merge static method

DrawablePaint? merge(DrawablePaint? a, DrawablePaint? b)

Will merge two DrawablePaints, preferring properties defined in a if they're not null.

If a is identical with DrawablePaint.empty, b will be ignored.

Implementation

static DrawablePaint? merge(DrawablePaint? a, DrawablePaint? b) {
  if (a == null && b == null) {
    return null;
  }

  if (b == null && a != null) {
    return a;
  }

  if (identical(a, DrawablePaint.empty) ||
      identical(b, DrawablePaint.empty)) {
    return a ?? b;
  }

  if (a == null) {
    return b;
  }

  // If we got here, the styles should not be null.
  assert(a.style == b!.style,
      'Cannot merge Paints with different PaintStyles; got:\na: $a\nb: $b.');

  b = b!;
  return DrawablePaint(
    a.style ?? b.style,
    color: a.color ?? b.color,
    shader: a.shader ?? b.shader,
    blendMode: a.blendMode ?? b.blendMode,
    colorFilter: a.colorFilter ?? b.colorFilter,
    isAntiAlias: a.isAntiAlias ?? b.isAntiAlias,
    filterQuality: a.filterQuality ?? b.filterQuality,
    maskFilter: a.maskFilter ?? b.maskFilter,
    strokeCap: a.strokeCap ?? b.strokeCap,
    strokeJoin: a.strokeJoin ?? b.strokeJoin,
    strokeMiterLimit: a.strokeMiterLimit ?? b.strokeMiterLimit,
    strokeWidth: a.strokeWidth ?? b.strokeWidth,
  );
}