* updates. (x,y) == (0,0) is the upper left screen corner, x increases
* to the right, y increases downwords.
* The cache is built in BufferView::updateMetrics which is called
* updates. (x,y) == (0,0) is the upper left screen corner, x increases
* to the right, y increases downwords.
* The cache is built in BufferView::updateMetrics which is called