Enum EitherWidget 

pub enum EitherWidget<L, R> {
    Left(L),
    Right(R),
}

Retained widget for Either: the live arm’s widget, delegated to for every pass. Keyboard broadcasts (InputEvent::Shortcut, InputEvent::Key) reach the live arm only; the other arm does not exist.

Variants

Left(L)

The left arm’s widget.

Right(R)

The right arm’s widget.

Trait Implementations

impl<L, R> Widget for EitherWidget<L, R>

where L: Widget, R: Widget,

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

Report the live arm’s name: the enum is a storage detail, never a tree element in its own right.

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

The live arm’s sliver face: a sliver arm stays a sliver through the enum, and a box arm keeps answering None.

fn is_focusable(&self) -> bool

The live arm’s answer: the enum’s pod is the arm’s Tab stop.

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

The live arm’s traversal children, so a narrowing arm (a navigator, an IndexedStack) stays narrowed through the enum.

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.