TreeGrid setShowRollOverCanvas() causing grid to scroll when rollover images are drawn, i.e. when user moves their mouse?

[user316]

Hello,

We have setShowRollOverCanvas() set to true on a TreeGrid which sometimes contains a large amount of data and a vertical scrollbar. There is an issue that when the user moves their mouse (without clicking on anything), it causes the grid to almost randomly scroll back and forth vertically, to the point where the grid is not usable. I isolated the cause of this, after I noticed that when I disable the rollover canvas, this stops happening. Is there some framework issue causing this? I looked through all the code and it is specific to the rollover canvas, and even when I make the rollover canvas code extremely simple, it still happens. Only when I actually set setShowRollOverCanvas() to false does this behavior stop.

A video of the behavior recorded by a user is here:

[Isomorphic]

What this looks like is that the rollOverCanvas may be sized taller than the current row, causing it to stick out of the viewport, which could cause scrolling depending on the contents of the Canvas. Does this help resolve it for you?

[user316]

What this looks like is that the rollOverCanvas may be sized taller than the current row, causing it to stick out of the viewport, which could cause scrolling depending on the contents of the Canvas. Does this help resolve it for you?

No, this isn't the issue. I tried in an experiment making the rollover canvas extremely small, but it didn't change any of the behavior. Is there any internal code in the framework that would cause the TreeGrid to scroll?

[Isomorphic]

We've tried adding a rollOverCanvas to a load-on-demand TreeGrid and can't reproduce the effect you're showing.

The only other speculation we have as to a cause is that you might have some code that performs scrolling for some reason, and it's being tripped by some behavior of the rollover Canvas (like perhaps you are trying to catch all visibility changes on children of the body.. something like that).

You might also enable the "scrolling" log category, and use SC.traceLogMessage() to get stack traces for the scrolling logs that appear for the problematic TreeGrid.