Trait QObjectHolder

Source

pub trait QObjectHolder:
    DispatchMetaCall
    + QMetaInfo
    + Default {
    // Provided methods
    fn get_qml_method_invoker(&self) -> QmlMethodInvoker { ... }
    fn default_with_attached_qobject() -> Rc<RefCell<Self>> { ... }
    fn attach_qobject(instance: &Rc<RefCell<Self>>) { ... }
    fn detach_qobject(&self) { ... }
    fn as_qvariant(&self) -> QVariant { ... }
}

Expand description

Provides access to the underlying QObject for types exposed to QML.

Automatically implemented by qobject. Do not implement this trait manually.

Provided Methods§

Source

fn get_qml_method_invoker(&self) -> QmlMethodInvoker

Returns a QmlMethodInvoker that can invoke methods on the underlying QObject from any thread.

§Example

let backend = Backend::default_with_attached_qobject();
let invoker = backend.borrow().get_qml_method_invoker();
invoker.invoke_method("dataReady");

Source

fn default_with_attached_qobject() -> Rc<RefCell<Self>>

Creates a default-initialized instance and attaches the required [QObject], enabling its use in QML.

The returned Rc<RefCell<Self>> owns the object. The QML side can access it only through a weak pointer.

The drop implementation of Self calls detach_qobject and thus destroys the associated QObject, which removes it from the QML side as well. If Self has a custom Drop implementation, you need to call Self::detach_qobject manually.

The attached QObject is bound to this specific allocation, so the object’s identity and lifetime must both be preserved.

Do not move or replace the Self inside the Rc<RefCell<Self>>. Operations such as Rc::try_unwrap, into_inner, or get_mut-then-move will break the connection between self and the associated QObject. Once the Self lives elsewhere, the next call in either direction can no longer reach it.

Source