onKey method

@override bool onKey(KeyEvent event, RenderContext ctx)

Implementation

@override
bool onKey(KeyEvent event, RenderContext ctx) {
  if (state.submitted && lockOnSubmit) return false;

  var cur = state.cursor.clamp(0, state.value.length);
  var v = state.value;
  String? next;

  if (event.key != null) {
    switch (event.key!) {
      case NamedKey.tab:
        if (state.value.isEmpty &&
            placeholder != null &&
            placeholder!.isNotEmpty) {
          state.value = placeholder!;
          state.cursor = state.value.length;
          state.error = null;
          onChanged?.call(state.value);
        }
        return false;
      case NamedKey.enter:
        _submit();
        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 (v.isEmpty && placeholder != null && placeholder!.isNotEmpty) {
          state.value = placeholder!;
          state.cursor = state.value.length;
          state.error = null;
          onChanged?.call(state.value);
          return true;
        }
        if (cur > 0) cur -= 1;
        state.cursor = cur;
        return true;
      case NamedKey.arrowRight:
        if (cur < v.length) cur += 1;
        state.cursor = cur;
        return true;
      case NamedKey.home:
        state.cursor = 0;
        return true;
      case NamedKey.end:
        state.cursor = v.length;
        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 &&
        c.runes.first != 0x7F) {
      next = v.substring(0, cur) + c + v.substring(cur);
      cur += c.length;
    }
  }

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