"Mappings Already Expanded" and Temporary Edges

[everbeek]

I think temporary edges are not being ignored properly when we compute whether all mappings have been expanded. Look into this.

[everbeek]

Fixed it so that I can expand to make the mapping links permanent and not temporary, but because no nodes get added, it doesn't go into the undo stack. It thus disappears when we undo then redo, and does not push us forward so we may undo just that expansion. Fixing that.

[everbeek]

I have it mostly working. It makes an undo/redo entry, which works, but when I first expand the edges alone, they appear, things seem frozen, then if I try to drag, they disappear. They can be brought back simply by undoing and redoing. I knew making this change would be odd, since everything is so node-add oriented...

[everbeek]

I hit bizarre problems while fixing this were resulting from needing to restart Chrome for some reason.

It is indeed partly working, but I am forced to undo and redo to get the edges to stick. The expansions set lists 0 nodes, which could be odd for the user...

The undo/redo, hmm, there's a hint in that before doing that, the hover over does not work. So the edges are properly registered as non-temporary, but I guess that the edges have not been added via the usual mechanism.

[everbeek]

Went and committed to #538...oops.

I had to hack around my normal computation and considerations for whether a mapping expansion was possible, then I had the undo.redo problem. The solution to that was simpler than I originally though: simply remove all temporary edges when triggering the mapping expansion. It works now.