Integration with FixedColumns

It would be great if FixedColumns and KeyTable played nicely together.

See also DataTables/DataTables #551.

[maticb]

I was recently working with keytable and fixed columns. I found that if you click on a cell inside the fixed columns, you cannot use keys to navigate from that cell, while you can navigate via keys if you "start" by clicking on a cell outside fixed columns, and then move with keys to the fixed columns cells, navigation will work flawlessly.

I have found an issue inside the _constructor's $( document ).on( 'click.keyTable', function ( e ) ).

The problem was, after _focus sets the this.s.lastFocus variable, it also called that._blur() inside the function mentioned above. Because at least in my case it did not properly return from the if clause. I had to add this if clause to check:

//If the click was inside the fixed columns container, don't blur
if ( $(e.target).parents().filter('.DTFC_Cloned').length ) {
    return;
}

It's not a pretty fix, and the proble may be because of my other code(I have a ton of custom features in my table), but just thought I'd drop this here in a comment just in case it helps.

I also noticed you use two different click.keyTable binds, I do not fully understand the differences between them so my fixed worked fine.

Interesting - I'm surprised that they work well together at all to be honest. It would need to take into account scrolling the table up to the fixed columns as well as being able to navigate the fixed columns.

Thanks for your comment on this - it would be nice if it is as easy as that...!