selected records with a safe copy/free lifecycle, including GIR boxed types, records with configured record-lifecycles, and plain value records.