Trait gtk4::prelude::WidgetExtManual

source ·

pub trait WidgetExtManual: Sealed + IsA<Widget> + 'static {
    // Provided method
    fn add_tick_callback<P: Fn(&Self, &FrameClock) -> ControlFlow + 'static>(
        &self,
        callback: P
    ) -> TickCallbackId { ... }
}

Expand description

Trait containing manually implemented methods of Widget.

Provided Methods§

source

fn add_tick_callback<P: Fn(&Self, &FrameClock) -> ControlFlow + 'static>( &self, callback: P ) -> TickCallbackId

Queues an animation frame update and adds a callback to be called before each frame.

Until the tick callback is removed, it will be called frequently (usually at the frame rate of the output device or as quickly as the application can be repainted, whichever is slower). For this reason, is most suitable for handling graphics that change every frame or every few frames. The tick callback does not automatically imply a relayout or repaint. If you want a repaint or relayout, and aren’t changing widget properties that would trigger that (for example, changing the text of a Label), then you will have to call WidgetExt::queue_resize() or WidgetExt::queue_draw() yourself.

FrameClock::frame_time() should generally be used for timing continuous animations and Gdk::FrameTimings::get_predicted_presentation_time() if you are trying to display isolated frames at particular times.

This is a more convenient alternative to connecting directly to the update signal of gdk::FrameClock, since you don’t have to worry about when a gdk::FrameClock is assigned to a widget.

`callback`

function to call for updating animations

Returns

an id for the connection of this callback. Remove the callback by passing the id returned from this function to [WidgetExtManual::remove()][crate::prelude::WidgetExtManual::remove()]

Implementors§

source §