drawBorder method
Implementation
@override
void drawBorder(Canvas canvas, Rect rect) {
if (this.borderWidth > 0) {
borderPaint.color = this.borderColor;
borderPaint.strokeWidth = this.borderWidth;
canvas.drawCircle(
rect.center,
min((rect.width - borderWidth) / 2.0,
(rect.height - borderWidth) / 2.0),
borderPaint);
}
}