fixed tab sizing: restore tab widths when the last tab is closed

[jacekkopecky]

This is meant to address a forgotten case in #40290 that wasn't addressed in #181729: when the last tab is closed, there is no more reason to hold the tabs at fixed length. This behaviour is consistent with Chrome and Safari.

For illustration, here's a before and after:

(my cursor is huge and the recording software misplaced it, but it was right over the close icons)

cc @bpasero

[bpasero]

I think this makes sense but what about the index that we pass in here [1], it is probably not the right value? Should we then remove it if we do not have it?

[1]

vscode/src/vs/workbench/browser/parts/editor/editorGroupView.ts

Line 1342 in 91070de

this.titleAreaControl.beforeCloseEditor(editor, index);

[jacekkopecky]

@bpasero The beforeCloseEditor is modeled to mirror closeEditor with the same arguments.

It looks like neither of the two implementors of these methods, NoTabsTitleControl and TabsTitleControl actually use the index parameter. When I tried to use it, it turned out to be undefined anyway, so I used the editor parameter instead.

Further, the beforeCloseEditor method on TabsTitleControl is the only one to use the editor parameter. I can try to cut out all the unnecessary stuff if you'd like.

[bpasero]

@jacekkopecky yeah I would think index parameter should be removed from beforeCloseEditor then.

[jacekkopecky]

Thank you @bpasero . Nice catch with the isLast call, I missed that.