Struct GroupItem 

pub struct GroupItem { /* private fields */ }

A group container with optional fill / stroke / inline label, in local item coordinates.

Visually, GroupItem renders a labelled box around its members. Logically, it’s the AT-grouping primitive: with no chrome and a label set, it announces itself to AT but draws nothing.

Implementations

impl GroupItem

pub fn new(local_bounds: Rect) -> Self

A group covering local_bounds in local coordinates. No chrome by default — call fill / stroke / show_label to give it visible outline / background / inline label.

pub fn label(self, label: impl Into<LocalizedString>) -> Self

Human-readable label, used as the default AT group name and (when show_label is enabled) rendered inline at top-leading.

pub fn show_label(self, show: bool) -> Self

Render the label inline at paint time.

pub fn label_inset(self, dx: f32, dy: f32) -> Self

Override the inset of the inline label from the local origin.

pub fn label_color(self, color: impl Into<ColorProp>) -> Self

Override the inline label colour. Defaults to the stroke colour if set, else Color::BLACK. Accepts a plain [Color], a theme role, or a reactive signal.

pub fn fill(self, color: impl Into<ColorProp>) -> Self

Background fill colour. Accepts a plain [Color], a theme role, a Signal<Color>, or a Signal<Role> — resolved against the active theme at paint time.

pub fn stroke(self, color: impl Into<ColorProp>, width: f32) -> Self

Border stroke (colour + scene-coord pixel width) — scales with zoom.

pub fn stroke_cosmetic(self, color: impl Into<ColorProp>, width: f32) -> Self

Cosmetic border stroke: holds a constant device-pixel width at any zoom. With corner_radius > 0 the rounded outline goes through the SDF cosmetic path; otherwise stroke_rect emits four CosmeticLine edges (one per side), which are hard-edged and crisp at any zoom.

pub fn stroke_styled( self, color: impl Into<ColorProp>, style: StrokeStyle, ) -> Self

Border stroke with an explicit [StrokeStyle] — dashed / dotted / custom caps. E.g. .stroke_styled(color, StrokeStyle::dashed(2.0, 6.0, 4.0)) for a dashed lane boundary.

pub fn corner_radius(self, radius: f32) -> Self

Rounded corners for fill and stroke. Default 0.0.

pub fn is_visual(&self) -> bool

Whether the group has any visual chrome configured.

pub fn access_label(self, label: impl Into<LocalizedString>) -> Self

Override the AT name announced for this item. Accepts anything convertible into LocalizedString — most commonly tr!(...) for translated labels, or any plain string (which auto-converts via From<String>).

pub fn access_description(self, description: impl Into<LocalizedString>) -> Self

Long-form context appended to the item’s announcement.

pub fn access_role(self, role: Role) -> Self

Override the AccessKit role for this item.

pub fn access_hidden(self, hidden: bool) -> Self

Hide this item from the AT tree.

pub fn access_subtree(self, mode: AccessSubtreeMode) -> Self

Set the AT subtree mode. Merge collapses descendants into this item’s AT node; Exclude prunes them; the default Inherit lets them emit normally.

pub fn access_merge_subtree(self) -> Self

Convenience: collapse all descendants into this item’s AT node so the subtree reads as one element.

pub fn access_exclude_subtree(self) -> Self

Convenience: prune all descendants from the AT tree.

pub fn access_value(self, value: impl Into<LocalizedString>) -> Self

Announce a string value for this item (e.g. a formatted data reading like "42 %"). Mirrors the widget-tier .access_value.

pub fn access_numeric_value(self, value: f64) -> Self

Announce a numeric value for this item, for slider/gauge-like data marks whose magnitude assistive tech should describe. Pair with access_numeric_range / access_numeric_step for full range semantics.

pub fn access_numeric_range(self, min: f64, max: f64) -> Self

Announce the numeric min/max bounds for this item.

pub fn access_numeric_step(self, step: f64) -> Self

Announce the numeric step (per-arrow increment) for this item.

Trait Implementations

impl Debug for GroupItem

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl SceneItem for GroupItem

fn shape_contains(&self, local_pt: Point) -> bool

Non-visual GroupItems pass clicks through to items beneath. Visual groups (with fill / stroke / inline label) AABB-hit-test so apps can wire group-level click handlers.

fn clone_shape_test(&self) -> Box<dyn Fn(Point, f32) -> bool + 'static>

Override the default AABB-only snapshot: logical-only groups (no fill, no stroke, no inline label) must MISS for dispatch so clicks fall through to items beneath. Without this override the snapshot would AABB-hit and capture every event over the group’s rect, blocking the items it contains.

fn local_bounds(&self) -> Rect

AABB in local item coordinates (origin at the item’s anchor). The Scene composes this with the item’s scene_transform to compute its scene-space AABB for the spatial index.

fn set_local_bounds(&mut self, bounds: Rect)

Write back new bounds. Called by Scene::set_local_bounds when the bounds change. Implementations update their stored bounds field; geometry-bearing items (e.g. crate::PathItem) must keep their geometry consistent with the new bounds.

fn paint(&self, canvas: &mut Canvas, ctx: &SceneItemPaintContext<'_>)

Paint the item into the canvas. The canvas already has this item’s scene_transform (parent chain × view) pushed, so coordinates are in local item space — (0, 0) is the item’s anchor.

fn set_fill(&mut self, fill: Option<ColorProp>) -> bool

Replace the primary fill colour, returning true if this item kind has a fill slot that accepted the change. Backs SceneModel::set_item_fill / clear_item_fill. Rectangles, paths, and groups set their fill; text items map it onto their foreground colour (so a None is rejected — text always has a colour); image items have no fill and return false. Default: no-op.

fn set_stroke(&mut self, stroke: Option<(ColorProp, StrokeStyle)>) -> bool

Replace the stroke (colour + [StrokeStyle]), returning true if this item kind has a stroke slot that accepted the change. Backs SceneModel::set_item_stroke / clear_item_stroke. Rectangles, paths, and groups accept it; text and image items return false. Default: no-op.

fn register_bindings(&self, ctx: &mut BuildContext<'_>, view_id: WidgetId)

Register reactive bindings the item depends on. Called once per SceneView::build for every item in the scene, with the SceneView’s WidgetId as view_id. Items with signal-bound state bind their signals here at the appropriate BindingLevel.

fn thumbnail_color(&self) -> Color

Dominant color to draw as the item’s representation in minimap-style thumbnails. Default: an opaque mid-grey, which gives a recognisable but neutral marker for any item. Built-in items override: RectItem returns its fill, PathItem returns stroke or fill, ImageItem returns the image’s dominant tint placeholder.

fn label(&self) -> Option<String>

Optional human-readable label, surfaced in debug introspection and used by the default SceneItem::accessibility impl as the AT name when an item author hasn’t overridden it via the per-item .access_label(...) chain.

fn accessibility( &self, builder: &mut AccessNodeBuilder, _ctx: &SceneItemA11yContext, )

Populate the AccessKit node for this item. Default: role [Role::GraphicsObject] plus the SceneItem::label as the AT name if set. The per-item .access_* builder chain layers overrides on top of whatever this method writes.

fn access_subtree_mode(&self) -> AccessSubtreeMode

AT subtree treatment for descendants.

fn initial_flags(&self) -> ItemFlags

The flags this item should carry into the Scene at insert time. Default: ItemFlags::default() — visible, enabled, selectable. Built-ins read their accumulated builder state (e.g. .draggable(true) flips IS_DRAGGABLE); custom items override this to opt into hover acceptance, focus, clipping, or IGNORES_TRANSFORMATIONS.

fn cache_mode(&self) -> CacheMode

Per-item paint caching strategy. Default CacheMode::None: the item’s paint runs every frame.