Additional NX options

[madmonk]

The composite option in the nx.conf configuration file currently doesn't actually seem to turn compositing on or off. It's fairly broken in nx anyway but may still have some value in certain apps and would therefore be good if it could be set at the application level if possible. The biggest problem when it is enabled is that certain UI elements are completely invisible. Conversely alpha blended areas of the UI appear completely black when disabled.

To turn on compositing I modified...

/usr/lib/winswitch/winswitch/virt/nx_server_util.py

and added the following code.

        def start_display(self, session, user, is_preload):

                if session.full_desktop:
                        args_list += self.get_X_geometry_args(session.screen_size)

+                args_list += ["+extension","Composite"]
+                args_list += ["-dpi", "96"]
+                #args_list += ["-nocomposite"]

                args_list += ["-name", name, session.display]
                env = session.get_env();

Perhaps the composite setting from the configuration file could enable or disable the extension as a workaround for this. I can also confirm that setting composite off in the nx.conf configuration file does not appear to disable compositing when the Composite extension is loaded as above. Likewise it would be nice if the DPI settings could be changed.

[Antoine Martin]

Already applied in r5240

The DPI is hardcoded at 96, though we could try to forward it from the client.

Xpra does this automatically via its protocol - though it doesn't always work for apps that try to bypass X11 properties and read directly from the pseudo-hardware - see ​xpra #163)