Struct ListRow 

pub struct ListRow { /* private fields */ }

A retained list row. Construct with a stable id and a title; press activates it (pointer, Enter/Space, or assistive technology).

Implementations

impl ListRow

pub fn new(id: impl Into<String>, title: impl Into<String>) -> ListRow

pub fn dense(self) -> ListRow

Show the row as a dense row: one quiet line at the caption’s size, as tall as that line and its inset (a reference under content).

pub fn row_height(self, px: f32) -> ListRow

Stand the row px tall, rather than the list’s row height for what it holds (ListRowFace::row_height).

pub fn set_dense(&mut self)

Self::dense, for a row a host has already built.

pub const fn is_dense(&self) -> bool

Whether the row stands dense (ListRowFace::dense).

pub fn card(self) -> ListRow

Show the row as a card: a surface of its own, its title wrapped over up to CARD_TITLE_LINES lines, and its facts on a line under the text instead of beside it (a board’s card).

pub fn set_card(&mut self)

Self::card, for a row a host has already built.

pub const fn is_card(&self) -> bool

Whether the row stands as a card: its own surface, as a card component showed it (CardBody::show_as_card).

pub fn set_activate(&mut self, event: Event)

Have a press on the row (or Enter or Space while it has the keyboard) report event: what a component’s card does when it opens what it stands for.

pub fn shortcuts(self, shortcuts: Vec<(Shortcut, Rc<dyn Fn()>)>) -> ListRow

The commands the row’s menu offers with the keys they declare: pressing one while the row has the keyboard runs it, as choosing it in the menu does.

pub fn two_line_title(self) -> ListRow

See ListRowFace::two_line_title.

pub fn title_family(self, family: FontChoice) -> ListRow

See ListRowFace::title_family: only for a list of fonts.

pub fn subtitle(self, text: impl Into<String>) -> ListRow

See ListRowFace::subtitle.

pub fn secondary(self, text: impl Into<String>) -> ListRow

See ListRowFace::secondary.

pub fn two_line_secondary(self) -> ListRow

See ListRowFace::two_line_secondary.

pub fn secondary_lines(self, lines: u8) -> ListRow

See ListRowFace::secondary_lines.

pub fn note(self, text: impl Into<String>) -> ListRow

See ListRowFace::note.

pub fn meta(self, text: impl Into<String>) -> ListRow

See ListRowFace::meta.

pub fn meta_spans(self, spans: &[(&str, Tone)]) -> ListRow

See ListRowFace::meta_spans.

pub fn item(self, item: impl Into<String>) -> ListRow

Say which item of its collection the row shows (AccessNode::item): a task’s issue, a note’s block. An action naming that item is drawn on this row.

pub fn value(self, text: impl Into<String>) -> ListRow

See ListRowFace::value.

pub fn title_value(self, text: impl Into<String>) -> ListRow

See ListRowFace::title_value.

pub fn set_value(&mut self, text: impl Into<String>)

Replace the trailing value (a ticking clock).

pub fn mark(self, icon: Icon) -> ListRow

See ListRowFace::mark.

pub fn mark_tone(self, tone: Tone) -> ListRow

The tone the row’s mark and its checkbox ring read in (ListRowFace::mark_tone).

pub fn tags(self, tags: &[(&str, ChipStyle)]) -> ListRow

See ListRowFace::tags.

pub fn count(self, count: usize) -> ListRow

See ListRowFace::count.

pub fn avatar( self, name: impl Into<String>, identity: impl Into<String>, ) -> ListRow

A person’s avatar in the leading column: the row is the person (a contact, an account). Something a person is on shows them as a fact instead (ListRowFace::avatar), on its facts column.

pub fn avatar_space(self) -> ListRow

The room an avatar takes, left empty (RowLeading::AvatarSpace): for a row without one in a list whose rows show avatars.

pub fn avatar_glyph(self, icon: Icon) -> ListRow

An app without artwork of its own in the leading avatar: its glyph on the neutral square, the mark the shell shows for it (AvatarFace::glyph).

pub fn avatar_image(self, image: ImageData) -> ListRow

The person’s picture for the leading avatar.

pub fn with_profile_photo(self, photo: &ProfilePhoto) -> ListRow

Use canonical normalized public identity pixels; no files are opened.

pub fn square(self) -> ListRow

Make the leading avatar square: an account or a site, not a person.

pub fn with_feel(self, feel: Feel) -> ListRow

Play the row’s own motion — its mark, its coming and going in a list — at feel rather than the theme’s pace.

pub fn set_feel(&mut self, feel: Feel)

Self::with_feel on a row already built.

pub fn checkbox_view( self, checked: bool, on_toggle: impl FnMut(bool) + 'static, ) -> ListRow

Self::checkbox published as the row’s view action check: a press on the box, Space on the focused row, a screen reader’s toggle, a script’s and an agent’s all reach on_toggle through the same action. The row’s control is id (Self::new).

pub fn leading_column(self, width: f64) -> ListRow

See ListRowFace::leading_column. A crate::widget::Section equalises the badge column of consecutive rows on its own.

pub fn nested(self) -> ListRow

See ListRowFace::nested.

pub fn depth(self, depth: u32) -> ListRow

See ListRowFace::depth.

pub fn tree_row(self) -> ListRow

See ListRowFace::tree_row.

pub fn badge_column(self, badges: Rc<[String]>) -> ListRow

The leading column fits every badge in badges, measured when the row is laid out: the rows of a VirtualList, which mounts only those on screen, keep one title edge with the rest.

pub fn tooltip(self, tooltip: impl Into<String>) -> ListRow

What the pointer resting on the row shows, where no part of it (the leading badge, an action, a title cut short) says more.

pub fn description(self, description: impl Into<String>) -> ListRow

What a reader hears of the row beyond its name and value — a task’s status beside its reference, say. It stays out of the pointer’s way: the row explains itself to a reader, not on hover.

pub fn active(self) -> ListRow

pub fn warning(self) -> ListRow

pub fn error(self) -> ListRow

pub fn idle(self) -> ListRow

pub fn struck(self) -> ListRow

The row stands for a removed item: its title struck through (ListRowFace::struck).

pub fn quiet(self) -> ListRow

The row reads as subordinate to the rows around it: its title in the weaker ink (ListRowFace::quiet).

pub fn change( self, identity: impl Into<String>, name: impl Into<String>, spoken: impl Into<String>, said: impl Into<String>, show: Option<Box<dyn FnMut()>>, ) -> ListRow

A change identity (called name) made to what the row shows and the person has not seen: their face on the trailing edge and their colour faintly under the row, at its own height, and said as a line under the row’s title; spoken (who, in which run) on hover and to assistive technology; pressing the face runs show.

pub fn shown_change(&self) -> Option<ShownChange<'_>>

The change the row shows, while the person has not seen it: who made it, what they are called and what they did, as the row draws them.

pub fn presence(self, identity: impl Into<String>) -> ListRow

The presence dot of the person identity.

pub fn disclosure(self) -> ListRow

pub fn checked(self, checked: bool) -> ListRow

See ListRowFace::checked.

pub fn set_checked(&mut self, checked: bool)

Move the check of a single-choice list.

pub fn emphasized(self, emphasized: bool) -> ListRow

pub fn selected(self, selected: bool) -> ListRow

pub fn with_enabled(self, enabled: bool) -> ListRow

A disabled row is dimmed, skipped by focus and inert.

pub fn set_enabled(&mut self, enabled: bool)

pub fn trailing(self, control: Box<dyn Widget>) -> ListRow

One persistent control at the trailing edge: a Toggle, a Button, a ToggleGroup, a small ProgressRing or a Badge. The row reserves its width, keeps it reachable by keyboard and assistive technology, and moves it under the text when the row is too narrow for both.

pub fn trailing_disclosure(self, button: Box<dyn Widget>) -> ListRow

Self::trailing for an icon button that opens what the row is about while the row itself does something else (a network row that connects, its chevron opening the network’s page). The button is centred on the column a Self::disclosure chevron stands in, so it lines up with the chevrons of the rows around it; its target keeps its own size, reaching into the row’s bleed.

pub fn tag_labels(&self) -> Vec<&str>

The row’s marks after its title (a status, a role), in order.

pub fn trailing_wrapped(&self) -> bool

Whether the trailing control sits under the text (the row is narrow).

pub fn action( self, icon: Icon, label: impl Into<String>, on_activate: impl FnMut() + 'static, ) -> ListRow

Add an action revealed while the row is hovered or focused.

pub fn action_binding( self, icon: Icon, label: impl Into<String>, binding: ActionBinding<()>, ) -> ListRow

Self::action through an exported resource action: the host resolves its policy (and asks for confirmation where it must) before it runs, and the action shows only while it is available.

pub fn swipe_action( self, icon: Icon, label: impl Into<String>, destructive: bool, on_activate: impl FnMut() + 'static, ) -> ListRow

Swiping the row toward its leading edge reveals icon; releasing past the threshold runs on_activate.

pub fn swipe_binding( self, icon: Icon, label: impl Into<String>, destructive: bool, binding: ActionBinding<()>, ) -> ListRow

Swiping the row toward its leading edge reveals icon; releasing past the threshold runs binding as its action, as Self::action_binding runs a trailing action.

pub fn on_activate(self, f: impl FnMut() + 'static) -> ListRow

Run f when the row is activated.

pub fn on_action(self, binding: ActionBinding<()>) -> ListRow

Route activation through an exported resource action.

pub fn on_effect(self, f: impl FnMut() + 'static) -> ListRow

Publish activation as a zero-argument effect, as Button::on_effect does: the closure keeps working and the row is discoverable and agent-driveable.

pub fn on_view(self, f: impl FnMut() + 'static) -> ListRow

Publish activation as a transient view action (opening, selecting), as Button::on_view does.

pub fn set_selected(&mut self, selected: bool)

pub fn is_selected(&self) -> bool

impl ListRow

pub fn shape(&self) -> RowShape

The kind of row this is: what a row of it on its way reserves.

impl ListRow

pub fn icon(self, icon: Icon) -> ListRow

pub fn badge(self, badge: impl Into<String>) -> ListRow

See RowLeading::Badge.

pub fn leading_tooltip(self, tooltip: impl Into<String>) -> ListRow

What the leading badge or icon stands for (“Retrieves the resource” for GET, “SSH” for a terminal glyph): the tooltip when the pointer rests on it, and the row’s accessible description.

pub fn thumbnail(self, image: ImageData) -> ListRow

See RowLeading::Thumbnail.

pub fn media(self, source: MediaSource, aspect: MediaAspect) -> ListRow

See RowLeading::Media: art from source at aspect, the placeholder with the title’s initials until it loads.

pub fn checkbox( self, checked: bool, on_toggle: impl FnMut(bool) + 'static, ) -> ListRow

See RowLeading::Checkbox: a selection checkbox. Pressing it (or Space on the focused row) runs on_toggle with the new state.

pub fn checkbox_with_icon( self, checked: bool, icon: Icon, on_toggle: impl FnMut(bool) + 'static, ) -> ListRow

Self::checkbox with a glyph after the box: a task checks off and still says how important it is. The glyph takes no press: it is what the row is, not a control.

pub fn swatch(self, colour: AlphaColor<Srgb>) -> ListRow

See RowLeading::Swatch.

pub fn signal(self, level: SignalLevel) -> ListRow

See RowLeading::Signal: the row leads with how strong its signal is, and is described by the meter’s name (“Strong signal”) unless a tooltip already says more.

impl ListRow

pub fn avatar_colour(self, colour: AlphaColor<Srgb>) -> ListRow

The colour the leading avatar is drawn in: its own presence colour, for an agent whose keeper chose one, rather than the colour its identity derives.

impl ListRow

pub fn with_swipe(self, props: SwipeActionProps) -> ListRow

The row with props as what swiping it across does.

Trait Implementations

impl ActionControl<()> for ListRow

fn bind_action(self, binding: ActionBinding<()>) -> Self

Invoke binding with the control’s committed value.

fn unavailable(self) -> Self

Present the control disabled: its action is not available.

impl ActionControls for ListRow

fn install_control_custody( &mut self, domain: &ControlDomain, attachment: CustodyAttachment, )

Bind retained producers before their first callback. Private holders must override this; child traversal alone never certifies full coverage.

fn take_control_invocation(&mut self) -> Option<ControlInvocation>

Drain one queued action-bound control intent from this subtree.

fn control_action_bindings(&self) -> Vec<ControlBindingMetadata>

Inventory action-native and explicitly legacy controls. A widget that owns an emitter prepends its metadata to its descendants’ inventory.

fn refresh_control_action_availability( &mut self, allowed: &HashSet<ActionAddress>, )

Push the fresh local permission-filtered action surface into every retained control: refresh this widget’s own emitter, then its children.

fn take_attributed_control_invocation( &mut self, ) -> Option<(ControlInvocation, Option<InvocationId>)>

Self::take_control_invocation, with the effect invocation the intent continues when an effect’s handler or completion queued it: the host applies it for that invocation’s invoker.

fn on_control_invocation_result( &mut self, address: &ActionAddress, result: &Result<ResourceOperationStart, DoorError>, )

Report the admission result of one queued local control invocation. Accepted means queued, not completed; confirmation remains an error while the host offers its normal confirmation UI. This notification grants no document authority and must not retry the invocation itself.

fn action_control_bindings(&self) -> Vec<ControlBindingMetadata>

Action-emitter bindings in the same order and exposure as the full inventory. Custom private inventories keep their authoritative default; wrappers can avoid allocating semantic-only accessibility snapshots.

fn has_action_control_bindings(&self) -> bool

Whether this exposed subtree contains controls consuming action availability. An override must match whether control_action_bindings contains an Action, including the same modal child exposure, regardless of current availability.

fn has_pending_control_invocation(&self) -> bool

Local control intent queued behind asynchronous startup preparation. A scheduling hint only; the host still checks live authority.

impl CardBody for ListRow

fn show_as_card(&mut self, selected: bool, activate: Event)

Show as a card: its own surface, its title wrapped over up to CARD_TITLE_LINES lines, its facts on a line under the title, and a press reporting activate — and selection, where it is the selected one.

impl Described for ListRow

fn set_props(&mut self, props: ListRowProps) -> bool

The texts, marks and selection change in place; a row whose leading column or trailing control changes shape is built again.

type Props = ListRowProps

fn from_props(key: &str, props: ListRowProps) -> ListRow

The widget of props, with key its stable id.

fn slot_views(&mut self, slot: &str) -> Option<&mut dyn SlotViews>

The views of its slot slot, to change by key in place: None when a change of what the slot holds builds the widget again.

fn part_views( &mut self, slot: &str, key: &str, of: &str, ) -> Option<&mut dyn SlotViews>

The views its slot slot holds for the part key — a part being a component the slot takes, whose props the widget reads — in that part’s own view slot of, to change them by key where they stand. None when a change inside a part builds the widget again.

impl Drop for ListRow

A row a rebuild drops leaves its mark for the one put in its place.

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl PublishesResources for ListRow

fn resources(&self, _doc: &AutoCommit) -> Vec<ResourceSpec>

The tree of resources this widget currently has open, each with the actions it exports, e.g. a playing video plus its comments. doc lets a provider enumerate resources living in the document.

fn caller_view_resources(&self, _doc: &AutoCommit) -> Vec<ResourceSpec>

Explicit host-local presentation/request controls for the portable caller palette. Only View operations are accepted; shared effects remain broker-owned.

fn action_directory_resource_page( &self, _doc: &AutoCommit, _cursor: &[u8], _max_results: usize, ) -> Option<ActionDirectoryResourcePage>

One cursor-addressable page of resource roots safe to expose through the broker pull directory. max_results is a hard ceiling; a live provider must return a non-empty opaque cursor when it has a tail. None is the default: an unbounded contextual Self::resources snapshot must not be reached from a remote query or revision.

fn action_directory_revision(&self, _doc: &AutoCommit) -> Option<String>

Revision of non-document bounded directory roots; None when this widget has no independently mutable remote directory state.

fn action_directory_invocation_domain( &self, _doc: &AutoCommit, ) -> ActionDirectoryInvocationDomain

Continuity coverage for this owning subtree’s effective invocation domain. Returning a value is a semantic promise, not authority; unknown coverage stays closed.

fn resource(&self, _doc: &AutoCommit, _id: &str) -> Option<ResourceSpec>

Resolve an addressable resource omitted from the contextual snapshot.

fn resource_pending(&self, _id: &str) -> bool

Whether id, which resolves to nothing now, may resolve once what the widget is reading off the UI thread lands (a row of a list not read yet). A caller resolving it is answered then, never kept waiting on a blocking read nor told it is unknown before the read ends.

fn resources_for( &self, participant: Option<&ParticipantId>, doc: &AutoCommit, ) -> Vec<ResourceSpec>

The tree as one participant (an agent task) sees it, built from that participant’s own view state. None is this widget’s own view. Multi-participant widgets override this and Self::resource_for, and never put one participant’s selection into another’s tree.

fn shared_resources_for( &self, participant: Option<&ParticipantId>, doc: &AutoCommit, ) -> Option<Vec<SharedResource>>

Self::resources_for as a SharedResource forest whose unchanged subtrees are the very nodes of the last one, so consumers skip what they have seen. None, the default, has callers wrap Self::resources_for. An answer must equal it exactly once materialised (SharedResource::to_resource).

fn resource_for( &self, participant: Option<&ParticipantId>, doc: &AutoCommit, id: &str, ) -> Option<ResourceSpec>

Self::resource in participant’s tree.

fn action_directory_visibility( &self, _doc: &AutoCommit, _resource_id: &str, ) -> Option<ActionAddress>

Explicit disclosure authority for an actionless resource container in the broker pull directory. None means its label and hierarchy are not remotely discoverable unless the resource itself has a safe view action.

fn document_action_result( &self, _doc: &AutoCommit, _address: &ActionAddress, _changes: &[Patch], ) -> Option<Value>

The result of document action address, which has just applied to doc as changes: a compact summary of what it produced, so its caller needs no second read to see what happened. Asked only for an action whose contract declares a JSON result, which this value must satisfy.

impl ReservedShape for ListRow

fn reserved_shape(&self) -> SkeletonShape

impl ResourceOperations for ListRow

fn resource_operation_handlers(&self) -> HashSet<String>

Every type this widget and its subtree dispatch.

fn start_operation( &mut self, op: &ResourceOperation<'_>, doc: &mut Edits<'_>, path: &ExId, ) -> Result<Option<ResourceOperationStart>, String>

Admit an exported effect or view operation. Document operations never enter it.

fn local_resource_operation_handlers(&self) -> &'static [&'static str]

Effect/view operation type ids this widget can actually dispatch.

fn poll_resource_operation( &mut self, invocation: InvocationId, cancellation_requested: bool, doc: &AutoCommit, path: &ExId, ) -> Option<InvocationUpdate>

Poll one admitted operation without blocking the UI thread.

impl RowActionRects for ListRow

fn row_action_rects(&self) -> Vec<Rect>

Where the row’s hover actions stand on screen, in the order it shows them: what a host presses to reach one from a script or a test.

impl RowSelectionSink for ListRow

fn take_selection(&mut self, selection: RowSelection)

Take the selection the list holds for this row.

impl Widget for ListRow

fn perform_action( &mut self, action: &Action, key_path: &[u64], _state: &mut Edits<'_>, _path: &(dyn Any + 'static), ) -> bool

An action on the row itself, or on one of its action buttons (its children in the accessibility tree, by position).

fn needs_animation_frame(&self) -> bool

Frames only while its leading checkbox is on its way.

fn perform_semantic_action( &mut self, target: &str, action: &Action, state: &mut Edits<'_>, path: &(dyn Any + 'static), ) -> bool

Run the action a button child of the row’s node was addressed by.

fn provide<'a>(&'a self, request: &mut Request<'a, '_>)

Answer a request for a capability this widget takes part in (see capability). Declare capabilities with crate::provides!.

fn provide_mut<'a>(&'a mut self, request: &mut RequestMut<'a, '_>)

Exclusive counterpart to Widget::provide.

fn set_interaction_environment(&mut self, environment: InteractionEnvironment)

Receive the host’s current input capabilities. The default propagates through retained containers, so app code does not need device branches.

fn sync(&mut self, state: &(dyn Any + 'static), path: &(dyn Any + 'static))

Pull model state into this widget before layout. The default syncs the children Widget::children_mut returns; a widget overrides it only to read state of its own, or to sync children it does not expose there.

fn update( &mut self, state: &(dyn Any + 'static), path: &(dyn Any + 'static), ) -> bool

Notice, between frames, state outside the document (a chrome revision, a momentum scroll still ticking) and report whether anything changed. The default updates every child Widget::children_mut returns without short-circuiting, so a container never freezes its descendants; an override checks state of its own and forwards.

fn build_layout( &mut self, taffy: &mut TaffyTree, theme: &Theme, node_map: &mut HashMap<NodeId, *mut dyn Widget>, ) -> NodeId

fn adjust_layout_style( &mut self, taffy: &mut TaffyTree, node: NodeId, text: &mut TextRenderer, ) -> bool

Adjust this node’s style using its allocated size, before final geometry is applied. Return true only when the style changed (or an inherited decision child hooks read). An override may measure its owned children through ordinary references, entering their callback binding when present. Never reenter descendants through the raw node map while borrowing their parent, change topology, or build another layout tree. The shared host solver visits every registered widget, repeats layout at most eight times and skips a frame that does not settle.

fn measure( &mut self, known: Size<Option<f32>>, available: Size<AvailableSpace>, text_renderer: &mut TextRenderer, ) -> Size<f32>

fn layout_info(&self) -> Option<LayoutInfo>

Read-only resolved decisions for widgets with an explicit layout policy. None means the widget has no such policy; ordinary manual widgets remain valid. Values are available after build/settlement and carry real origins.

fn apply_layout(&mut self, taffy: &TaffyTree, node: NodeId, origin: Point)

Take the geometry layout gave this node. The default keeps none, for widgets that neither draw nor hit-test.

fn draw( &mut self, scene: &mut Scene, transform: Affine, text_renderer: &mut TextRenderer, theme: &Theme, presence: &PresenceCtx, )

Paint into scene. The default paints nothing.

fn handle_event(&mut self, event: &WindowEvent, ctx: &mut EventCtx<'_>)

Handle one input event with the runtime services for this retained node.

fn cursor_shape(&self, point: Point) -> Option<CursorIcon>

point is logical coords, same space as Widget::get_rect; None defers to the default arrow. The host hit-tests the whole tree via node_map and picks the smallest-area claim, so containers need not override this.

fn tooltip_target_at(&self, point: Point) -> Option<(Rect, String)>

fn is_focusable(&self) -> bool

fn set_focus(&mut self, focused: bool)

fn is_focused(&self) -> bool

fn is_enabled(&self) -> bool

A disabled (false) widget is excluded from focus traversal, must reject input in handle_event, and renders dimmed (see DISABLED_ALPHA).

fn needs_redraw(&self) -> bool

Default false (clean). A widget is clean until something it reads changes: a leaf that keeps state says so by tracking a dirty: bool (set in handle_event/sync, cleared in mark_drawn()), and one that paints from the people on the document reads the frame’s presence (crate::presence::frame::frame). Containers MUST forward: dirty iff any descendant is.

fn mark_drawn(&mut self)

Called after this widget’s scene lands in the composed frame, to clear a dirty flag. Default forwards to children.

fn is_layout_dirty(&self) -> bool

Default true; widgets with a fixed intrinsic size should override to false unless a size-affecting mutation landed. Containers MUST forward: layout-dirty iff any descendant is.

fn accessibility_child_description(&self, child_index: usize) -> Option<String>

What describes one retained children entry to assistive technology, when this widget holds the words for it: a row’s secondary line is its trailing switch’s description. The bridge sets it as that child’s node’s description unless the child describes itself.

fn children(&self) -> Vec<&dyn Widget>

fn children_mut(&mut self) -> Vec<&mut dyn Widget>

fn wants_pointer_capture(&self) -> bool

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

fn test_id(&self) -> Option<&str>

Stable id for the e2e test harness; None falls back to a path-based key. Must be unique across the live tree — the registry resolves on first match, so a duplicate shadows the second occurrence.

fn get_rect(&self) -> Rect

The rectangle this widget occupies. The default, for widgets that keep no geometry, is empty.

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

Downcast to the concrete widget, for hosts and tests that reach a known widget through dyn Widget. Default None (a widget may borrow and so not be 'static); a widget opts in with Some(self), and a Decorator answers itself.

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

fn accessibility(&self) -> Option<AccessNode>

Role, name/description/value, and AccessState. Default None means presentational: the node is skipped and children reparent onto the parent. State must be derived, not stored so it can’t drift from draw; names must already be i18n!-resolved.

fn native_input_snapshot( &self, _state: &(dyn Any + 'static), _path: &(dyn Any + 'static), ) -> Option<Value>

Read-only state evidence for opt-in scheduled native input diagnostics. Called only around diagnostic inputs, never during ordinary input or paint. Keep this inexpensive and root-local; snapshots may be logged verbatim. This verifies widget state, not rendered pixels or display presentation.

fn view_only_scroll(&self, _event: &WindowEvent) -> bool

Opt in only when this wheel event changes scroll geometry and nothing else: no document edit, focus or selection, action availability, resource declaration, pending command or work that requires sync. The runner still lays out, paints and refreshes accessibility geometry; unknown handlers stay on the full path.

fn primary_vertical_scroll(&self) -> Option<PrimaryScrollRegion>

Explicit app-owned region; never search secondary children implicitly.

fn apply_primary_vertical_scroll( &mut self, _action: PrimaryScrollAction, ) -> PrimaryScrollResult

fn callback_binding(&self) -> Option<CallbackBinding>

Runtime binding inherited by descendants in a matching layout topology.

fn has_separate_document_owner(&self) -> bool

Whether this widget introduces a document owner distinct from the runner’s outer State. This is a compatibility check, never identity or authority for history access or restore.

fn history_owner(&self) -> Option<HistoryOwner>

Opaque actual custody for framework History source registration.

fn record_owners(&self) -> Vec<HistoryOwner>

Records this widget keeps open beside the document it shows, each synced on its own route: a framework app’s records in the person’s own workspace (crate::record::person). They take no part in this widget’s history or controls.

fn mount_native_views(&mut self, host: &NativeViewHost<'_>)

Attach native child views through this owner’s retained lifecycle topology. Presentation containers with inactive or hidden live descendants override this traversal so lifecycle ownership stays independent of drawing and input visibility.

fn unmount_native_views(&mut self)

Tear native children down while their parent window still exists.

fn native_view_frame_start(&mut self)

Begin a native-view frame through this owner’s retained lifecycle topology.

fn set_platform_conventions(&mut self, conventions: PlatformConventions)

Receive host-selected platform conventions. The default propagates to retained children, keeping target-OS branches out of app code.

fn set_window_bar_control(&mut self, in_bar: bool)

Tell this widget whether it stands in a window bar. A bar’s controls are drawn at the bar’s control height whatever the pointer; the target a finger needs reaches beyond the drawn shape, invisibly. The default propagates to children.

fn settle(&mut self, edits: &mut Edits<'_>, path: &ExId)

Apply, after the sync pass, what the widget took up there and must write: a worker’s answer, a chooser’s file, an event a child queued. Writes go only through typed actions on edits; the host syncs again when the document changed. The default settles the returned children.

fn observe_physical_input(&mut self, _input: PhysicalInput)

Observe this app’s ordinary foreground physical input before framework shortcuts consume it. Keep feedback ephemeral; this is not an input grant.

fn for_each_child(&self, visitor: &mut dyn FnMut(&dyn Widget))

Allocation-free read-only child traversal. Existing custom containers inherit a compatibility adapter over Self::children; toolkit containers override this to walk their retained storage directly.

fn for_each_child_in_clip(&self, visitor: &mut dyn FnMut(&dyn Widget))

The children of Self::for_each_child that may paint inside the layout_clip in effect: what a scroll view’s damage and copy plan need. Every child by default; a long column visits only those near the clip, so a frame costs what is shown, not what the column holds.

fn for_each_hosted_child(&self, _visitor: &mut dyn FnMut(&dyn Widget))

Children this widget keeps in the retained tree but does not route input to: a subtree it does not own and answers the person’s events for itself, like a host drawing another widget’s card over the windows. Inspection, named controls and the accessibility tree walk these after the children Self::children lists, so what is walked there keeps the paths, sibling indices and registry entries it had.

fn for_each_layout_child(&self, _visitor: &mut dyn FnMut(&dyn Widget)) -> bool

Every child this widget’s Self::build_layout gives a layout node, also those Self::for_each_child keeps from routing (a hidden pane, a title, a spacer). A retained layout is checked against this walk before it is called through again, so a widget that replaced a child without reporting it gets a new layout instead of a call into freed memory. A child missing here cannot be checked, so debug builds stop on it. A wrapper that stands for its inner widget’s node visits the inner widget itself.

fn window_slot(&self, _id: String) -> Option<ToolbarAction>

This control as an action of the window’s bar, sent back as id (crate::window_toolbar::ToolbarAction): a button’s icon and name. None for anything that is not a button.

fn stands_for(&self, address: *const ()) -> bool

Whether this widget is the one at address, or stands in the tree for it: a Decorator stands for every widget it wraps, so a scroller drawn inside one is found where the decorator is (crate::scroll_copy::offer).

fn focus_reveal_context(&self) -> Option<Rect>

Context that should remain visible with a focused descendant, such as a form control and its validation message. Opt-in scroll containers use this block when it fits; otherwise they prioritise the control.

fn reveal_descendant(&mut self, target: *const dyn Widget) -> bool

Reveal a newly keyboard-focused descendant inside any enclosing viewport. Containers override this to scroll; ordinary widgets simply recurse toward the target and report whether it was found.

fn test_rects(&self) -> Vec<(String, Rect)>

Named hit rects for widgets that paint several affordances into one rect instead of composing children. Same space as Widget::get_rect; zero-area entries are dropped.

fn child_clip_rect(&self) -> Option<Rect>

Absolute logical clip applied to ordinary children during painting and pointer routing. Inspectors and enclosing scroll regions must respect this boundary instead of treating clipped descendants as visible extent.

fn snap_points(&self, axis: ScrollAxis, out: &mut Vec<f32>)

Offsets along axis that this widget, as a scroll view’s content, offers it to settle on, measured from its own leading edge: a board’s lanes (crate::widget::Board). None leaves a scroller stopping wherever the hand left it.

fn take_action_palette_request(&mut self) -> Option<ActionAddress>

One-shot request to open the host’s action palette directly at a typed resource action. Parameter collection and permission checks remain host policy; widgets only name an address already present in resources().

fn take_search_request(&mut self) -> bool

One-shot request to open the host’s search palette, the same one the platform search shortcut opens. An app’s own search button latches it so search stays one shared host surface rather than an app overlay.

fn claims_raw_touch(&self, _point: Point) -> bool

Opt out of touch-to-pointer emulation for contacts that begin at point (logical coords, same space as Widget::get_rect).

fn touch_claim(&self, _point: Point) -> TouchClaim

What a one-finger contact that begins at point (logical coords) means here, when a drag moves something rather than scrolling.

fn tooltip(&self) -> Option<&str>

Revealed after a dwell over the widget’s rect, via the toolkit’s one tooltip mechanism (crate::widget::tooltip::TooltipHost), hit-tested like cursor_shape so containers need not forward it. An icon-only control should also use this as its accessible name.

fn tooltip_side(&self) -> TooltipSide

Which side of the control its tooltip goes: below by default, beside it for a control in a vertical rail.

fn is_default_keyboard_focus(&self) -> bool

Preferred control when its app is explicitly activated without a valid saved control. Hosts still enforce visibility, enabled state and scope.

fn keyboard_input_scope(&self) -> Option<u64>

Exact app instance whose non-text shortcuts this subtree owns when activation has no control target. Unbound desktop chrome may declare the active tab; component boundaries default to their captured owner.

fn set_full_bleed(&mut self, _full_bleed: bool)

The window holding this content fills its display (a maximized window): it has nothing beside it to round its corners against or to set it apart from, so content that frames or clips itself to the window’s shape draws edge to edge instead. A client surface drawn that way, last and unclipped, is one the display can scan out directly. Content that frames nothing ignores it.

fn set_invalid(&mut self, _invalid: bool)

The form’s validation verdict for this control, set by Field::with_error: an invalid control edges itself in danger ink and reports invalid to assistive technology. Controls without a field face ignore it.

fn focus_requested(&mut self, target: Option<NodeId>, tree: &TaffyTree)

An explicit runner focus request, after resolving the actual keyboard owner. Retained flags and layout restoration are not user gestures. Containers can observe this to reveal the owning viewport.

fn context_menu_anchor(&self) -> Option<Rect>

The box a context menu opened from the keyboard stands against: the item that has the keyboard, so the menu opens under it rather than under the whole widget. A widget that holds items (a list) answers for the one with the keyboard; None leaves the menu to stand under the focused widget’s own box.

fn wants_tab_input(&self) -> bool

Whether a focused widget owns Tab instead of the host’s focus traversal. This is deliberately opt-in: ordinary form fields and controls retain platform-standard Tab/Shift+Tab navigation, while a code editor or terminal can receive the key for indentation or completion. A widget around the focus may claim it too: a sheet that walks its own controls with Tab.

fn ime_cursor_rect(&self) -> Option<Rect>

Caret rectangle for the platform input method, in window-logical coordinates. Returning Some enables IME for the focused widget and positions its candidate window; non-text controls keep the default None and therefore disable IME.

fn traps_focus(&self) -> bool

While any widget answers true, the host restricts Tab/directional focus to this subtree (wrapping at the ends) and restores the prior focus once it goes back to false. Default false.

fn scopes_keyboard_focus(&self) -> bool

Whether Tab and directional focus travel stay inside this subtree while no trap holds focus: the content of the focused desktop window, so keyboard travel cycles through the app the person is in and never wanders onto the desktop’s chrome (its bars, menus and window titles), which the keyboard reaches through its own shortcuts. Unlike Self::traps_focus it moves no focus when it starts or ends, and pointer input is unaffected. Default false.

fn take_app_activation(&mut self) -> Option<u64>

One-shot (reading MUST clear it): the app instance the person just brought forward (a window they opened, clicked or switched to), whose keyboard focus the host restores, or puts on its default control, so what they type next reaches it. Default forwards the first request found among the children.

fn take_focus_request(&mut self) -> Option<String>

One-shot (reading MUST clear it): the test id of the control this subtree asks to take the keyboard once the runner laid it out, such as the first field of a view a person’s press just opened, so what they type next lands there. The runner focuses it as a press focuses a control, blurring any other; a control it does not find (or that takes no focus) leaves focus where it is. Default forwards the first request found among the children.

fn accessibility_shared(&self) -> Option<SharedAccessNode>

Self::accessibility with its synthetic children shared, for a widget that keeps them between frames: each child it did not change is handed over as the very Arc of the last frame, which the semantic tree takes as unchanged without copying or comparing it.

fn accessibility_hidden(&self) -> bool

Whether Self::accessibility reports this subtree hidden, for a host that asks it of every node to prune focus traversal. Widgets whose node is costly to build (text values, per-block children, a translated name) answer without building it: the focus walk asks every widget in the window on every recomputation. Any override must agree with accessibility(); debug builds check it in the walk.

fn accessibility_root(&self) -> Option<AccessNode>

Self::accessibility’s own node with its children left empty: its role, identity (semantic_key) and state. Focus capture and focus order read only these, for every node on every frame, so a widget whose node carries a large subtree (a document exporting its every block) answers without building it. An override must equal accessibility() with children cleared.

fn synthetic_accessibility_rect(&self, _path: &[usize]) -> Option<Rect>

Geometry for an immediate-mode semantic child from AccessNode::children. The path is its child-index path beneath this widget’s accessibility node. Returning a rect lets AccessKit activation inject the same click as pointer input.

fn focus_synthetic_accessibility(&mut self, _path: &[usize]) -> bool

Move this widget’s own immediate-mode focus to a synthetic semantic child. Retained widgets continue to use the ordinary taffy focus path.

fn accessibility_child_parent(&self, _child_index: usize) -> Option<usize>

Reparent one retained children entry beneath a synthetic child returned by accessibility. The returned index addresses AccessNode::children for this frame. Collections use this to place a real interactive row delegate inside its virtual ListItem/TreeItem instead of exporting a duplicate.

fn accessibility_child_path(&self, child_index: usize) -> Option<Vec<usize>>

Reparent one retained children entry beneath a nested path of synthetic children returned by accessibility.

fn accessibility_represents_child(&self, _child_index: usize) -> bool

Whether one retained children entry is already represented in this widget’s own synthetic accessibility tree, so the bridge must not export it a second time. A host that publishes a child’s semantics itself (to add its own controls inside the same dialog) answers true for that child; assistive technology then sees one copy, not two.

fn lays_out_child(&self, _child_index: usize) -> bool

Whether this widget lays one retained children entry out itself (an Embedded part of a painted page) rather than through the window’s layout, which then gives it no node. The accessibility walk reaches such a child, and every widget inside it, through this widget’s node.

fn ime_requires_deferred_ack(&self) -> bool

This field needs a host that consumes deferred receipts. Ordinary native Wayland windows must not advertise it until they have that delivery path.

fn ime_refuses_ordinary_commits(&self) -> bool

Ordinary input-method commits (a composing keyboard IME, the on-screen keyboard) cannot reach this field: its text arrives only through deferred receipts (a browser page field), so hosts keep standard text input closed outside a dictation session. A field that needs deferred receipts for dictation but turns an ordinary commit into its own acknowledged edit (Terminal’s native editor) does not refuse them.

fn start_deferred_text(&mut self) -> Option<Receipt>

Begin one bounded deferred session after explicit host consent, preserving the existing original-field fingerprint. This grants no microphone access.

fn commit_deferred_text(&mut self, text: &str) -> Option<Receipt>

A private asynchronous final. None leaves ordinary synchronous IME dispatch to the host. A receipt binds this original field and must be acknowledged before the host releases its private recovery transcript.

fn ime_content(&self) -> Option<InputContent>

The focused widget wants platform text input (Wayland text-input-v3, native IMEs elsewhere). None is intentionally the default: enabling an IME for buttons, canvas tools or games makes the compositor raise an on-screen keyboard over content that cannot accept the committed text.

fn ime_multiline(&self) -> bool

Whether the original focused editor accepts line feeds as text. This is field policy, never inferred from a multiline accessibility presentation. Wrappers inherit only one unambiguous child at their active IME caret.

fn ime_edit_fingerprint(&self, key: &[u8; 32]) -> Option<[u8; 32]>

Opaque local invalidation of deferred input, including selection edits that leave the caret rectangle unchanged. The host supplies an ephemeral secret key; no text or selection is retained in the resulting digest. The default shares the accessibility door and excludes protected or read-only controls. Text controls can override it to avoid cloning text.

fn presented(&self) -> bool

Default true; false only for a widget standing in for a window’s content whose first frame has not drawn. Must latch: once true, never false again for the same content.

fn arrives_from(&self) -> Source

Where this content’s first frame comes from while it has not presented: this device (an app starting here), another device or a host. A frame from this device may hold the window’s first frame up to one frame budget; any other reserves the window’s place and says where it comes from after a while.

fn arrival_progress(&self) -> Option<Progress>

How much of what this content’s first frame waits on has come, when that measures itself (its app downloaded before it starts).

fn arrival_shape(&self) -> SkeletonShape

The shape this content declares for the placeholder standing in for its first frame. Undeclared, the placeholder is the ground alone: nothing guesses what a window will show.

fn text_review(&self) -> Option<(usize, String)>

(caret_byte, text), byte offset on a char boundary. The host diffs this before/after an event so caret-only moves (arrows, Home/End) get announced, not just typing.

fn on_external_event( &mut self, _payload: &str, _state: &mut Edits<'_>, _root: &(dyn Any + 'static), )

Delivers an out-of-band string payload from crate::app::UserEvent::External (e.g. a worker thread streaming output into a status log). Default no-op; the App redraws and re-syncs after dispatch, so mutating state here is enough.

fn on_nav_gesture( &mut self, dir: NavDirection, state: &(dyn Any + 'static), path: &(dyn Any + 'static), ) -> bool

Global back/forward gesture (swipe/edge-pull), recognised by crate::gesture::NavGestureRecognizer and delivered to the whole tree; return true once consumed. Default forwards to children, so a widget that owns history becomes swipe-navigable for free.

fn nav_availability(&self) -> NavAvailability

Which directions Self::on_nav_gesture would consume now. A widget that owns history overrides this beside on_nav_gesture.

fn take_focus_reset(&mut self) -> bool

One-shot (reading MUST clear it) signal to move focus to this subtree’s first focusable widget after the next rebuild. Only consulted under crate::app::App::autofocus_on_structure_change; a wizard raises it on step transitions.

fn take_accessibility_request(&mut self) -> Option<AccessibilityRequest>

One-shot (reading MUST clear it) request to change the window’s accessibility preferences, raised by a control the person used. The host applies it before the next frame. Default forwards the first request found among the children.

fn dev_route(&self) -> Option<RouteSnapshot>

Route history when this widget, or one it contains, is a Router.

fn restore_dev_route(&mut self, route: &RouteSnapshot) -> bool

Put route back. Returns whether a router in this subtree accepted it.

fn appearance_intent(&self) -> Option<AppearanceIntent>

Theme/high-contrast/reduced-motion/scale, polled under crate::app::App::appearance_reconcile — how a settings pane re-themes the running app live without a back-channel. Level-triggered; the App recurses Self::children itself, so containers need not forward it. First Some wins.

fn minimum_window_width(&self) -> Option<f64>

The narrowest this window still works at, in logical pixels: the minimum of its compact layout (a NavShell answers with one column at a time). The host states it to the window system, so the desktop stops a resize there. None: no opinion. The host walks the tree itself (minimum_window_width), so containers need not forward it; the first Some wins.

fn preferred_window_size(&self) -> Option<(f64, f64)>

The whole size this window wants, in logical pixels, when the app is the window’s only content and knows how big it must be: the on-screen keyboard parked to a strip. The host states it as the window’s minimum and maximum, so the desktop shapes the surface to it. None: the window is the user’s and the app lays itself out in whatever it gets.

fn set_motion_reduced(&mut self, reduced: bool)

Apply the effective reduced-motion preference before the host asks this subtree whether it needs another animation frame. The default forwards recursively, making the preference a framework policy instead of an optional convention that every container has to remember to implement.

fn needs_idle_sync(&self) -> bool

Whether sync still needs to run on idle frames without input or collab events — e.g. waiting out a document-adoption grace window.

fn disclosing(&self) -> Option<Disclosing>

While this widget is a band on its way in or out (motion::Disclosure: an in-window banner arriving or leaving), or a content-sized container one moves in, how far what follows it is drawn from where it is laid out. A moving band stands out of the layout; its container places it (Self::place_disclosing) and draws the widgets after it lower by transform, so they move with the band’s edge instead of being laid out again every frame. None at rest (the default).

fn place_disclosing(&mut self, _slot: Rect)

Where a band on its way (Disclosing::Band) stands while it is out of the layout: its slot’s top and width (slot’s height is zero), set by its container after each layout.

fn is_band(&self) -> bool

A band that comes and goes (an in-window banner): when its view stops building it, its column draws it leaving (widget::Disclosing). Its column leaves it out of its identity across rebuilds.

fn note_placement(&mut self, _placement: Placement)

Where a band stands in its column, set by the column after each layout: what it leaves when dropped, so the column a rebuild makes can draw it leaving.

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

Why this widget itself asks for animation frames, for diagnostics that name a desktop which keeps painting. None when it has nothing to add to its name and geometry.

fn next_wake_deadline(&self) -> Option<Instant>

Earliest wall-clock deadline at which this subtree needs a sync or redraw with no input: the loop sleeps until then (not animation).

fn holds_frame_until(&self, now: Instant) -> Option<Instant>

Until when the frame that would show this subtree waits for data it reads from this device (crate::arriving): a local read that has not answered and is still inside its frame budget. The host keeps the frame on screen until then, or until the data lands, so the person never sees the space empty and then filled. Containers forward (the default does).

fn serve_deadline(&mut self, _now: Instant) -> bool

A deadline this subtree asked for (Self::next_wake_deadline) is due at now: do the work it was for, and say whether anything changed. The default says it did.

fn modal_capture(&self) -> Option<Rect>

Some(rect) when this subtree holds an open modal, its panel box. While any widget reports Some, the host suppresses its own global focus shortcuts and swallows unhandled pointer presses so nothing behind the modal is clickable. Containers MUST forward (the default does, via first Some among children).

fn dismiss_presented_modal(&mut self) -> bool

Close every modal this subtree presents, as its own way out does (a host whose surface is a modal sheet calls it when the shell takes the sheet down). Whether any was presented; containers forward.

fn presents_modal(&self) -> bool

Whether this subtree presents a modal still drawn (arriving, open or leaving): the counterpart of Widget::dismiss_presented_modal.

fn take_structure_dirty(&mut self) -> bool

True if this subtree’s structural composition changed since the last frame; reading clears it. The default drains every retained child and reports whether any was dirty.

fn take_structure_change(&mut self) -> StructureChange

Self::take_structure_dirty, saying whether the frame’s damage can still describe the rebuild (StructureChange::Described). Reading clears what take_structure_dirty clears; the two must agree on whether there is a change. The default is the flag, as a StructureChange::Rebuild: only a widget that knows every pixel its change touches lands in its own damage says less, and a container forwards a child’s StructureChange::Described only by overriding this.

fn remount_children(&mut self, remount: &mut Remount<'_>) -> bool

Carry out a StructureChange::Children this widget or one under it reported, in the retained layout tree, through remount (see remount). Returns false when it cannot be carried out in place: the host then rebuilds its tree, and the change is carried out by Self::build_layout. A widget reports such a change until either has carried it out. The default carries out its children’s.

fn has_pending_visual_work(&self) -> bool

Work already requested by this view whose completion will replace a placeholder. Unlike animations, this can be awaited by still captures.

fn has_transient_feedback(&self) -> bool

Temporary feedback currently presented, such as a save acknowledgement. Captures may intentionally include it; scene-invariance checks can wait for it to disappear separately from unfinished placeholder work.

fn collect_damage(&self, regions: &mut Vec<Rect>)

Logical-pixel bounds whose visual output differs from the last frame.

fn damage_covers_own_box(&self) -> bool

Whether, after this frame’s draw, this widget’s own Self::collect_damage covers every pixel a relayout changed by moving or resizing its layout box: a host that repaints where moved widgets were and are may then leave this widget’s box to it (its children’s boxes still count). A block editor that grew by a paragraph says where its blocks were and are; the default does not claim it.

fn mark_children_drawn(&mut self)

Rest this widget’s children after a frame drew them, for a widget that keeps its own dirty flag: it clears the flag itself, then calls this.

fn release_scene_cache(&mut self)

Release retained encoded-scene storage in this subtree without marking its visual/model state dirty. Outer caches call this after a successful reuse: while the outer display list is authoritative, keeping byte-for-byte descendant encodings only duplicates memory. A later outer rebuild causes descendants to record/cache normally.

fn composition_follows_allocation(&self) -> bool

Whether this widget composes its children from the size it was last allocated (it reads its own rect while building its layout: a compact layout under a width, a count of columns, an inset from a drawer). A window resize then needs a second composition against the new allocation, as well as the re-solve every resize gets. Widgets that compose independently of their allocation, or that report take_structure_dirty themselves when a new allocation changes what they show, keep the default: a resize re-solves the retained tree in place instead of recomposing all of it.

fn layout_needs_measure(&self) -> bool

Whether a layout_dirty frame needs taffy to re-solve sizes (compute_layout) rather than just reposition already-solved boxes. Scrollable is the motivating override: it translates its origin in apply_layout without changing any taffy size, so re-solving on every scroll frame is pure waste.

fn paint_bounds(&self) -> Rect

Everything this widget paints, children included; draw_child skips the draw when it misses the viewport. Override for widgets that paint past their own rect.

fn draw_overlay( &mut self, scene: &mut Scene, transform: Affine, text_renderer: &mut TextRenderer, theme: &Theme, presence: &PresenceCtx, )

Top-layer pass, run once after the whole draw recursion, so anything emitted here composites above every sibling regardless of tree order — the toolkit’s overlay mechanism for content that escapes its layout box (an open Dropdown, a popover). Default recurses children_mut.