Derive Macro gui_derive::Widget

#[derive(Widget)]
{
    // Attributes available to this derive:
    #[gui]
}

Custom derive functionality for the gui::Widget trait.

Using this macro a default implementation of the gui::Widget trait can be created. Note that this trait is just a unification of the gui::Object, gui::Renderable, and gui::Handleable traits. Note furthermore that only implementations of the former two will be auto generated. The reason for this behavior is that gui::Handleable most likely needs customization to accommodate for custom event handling behavior.

This macro roughly expands to the following code:

impl gui::Renderable for TestWidget {
  fn type_id(&self) -> TypeId {
    TypeId::of::<TestWidget>()
  }
  fn render(
    &self,
    cap: &dyn gui::Cap,
    renderer: &dyn gui::Renderer,
    bbox: gui::BBox,
  ) -> gui::BBox {
    renderer.render(self, cap, bbox)
  }
}

impl gui::Object for TestWidget {
  fn id(&self) -> gui::Id {
    self.id
  }
}

impl gui::Widget<Event, Message> for TestWidget {
  fn type_id(&self) -> TypeId {
    TypeId::of::<TestWidget>()
  }
}