Struct GridView 

pub struct GridView<T: 'static> { /* private fields */ }

A virtualized 2D tile grid backed by a ListModel<T>.

Implementations

impl<T: 'static> GridView<T>

pub fn new( model: ListModel<T>, delegate: impl Fn(&TileContext<'_, T>) -> Box<dyn Widget> + 'static, ) -> Self

Create a grid backed by a ListModel<T>. The delegate builds the widget for each tile from a TileContext.

pub fn from_source<S: ListDataSource<Item = T>>( source: S, delegate: impl Fn(&TileContext<'_, T>) -> Box<dyn Widget> + 'static, ) -> Self

Create a grid backed by any ListDataSource (large / external data).

pub fn enabled(self, enabled: impl Into<Prop<bool>>) -> Self

Enable or disable the whole view. A disabled view greys out and stops accepting focus / selection / keyboard input (arena-gated).

pub fn sizing(self, sizing: impl Into<Prop<GridSizing>>) -> Self

Set the tile sizing / column-count policy.

Accepts a plain GridSizing (static) or a Signal<GridSizing> (reactive). A bound signal is observed at [BindingLevel::Rebuild]: when it changes, build() rebuilds the cached layout strategy and reflows — the internal scroll_y / focused_index / selection are field signals on the same widget instance, so they survive the rebuild (no scroll jump). This is the card-size-slider path; mirrors TabWidget::sizing.

pub fn tile_size(self, width: f32, height: f32) -> Self

Sugar for GridSizing::Fixed — every tile is exactly width × height.

pub fn column_count(self, count: usize, tile_height: f32) -> Self

Sugar for GridSizing::FixedColumnCount — exactly count columns.

pub fn variable_row_heights(self, estimated: f32) -> Self

Switch to variable row heights: each row is sized to its tallest tile (SwiftUI LazyVGrid semantics). estimated seeds rows that haven’t been measured yet; the scroll position is anchored when an estimate is later corrected. Combine with item_height for exact heights.

pub fn item_height(self, f: impl Fn(usize) -> f32 + 'static) -> Self

Supply an exact per-item natural height. Width-independent, so it doesn’t depend on the runtime column count: VariableRowGrid sizes each row to max(item_height(i)) over its items. Implies variable row heights, gives an exact scrollbar, and removes anchoring jitter.

pub fn waterfall(self, estimated: f32) -> Self

Switch to a Pinterest-style waterfall: per-item variable heights flow into the currently-shortest column. Column count comes from the configured sizing; heights are auto-measured (or exact via item_height). estimated seeds unmeasured items.

pub fn column_spacing(self, spacing: f32) -> Self

Horizontal gap between tiles (default 8).

pub fn row_spacing(self, spacing: f32) -> Self

Vertical gap between tile rows (default 8).

pub fn spacing(self, spacing: f32) -> Self

Set both column and row spacing.

pub fn content_inset(self, inset: EdgeInsets) -> Self

Inset from the scroll-content edge to the tiles.

pub fn selection(self, sel: SelectionModel) -> Self

Set the selection model (modes None / Single / Multi).

pub fn on_selection_changed( self, f: impl Fn(&BTreeSet<usize>) + 'static, ) -> Self

Called whenever the selection set changes — including programmatic changes — with the new set of selected indices.

pub fn marquee_selection(self, enabled: bool) -> Self

Enable / disable rubber-band marquee selection (default enabled; only active when the selection model is in Multi mode).

pub fn wrap_navigation(self, enabled: bool) -> Self

Whether arrow navigation wraps across row/grid edges (default false).

pub fn tab_traversal(self, traversal: GridTabTraversal) -> Self

How Tab moves out of (or within) the grid (default OutOfGrid).

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

Suppress the internal scrollbar (mount your own via the signal accessors so it survives rebuilds).

pub fn overscroll_behavior(self, behavior: OverscrollBehavior) -> Self

Scroll-chaining behavior at the boundary (default Chain).

pub fn smooth_scrolling(self, enabled: bool) -> Self

Enable or disable animated wheel scrolling (enabled by default).

pub fn smooth_scroll_duration(self, duration: Duration) -> Self

Duration of the smooth scroll animation (default 150 ms).

pub fn scroll_bar_style(self, style: ScrollBarMode) -> Self

How the scroll bar is displayed (default Permanent). Overlay and Thin float the bar over the content instead of reserving a layout column, mirroring ScrollArea::scroll_bar_style.

pub fn scroll_y_signal(&self) -> &Signal<f32>

The vertical scroll offset signal.

pub fn max_scroll_y_signal(&self) -> &Signal<f32>

The maximum scroll offset signal (content_height - viewport_height).

pub fn viewport_ratio_y_signal(&self) -> &Signal<f32>

The vertical viewport-to-content ratio signal (drives the thumb size).

pub fn ensure_index_visible(&self, index: usize, anchor: ScrollAnchor)

Scroll the minimum distance to bring index into view per anchor.

pub fn scroll_to_index(&self, index: usize, anchor: ScrollAnchor)

Scroll to index, forcing the viewport position per anchor (Auto behaves like ensure_index_visible).

pub fn sections<P: SectionProvider>(self, provider: P) -> Self

Group the flat model into sections, rendering a header above each section’s tile band. Sections compose with the uniform tile layout.

pub fn section_header_delegate( self, f: impl Fn(usize, &str) -> Box<dyn Widget> + 'static, ) -> Self

Custom section-header widget builder (section_index, title). Without it a default bold-text header is used.

pub fn section_header_height(self, height: f32) -> Self

Height of each section header row (default 28).

pub fn pinned_section_headers(self, enabled: bool) -> Self

Keep the current section’s header pinned to the top while scrolling through it (SwiftUI pinnedViews:[.sectionHeaders]).

pub fn a11y_label(self, label: impl Into<String>) -> Self

Accessible label for the grid container.

pub fn style(self, style: impl GridViewStyle) -> Self

Per-call Tier-3 decoration style override (focus ring, marquee, insertion bar, pinned-header surface). Precedence: this override → theme.style_slots.grid_view → the stock RecipeGridViewStyle.

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

Widget shown when the model is empty.

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

Widget overlaid while is_loading reads true.

pub fn is_loading(self, flag: impl Into<Prop<bool>>) -> Self

Reactive loading flag; when true the loading_view is shown above the grid.

pub fn reorderable(self, enabled: bool) -> Self

Enable intra-grid drag reordering (and keyboard Alt+Arrow). The move is routed through the source’s accept_drop (a built-in ListModel reorders via move_item; an external source applies its own command).

pub fn exportable(self, mode: DragTransferMode) -> Self

where T: Clone,

Make tiles droppable outside this view — on a DropTarget, another data view, or the OS.

A dragged tile (or the whole selection, when the pressed tile is part of a multi-selection) carries clones of its items in a public RowDragData<T>, so a foreign receiver can pull them out with payload.get_typed::<RowDragData<T>>() / DropTarget::on_drop_typed::<RowDragData<T>>() — no serialization. This also makes tiles a drag source even without reorderable.

mode chooses what happens to the origin rows once a foreign target accepts them: DragTransferMode::Move removes them (via the source’s on_drag_out, or on_rows_transferred_out), DragTransferMode::Copy leaves them. A same-view reorder is never a transfer, so mode never affects it. Requires T: Clone.

pub fn export_external( self, f: impl Fn(&[T]) -> Vec<(String, Vec<u8>)> + 'static, ) -> Self

where T: Clone,

Additionally advertise the dragged tiles as MIME data so they can be dropped on a DropZone or exported to another application / window via the OS. f maps the dragged items to (mime_type, bytes) pairs (e.g. text/plain, text/uri-list, an app-specific application/x-…). Implies exportable (defaulting to DragTransferMode::Move if not already set). Requires T: Clone.

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

Override how rows moved out to a foreign target are removed from this view. Receives the dragged rows’ indices (descending-safe) and the live context. Without this, an exportable Move drag removes them through the source’s on_drag_out (works out of the box for a ListModel).

pub fn accept_foreign_rows(self, accept: bool) -> Self

Accept exported rows dropped from a different view or source without writing a custom ListDataSource. Pair with on_rows_received, which is handed the dropped items and the insertion index. (Same-view reorder is reorderable; a custom ListDataSource can still accept foreign drops through its can_accept/accept_drop instead.)

pub fn on_rows_received( self, f: impl Fn(Vec<T>, usize, &mut EventContext<'_>) + 'static, ) -> Self

Handler for rows accepted via accept_foreign_rows: (items, insertion_index, ctx). Insert them into your model at the index.

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

Accept external drops at a flat insertion index. Returns true when the drop is accepted.

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

Called when a tile is activated (a click per activate_on, or Enter on the focused tile) — the “open / default action”, distinct from selection.

pub fn activate_on(self, mode: ActivateOn) -> Self

Choose single- vs double-click tile activation (default ActivateOn::DoubleClick). Enter activates in either mode.

pub fn tile_context_menu( self, f: impl Fn(usize, Point, &mut EventContext<'_>) -> Option<Box<dyn Widget>> + 'static, ) -> Self

Per-tile context-menu factory: (index, pointer_position, ctx) → optional menu widget.

pub fn type_ahead_label(self, f: impl Fn(usize) -> String + 'static) -> Self

Supply a per-item label for type-ahead navigation (typing letters jumps to the first matching item). Required to enable type-ahead.

pub fn tile_a11y_label(self, f: impl Fn(usize) -> String + 'static) -> Self

Supply a per-item accessible name applied to each tile’s GridCell (Node::label), so a screen reader announces a concise item name in addition to the row/column position. Without it, the cell’s name is left to its contents.

pub fn type_ahead_timeout(self, timeout: Duration) -> Self

Type-ahead reset timeout (default 500 ms; ZERO disables).

Trait Implementations

impl<T: 'static> Debug for GridView<T>

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

Formats the value using the given formatter.

impl<T: 'static> Widget for GridView<T>

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

Compose child widgets. Called once after the widget is placed in the arena, and again on environment change (theme switch, locale switch). Takes &mut self — store child IDs, signal handles, any state needed later. Returns the list of root child IDs (empty for leaf widgets).

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

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

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

Position children within the allocated bounds.

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

Declare this widget’s accessibility identity.

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

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

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

Return the child widget IDs that this widget manages.

fn clips_children(&self) -> bool

Whether this widget clips its children to its bounds.

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

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

fn cacheable_layout(&self) -> bool

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

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

Draw the widget’s visual representation.

fn wants_after_paint(&self) -> bool

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

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

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

fn wants_post_paint(&self) -> bool

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

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

Draw a foreground layer over this widget’s children.

fn wants_descendant_redirects(&self) -> bool

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

fn preserves_children_on_rebuild(&self) -> bool

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

fn tooltip_has_content(&self) -> bool

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

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

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

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

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