Struct TransformTrackingHelper 

pub struct TransformTrackingHelper { /* private fields */ }

Tracks the transform of a visual to the root of its visual tree: tells when it changes because the bounds of the visual or of one of its ancestors changed, or because the visual was attached or detached.

The helper does not keep the tracked visual alive; the visual keeps the helper alive for as long as it is tracked.

Implementations

impl TransformTrackingHelper

pub fn new(defer_after_render_pass: bool) -> Rc<TransformTrackingHelper>

Creates the helper. With defer_after_render_pass a change of bounds is processed after the next render pass, otherwise right before it.

pub fn set_visual(&self, visual: Option<&Ref<Visual>>)

Sets the visual to track, or stops tracking.

pub fn matrix(&self) -> Option<Matrix>

The transform of the tracked visual to its visual root, if it is attached to one.

pub fn matrix_changed( &self, handler: impl Fn() + 'static, ) -> Rc<dyn IDisposable>

Raised when matrix has changed. Disposing the returned handle unsubscribes.

pub fn dispose(&self)

Stops tracking the visual.

pub fn track( visual: &Ref<Visual>, defer_after_render_pass: bool, cb: impl Fn(&Ref<Visual>, Option<Matrix>) + 'static, ) -> Rc<dyn IDisposable>

Tracks the transform of a visual, calling cb with the visual and its transform whenever it changes. Disposing the returned handle stops tracking.

pub fn observe( visual: &Ref<Visual>, defer_after_render_pass: bool, ) -> Rc<dyn IObservable<Option<Matrix>>>

Returns an observable of the transform of a visual to its visual root.

Trait Implementations

impl IDisposable for TransformTrackingHelper

fn dispose(&self)