how can draw this in skia ?

[Bayramito]

What is the easiest way to achieve such shape in Skia ? @william-candillon
Hardest part is NOT only drawing it, but making it animated. imagine there is a square shape element inside and this element can move up and down. When element is UP it will be straight line (only rounded box) but when there is a element it will be drawn depends on elements position.

Effect like something putting in a water. Its like masking the element.