Moving a wide column causes problems in Grid

[mattrunyon]

Description

If you try to rearrange columns with a wide column that expands off screen, some errors are thrown and it's possible to get to a state where you have data off screen and no horizontal scroll bar (I can't figure out how to reproduce the no scroll bar error).

Steps to reproduce
Use this table

from deephaven.TableTools import newTable, stringCol

source = newTable(
    stringCol("Narrow", "A" , "B", "C", "D"),
    stringCol("Wide", "A"*5000 , "B"*5000, "C"*5000, "D"*5000),
)

Shrink so there's a horizontal scroll bar
The wide column should overflow to the right
Try to reorder the narrow column past the wide column

Expected results

No error

Actual results

Errors. I think the draggingColumn index is not being set properly. When I log and drag the wide column towards the narrow (column 1 towards 0), I get a draggingColumn index of 0 for some reason

Versions

• Deephaven: 0.9.0
• OS: Mac
• Browser: Chrome