realContentSize method

Future<Rect> realContentSize({ Color ignoreColor = const Color(0xffffffff), double tolerance = 1, })

Get the real content size of the image.

Implementation

Future<Rect> realContentSize({
  Color ignoreColor = const Color(0xffffffff),
  double tolerance = 1,
}) async {
  Completer<Rect> completer = Completer();
  final ByteData? byteData =
      await toByteData(format: ImageByteFormat.rawRgba);
  if (byteData.isNull) {
    completer.complete(rect());
  } else {
    final Uint32List uint32list = byteData!.buffer.asUint32List();
    late double minDx = -1;
    late double minDy = -1;
    late double maxDx = -1;
    late double maxDy = -1;
    bool isAssign = false;
    uint32list.iFor((index, element) {
      final bool isDiff = element.uInt32toColor
          .euclideanDistanceColorDifference(ignoreColor,
              tolerance: tolerance);
      if (isDiff) {
        final int dx = index % width;
        final int dy = index ~/ width;
        if (!isAssign) {
          isAssign = true;
          minDx = dx * 1;
          maxDx = dx * 1;
          minDy = dy * 1;
          maxDy = dy * 1;
        } else {
          minDx = min(dx * 1, minDx);
          minDy = min(dy * 1, minDy);
          maxDx = max(dx * 1, maxDx);
          maxDy = max(dy * 1, maxDy);
        }
      }
    });
    final Offset start = Offset(minDx, minDy);
    final Size realSize = Size((maxDx - minDx), (maxDy - minDy));
    completer.complete(start & realSize);
  }
  return completer.future;
}