MultiGrid with fixedRowCount is rendering incorrect width

[marcelmokos]

Issue: #660

I am first time contributor to react-virtualized. Please excuse me for not providing a code example. I can create one if it will be necessary for accepting PR.

CellMeasurer during rerendering of the table is setting width: "auto" to the table cells in measure methods. This width "auto" is causing incorrect cell rendering mostly visible on cell backgrounds.

This fix of CellMeasurer is remembering width and height of the cell before measuring.
Measuring is setting styles for width and height to "auto" prior measuring.
The fix is setting remembered width and height back after measuring.

[bvaughn]

Hey @marcelmokos! Welcome 😄

I'm not sure I understand the need for this fix. CellMeasurer only sets width to "auto" if its cache is configured not to have a fixed-width- and it only does so initially (when the cell hasn't yet been measured). Once the cell(s) have been measured, the list/table/grid is always re-rendered (because of how positions are calculated and cached) at which point the "auto" value won't be set again because size is already known.

I'd need to know more (probably a Plnkr that repros the unexpected issue you're seeing, that I could actually take a look at) before I want to change this code because it seems like the current implementation is reasonable.

[marcelmokos]

Thanks, I will create a public example.

[marcelmokos]

Thanks for your awesome library.
I was able to create examples.

This example uses not modified CellMeasurer, CellMeasurerCache
I am using the width of the component to determine if the cache should be invalidated. When the cache invalidates items are rendered incorrectly.

This example uses modified CellMeasurer, CellMeasurerCache that allows resizing of the table when width of the table changes
This PR is not about CellMeasurerCache change am just showing why I am proposing the change of CellMeasurer. With proposed change in CellMeasurer, I am no longer experiencing the issue after deleting cache.

[bvaughn]

Thanks for the demos. 😄

[bvaughn]

This has been released via 9.7.6