This will allow for a cleaner and more predictable focus behavior,
as this will give the capability to the dialog to grab focus
on either the "Done" button or summary section depending on the
writability, as opposed to the current approach, where the
summary section assumes that it is already writable and grabs focus,
which then the dialog sets focus on the "Done" button.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/782>
- Fix a bug where clicking the "Add Event" button created an empty title in the event editor dialog.
- Add "error" class when the user writes an invalid event name.
- Add new function to validate event name.
Because the sections are split into files, the event editor will need a signal to check that each section is correct, and each section will have to emit the signal. This will need to be done in a future commit.