ludic/packages/ludic.ui/style.ludic
Orkuncakilkaya 1dad96102a feat(ui): ludic.ui is a UI framework - input, controls, render3d backend, the CSS a game needs
A game no longer writes a host:
- The runtime reads Input itself: focus and keyboard navigation (Tab, arrows, Enter/Space,
  autofocus), the pointer (hover, :active, click on release, drag), and scroll boxes with the
  wheel, a draggable scrollbar, clipping and scroll-into-view.
- HTML's controls are built in (button, checkbox, radio, range, select, text, key capture), made
  of plain parts a stylesheet styles, each reporting with on-change and event.value.
- ludic.ui/render3d.ludic draws with render3d's overlay: textures, named atlases (icon:NAME),
  nine-slice border-image, rounded rects and rings, clipping, and a scale.
- Hooks for the program's language, sounds and clock (ui_translator, ui_sounds, ui_clock).
- ui_dev: hot reload, errors on screen, LUDIC_UI_DUMP.
- CSS:
  - colours as #rgb / #rrggbbaa / rgb() / rgba() / names;
  - border-radius and outline (following the radius), box-shadow, background-image and a tinted
    border-image;
  - group opacity, @keyframes / animation, transition;
  - :focus, :focus-visible and :focus-within.
- HTML mixed content, and boolean attributes.
- render3d gains tex_width / tex_height, and the XML reader keeps text runs in order.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-24 17:26:09 +03:00

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# style.ludic - stylesheets: `.chip { bg: bg2; pad: 6 } button { h: 40 }` in a <style>, or an .lss
# file brought in by <import src="look.lss"/> (which may `@import "base.lss";` in turn). A selector is
# a tag, a .class, both, or *; a property is any attribute, {holes} and all. The more specific rule
# wins, then the later; an attribute beats them all.
export property UiRule {
sel: UiSel = null
spec: int = 0
md: UiMedia = null # the @media it sits in, if any
keys: []string = null
vals: []UiExpr = null
}
export property UiSheet {
rules: []UiRule = null
}
function sheet_read(f: UiFile, t: UiTpl) -> void {
var src = t.raw
let from = bd_name(t, "src", "")
if from != "" { src = lib_text(lib_beside(f.path, from)) }
lss_text(f, src)
}
function lss_is(path: string) -> bool { return len(path) > 4 and path[len(path) - 4..len(path)] == ".lss" }
# a stylesheet file: a file with rules and imports and nothing else
function lss_file(src: string, path: string) -> UiFile {
let f = lib_new(path)
f.src = src
lss_text(f, src)
f.sheet = sheet_of(f)
return f
}
function lss_text(f: UiFile, src: string) -> void {
let err = new []string
lss_block(f, lss_strip(src), null, err)
for i in 0 .. len(err) { ui_err(`{f.path}: <style> {err[i]}`) }
}
# rules, @imports and @media blocks; the rules in a @media block carry its condition
function lss_block(f: UiFile, src: string, md: UiMedia, err: []string) -> void {
let r = new UiRd
r.s = src
while r.err == "" {
rd_ws(r)
if r.i >= len(r.s) { break }
if rd_op(r, "@import") {
lss_import(f, lss_upto(r, 59))
continue
}
if rd_op(r, "@keyframes") {
let name = lss_upto(r, 123)
an_read(name, lss_upto(r, 125), err)
continue
}
if rd_op(r, "@media") {
let cond = md_parse(lss_upto(r, 123))
lss_block(f, lss_upto(r, 125), cond, err)
continue
}
let sels = lss_upto(r, 123)
let body = lss_upto(r, 125)
let at = len(f.own)
lss_rule(f, sels, body, err)
for i in at .. len(f.own) { f.own[i].md = md }
}
if r.err != "" { push(err, r.err) }
}
# @import "base.lss"; - its rules come before this file's own
function lss_import(f: UiFile, what: string) -> void {
var p = tpl_words(what)
if len(p) > 5 and p[0..4] == "url(" { p = p[4..len(p) - 1] }
if len(p) >= 2 and (p[0] == 34 or p[0] == 39) { p = p[1..len(p) - 1] }
let other = lib_file(lib_beside(f.path, p))
if other != null {
push(f.imp, other)
push(f.imp_as, "")
}
}
# the text up to the character `c`, which is taken too; a {hole} inside a body is skipped whole
function lss_upto(r: UiRd, c: int) -> string {
let at = r.i
var depth = 0
while r.i < len(r.s) and (r.s[r.i] != c or depth > 0) {
if c == 125 and r.s[r.i] == 123 { depth += 1 }
if c == 125 and r.s[r.i] == 125 { depth -= 1 }
r.i += 1
}
let out: string = r.s[at..r.i]
if r.i < len(r.s) { r.i += 1 } else { rd_fail(r, "a closing brace") }
return out
}
function lss_strip(src: string) -> string {
var out = ""
var at = 0
var i = 0
while i + 1 < len(src) {
if src[i] == 47 and src[i + 1] == 42 {
out = out + src[at..i]
var j = i + 2
while j + 1 < len(src) and not (src[j] == 42 and src[j + 1] == 47) { j += 1 }
i = j + 2
at = i
} else { i += 1 }
}
if at < len(src) { out = out + src[at..len(src)] }
return out
}