parseOrigin static method

CSSOrigin? parseOrigin(String origin, RenderStyle renderStyle, String property)

Implementation

static CSSOrigin? parseOrigin(String origin, RenderStyle renderStyle, String property) {
  if (origin.isNotEmpty) {
    List<String> originList = origin.trim().split(_spaceRegExp);
    String? x, y;

    if (originList.length == 1) {
      // Default is center.
      x = originList[0];
      y = CENTER;
      // Flutter just support two value: x/y.
      // FIXME: when flutter support three value
    } else if (originList.length == 2 || originList.length == 3) {
      x = originList[0];
      y = originList[1];
    }
    // When origin property is not null, default is not center.
    double offsetX = 0, offsetY = 0, alignX = -1, alignY = -1;
    // The y just can be left right center when x is top bottom, otherwise illegal
    // switch to right place.
    if ((x == TOP || x == BOTTOM) &&
        (y == LEFT || y == RIGHT || y == CENTER)) {
      String? tmp = x;
      x = y;
      y = tmp;
    }

    // Handle x.
    if (CSSLength.isLength(x)) {
      offsetX = CSSLength.parseLength(x!, renderStyle, property).computedValue;
    } else if (CSSPercentage.isPercentage(x)) {
      alignX = CSSPercentage.parsePercentage(x!)! * 2 - 1;
    } else if (x == LEFT) {
      alignX = -1.0;
    } else if (x == RIGHT) {
      alignX = 1.0;
    } else if (x == CENTER) {
      alignX = 0.0;
    }

    // Handle y.
    if (CSSLength.isLength(y)) {
      offsetY = CSSLength.parseLength(y!, renderStyle, property).computedValue;
    } else if (CSSPercentage.isPercentage(y)) {
      alignY = CSSPercentage.parsePercentage(y!)! * 2 - 1;
    } else if (y == TOP) {
      alignY = -1.0;
    } else if (y == BOTTOM) {
      alignY = 1.0;
    } else if (y == CENTER) {
      alignY = 0.0;
    }
    return CSSOrigin(Offset(offsetX, offsetY), Alignment(alignX, alignY));
  }
  return null;
}