Slider

A material slider for selecting a value from a continuous or discrete range.

Example

slider(
  value: 40,
  min: 0,
  max: 100,
  divisions: 10,
  label: "{value}%",
  on_change: ->(event) { page.update(preview, opacity: event.control.value / 100.0) }
)

Common properties

• value
• min / max
• divisions — snap to discrete steps
• label — tooltip shown while dragging ("{value}" interpolates)
• active_color / inactive_color
• thumb_color
• round — decimal places for the displayed value

Range slider

For two-handle selection, use range_slider with start_value / end_value:

range_slider(start_value: 20, end_value: 80, min: 0, max: 100, divisions: 10)

Usage

on_change fires continuously while dragging; use on_change_end to react only when the user releases.

Complete API

Helpers

• slider(**props)

Accepted properties

• active_color — Active color.
• adaptive — Adapts to the platform (Material/Cupertino) when true.
• align — Alignment of the control within its parent.
• animate_align — Animates alignment changes.
• animate_margin — Animates margin changes.
• animate_offset — Animates offset changes.
• animate_opacity — Animates opacity changes.
• animate_position — Animates position changes.
• animate_rotation — Animates rotation changes.
• animate_scale — Animates scale changes.
• animate_size — Animates size changes.
• aspect_ratio — Width-to-height ratio to maintain.
• autofocus — Requests focus when first shown.
• badge — Badge drawn on the corner of the control.
• bottom — Bottom offset when positioned inside a stack.
• col — Responsive column span (1-12) per breakpoint.
• data — Arbitrary value you can attach to the control and read back in handlers.
• disabled — Disables interaction when true.
• divisions — Number of discrete steps between min and max.
• expand — Fills the available space along the parent's main axis when true.
• expand_loose — Like expand, but only grows up to the child's natural size.
• height — Fixed height in logical pixels.
• inactive_color — Inactive color.
• interaction — Sets the interaction property.
• key — Stable identity used to preserve state across rebuilds.
• label — Text label shown for the control.
• left — Left offset when positioned inside a stack.
• margin — Outer spacing around the control.
• max — Maximum value.
• min — Minimum value.
• mouse_cursor — Cursor shown when hovering the control.
• offset — Translation offset applied to the control.
• opacity — Opacity from 0.0 (transparent) to 1.0 (opaque).
• overlay_color — Overlay color.
• padding — Inner spacing between the border and the content.
• right — Right offset when positioned inside a stack.
• rotate — Rotation applied to the control.
• round — Sets the round property.
• rtl — Renders right-to-left when true.
• scale — Scale transform applied to the control.
• secondary_active_color — Secondary active color.
• secondary_track_value — Sets the secondary track value property.
• size_change_interval — Throttle interval for on_size_change, in ms.
• thumb_color — Thumb color.
• tooltip — Text shown on hover/long-press.
• top — Top offset when positioned inside a stack.
• value — The control's current value.
• visible — Hides the control when false.
• width — Fixed width in logical pixels.
• year_2023 — Sets the year 2023 property.

Events

• on_animation_end — Fired when an animation completes.
• on_blur — Fired when the control loses focus.
• on_change — Fired when the value changes.
• on_change_end — Fired when the user finishes changing the value.
• on_change_start — Fired when the user starts changing the value.
• on_focus — Fired when the control gains focus.
• on_size_change — Fired when the control's size changes.

Wire reference

• Family: materials
• Widget type: slider