Trait ContentExt

Source
pub trait ContentExt: 'static {
    // Required methods
    fn get_preferred_size(&self) -> Option<(f32, f32)>;
    fn invalidate(&self);
    fn connect_attached<F: Fn(&Self, &Actor) + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId;
    fn connect_detached<F: Fn(&Self, &Actor) + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId;
}
Expand description

Trait containing all Content methods.

§Implementors

Canvas, Content, Image

Required Methods§

Source

fn get_preferred_size(&self) -> Option<(f32, f32)>

Retrieves the natural size of the self, if any.

The natural size of a Content is defined as the size the content would have regardless of the allocation of the actor that is painting it, for instance the size of an image data.

§width

return location for the natural width of the content

§height

return location for the natural height of the content

§Returns

true if the content has a preferred size, and false otherwise

Source

fn invalidate(&self)

Invalidates a Content.

This function should be called by Content implementations when they change the way a the content should be painted regardless of the actor state.

Source

fn connect_attached<F: Fn(&Self, &Actor) + 'static>( &self, f: F, ) -> SignalHandlerId

This signal is emitted each time a Content implementation is assigned to a Actor.

§actor

a Actor

Source

fn connect_detached<F: Fn(&Self, &Actor) + 'static>( &self, f: F, ) -> SignalHandlerId

This signal is emitted each time a Content implementation is removed from a Actor.

§actor

a Actor

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§