# ui_select_disabled.ludic - <option disabled="{...}">: a value on a disabled option is set to the
# nearest enabled one, the arrow toward disabled options is drawn disabled, and the arrows step past
# them (a host's cap on the fog): clamped 2 next-on 0 next 0 prev 2
import "ludic.ui"
program UiSelectDisabled {
  numbers float
  state SelState { v: int = 4 }
  view V (sel_st: mut SelState) {
    v = sel_st.v
    on set(x: int) { sel_st.v = x }
  }
  const PAGE: string = "<ui><screen name='s'><select label='Fog' value='{v}' on-change='set(event.value)'><option value='{0}'>0</option><option value='{1}'>1</option><option value='{2}'>2</option><option value='{3}' disabled='{v >= 0}'>3</option><option value='{4}' disabled='{true}'>4</option></select></screen></ui>"
  function frame(ui_st: mut UiState, x: float, y: float, down: bool) -> UiNode {
    let i = new UiInput
    i.x = x
    i.y = y
    i.down = down
    ui_input(ui_st, i)
    ui_show(ui_st, "s", view_v(), 0.0, 0.0, 400.0, 400.0)
    let root: UiNode = ui_nodes(ui_st, "s", view_v())
    ui_place(ui_st, root, 0.0, 0.0, 400.0, 400.0)
    return root
  }
  function part(n: UiNode, cls: string) -> UiNode {
    for i in 0 .. len(n.children) {
      if List.contains(n.children[i].classes, cls) { return n.children[i] }
      let f = part(n.children[i], cls)
      if f != null { return f }
    }
    return null
  }
  function click(ui_st: mut UiState, cls: string) -> void {
    let root = frame(ui_st, -1.0, -1.0, false)
    let p = part(root, cls)
    let x = p.x + p.cw / 2.0
    let y = p.y + p.ch / 2.0
    frame(ui_st, x, y, false)
    frame(ui_st, x, y, true)
    frame(ui_st, x, y, false)
    frame(ui_st, x, y, false)
  }
  entry (ui_st: mut UiState, sel_st: SelState) {
    ui_backend(ui_st, new UiBackend)
    ui_load_text(ui_st, PAGE, "s.xml")
    frame(ui_st, -1.0, -1.0, false)
    let root = frame(ui_st, -1.0, -1.0, false)
    let clamped = sel_st.v
    let nx = part(root, "ui-next")
    let at_cap = `{nx.enabled}`
    click(ui_st, "ui-next")
    let wrapped = sel_st.v
    click(ui_st, "ui-prev")
    print(`clamped {clamped} next-on {at_cap} next {wrapped} prev {sel_st.v}`)
  }
}