ludic/selfhost/backend/game/emit_ui.ludic

# emit_ui.ludic — a `ui` block is data: the compiler flattens the widget tree
# and emits @ui_build(), which hands every property to the Ludic UI runtime via
# rt_ui_set(index, key, value). Mirrors compiler/back/ir_ui.c. Layout/drawing/
# focus all live in runtime/native/ui.ludic.

var uiw: []Node              # flattened widgets, pre-order
var uiw_parent: []int
var ui_roots: []int          # first-widget index of each ui block

function ui_wtype(w: Node) -> int {
  let s = w.s
  if (s == "panel") { return 0 };  if (s == "col") { return 1 };  if (s == "row") { return 2 }
  if (s == "label") { return 3 };  if (s == "button") { return 4 }
  if (s == "image") { return 5 };  if (s == "spacer") { return 6 }
  return 0
}
function ui_prop(w: Node, key: pointer) -> Node {
  var i = 0
  while i < len(w.b.kids) { if (w.b.kids[i].s == key) { return w.b.kids[i].a };  i += 1 }
  return null
}
# a widget's props plus the text props (font, size, fg, align) it inherits from the
# nearest ancestor that sets them — so a panel states the menu's look once.
function ui_props_with_inherited(i: int) -> []Node {
  let w = uiw[i]
  let out = new []Node
  var p = 0
  while p < len(w.b.kids) { push(out, w.b.kids[p]);  p += 1 }
  let keys = new []pointer
  push(keys, "font");  push(keys, "size");  push(keys, "fg");  push(keys, "align")
  var k = 0
  while k < len(keys) {
    if ui_prop(w, keys[k]) == null {
      var a = uiw_parent[i]
      while a >= 0 {
        let v = ui_prop(uiw[a], keys[k])
        if (v != null) { let fi = node(E_FINIT);  fi.s = keys[k];  fi.a = v;  push(out, fi);  a = -1 }
        else { a = uiw_parent[a] }
      }
    }
    k += 1
  }
  return out
}
function ui_flatten(w: Node, parent: int) -> void {
  let idx = len(uiw)
  push(uiw, w);  push(uiw_parent, parent)
  var i = 0
  while i < len(w.kids) { ui_flatten(w.kids[i], idx);  i += 1 }
}
function ui_flatten_all() -> void {
  uiw = new []Node;  uiw_parent = new []int;  ui_roots = new []int
  var i = 0
  while i < len(prog) {
    if prog[i].kind == N_UI and prog[i].ival == 1 { push(ui_roots, len(uiw));  ui_flatten(prog[i].a, -1) }
    i += 1
  }
}
function has_ui() -> bool {
  var i = 0
  while i < len(prog) { if prog[i].kind == N_UI and prog[i].ival == 1 { return true };  i += 1 }
  return false
}

# index of a UI_<name>: a ui block's root, or a widget's id=
function ui_index_of(nm: pointer) -> int {
  if uiw == null { ui_flatten_all() }   # a UI_ id may be read before @ui_build is emitted (a function, a listener)
  let s = nm[3..len(nm)]          # strip "UI_"
  let u = 0;  var bi = 0
  var i = 0
  while i < len(prog) {
    if prog[i].kind == N_UI and prog[i].ival == 1 { if (prog[i].s == s) { return ui_roots[bi] };  bi += 1 }
    i += 1
  }
  i = 0
  while i < len(uiw) {
    let idp = ui_prop(uiw[i], "id")
    if (idp != null) { if idp.kind == E_ID and (idp.s == s) { return i } }
    i += 1
  }
  return 0
}
function is_ui_ident(nm: pointer) -> bool {
  return len(nm) > 3 and nm[0] == 'U' and nm[1] == 'I' and nm[2] == '_'   # "UI_"
}

function ll_ui_set(idx: int, key: int, val: pointer) -> void {
  emit("  call void @fn_rt_ui_set(i32 ");  emit(itoa(idx));  emit(", i32 ");  emit(itoa(key));  emit(", i32 ");  emit(val);  emit(")\n")
}
function ui_prop_key(k: pointer) -> int {
  if (k == "w") { return 2 };  if (k == "h") { return 3 };  if (k == "x") { return 4 };  if (k == "y") { return 5 }
  if (k == "pad") { return 7 };  if (k == "gap") { return 8 };  if (k == "bg") { return 9 };  if (k == "fg") { return 10 }
  if (k == "border") { return 11 };  if (k == "grow") { return 13 };  if (k == "font") { return 14 };  if (k == "size") { return 15 }
  if (k == "inset") { return 16 };  if (k == "focus") { return 17 }
  return -1
}

function emit_ui_build() -> void {
  ui_flatten_all()
  ll_t = 0;  ll_lbl = 0;  g_term = false;  loc_reset();  nloop = 0
  let fbody = buf_new()
  falloc = buf_new()
  let saved = code
  code = fbody
  emit("  call void @fn_rt_ui_reset(i32 ");  emit(itoa(len(uiw)));  emit(")\n")
  var i = 0
  while i < len(uiw) {
    let w = uiw[i]
    let t = ui_wtype(w)
    ll_ui_set(i, 0, itoa(t))
    ll_ui_set(i, 1, itoa(uiw_parent[i]))
    if t == 4 { ll_ui_set(i, 17, "1") }
    let props = ui_props_with_inherited(i)
    var p = 0
    while p < len(props) {
      let pr = props[p]
      let k = pr.s
      let v = pr.a
      if (k == "id") or (k == "goto") { p += 1;  continue }
      if (k == "text") {
        let sv = emit_expr(v)
        emit("  call void @fn_rt_ui_static_text(i32 ");  emit(itoa(i));  emit(", ptr ");  emit(sv.code);  emit(")\n")
      } else { if (k == "skin") or (k == "image") {
        let sv = emit_expr(v)
        let r = emit_bind(`call i32 @fn_rt_image_load(ptr {sv.code})`)
        if (k == "skin") { ll_ui_set(i, 20, r) } else { ll_ui_set(i, 19, r) }
      } else { if (k == "align") {
        if v.kind == E_ID {
          var a = 0
          if (v.s == "center") { a = 1 };  if (v.s == "end") { a = 2 }
          ll_ui_set(i, 12, itoa(a))
        } else { let vv = emit_expr(v);  ll_ui_set(i, 12, vv.code) }
      } else {
        let key = ui_prop_key(k)
        if key >= 0 {
          let vv = emit_expr(v)
          ll_ui_set(i, key, vv.code)
          if key == 4 or key == 5 { ll_ui_set(i, 6, "1") }
        }
      } } }
      p += 1
    }
    i += 1
  }
  code = saved
  emit("define void @ui_build() {\nentry:\n")
  emit(buf_str(falloc))
  emit(buf_str(fbody))
  emit("  ret void\n}\n\n")
}