Struct AutoScrollZoneWidget 

pub struct AutoScrollZoneWidget { /* private fields */ }

The retained widget for an AutoScrollZone.

Trait Implementations

impl SliverWidget for AutoScrollZoneWidget

fn layout_sliver( &mut self, ctx: &mut LayoutCtx<'_>, sc: &SliverConstraints, ) -> SliverGeometry

Pass-through, like Widget::layout: the child sits at the origin and receives sc unchanged, under the child pod’s layout skip.

impl Widget for AutoScrollZoneWidget

fn as_sliver(&mut self) -> Option<&mut (dyn SliverWidget + 'static)>

A zone is a sliver exactly when its child is: the transparent layout runs through the child pod, so the sliver face is the zone itself and the pod stays sized for this wrapper’s own paint (the ComponentWidget pattern).

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

Choose a size within bc and return it. Under a render root the call may be skipped (see ChildPod::layout_child), so the result must depend only on bc, the context’s globals and state changed through a pod-dirtying channel: a LAYOUT rebuild, request_layout, an unpaced frame request, or a handled / redraw-requesting event.

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

Emit draw commands into scene. Paint may advance animation state; it must then call PaintCtx::request_frame until the animation rests.

fn event(&mut self, ctx: &mut EventCtx<'_>, event: &InputEvent) -> EventResult

Handle an input event and report whether it was consumed; defaults to EventResult::Ignored. Containers forward via ChildPod::event_child.

fn semantics(&self, ctx: &mut SemanticsCtx)

Contribute accessibility node(s) after layout; defaults to none. A container forwards via ChildPod::semantics_child.

fn visit_children(&self, visitor: &mut dyn FnMut(&ChildPod))

Visit this widget’s owned ChildPods in paint order, for read-only tooling; defaults to none and must not mutate pass state.

fn type_name(&self) -> &'static str

This widget’s concrete type name, for diagnostics only (docs/LIMITATIONS.md focus-wrapper-erasure-swap-blind); override only in a transparent wrapper.

fn is_focusable(&self) -> bool

Whether keyboard traversal (Tab / Shift+Tab at the root) may stop on this widget’s pod.

fn visit_focus_children(&self, visitor: &mut dyn FnMut(&ChildPod))

Visit the children traversal may enter, in focus order; defaults to Widget::visit_children. A container showing only some children narrows it.