Use image buttons if action icons are available

[danirabbit]

Problem

text buttons can be unweildy looking and especially with localization can really stretch out notifications as in #237

Proposal

If app actions have an associated icon, we should use image buttons (with the text as tooltip) instead of text buttons. It looks really nice and integrated.

We can use this bubble style from sound indicator for example:

Prior Art (Optional)

[lenemter]

Freedesktop notifications spec actually has capability "action-icons" - Supports using icons instead of text for displaying actions. Using icons for actions must be enabled on a per-notification basis using the "action-icons" hint.

We probably should implement and use it

[danirabbit]

@lenemter is that from the old spec or the new one? I'm not seeing anything about action-icons in the portal spec? https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Notification.html#org-freedesktop-portal-notification-addnotification

We should probably make sure we're building for what the libraries are capable of since sandboxed apps won't have access to call notification server directly

[lenemter]

@danirabbit It's from the freedesktop spec: https://specifications.freedesktop.org/notification-spec/latest/

The fdo spec and portal spec are completely different things -- fdo notification spec is old and describes general notification server protocol, while portal is the new opinionated clean spec. We have to implement both since not all applications use portals to send notifications

We can use button purposes from portal spec since it doesn't support hints but that should be done on portals side after elementary/portals#128 is merged.

[danirabbit]

@lenemter I think we don't have to implement both because we should assume apps are in Flatpak and can't use the old spec :p

[lenemter]

@danirabbit There are many apps that use sandbox hole just to talk to notification server because it's more flexible. And I'm generally -1 on assuming that every app out there have migrated from the old spec to the new one

[danirabbit]

@lenemter I don't think we should encourage this. We actually warn against it in AppCenter. Personally I feel like we should block notifications that aren't send through portals because there's no reasonable way to control them from the user side, but at the very least we should write for the path that we actually recommend developers take and not around misbehaving apps

[lenemter]

because there's no reasonable way to control them from the user side

That's not true. We currently control notifications based on whether there is X-GNOME-UsesNotifications in desktop file. We literally do not care whether the app is flatpak or not. Both flatpak and non-flatpak apps can behave as intended or misbehave.

[danirabbit]

Right and it only works if app developers do all the right things, which makes it unreasonable. It's a hack which is why we have portals instead is to go back and fix all the old hacks that don't work in practice