Struct Slider 

pub struct Slider { /* private fields */ }

A draggable value selector bound to a Signal<f32> in a continuous or discrete range. Visual chrome is fully delegated to a [SliderStyle] implementation.

Implementations

impl Slider

pub fn new(value: Signal<f32>, min: f32, max: f32) -> Self

Create a horizontal slider bound to value with the given inclusive range. Use orientation to switch to vertical.

pub fn on_change(self, f: impl Fn(f32, &mut EventContext<'_>) + 'static) -> Self

Run f for every value this control produces under the user’s hand, with an EventContext, so it can do what a bare Signal write cannot (ctx.send_intent(...), opening a window). Fires for a track click, for each step of a drag, for the arrows, for an assistive technology’s Increment / Decrement / SetValue, and for a reset to the default_value.

A drag fires this repeatedly — once per value it actually produces, not once per pointer sample, since a write that changes nothing reports nothing. It is still the wrong place for work that should happen once per interaction: persisting to disk, a network call, an undo entry. There is no commit-on-release callback yet; observe the signal and do that work when the value settles.

Does not fire for programmatic writes to the bound signal — there is no event in flight to carry. Observe the signal for that.

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

Set the discrete step size for keyboard arrows and accessibility Increment/Decrement actions. When unset, defaults to 1 % of the range.

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

Set the step size for PageUp / PageDown. When unset, ten times the effective step — so with the default step of 1 % of the range a page is 10 % of it, which is what QAbstractSlider::pageStep, GtkScale’s page increment and <input type=range> in both WebKit and Blink all give, and the same 10 x rule SpinBox::page_step uses.

pub fn orientation(self, orientation: Orientation) -> Self

Set the slider orientation (Horizontal by default). Vertical sliders map Up/Down arrow keys to increase/decrease.

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

Set the enabled state, statically or reactively. Forwarded to the arena at build time via ctx.enabled_when(slider_id, self.enabled.clone()).

pub fn variant(self, variant: SliderVariant) -> Self

Pick a Tier-1 design-language variant (SliderVariant::Continuous / Discrete / Range). The active [SliderStyle] decides what to do with the hint — IntUI’s default impl paints ticks for Discrete and ignores Range (the widget itself doesn’t yet wire dual-thumb behaviour).

pub fn tick_count(self, count: u32) -> Self

Configure the tick count for a Discrete slider. The IntUI default paints n evenly spaced tick marks above the track (or to the leading side for vertical orientation).

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

Override the active [SliderStyle] for this widget instance only.

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

Set an accessible name for the slider, announced by screen readers. ARIA requires sliders to have a label; when none is set here the caller is responsible for labelling via a wrapping element.

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

Attach a plain single-line tooltip shown after a hover delay. Mutually exclusive with rich_tooltip, rich_tooltip_content, and composite_tooltip — the last setter wins and clears the others. Independent of value_tooltip, which neither replaces nor is replaced by any of them.

pub fn rich_tooltip(self, key: impl Into<String>) -> Self

Attach a rich tooltip driven by a registry key. The registry entry supplies title, body markup, optional shortcut chip and cascade links. Mutually exclusive with the other tooltip setters.

pub fn rich_tooltip_content(self, content: TooltipContent) -> Self

Attach a rich tooltip from an inline TooltipContent value, bypassing the registry lookup. Mutually exclusive with the other tooltip setters.

pub fn composite_tooltip(self, content: impl Widget + 'static) -> Self

Attach a composite tooltip whose body is an arbitrary widget tree. Uses the heavier tooltip_delay_heavy delay. Mutually exclusive with the other tooltip setters.

pub fn value_tooltip( self, format: impl Fn(f32) -> LocalizedString + 'static, ) -> Self

Show the value as text by the thumb, formatted by format, while the slider is hovered, dragged, or focused from the keyboard.

Unlike a tooltip, the readout is up at once, with no hover delay; a press does not close it, so it stays up through a drag; and it moves with the thumb and changes as the value does, without a rebuild. By default it sits above a horizontal slider’s thumb, or below it near the top of the window, and beside a vertical slider, on the inline-start side when there is room, so it covers neither the thumb nor the track; value_tooltip_placement picks another side. It is re-placed on every layout pass from where the slider is then, so it follows a value the application writes, a scroll that moves the slider and a resize that stretches it. Its chrome is the theme’s tooltip chrome unless value_tooltip_style gives it another.

It takes no input of its own. A press or a hover on it reaches what is under it, and a press there closes a popover it is outside of. Escape hides it until the next hover, drag or key, and goes on to whatever else wanted the key, the focused field included, as a plain tooltip’s Escape does. Focus leaving the slider takes it down only when nothing else holds it up: the pointer still on the slider keeps it.

The text is also the slider’s accessible value, published beside the number: UI Automation and macOS carry it, so a reader there says “-3.0 dB” rather than “-3”. AT-SPI carries the number alone, so Orca keeps reading the number.

format receives the value the bound signal holds, on every change to it. It returns a [LocalizedString], so a tr!(..) message re-resolves on a locale change and lit!(..) serves text that is not translated.

A tooltip, rich or composite tooltip set beside it keeps its hover delay, its place under the slider and the accessible description it gives, and both show; to name the control in the readout instead, say so in format.

pub fn value_tooltip_placement( self, placement: SliderValueTooltipPlacement, ) -> Self

Choose where the value_tooltip readout sits: above or below the thumb, or at the pointer while a drag moves the value. SliderValueTooltipPlacement::Auto by default, which is where the readout has always gone. Has no effect without a value_tooltip.

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

Paint the value_tooltip readout with style rather than the active theme’s tooltip chrome (theme.style_slots.tooltip, else the built-in recipe). Only this slider’s readout changes; its plain, rich or composite tooltip keeps the theme’s. Has no effect without a value_tooltip.

pub fn jump_on_press(self, on: bool) -> Self

Move the value to the pointer as soon as a mouse button goes down on the slider, rather than when the click is released or a drag starts. Off by default.

With it off, a press writes nothing: the value moves when the pointer has travelled far enough to start a drag, or to the click’s position when it is released without one. With it on, a primary press of a mouse moves the value to the pointer at once, a drag that follows carries on from there without a jump, and the release of a click adds nothing. on_change reports the press’s value as a user change.

Touch and pen keep the default whatever this says: a contact landing on a slider may be the start of a scroll or of something an ancestor claims, so it writes nothing until it is a drag or a tap. The second press of a double-click does not jump either when a default_value is set, since that click resets. The keyboard and the accessibility actions are unaffected.

pub fn default_value(self, value: f32) -> Self

Let the user put the value back to value: with a double-click on the slider, or with the “Reset to default” accessibility action, which this also advertises.

The reset is a user change, written through the same path as a drag or an arrow key, so on_change reports it unless the value was already there. It is clamped to the range and not snapped to the step: a default between two steps lands where it was asked to. A double-click’s first click jumps the value to where it landed, as every click on the track does, so on_change reports that value and then the default; further clicks in the same burst leave the default where it is. A disabled slider ignores the double-click, and neither offers nor takes the action.

An application’s own .access_custom_action(..) on the slider is offered beside the reset, not instead of it.

Trait Implementations

impl Debug for Slider

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

Formats the value using the given formatter.

impl Widget for Slider

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

What a slider paints inside its one node: a track and a knob.

The node itself is the target — a press anywhere on it jumps the value and a drag from anywhere moves it — so it is reported whole, and it is what the conformance audit measures (the shipped body is at least 24 dp across, MIN_CROSS_SIZE in styles/recipe_slider_style.rs). The knob is reported as a grab because that is the affordance a user aims at, and because nothing else in the tree can see that it exists: it is drawn on the same canvas as the track, and its diameter comes from the resolved [SliderStyle], not from any layout.

The geometry is derived exactly as the body paints it, mirrored under RTL, so the report and the picture cannot drift.

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

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

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

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

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

Position children within the allocated bounds.

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

Return the child widget IDs that this widget manages.

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

Declare this widget’s accessibility identity.

fn 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 culls_children(&self) -> bool

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

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

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

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

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

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

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

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

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

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

The descendant whose accessibility node stands for this widget.

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

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

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

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

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

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

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

Whether this widget clips its children to its bounds.

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

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

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

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

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

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

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

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

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

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

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

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

fn 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).