Support notification pictures

[maximbaz]

It would be very nice to be able to get a profile picture of the sender rendered in the notification, just like Signal Desktop does.

Here's what I recommend to consider:

1. Find the path to sender's profile.

I can see some pics in ~/.local/share/signal-cli/avatars/contact-+<num> and ~/.local/share/signal-cli/avatars/profile-+<num>, not quite sure what's the difference, they seem to be somewhat duplicate, and I have more or contact- ones.

2. If image is not found, use hardcoded value scli.

3. Change default NOTIFICATION_COMMAND to be notify-send -i "%i" scli '%s - %m' (where %i is one of the two strings above)

This would achieve the following:

• If profile picture was found, it would be shown in the notification.
• If profile picture was not found, we will send a hardcoded scli value.
  • user can then create scli.<ext> picture in any of the default icon locations, and this icon would be used as a "fallback icon"
  • user can also do nothing, and so if scli icon does not exist, it would be ignored by notify-send, i.e. the behavior would be as today, no icon.

[exquo]

Nice suggestion, thanks! Should be a pretty low hanging fruit for us to implement, too.

I'm also not sure why some avatar files start with contact- and other with profile-. Asked upstream. In practice, scli can check existence for both, and use whichever it finds.

In addition to the steps you describe, we can add a 'generic icon name' fallback, using one of the stock icon names (like mail-message-new) from the freedesktop spec. I remember checking them for this purpose sometime back, but I guess I found them too "90s" looking :). And the users who really wanted a scli icon in notifications could add it in the --notification-command.

[maximbaz]

I agree, this is also a good approach to set default value to fallback to some existing icon!