clearRect method
Implementation
void clearRect(double x, double y, double w, double h) {
Rect rect = Rect.fromLTWH(x, y, w, h);
addAction((Canvas canvas, Size size) {
// Must saveLayer before clear avoid there is a "black" background
Paint paint = Paint()
..style = PaintingStyle.fill
..blendMode = BlendMode.clear;
canvas.drawRect(rect, paint);
});
}