code: func ControlInRect(c Control, x int, y int, w int, h int) bool {
  	xx, yy := c.Pos()
  	ww, hh := c.Size()
  
  	return xx >= x && ww <= x+w && yy <= y+h &&
  		yy+hh <= y+h && yy >= y && yy+h >= y
  }
docs: // ControlInRect returns true if c is within a given rect