TableView slow vertical scrolling with 300+ columns

[Martin Desruisseaux]

Hello Ed

> At the center of our product is an extension of the TableView control that's responsible for displaying all the output from our pivot reporting engine.  Depending on how the user configures the layout of their pivot reports, sometimes there are a legitimately large number of columns (300+).  When that happens, while the horizontal scrolling remains perfectly smooth, the vertical scrolling degrades to a somewhat juddery state and CPU usage spikes.
>
> (…snip…)
> So, my questions to the list are:
>
>    1.  Has anyone seen this issue raised anywhere else?
>    2.  If yes, has anyone taken a look into it yet, and possibly even found a fix?
>    3.  If no to both of the above, shall I submit it through the correct channels then have a crack at fixing myself?  Or is the issue likely to be a much deeper and far-reaching one than I?m anticipating?

By coincidence I'm developing right now a GridView for displaying large 
grids (millions of rows and columns) using JavaFX VirtualFlow. It seems 
to work smoothly up to now. That GridView is specifically designed for 
rendering the sample values of large java.awt.image.RenderedImage using 
its tile management capacity (tiles loaded in background thread when 
first requested). It is not my goal to create a general purpose GridView 
at this time. However it should be possible to remove the 
RenderedImage-specific code and replace it by another model with not too 
much effort. The code is at [1].

About improving TableView for managing thousands of columns, I believe 
that one difficulty is that TableView depends extensively on 
TableColumn, which provides a lot of capability (resizing, sorting, 
reordering, hiding, etc.) at the cost of more complexity that may be 
difficult to optimize. By contrast, above-cited GridView has a lot of 
restrictions (all cells of the same size, no sorting, no reordering, 
etc.) for easier implementation.

     Martin

[1] https://github.com/apache/sis/tree/geoapi-4.0/application/sis-javafx/src/main/java/org/apache/sis/gui/coverage