Kendo-ui-core: Hiding a column leaves ghost merged cell visible

[petyosi]

Steps to reproduce:

load the file below in http://demos.telerik.com/kendo-ui/spreadsheet/index
hideIssueWorkbook_simplified_1yr_nomonths.xlsx

hide B:F columns. Result here:

[mishoo]

I pushed a rendering fix, but it's not complete yet. Can be seen in playground/spreadsheet/merged.html — the initial rendering is fine. If you unhide columns B, C, D and then select and hide them again, the bad rendering appears to come back. The problem now is that the hidden columns remain selected (which Should Not Happen™). You can move up and down to see the other hidden cells while they are active. Once you press left or right and leave the hidden columns, you can no longer select them until you unhide them.

I suggest the next proper fix would be to move selection to the next (or previous) visible column (or row) after hiding columns/rows. (G.Sheets does the same)

[mishoo]

BTW, somewhat funny: one can hide all rows and all columns in a sheet, and then there is no way to unhide :-). I'd call it a minor issue, should we attempt to fix? (probably add a "unhide all" item in the context menu of the top-left header cell?)

[petyosi]

All in for the selection change.

[tsvetomir]

An "Unhide All" option in the context menu will help. The case is not handled very well in Excel as well - it's possible to end up with all columns hidden and no option to show them :)

[mishoo]

Done the selection update. I don't quite like the code though :-( reviews/critics welcome. :-)

[tsvetomir]

The while(true) loop makes me cringe a bit, but it's expresses the intent fairly well. I'd leave it as it is.

Thanks!