#173 preparatory work:

* move x11 filter intialization to xposix platform gui module
* move X11Event to common module we can import in other extensions
* add hooks to gdk_bindings so other modules can inject their event parsers (will be used by XInput2)
* make sure we check the return code of all extension query functions
* provide utility functions so other modules can inject event mappings and event names
* make sure we only add events if the event base is valid

git-svn-id: https://xpra.org/svn/Xpra/trunk@15792 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/platform/xposix/gui.py

@@ -525,15 +525,30 @@ def __init__(self, client, opts):
         self.upower_resuming_match = None
         self.upower_sleeping_match = None
         self.login1_match = None
+        self.x11_filter = None
         if client.xsettings_enabled:
             self.setup_xprops()
         self.setup_dbus_signals()
 
     def ready(self):
         pass
 
+    def init_x11_filter(self):
+        if self.x11_filter:
+            return
+        try:
+            from xpra.x11.gtk2.gdk_bindings import init_x11_filter  #@UnresolvedImport
+            self.x11_filter = init_x11_filter()
+            log("x11_filter=%s", self.x11_filter)
+        except:
+            self.x11_filter = None
+
     def cleanup(self):
         log("cleanup() xsettings_watcher=%s, root_props_watcher=%s", self._xsettings_watcher, self._root_props_watcher)
+        if self.x11_filter:
+            from xpra.x11.gtk2.gdk_bindings import cleanup_x11_filter   #@UnresolvedImport
+            self.x11_filter = None
+            cleanup_x11_filter()
         if self._xsettings_watcher:
             self._xsettings_watcher.cleanup()
             self._xsettings_watcher = None
@@ -617,6 +632,7 @@ def do_setup_xprops(self, *args):
             return
         ROOT_PROPS = ["RESOURCE_MANAGER", "_NET_WORKAREA", "_NET_CURRENT_DESKTOP"]
         try:
+            self.init_x11_filter()
             from xpra.x11.xsettings import XSettingsWatcher
             from xpra.x11.xroot_props import XRootPropWatcher
             if self._xsettings_watcher is None:

src/xpra/x11/gtk2/common.py

@@ -0,0 +1,27 @@
+# This file is part of Xpra.
+# Copyright (C) 2017 Antoine Martin <antoine@devloop.org.uk>
+# Xpra is released under the terms of the GNU GPL v2, or, at your option, any
+# later version. See the file COPYING for details.
+
+from gtk import gdk
+
+# Just to make it easier to pass around and have a helpful debug logging.
+# Really, just a python objects where we can stick random bags of attributes.
+class X11Event(object):
+    def __init__(self, name):
+        self.name = name
+
+    def __repr__(self):
+        d = {}
+        for k,v in self.__dict__.items():
+            if k=="name":
+                continue
+            elif k=="serial":
+                d[k] = "%#x" % v
+            elif v and type(v)==gdk.Window:
+                d[k] = "%#x" % v.xid
+            elif v and type(v)==gdk.Display:
+                d[k] = "%s" % v.get_name()
+            else:
+                d[k] = v
+        return "<X11:%s %r>" % (self.name, d)