Add pop-up notification (toast) for undo/redo

A small pop-up notification that times out on its own should be added on the user performing an undo/redo. See #819 (comment 51642).

changed milestone to %Xfce 4.18

added 2. Feature 8. GSoC 2022 labels

assigned to @hi-im-buggy

@alexxcons

A quick and dirty implementation of this can be done by using xfce_dialog_show_info, but this shows a complete new window and this window steals focus and does not auto-timeout. For this reason I think it's not the way to go.

I think Thunar's notification on undo should resemble what Nautilus does for deletion

Nautilus does these 'toast notifications' using libadwaita, which is built on top of gtk4, so this won't work out for Thunar, which is still sticking to gtk3.

This can be implemented manually in gtk3 using an overlay. I think making an overlay a parent of the standard view, and adding the notification on top if this, along with some sort of timer to destroy the widget after a certain amount of time should work.

In terms of implementation details, in order to make the actual popup, information from thunar_job_operation_undo and thunar_job_operation_redo would be needed, and so would a reference on the standard view to get the parent overlay widget. I can think of a couple ways to go about this:

1. Somehow get a reference on the standard view in thunar_job_operation_undo/thunar_job_operation_redo.
2. Use a signal on a commonly accessible object like the application itself, and then emit a signal on undo/redo without error, and connect a callback on the view to display the overlay with this.

Either way, I have to start with making the overlay work with the standard view, so I'll try that out. Then I'll go forward with the first method to actually make the popup.

Gna, I did not have time to join this discussion in time ... we already have a user-notification mechanism in thunar which uses libnotify (e.g. thunar-notify.h)

While generally as well the overlay notification would be fine for me, I would prefer to use the same notification concept for all notifications within thunar (afaik libnotify is as well used by other xfce components).

mentioned in issue #819 (closed)

mentioned in merge request !300 (closed)

mentioned in merge request !302 (merged)

mentioned in commit d77eee4d

Fixed by !302 (merged) thanks to @hi-im-buggy .... I'll close this issue, though feel free to open a new issue for optional toast notifications, like discussed on !300 (comment 56167)

closed

mentioned in commit 697e188d