# ui_fill.ludic — linear-gradient backgrounds (a direction or an angle, stops placed or spread) drawn
# as whole-pixel bands; object-fit contain and cover for a picture of its own size; aspect-ratio
# making a height from a width, and a native's width from its height.
import "ludic.ui"
program UiFill {
  numbers float
  state UiFillState {
    rects: []string = new []string
    pics: []string = new []string
    clips: int = 0
  }
  const STYLE: string = "<style>.g { width: 100px; height: 20px; background: linear-gradient(to right, #000000, #ffffff) }\n.h { width: 50px; height: 40px; background-image: linear-gradient(180deg, #ff0000 0%, #0000ff 50%, #0000ff) }\nimg { width: 100px; height: 100px }\n.contain { object-fit: contain }\n.cover { object-fit: cover }\n.r { width: 160px; aspect-ratio: 16 / 9 }\nknob { height: 30px; aspect-ratio: 2 }</style>"
  const BODY: string = "<screen name='f'><div class='g'/><div class='h'/><img class='contain' src='wide.png'/><img class='cover' src='wide.png'/><div class='r'/><row><knob/></row></screen>"
  function rec_rect(ui_fill_st: mut UiFillState, x: float, y: float, w: float, h: float, c: int, a: float) -> void { push(ui_fill_st.rects, `{int(x)},{int(y)} {int(w)}x{int(h)} {ui_hex(c)}`) }
  function rec_image(ui_fill_st: mut UiFillState, src: string, x: float, y: float, w: float, h: float, c: int, a: float) -> void { push(ui_fill_st.pics, `{int(x)},{int(y)} {int(w)}x{int(h)}`) }
  function rec_clip(ui_fill_st: mut UiFillState, x: float, y: float, w: float, h: float) -> void { ui_fill_st.clips += 1 }
  function no_clip() -> void { }
  function no_text(x: float, y: float, s: string, size: float, c: int, a: float) -> void { }
  function nat_w(src: string) -> float { return 200.0 }
  function nat_h(src: string) -> float { return 100.0 }
  function knob_measure(n: UiNode, avail: float) -> void { }
  function knob_draw(n: UiNode) -> void { }
  entry (ui_fill_st: UiFillState, ui_st: mut UiState) {
    let b = new UiBackend
    b.rect = fn rec_rect
    b.text = fn no_text
    b.image = fn rec_image
    b.image_w = fn nat_w
    b.image_h = fn nat_h
    b.clip = fn rec_clip
    b.unclip = fn no_clip
    ui_backend(ui_st, b)
    ui_native(ui_st, "knob", fn knob_measure, fn knob_draw)
    ui_load_text(ui_st, "<ui>" + STYLE + BODY + "</ui>", "f.xml")
    ui_show(ui_st, "f", null, 0.0, 0.0, 400.0, 600.0)
    let r: UiNode = ui_nodes(ui_st, "f", null)
    ui_place(ui_st, r, 0.0, 0.0, 400.0, 600.0)
    let n = len(ui_fill_st.rects)
    print(`{ui_fill_st.rects[0]} .. {ui_fill_st.rects[49]} | {ui_fill_st.rects[50]} .. {ui_fill_st.rects[59]} .. {ui_fill_st.rects[69]} of {n} | {ui_fill_st.pics[0]} | {ui_fill_st.pics[1]} clipped {ui_fill_st.clips} | ratio {int(r.children[4].ch)} knob {int(r.children[5].children[0].cw)}`)
  }
}