Deck

Scrollable list where every item occupies a fixed number of rows. All visual content is delegated to a caller-supplied render function — no per-item widget allocations. Suited for rich multi-line cards such as colour pickers, contact cards, or navigation menus.

Constructor: NewDeck(id, class string, render ItemRender, itemHeight int) *Deck

itemHeight must be >= 1 (panics otherwise). index starts at -1.

Render function

type ItemRender func(r *Renderer, x, y, w, h, index int, data any, selected bool)

Called once per visible slot. x/y/w/h are the slot's absolute content-area coordinates. The function is responsible for all drawing within those bounds.

Methods

• Get() []any — returns the current items slice
• Set(items []any) — replaces all items; resets index to 0 (or -1 if empty)
• SetDisabled(indices []int) — replaces the non-selectable index list
• Select(index int) — highlights item at index; adjusts scroll; dispatches "select"
• Selected() int — returns the highlighted index (-1 if none)
• Move(count int) — moves highlight by count (skips disabled items, clamps at bounds)
• First() — highlights first enabled item
• Last() — highlights last enabled item
• PageUp() — moves up by the number of fully visible slots
• PageDown() — moves down by the number of fully visible slots

Events

Event	Data	Description
"activate"	int	Enter pressed, or an already-selected item clicked again
"select"	int	Highlighted item changed

Notes

Flags: "focusable"

Keyboard: ↑/↓ move by one; PgUp/PgDn move by visible slot count; Home/End jump to first/last; Enter activates.

Mouse: single click selects; clicking the already-selected item activates.

Scrollbar uses row-based units (offset × itemHeight) so the thumb remains proportional regardless of item height.

Style selector: "deck" with :focused, :hovered, :disabled states. Item-level styling is the render function's responsibility.