Not correctly handling AppIndicators' status changes
The panel's Status Tray plugin is not at all correctly handling AppIndicators' status changes because it only detects whether status is
Passive or not, cf.
sn_item_status_is_exposed(). But status is a tri-state value; it may not only be
Active but might be
NeedsAttention as well (according to
Only in the case if status equals
NeedsAttention, the attention icon and its description shall be shown. With your implementation, the attention icon is displayed as soon as it is set by receiving the signal
NewAttentionIcon and status not being
Passive (cf. property
exposed), which lets any application like Solaar always display the attention icon, also if status remains to just be
Active all the time. But then the shown icon shall be the regular instead of the attention icon (according to StatusNotifierItem's documentation for instance).