scrolly position calculation is sad

[Dimitri John Ledkov]

scrolly position calculation is sad

so, in zdev view we disabled display of the window scrollbar, because it was too intensive with too many widgets.

However, zdev view is not dynamically updated, and knows exactly how many items there are, and what relative position within a screen they are. So we could add attributes on widgets to self-declare N/Total number related to each row. Or, cause it's a table, make the table row number a property as well as total number of rows, such that getting the focused widget will make scrollbar position calculation an O(1) operation rather than O(n) as it currently is.

[Michael Hudson-Doyle (mwhudson)]

This got fixed just before 20.04.