onKey method

@override bool onKey(KeyEvent event, RenderContext ctx)

Implementation

@override
bool onKey(KeyEvent event, RenderContext ctx) {
  var cur = state?.cursor ?? value.length;
  var v = state?.value ?? value;
  if (cur > v.length) cur = v.length;

  String? next;
  if (event.key != null) {
    switch (event.key!) {
      case NamedKey.enter:
        onSubmit?.call();
        return true;
      case NamedKey.backspace:
        if (cur > 0) {
          next = v.substring(0, cur - 1) + v.substring(cur);
          cur -= 1;
        }
      case NamedKey.delete:
        if (cur < v.length) {
          next = v.substring(0, cur) + v.substring(cur + 1);
        }
      case NamedKey.arrowLeft:
        if (cur > 0) cur -= 1;
        if (state != null) state!.cursor = cur;
        return true;
      case NamedKey.arrowRight:
        if (cur < v.length) cur += 1;
        if (state != null) state!.cursor = cur;
        return true;
      case NamedKey.home:
        cur = 0;
        if (state != null) state!.cursor = cur;
        return true;
      case NamedKey.end:
        cur = v.length;
        if (state != null) state!.cursor = cur;
        return true;
      default:
        return false;
    }
  } else {
    if (event.ctrl || event.alt) return false;
    final c = event.char;
    if (c != null && c.runes.length == 1 && c.runes.first >= 0x20) {
      next = v.substring(0, cur) + c + v.substring(cur);
      cur += c.length;
    }
  }

  if (next != null) {
    if (state != null) {
      state!.value = next;
      state!.cursor = cur;
    }
    onChanged?.call(next);
    return true;
  }
  return false;
}