Struct TransformLayer 

pub struct TransformLayer<W: Widget + Send + Sync + 'static> {
    pub child: W,
    pub scroll_y: Atom<f32>,
    pub scroll_x: Atom<f32>,
    pub viewport_h: f32,
}

Captures a child widget into an independent Picture and applies a 2D scroll offset on the GPU without re-rendering the child (D080, Phase 17/19).

Phase 17: CPU shift in paint() — UV offset uniform wired in compositor. Phase 19: child is recorded into a separate PictureRecorder and pushed into PaintCtx.transform_entries (D087) for the platform to replay into its own SkiaCanvas and present as an extra GPU compositor layer (D088).

Fields

child: W

scroll_y: Atom<f32>

Scroll offset in logical pixels, positive = scroll down.

scroll_x: Atom<f32>

Horizontal scroll offset in logical pixels.

viewport_h: f32

Viewport height in logical pixels — content beyond this is clipped.

Implementations

impl<W: Widget + Send + Sync + 'static> TransformLayer<W>

pub fn new(child: W, viewport_h: f32, scroll_y: Atom<f32>) -> Self

Trait Implementations

impl<W: Widget + Send + Sync + 'static> Widget for TransformLayer<W>

fn layout(&self, ctx: &LayoutCtx<'_>) -> Size

Measure under ctx.constraints and return a size within them.

fn paint(&self, ctx: &mut PaintCtx<'_>)

Record draw commands for ctx.rect.

fn children(&self) -> Children<'_>

Declare this widget’s children. Drives every default below.

fn flex_factor(&self) -> f32

Flex weight inside Row/Column. Wrappers are transparent by default.

fn into_element(self) -> Element

where Self: Sized + 'static,

Wrap this widget in an Element so it can be returned from Component::build().