Struct TileHost 

pub struct TileHost {
    pub focused: bool,
    /* private fields */
}

Fields

focused: bool

Implementations

impl TileHost

pub fn take_host_intent(&mut self) -> Option<AppHostIntent>

pub fn mount_component( component: AppComponent, sink: impl Fn(WakeEvent) + Send + Sync + 'static, ) -> Result<TileHost, LaunchError>

Bind a prepared component’s wake lifetime before mounting it in a group. Setup failure retains the component’s record and recovery reports.

pub fn from_component(component: AppComponent) -> TileHost

pub fn register_document_history( &mut self, definition: &'static HistoryDefinition, ) -> Result<(), HistoryRegistrationError>

pub fn new(content: TileContent) -> TileHost

pub fn set_panic_scope(&self, tab: u64)

Name tab to a panic hook while this tile’s application runs: see panic_scope.

pub fn set_opening_name(&mut self, name: &str)

pub fn bind_record(&mut self, store: RecordStore, tab: RecordCheckout)

Idempotent on the same record — rebinding would hand the tab a fresh empty document, and the tree re-binds every tile on rebuild.

pub fn bind_or_create_record(&mut self, store: RecordStore, tab: RecordCheckout)

Admit a newly created scratch resource owned by this caller. Creation applies only to this exact checkout, never to later record intents.

pub fn refuse_record_binding(&mut self, reason: String)

Keep a failed fresh creation unavailable without attaching an existing record with the same spelling. Ordinary binding refresh cannot clear it; the owner must explicitly replace the resource/content first.

pub fn record_creation_refused(&self) -> bool

pub fn record_transition_error(&self) -> Option<&str>

pub fn kind_string(&self) -> String

pub fn content_mut(&mut self) -> &mut TileContent

Mutable legacy content access. Canonical components use checked replacement.

Panics

Refuses extraction of a canonical component through the legacy content API.

pub fn replace_component( &mut self, component: AppComponent, ) -> Vec<ComponentCloseReport>

Replace a component after its complete closed-owner cleanup. The caller retains returned reports until recovery is durably resolved.

pub fn replace_content(&mut self, content: TileContent)

Used when a window announced before it existed (an opening card) becomes the app; replacing the tab instead would hand focus elsewhere. Keeps the record binding but resets announced so the new occupant is told its scope, and flags a structural rebuild since App and the card variants have different taffy shapes.

pub fn content(&self) -> &TileContent

pub fn set_focused(&mut self, focused: bool)

pub fn start_spawn_animation(&mut self)

A call mid-animation restarts the curve.

pub fn spawn_in_flight(&self) -> bool

pub fn complete_content_rect(&self) -> Option<Rect>

Desktop-space card rect for an app-provided complete semantic canvas. The provider reports tile-content size; the shell card grows from the live tile’s top-left and never shrinks below the live window surface.

pub fn draw_complete_content_capture( &mut self, scene: &mut Scene, transform: Affine, tr: &mut TextRenderer, theme: &Theme, presence: &PresenceCtx, ) -> Option<Rect>

Paint a complete app-provided canvas in the ordinary window card. The app owns only its semantic pixels; shared clipping, corner radius and focus edge remain toolkit code, exactly as on screen.

Trait Implementations

impl ActionControls for TileHost

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 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 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 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 AudiencePresentationProvider for TileHost

fn audience_presentation_request(&self) -> Option<AudiencePresentationRequest>

Request a real audience toplevel on a different output.

fn on_audience_presentation_changed(&mut self, active: bool)

Report whether the audience toplevel is currently live.

fn draw_audience_presentation( &mut self, scene: &mut Scene, transform: Affine, text_renderer: &mut TextRenderer, theme: &Theme, rect: Rect, ) -> bool

Paint the audience-only projection of the app’s existing state.

fn handle_audience_presentation_event( &mut self, event: &WindowEvent, state: &mut Edits<'_>, path: &ExId, ) -> bool

Route controls originating on the audience surface.

fn on_audience_presentation_closed(&mut self)

Treat closing the audience toplevel as an explicit stop request.

impl CollaborationTopology for TileHost

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

impl ComponentLifecycle for TileHost

fn unsaved_documents(&self, doc: &AutoCommit) -> Vec<UnsavedDocument>

App-declared external document obligations. An in-memory record set is not evidence that an editable file has been saved.

fn checkpoint_components(&mut self) -> Vec<String>

Non-destructive persistence checkpoint. Never closes a wake scope or removes a tree; a failed host close must leave every child usable.

fn finish_admitted_close(&mut self) -> Vec<ComponentCloseReport>

Only the host may call this after every checkpoint succeeded, without dispatching another document mutation in between.

fn close_components(&mut self) -> Vec<ComponentCloseReport>

Capture and close nested components before removing their live trees, transferring all recovery reports to the caller.

fn take_component_close_reports(&mut self) -> Vec<ComponentCloseReport>

Drain inert close-report ownership once; never invoke ordinary app callbacks through a closed component.

fn on_window_close_requested(&mut self) -> WindowCloseAdmission

Admit or defer the primary native window’s ordinary close request. Roots that defer must later produce a one-shot close intent.

fn take_window_close_intent(&mut self) -> bool

One-shot approval after an earlier deferred ordinary window close.

fn take_replacement(&mut self) -> Option<ComponentReplacement>

The component this root’s own component asked to show in its place (AppComponent::take_replacement), for the host that mounted it. A component nested deeper answers to the host that mounted it, so the default reaches no child.

fn take_save_status_presentation(&mut self) -> bool

One-shot: the durability of this root’s own component’s record changed since this was last asked, and the root already synced with the new state. A host that asks (an App) presents it with a frame of its own, not a rebuilt tree; one that does not ask sees it through take_structure_dirty.

impl Continuable for TileHost

fn continuation_metadata( &self, state: &AutoCommit, path: &ExId, ) -> Option<ContinuationMetadata>

Return a compact, path-free projection of state that may be resumed on another device owned by the same person.

fn restore_continuation_metadata( &mut self, metadata: &ContinuationMetadata, state: &mut Edits<'_>, path: &ExId, ) -> bool

Apply a continuation projection after launch. Implementations must not change focus or start media; malformed or unknown metadata is ignored.

fn restore_live_continuation_metadata( &mut self, metadata: &ContinuationMetadata, state: &AutoCommit, path: &ExId, ) -> bool

Apply a live owner view to an already-bound resource. This opt-in capability receives no writable document and must preserve focus. Missing resources or anchors are refused so the host can defer or cancel the projection when its authenticated source disappears.

impl FloatingSurfaceProvider for TileHost

fn on_floating_surface_focus_changed(&mut self, id: Option<&str>, focused: bool)

Route native keyboard focus to the exact presentation instance.

fn on_floating_surface_ime_source_changed(&mut self, id: Option<&str>)

Keep the exact secondary presentation’s editor logically focused while the platform deliberately retains text-input focus on its source.

fn on_floating_surface_event_source(&mut self, id: Option<&str>)

Identify the native surface delivering the current input event. The host resets this immediately after dispatch; it grants no authority.

fn floating_surface_accessibility(&self, id: &str) -> Option<AccessNode>

The retained semantic subtree presented in one secondary window.

fn perform_floating_surface_accessibility_action( &mut self, id: &str, target: &str, action: &Action, state: &mut Edits<'_>, path: &ExId, ) -> bool

fn floating_surface_ime(&self, id: &str) -> Option<(ImePurpose, Rect)>

IME purpose and desktop-logical caret rect for one secondary window.

fn take_floating_surface_request(&mut self) -> Option<FloatingSurfaceRequest>

One-shot request to hand app content to the shared floating-surface host. Shell and in-app hosts consume the same description, so PiP does not require a second rendering/widget API.

fn take_capture_studio_request(&mut self) -> Option<CaptureMode>

One-shot request for the session shell’s shared capture/PiP chooser.

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

Rising-edge source-geometry updates for an adopted floating surface.

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

Paint app-owned content whose presentation has moved into shell space.

fn draw_floating_surface( &mut self, id: &str, scene: &mut Scene, transform: Affine, text_renderer: &mut TextRenderer, theme: &Theme, presence: &PresenceCtx, ) -> bool

Paint exactly one app-owned presentation into its native window.

fn set_floating_surface_bounds(&mut self, bounds: Rect)

Push the shell’s authoritative combined-output bounds into the owner.

fn floating_surface_presentations(&self) -> Vec<FloatingSurfacePresentation>

Desktop-space presentations that need a native secondary window.

fn active_floating_surface_ids(&self) -> Vec<String>

Stable IDs whose underlying activity still exists.

fn on_floating_surface_host_message( &mut self, message: &FloatingSurfaceHostMessage, )

Deliver an acknowledged shell lifecycle edge back to the owner.

impl FrameworkHistoryTopology for TileHost

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

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

impl FullscreenProvider for TileHost

fn fullscreen_intent(&self) -> Option<bool>

None means no opinion; otherwise this is a level-triggered intent.

fn fullscreen_params(&self) -> FullscreenRequest

Select the output and mirrored-vs-distinct presentation mode.

fn on_fullscreen_changed(&mut self, active: bool)

Report an actual OS fullscreen transition, including compositor exits.

impl PublishesPresence for TileHost

fn presence_key(&self) -> Option<PresenceKey>

Presence identity is the record shown, not the tile — the only thing that tells two tabs of one app apart, since a peer’s caret is a position in a document. Unbound tiles report nothing.

fn presence_payload(&self) -> Option<(PresenceKey, PresencePayload)>

Outbound presence (typically caret/selection) broadcast while this widget holds focus; the host polls the focused widget after each event and diffs it out to peers.

impl SearchSource for TileHost

fn search_providers(&self) -> Vec<Box<dyn SearchProvider>>

One SearchProvider per findable kind.

fn activate_search_result( &mut self, action_id: &str, doc: &mut Edits<'_>, path: &(dyn Any + 'static), )

Activate a hit: presentation (navigation), not a document action; mutate the model only if selecting changes shared state.

impl ViewState for TileHost

fn view_state(&self) -> Option<ViewContribution>

This root’s contribution, restored through Self::restore_view_state.

fn restore_view_state(&mut self, view: &ViewContribution)

impl Widget for TileHost

fn presented(&self) -> bool

Only an app can answer anything but true — a stub/notice is painted by this process and is on screen the moment the tile is.

fn opening(&self) -> bool

Current content keeps its readiness through resize, but a replacement gets its own opening presentation. A visible tile shows that card immediately rather than disappearing while the new app starts.

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

Attach native child views through this owner’s retained lifecycle topology.

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

Admit an exported effect or view operation: the one entry every handler implements. Document operations never enter it.

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.

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

Opaque actual custody for framework History source registration.

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 callback_binding(&self) -> Option<CallbackBinding>

Runtime binding inherited by descendants in a matching layout topology.

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

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

fn sync(&mut self, s: &(dyn Any + 'static), p: &(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 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 (a resource’s dispatcher); the host syncs again when the document changed. The default settles the children Widget::children_mut returns.

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

Notice, between frames, state that lives 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 at build-time state; a widget overrides it to check state of its own and then forward.

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

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, tr: &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 name(&self) -> &'static str

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 get_rect(&self) -> Rect

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

fn wants_pointer_capture(&self) -> bool

fn take_structure_dirty(&mut self) -> bool

True if this subtree’s structural composition (children inserted/removed) changed since the last frame; the App rebuilds the taffy tree when so. Reading clears it. The default drains every retained child (no short-circuit, so no child keeps a stale flag) and reports whether any was dirty; a leaf has no children and reports false. A container that changes its own child list sets its own flag and ORs it with this traversal.

fn needs_animation_frame(&self) -> bool

App polls this in Event::AboutToWait; without it a curve would freeze partway until an unrelated event woke it again.

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/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 synchronization/publication path.

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 room (crate::record::person). They take no part in this widget’s history or controls.

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

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

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

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

fn is_focusable(&self) -> bool

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_focus(&mut self, _focused: bool)

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 is_focused(&self) -> bool

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.

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

Perform an accessibility Action on this widget, or on one of its synthetic accessibility nodes. May mutate the CRDT like handle_event.

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

Handle an action addressed to a synthetic accessibility child created by this widget. target is the opaque stable value supplied through AccessNode::with_action_target.

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 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 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_purpose(&self) -> Option<ImePurpose>

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 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_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_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 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 take_committed_action(&mut self) -> Option<Vec<ChangeHash>>

The affordance-driven twin of the Ctrl+K palette: when a widget’s own control dispatches the same tilo_actions action its ActionSpec exports, it reports the document heads captured just before here, so the host can record one undo boundary the same way a palette dispatch does. Rising-edge: reading MUST clear it.

fn keeps_undo_step_open(&self) -> bool

Whether the undo step this widget’s last reported boundary opened stays open for the actions that continue it — the rest of a word typed a keystroke at a time. A hosted component then closes the step at the widget’s next boundary, or before an undo, a save or a merge, instead of after this event. Answered by the widget itself, never its children.

fn set_undo_status(&mut self, _status: &mut dyn FnMut() -> UndoStatus)

Host → widget: the live state of the undo history, published once per frame to every laid-out widget.

fn take_undo_request(&mut self) -> Option<UndoRequest>

Widget → host: an undo or redo the user asked for.

fn handle_local_undo_request(&mut self, request: UndoRequest) -> bool

Offer a host keyboard undo/redo shortcut to focused widget-local history before the application document consumes it.

fn apply_room_action( &mut self, _doc: &mut Edits<'_>, _type_id: &str, _payload: &[u8], ) -> bool

Apply an action another app in this room published, if this app owns the document — lets an app address a document it doesn’t hold by saying what should happen instead of writing bytes directly, keeping each document to one writer. An unrecognised type_id is silently declined, not an error.

fn semantic_readers(&self) -> &'static [RegisteredSemanticReader]

Inert immutable-reader registrations owned by this actual widget. Registration alone supplies no qualified owner frame or disclosure.

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

Earliest wall-clock deadline at which this subtree needs a sync/redraw even if there is no input. Unlike needs_animation_frame, this keeps the event loop asleep until the requested instant and is appropriate for filesystem/status polling rather than animation.

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 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 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 needs_redraw(&self) -> bool

Default true (dirty every frame). Opt into incremental redraw by tracking a dirty: bool, setting it in handle_event/sync, and clearing it in mark_drawn(). Containers MUST forward: dirty iff any descendant is.

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_drawn(&mut self)

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

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 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 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.