@Override
    protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
        setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));
    }
Compute the new value, moving by small increments.

@param goal   the goal to reach
@param actual the actual value
@return the new value
main/src/main/java/cgeo/geocaching/ui/CompassView.java