paintFor function

Paint paintFor(Fill fill, Rect bounds)

fill as a paint; gradient handles resolve against bounds: the box, never a stroke band.

Implementation

ui.Paint paintFor(Fill fill, ui.Rect bounds) {
  final ui.Paint paint = ui.Paint();
  switch (fill) {
    case SolidFill(:final color):
      paint.color = color.toColor();
    case LinearGradientFill(:final begin, :final end, :final stops, :final opacity):
      assert(stops.length >= 2, 'LinearGradientFill needs at least two stops');
      final List<GradientStop> sorted = _sorted(stops);
      paint.shader = ui.Gradient.linear(_point(begin, bounds), _point(end, bounds), _colors(sorted, opacity), <double>[
        for (final GradientStop s in sorted) s.position / 100,
      ]);
    case RadialGradientFill(:final center, :final end, :final width, :final stops, :final opacity):
      assert(stops.length >= 2, 'RadialGradientFill needs at least two stops');
      final List<GradientStop> sorted = _sorted(stops);
      final ui.Offset origin = _point(center, bounds);
      final ui.Offset axisA = _point(end, bounds) - origin;
      final ui.Offset axisB = _point(width, bounds) - origin;
      // A unit circle mapped so (1, 0) lands on end and (0, 1) on width.
      // Collinear axes have no area: use the last stop's color, as SVG does.
      if ((axisA.dx * axisB.dy - axisA.dy * axisB.dx).abs() < 1e-9) {
        paint.color = _colors(<GradientStop>[sorted.last], opacity).single;
      } else {
        paint.shader = ui.Gradient.radial(
          ui.Offset.zero,
          1,
          _colors(sorted, opacity),
          <double>[for (final GradientStop s in sorted) s.position / 100],
          ui.TileMode.clamp,
          .fromList(<double>[
            axisA.dx,
            axisA.dy,
            0,
            0,
            axisB.dx,
            axisB.dy,
            0,
            0,
            0,
            0,
            1,
            0,
            origin.dx,
            origin.dy,
            0,
            1,
          ]),
        );
      }
  }
  return paint;
}