retrieveStrokeColor function

Color retrieveStrokeColor(GeometryMixin node, [ int index = 0, bool all = false ])

Converts the strokes of a given node to a single Color object.

Implementation

Color retrieveStrokeColor(GeometryMixin node,
    [int index = 0, bool all = false]) {
  final strokes = node.strokes.visible();
  if (strokes.isEmpty) {
    // Some methods expect a non-null color.
    return const Color(0x00000000);
  }

  // If we want to disregard the single color index and retrieve all of the
  // colors, we set [all] to true and we blend all the colors.
  if (all) {
    Color? stroke;
    // We get all the paints that have a color and reverse the list because the
    // strokes most recently added are the ones that are on top.
    for (PaintModel paint
        in strokes.where((element) => element.color != null).toList()) {
      // Beginning stroke.
      if (stroke == null) {
        stroke = paint.toFlutterColor()!;
      } else {
        // Blend.
        stroke = Color.alphaBlend(paint.toFlutterColor()!, stroke);
      }
    }

    if (stroke == null) {
      final List<PaintModel> gradients = strokes
          .where((element) =>
              element.gradientStops != null &&
              element.gradientStops!.isNotEmpty)
          .toList();

      if (gradients.isNotEmpty) {
        return gradients.last.gradientStops![0].color.toFlutterColor();
      } else {
        // Return black when something unknown is found until we have better
        // support for gradients. Some methods expect a non-null color, so
        // returning null may crash the UI.
        return const Color(0xff000000);
      }
    }

    return stroke;
  }

  // Otherwise, we retrieve a single index color.
  final PaintModel stroke = node.strokes[index];

  if (stroke.color != null) {
    return stroke.toFlutterColor()!;
  } else if (stroke.gradientStops != null && stroke.gradientStops!.isNotEmpty) {
    return stroke.gradientStops![0].color.toFlutterColor();
  } else {
    // Return black when something unknown is found until we have better support
    // for gradients. Some methods expect a non-null color, so returning null
    // may crash the UI.
    return const Color(0xff000000);
  }
}