paint method
- Canvas canvas,
- Rect rect, {
- double? gapStart,
- double gapExtent = 0.0,
- double gapPercentage = 0.0,
- TextDirection? textDirection,
override
Draw a rounded rectangle around rect
using borderRadius.
The borderSide defines the line's color and weight.
The top side of the rounded rectangle may be interrupted by a single gap
if gapExtent
is non-null. In that case the gap begins at
gapStart - gapPadding
(assuming that the textDirection
is TextDirection.ltr).
The gap's width is (gapPadding + gapExtent + gapPadding) * gapPercentage
.
Implementation
@override
void paint(
Canvas canvas,
Rect rect, {
double? gapStart,
double gapExtent = 0.0,
double gapPercentage = 0.0,
TextDirection? textDirection,
}) {
assert(gapPercentage >= 0.0 && gapPercentage <= 1.0);
assert(_cornersAreCircular(borderRadius));
final Paint paint = borderSide.toPaint();
final RRect outer = borderRadius.toRRect(rect);
final RRect center = outer.deflate(borderSide.width / 2.0);
if (gapStart == null || gapExtent <= 0.0 || gapPercentage == 0.0) {
canvas.drawRRect(center, paint);
} else {
final double extent = lerpDouble(0.0, gapExtent + gapPadding * 2.0, gapPercentage)!;
final double start = switch (textDirection!) {
TextDirection.rtl => gapStart + gapPadding - extent,
TextDirection.ltr => gapStart - gapPadding,
};
final Path path = _gapBorderPath(canvas, center, math.max(0.0, start), extent);
canvas.drawPath(path, paint);
}
}