Struct SceneCard 

pub struct SceneCard { /* private fields */ }

A heavyweight scene item’s container: surface, header, body, modes, gestures and accessibility. See the scene_card module docs.

Implementations

impl SceneCard

pub fn new(model: SceneModel, item: ItemId) -> Self

A card bound to one heavyweight entry of model.

The card is the widget the view’s delegate returns for item:

SceneView::with_model(model.clone())
    .delegate_typed::<Note>(move |note, id| {
        Box::new(SceneCard::new(model.clone(), id).body(view_of(note)))
    })

pub fn header(self, widget: impl IntoTeksiChild) -> Self

The grab handle, and the card’s title strip.

A press here moves the card and nothing else — see the scene_card module docs for the three-row table that makes that true.

Takes a widget, a Box<dyn Widget> (the shape a card factory hands back), or a [WidgetId] already in the tree — one method per slot, so the caller does not pick a spelling to match what they happen to hold.

pub fn header_trailing(self, widget: impl IntoTeksiChild) -> Self

A control at the trailing end of the header — a ⋮ menu, a colour swatch, a pin.

Wrapped in a DeadZone, so the header drags everywhere except here and a click on the control with a few pixels of jitter still reads as a click.

Takes a widget, a boxed widget or a [WidgetId], like header.

pub fn body(self, widget: impl IntoTeksiChild) -> Self

The content. Anything at all: a text editor, an image, a chart, a SceneView of its own.

Not wrapped in anything — the card root’s dead zone already covers it, and wrapping would put a node between the body and the card that the body’s own gesture arena would have to argue with.

Takes a widget, a boxed widget or a [WidgetId], like header.

pub fn surface(self, f: impl Fn(WidgetId) -> Box<dyn Widget> + 'static) -> Self

Replace the chrome. The closure is handed the id of the card’s content (header plus body, already stacked) and returns the widget that wraps it.

The default is Card::new().variant(CardVariant::Elevated).content(content), so the card is Tier-3 themed through the existing style_slots.card with no new style protocol. Override it for a different variant, a per-card colour, or a surface of your own:

card.surface(|content| {
    Box::new(Card::new().variant(CardVariant::Outlined).content(content))
})

pub fn mode(self, mode: Signal<CardMode>) -> Self

Bind the card’s mode to an app-owned signal.

Two-way: the card writes into it and reads from it, so a toolbar button or a shortcut can put a card into Editing and the card will focus its body. Observe it to persist on commit — see the scene_card module docs for why there is no separate on_commit.

pub fn mode_signal(&self) -> Signal<CardMode>

The card’s mode signal, for an app that did not supply one.

pub fn selection(self, selection: SceneSelection) -> Self

The scene selection this card takes part in.

Pass the same handle the view was given (SceneView::selection_model), so a tap on the card and a marquee across it mean the same thing. Without one the card still tracks its own CardMode, but a tap selects nothing.

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

The card’s accessible name. Locale-reactive when given a tr! string.

pub fn activate_label(self, label: impl Into<Prop<String>>) -> Self

The name of the custom accessibility action that enters edit mode. Defaults to an untranslated "Edit".

pub fn movable(self, movable: bool) -> Self

Whether the header moves the card. true by default; false leaves the header as an ordinary strip (and the selection frame as the only way to move the card).

pub fn height_for_width(self) -> Self

Give the card’s height to its content: SizePolicy::HeightForWidth on the entry.

The width stays the model’s — you resize a note by dragging its edge — and the height follows the words on every pass that lays the card out.

One consequence worth knowing before you reach for it: the height axis of the selection frame does nothing on such a card. Not “writes a value that is then corrected” — nothing at all. The scale’s vertical component is neutralised at the model door (Scene::apply_transform_delta), because a height written there is one the next pass measures straight back over: the gesture’s whole contribution would be a reversible step that undoes nothing, and a top-edge drag would move the card rather than resize it. Dragging a side or corner still changes the width, and the words decide the rest. That is the intended reading of “the content decides” — and it is why this is opt-in rather than the default.

The horizontal half is an ordinary resize and converges: the preview reflows the card live as the handle moves, nothing reaches the model until the release, and the release writes the width once.

pub fn size_policy(self, policy: SizePolicy) -> Self

height_for_width, stated in full. See SizePolicy.

pub fn on_activate(self, f: impl Fn(&mut EventContext<'_>) + 'static) -> Self

Double-click, Enter on the focused card, or the AT Edit action.

Runs before the mode flips, and any write it makes to the mode is the decision: the card leaves the mode alone and does nothing further. Write CardMode::Editing to drive an edit flow of your own, or anything else to refuse this activation. A hook that writes nothing lets the card flip to Editing as usual.

The comparison is against the mode the hook found, not against a fixed value, because a double-click arrives with the card already Selected — the press selected it — and a rule phrased against a fixed value could not tell a refusal from the state the gesture had already produced.

Trait Implementations

impl Debug for SceneCard

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

Formats the value using the given formatter.

impl Widget for SceneCard

fn build(&mut self, ctx: &mut BuildContext<'_>) -> Vec<WidgetId>

Compose child widgets. Called once after the widget is placed in the arena, and again whenever the widget is marked for rebuild — a BindingLevel::Rebuild binding, rebuild_single_widget, or a density switch. A theme or locale switch does not rebuild: set_theme and set_locale mark layout + paint dirty and leave the built subtree standing, so anything derived from the theme or the locale must be read per pass or bound to a signal rather than captured here. Takes &mut self — store child IDs, signal handles, any state needed later. Returns the list of root child IDs (empty for leaf widgets).

fn layout_response( &self, proposal: SizeProposal, ctx: &LayoutContext<'_>, ) -> LayoutResponse

Respond to the parent’s size proposal with this widget’s wanted size, grow/shrink weights, and compression floor (see [LayoutResponse]).

fn children(&self) -> Vec<WidgetId>

Return the child widget IDs that this widget manages.

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

Declare this widget’s accessibility identity.

fn as_any(&self) -> Option<&dyn Any>

Downcast hook. Default implementation returns None; concrete widgets override with Some(self) when they want to expose their concrete type to test-level introspection or reflection. The trait already bounds on std::any::Any so concrete types satisfy the 'static requirement.

fn as_any_mut(&mut self) -> Option<&mut dyn Any>

Mutable counterpart of as_any. Default returns None; widgets that want to expose mutable state to tests (e.g. so a test can mutate a Scene inside a SceneView post-layout) override with Some(self). Should follow the same opt-in pattern as as_any: only widgets that opt into & introspection should opt into &mut.

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

Concrete type name of this widget (e.g. "teksilo_widgets::button::Button"). The default implementation resolves at the impl site via std::any::type_name::<Self>(), so calls through &dyn Widget correctly dispatch to the monomorphized fn for the concrete type — getting the concrete name through the vtable without per-impl boilerplate.

fn cacheable_layout(&self) -> bool

Whether this widget’s layout_response may be memoized by the per-pass layout cache. Defaults to true.

fn place_children( &self, _bounds: Rect, _proposal: SizeProposal, _children: &mut [WidgetPlacement], _ctx: &LayoutContext<'_>, )

Position children within the allocated bounds.

fn paint(&self, _bounds: Rect, _canvas: &mut Canvas, _ctx: &PaintContext<'_>)

Draw the widget’s visual representation.

fn wants_after_paint(&self) -> bool

Whether this widget wants its after_paint hook to fire each frame. Returning false (the default) saves a virtual call per widget per frame for the vast majority of widgets that don’t aggregate descendant geometry.

fn after_paint(&self, _view: &WidgetTreeView<'_>, _ctx: &PaintContext<'_>)

Called once per frame after this widget’s subtree has finished painting. Receives a read-only view of the layout-resolved arena so a parent can read its descendants’ final bounds — e.g. TitleBar aggregates its drag region and control-button rects into a single HitRegions payload for the Windows backend’s WM_NCHITTEST.

fn wants_post_paint(&self) -> bool

Whether this widget wants its post_paint hook to fire each frame. Returning false (the default) saves a virtual call per widget per frame for the vast majority of widgets that don’t draw a foreground over their children.

fn post_paint( &self, _bounds: Rect, _canvas: &mut Canvas, _ctx: &PaintContext<'_>, )

Draw a foreground layer over this widget’s children.

fn wants_descendant_redirects(&self) -> bool

Whether this widget wants the AT walker to consult its a11y_redirect_descendant hook for every descendant during AT tree emission, not just its direct arena children.

fn culls_children(&self) -> bool

Whether this widget decides, on every layout pass, which of its children exist at all.

fn a11y_redirect_descendant( &self, _self_id: WidgetId, _descendant: WidgetId, ) -> Option<NodeId>

Optional redirection hook for AT-tree placement of a child.

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

Suggest an accessible title to an enclosing container that wraps this widget as content — typically a modal / dialog shell that wants to propagate the inner content’s visible title as the shell’s own accessible name.

fn accessible_title_node(&self) -> Option<WidgetId>

The widget that paints this one’s title, when it has one.

fn initial_focus_hint(&self) -> Option<WidgetId>

Optional hint that directs initial focus to a specific descendant when this widget is the root of a deferred-built modal surface.

fn accessibility_proxy(&self) -> Option<WidgetId>

The descendant whose accessibility node stands for this widget.

fn context_menu_key_target(&self) -> Option<WidgetId>

Which descendant a keyboard request for a context menu should target.

fn accessibility_children(&self) -> Option<Vec<WidgetId>>

Optional override for the child ORDER presented to assistive technology, when it must differ from the paint / z-order child order returned by children.

fn clips_children(&self) -> bool

Whether this widget clips its children to its bounds.

fn focus_reveal_rect(&self, _bounds: Rect) -> Option<Rect>

The rectangle (in absolute tree coordinates) that best represents this widget when the framework reveals it into an ancestor scroll area on focus gain. Returning None (the default) reveals the widget’s whole bounds — correct for most controls.

fn hit_shape(&self, _local_point: Point, _bounds: Rect) -> bool

Whether the point lies inside this widget’s actual shape, not just its rectangular bounds. Consulted by hit-testing right after the bounds check: returning false for a point that is inside the bounding box makes the widget transparent to the click there, so it falls through to whatever sibling is painted underneath (the same machinery as a fully pass-through node, but shape-aware).

fn accepts_child_hit(&self, _child: WidgetId, _point: Point) -> bool

Veto a hit on one of this widget’s direct children, per point.

fn hit_outset(&self, _kind: PointerKind, _tokens: &InputTokens) -> EdgeInsets

How far outside its own bounds this widget still absorbs a press, per edge, for the pointer that is asking.

fn hit_slop(&self, _kind: PointerKind, _tokens: &InputTokens) -> Option<HitSlop>

This widget’s own say in the miss-only slop pass, overriding the density default for its node.

fn hit_distance(&self, local_point: Point, bounds: Rect) -> Option<f32>

How far a missed press is from this widget’s actual silhouette, in the widget’s own bounds space.

fn target_regions(&self, _bounds: Rect) -> Vec<TargetRegion>

The interactive sub-regions this widget paints inside its own single node — a scroll bar’s thumb, a slider’s knob, a header cell’s filter affordance.

fn preserves_children_on_rebuild(&self) -> bool

How rebuild_single_widget treats this widget’s existing children when re-running its build().

fn tooltip_has_content(&self) -> bool

Whether this widget, used as tooltip content, currently has anything worth showing.

fn declare_shortcuts(&self) -> Vec<Shortcut>

Declare the rebindable keyboard shortcuts this widget exposes, without installing handlers. The framework calls this at arena insertion time (before build()) and at certain lazy boundaries (e.g. Switcher walks declarations on its not-yet-mounted Pending slots), so settings UIs and the ShortcutRegistry see the keystrokes the moment the owning container mounts — even if build() hasn’t run.

fn take_handler_set(&mut self) -> Option<HandlerSet>

Extract attached handler set from a WidgetWithHandlers wrapper. Called during arena insertion to transfer handlers to the WidgetNode. Default: returns None (no attached handlers).