Create a custom View from scratch that draws a shape

This tests your understanding of the Android View rendering pipeline. A strong answer covers four steps: parse XML attributes in the constructor; override onMeasure to resolve dimensions against parent MeasureSpec modes; override onDraw to render with Canvas and Paint; and call invalidate to request redraw. Note that onMeasure must call setMeasuredDimension. A red flag is treating onMeasure as a simple size setter, allocating objects in onDraw, or confusing layout with draw.