Add actions to transformation panel

[ollimeier]

Fixes #1683

[justvanrossum]

We have a fundamental problem here: the actions only get registered once the panel gets updated/shown. This means that if you hide the panel, then reload, any shortcuts do not work.

We somehow need to refactor this, but I need to think a bit more about how to best approach it.

Also: there is an existing bug where you get a console error message if you use one of the actions while there is no selection:

[ollimeier]

We have a fundamental problem here: the actions only get registered once the panel gets updated/shown. This means that if you hide the panel, then reload, any shortcuts do not work.

We somehow need to refactor this, but I need to think a bit more about how to best approach it.

Also: there is an existing bug where you get a console error message if you use one of the actions while there is no selection:

I am not able to reproduce the error. Can you please let me know if this error still exists after my latest changes?

[justvanrossum]

Yes, the error still exists, but only in the "remove overlaps" action/button: make sure there is no selected glyph in the canvas, then push the "remove overlaps" button. (All other buttons appear to be fine in this case.)

[ollimeier]

Yes, the error still exists, but only in the "remove overlaps" action/button: make sure there is no selected glyph in the canvas, then push the "remove overlaps" button. (All other buttons appear to be fine in this case.)

Ah, I see. Thanks. I fixed it.

[justvanrossum]

Two minor nits, then this is done I think.