drawSelf method
Implementation
@protected
bool drawSelf(Canvas canvas, ViewGroup parent) {
double sx = 0;
double sy = 0;
computeScroll();
sx = _scrollX;
sy = _scrollY;
canvas.save();
canvas.translate(left - sx, top - sy);
canvas.scale(scaleX, scaleY);
canvas.clipRect(Rect.fromLTRB(sx, sy, sx + width, sy + height));
draw(canvas);
canvas.restore();
return false;
}