missing tray icons - forward notification area

[ammoled]

XPRA does not display the tray icons of attached applications such as xchat.

[Antoine Martin]

and it may never do

[Antoine Martin]

This is a very difficult problem to solve - I am not even sure it can be solved:

• there are at least two main implementations of "tray icons" on *nix: gtk's "StatusIcon" and Ubuntu's "appindicator" (see #43 for an example of how much of a mess it is to try to support them all)
• none of these support overriding at present (and afaik none use dbus..), so the code would have duplicated in each case

Pointers welcome.

[Antoine Martin]

Looks like I was wrong about them not using dbus, so we may be able to do something after all (as was done for #22), some more pointers:

• ​gtk.StatusIcon (pygtk docs)
• ​appindicators
• ​KDE Plasma NewSystemTray
• ​system trays (A Seigo blog entry)

[Antoine Martin]

Or even by implementing the raw X11 specification: ​docking a tray icon - although this is probably more difficult (we would need a fake area to dock into then we need to implement ​XEmbed).

[Antoine Martin]

comment:3 is wrong about being wrong about dbus (..): the spec does not use dbus, and most apps will not use a dbus interface either, so we must implement the docking tray icon spec directly.

Found ​pypanel which may serve as a good base for implementing our own tray icon forwarding code.

[Antoine Martin]

adds a hardcoded area for tray icons to dock into - ugly hack for now

[Antoine Martin]

much more complete implementation

[Antoine Martin]

we can almost click on the forwarded icon too

[Antoine Martin]

updated patch for r2088

[Antoine Martin]

updated patch with cleanups

[Antoine Martin]

work on transparency

[Antoine Martin]

• r2094 adds the server-side part
• r2097 adds the client-side part

---

It is mostly working as it is, but with some limitations we should address:

• missing transparency: we set _NET_SYSTEM_TRAY_VISUAL to the 32-bit visual - but somehow the docking requests we receive are for 24-bit visual windows, not sure why.
• ​gtk.StatusIcon only gives us two events for mouse clicks: ​activate and ​popup-menu so we end up simulating a button press and release on the remote tray area. By implementing the system tray using raw X11 calls we ought to be able to get more useful events to forward, the win32 implementation can probably supply the same too in OnTaskbarNotify. We can then use the StatusIcon version as fallback for platforms without native support (ie: osx or pure-python builds).
• we should avoid the round-trip via a pixmap backing to get the pixbuf
• detect when we lose the tray selection and cleanup
• support balloon messages

[Antoine Martin]

adds the ability to handle 32-bit window backing

[Antoine Martin]

We probably also need to split this code into a separate executable so that we can exit/upgrade xpra without losing the trays.

[Antoine Martin]

For transparency, see #279

[Antoine Martin]

transparency fixed in r3475 for *nix

[Antoine Martin]

Works well enough.

[Antoine Martin]

win32 native code in use as of r4640 - which allows us to do things other implementations cannot do: hovering events, etc

[Antoine Martin]

(setting correct milestone the work was completed in)

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/77