Define call_function interface.

core/buffer.py

@@ -234,6 +234,9 @@ class Buffer(QGraphicsScene):
     def execute_function(self, function_name):
         getattr(self, function_name)()
 
+    def call_function(self, function_name):
+        return getattr(self, function_name)()
+
     def fake_key_event_filter(self, event_string):
         pass
 

eaf.py

@@ -243,8 +243,17 @@ class EAF(dbus.service.Object):
         if buffer_id in self.buffer_dict:
             try:
                 self.buffer_dict[buffer_id].execute_function(function_name)
+            except AttributeError:
+                self.message_to_emacs("Can't execute function: " + function_name)
+
+    @dbus.service.method(EAF_DBUS_NAME, in_signature="ss", out_signature="s")
+    def call_function(self, buffer_id, function_name):
+        if buffer_id in self.buffer_dict:
+            try:
+                return self.buffer_dict[buffer_id].call_function(function_name)
             except AttributeError:
                 self.message_to_emacs("Can't call function: " + function_name)
+                return ""
 
     @dbus.service.method(EAF_DBUS_NAME, in_signature="ss", out_signature="")
     def send_key(self, buffer_id, event_string):