This patch ensures the following notifications behavior:
- Urgent notifications that have long title or banner text are auto-expanded
correctly.
- Single-line notifications that have _expandNotification() called (e.g.
because the user mouses over to them), are treated as expanded, which means
they get fully expanded if they are updated with more content and the user
can escape them.
- The position of expanded notifications is updated when they are updated.
- Notification banner is shown again on the first line if it can fully fit
there after a notification is updated, even if it was previously hidden
because the notification was expanded and the old banner did not fully fit.
- New notifications are immediately hidden if the user mouses away from them.
- If a new notification is updated while it is shown, we extend the time it
will be shown.
- If a new notification is updated while it is hiding, we stop hiding it and
show it again.
- If a summary notification is updated while it is hiding, we let it finish
hiding and show a new notification with the updated information.
Implementation details:
- Single-line notifications now have 4px bottom padding instead of 8px, which
means that their height matches the tray height, they are fully shown in the
banner mode, and don't pop out by 4px when the notification is expanded.
- Notification keeps a flag that indicates whether it is expanded, updates
its expanded look when it is updated, and emits an 'expanded' signal
indicating that its layout has possibly changed. The message tray connects
to this 'expanded' signal when it is showing a notification in the expanded
state and updates the position of the notification accordingly when this
signal is received so that the notification is fully shown. This is better
than connecting to 'notify::height' signal on the notification bin, since
it results in fewer callbacks.
https://bugzilla.gnome.org/show_bug.cgi?id=617209