--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/light9/editchoicegtk.py	Thu Jun 06 04:26:21 2013 +0000
@@ -0,0 +1,84 @@
+import gtk
+from rdflib import URIRef
+
+class Local(object):
+    """placeholder for the local uri that EditChoice does not
+    manage. Set resourceObservable to Local to indicate that you're
+    unlinked"""
+
+class EditChoice(gtk.HBox):
+    """
+    this is a gtk port of editchoice.EditChoice
+    """
+    def __init__(self, graph, resourceObservable, label="Editing:"):
+        """
+        getResource is called to get the URI of the currently
+        """
+        self.graph = graph
+
+        # the outer box should have a distinctive border so it's more
+        # obviously a special drop target
+        gtk.HBox.__init__(self)
+        self.pack_start(gtk.Label(label), expand=False)
+
+        # this is just a label, but it should look like a physical
+        # 'thing' (and gtk labels don't work as drag sources)
+        self.currentLink = gtk.Button("http://bar")
+
+        self.pack_start(self.currentLink)
+
+        self.unlinkButton = gtk.Button(label="Unlink")
+        self.pack_start(self.unlinkButton, expand=False)
+        self.unlinkButton.connect("clicked", self.onUnlink)
+        
+        self.show_all()
+
+        self.resourceObservable = resourceObservable
+        resourceObservable.subscribe(self.uriChanged)
+
+        self.makeDragSource()
+        self.makeDropTarget()
+         
+    def makeDropTarget(self):
+        def ddr(widget, drag_context, x, y, selection_data, info, timestamp):
+            if selection_data.type != 'text/uri-list':
+                raise ValueError("unknown DnD selection type %r" %
+                                 selection_data.type)
+            self.resourceObservable(URIRef(selection_data.data.strip()))
+        
+        self.currentLink.drag_dest_set(flags=gtk.DEST_DEFAULT_ALL,
+                            targets=[('text/uri-list', 0, 0)],
+                            actions=gtk.gdk.ACTION_LINK  | gtk.gdk.ACTION_COPY)
+        self.currentLink.connect("drag_data_received", ddr)
+                
+    def makeDragSource(self):
+        self.currentLink.drag_source_set(
+            start_button_mask=gtk.gdk.BUTTON1_MASK,
+            targets=[('text/uri-list', 0, 0)],
+            actions=gtk.gdk.ACTION_LINK | gtk.gdk.ACTION_COPY)
+
+        def source_drag_data_get(btn, context, selection_data, info, time):
+            selection_data.set(selection_data.target, 8,
+                               self.resourceObservable())
+
+        self.currentLink.connect("drag_data_get", source_drag_data_get)
+
+                
+    def uriChanged(self, newUri):
+        # if this resource had a type icon or a thumbnail, those would be
+        # cool to show in here too
+        if newUri is Local:
+            self.currentLink.set_label("(local)")
+            self.currentLink.drag_source_unset()
+        else:
+            self.graph.addHandler(self.updateLabel)
+            self.makeDragSource()
+        self.unlinkButton.set_sensitive(newUri is not Local)
+
+    def updateLabel(self):
+        uri = self.resourceObservable()
+        label = self.graph.label(uri)
+        self.currentLink.set_label(label or uri or "")
+
+    def onUnlink(self, *args):
+        self.resourceObservable(Local)