* Refactored payload handling mechanism.

* Paging is now integrated into the IPythonWidget.
* The first cut at %edit support is now connected to the edit payload. This needs some more work.

IPython/frontend/qt/console/frontend_widget.py

@@ -339,9 +339,19 b' class FrontendWidget(HistoryConsoleWidget, BaseFrontendMixin):'
     def _process_execute_ok(self, msg):
         """ Process a reply for a successful execution equest.
         """
+        payload = msg['content']['payload']
+        for item in payload:
+            if not self._process_execute_payload(item):
+                warning = 'Received unknown payload of type %s\n'
+                self._append_plain_text(warning % repr(item['source']))
+
+    def _process_execute_payload(self, item):
+        """ Process a single payload item from the list of payload items in an
+            execution reply. Returns whether the payload was handled.
+        """
         # The basic FrontendWidget doesn't handle payloads, as they are a
         # mechanism for going beyond the standard Python interpreter model.
-        pass
+        return False
 
     def _show_interpreter_prompt(self):
         """ Shows a prompt for the interpreter.

IPython/frontend/qt/console/ipython_widget.py

@@ -24,8 +24,8 b' class IPythonWidget(FrontendWidget):'
     """
 
     # Signal emitted when an editor is needed for a file and the editor has been
-    # specified as 'custom'.
-    custom_edit_requested = QtCore.pyqtSignal(object)
+    # specified as 'custom'. See 'set_editor' for more information.
+    custom_edit_requested = QtCore.pyqtSignal(object, int)
 
     # The default stylesheet: black text on a white background.
     default_stylesheet = """
@@ -51,9 +51,13 b' class IPythonWidget(FrontendWidget):'
     in_prompt = 'In [<span class="in-prompt-number">%i</span>]: '
     out_prompt = 'Out[<span class="out-prompt-number">%i</span>]: '
 
-    # FrontendWidget protected class attributes.
+    # FrontendWidget protected class variables.
     #_input_splitter_class = IPythonInputSplitter
 
+    # IPythonWidget protected class variables.
+    _payload_source_edit = 'IPython.zmq.zmqshell.ZMQInteractiveShell.edit_magic'
+    _payload_source_page = 'IPython.zmq.page.page'
+
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
@@ -116,6 +120,18 b' class IPythonWidget(FrontendWidget):'
 
         self._append_html(traceback)
 
+    def _process_execute_payload(self, item):
+        """ Reimplemented to handle %edit and paging payloads.
+        """
+        if item['source'] == self._payload_source_edit:
+            self.edit(item['filename'], item['line_number'])
+            return True
+        elif item['source'] == self._payload_source_page:
+            self._page(item['data'])
+            return True
+        else:
+            return False
+
     def _show_interpreter_prompt(self, number=None, input_sep='\n'):
         """ Reimplemented for IPython-style prompts.
         """
@@ -170,7 +186,7 b' class IPythonWidget(FrontendWidget):'
     # 'IPythonWidget' interface
     #---------------------------------------------------------------------------
 
-    def edit(self, filename):
+    def edit(self, filename, line=None):
         """ Opens a Python script for editing.
 
         Parameters:
@@ -178,6 +194,9 b' class IPythonWidget(FrontendWidget):'
         filename : str
             A path to a local system file.
         
+        line : int, optional
+            A line of interest in the file.
+        
         Raises:
         -------
         OSError
@@ -189,7 +208,7 b' class IPythonWidget(FrontendWidget):'
                 message = 'Failed to open %s with the default application'
                 raise OSError(message % repr(filename))
         elif self._editor is None:
-            self.custom_edit_requested.emit(filename)
+            self.custom_edit_requested.emit(filename, line)
         else:
             Popen(self._editor + [filename])
 
@@ -211,8 +230,8 b' class IPythonWidget(FrontendWidget):'
             This parameter also takes two special values:
                 'default' : Files will be edited with the system default 
                             application for Python files.
-                'custom'  : Emit a 'custom_edit_requested(str)' signal instead
-                            of opening an editor.
+                'custom'  : Emit a 'custom_edit_requested(str, int)' signal 
+                            instead of opening an editor.
         """
         if editor == 'default':
             self._editor = 'default'

IPython/frontend/qt/console/rich_ipython_widget.py

@@ -14,7 +14,8 b' class RichIPythonWidget(IPythonWidget):'
         text version.
     """
 
-    # Protected class variables.
+    # RichIPythonWidget protected class variables.
+    _payload_source_plot = 'IPython.zmq.pylab.backend_payload.add_plot_payload'
     _svg_text_format_property = 1
 
     #---------------------------------------------------------------------------
@@ -58,12 +59,10 b' class RichIPythonWidget(IPythonWidget):'
     # 'FrontendWidget' protected interface
     #---------------------------------------------------------------------------
 
-    def _process_execute_ok(self, msg):
+    def _process_execute_payload(self, item):
         """ Reimplemented to handle matplotlib plot payloads.
         """
-        payload = msg['content']['payload']
-        for item in payload:
-            if item['source'] == 'IPython.zmq.pylab.backend_payload.add_plot_payload':
+        if item['source'] == self._payload_source_plot:
                 if item['format'] == 'svg':
                     svg = item['data']
                     try:
@@ -77,36 +76,12 b' class RichIPythonWidget(IPythonWidget):'
                         cursor.insertBlock()
                         cursor.insertImage(format)
                         cursor.insertBlock()
+                return True
                 else:
                     # Add other plot formats here!
-                    pass
-            elif item['source'] == 'IPython.zmq.zmqshell.ZMQInteractiveShell.edit_magic':
-                # TODO: I have implmented the logic for TextMate on the Mac.
-                # But, we need to allow payload handlers on the non-rich
-                # text IPython widget as well. Furthermore, we should probably
-                # move these handlers to separate methods. But, we need to
-                # be very careful to process the payload list in order. Thus,
-                # we will probably need a _handle_payload method of the 
-                # base class that dispatches to the separate handler methods
-                # for each payload source. If a particular subclass doesn't 
-                # have a handler for a payload source, it should at least
-                # print a nice message.
-                filename = item['filename']
-                line_number = item['line_number']
-                if line_number is None:
-                    cmd = 'mate %s' % filename
+                return False
                 else:
-                    cmd = 'mate -l %s %s' % (line_number, filename)
-                os.system(cmd)
-            elif item['source'] == 'IPython.zmq.page.page':
-                # TODO: This is probably a good place to start, but Evan can
-                # add better paging capabilities.
-                self._append_plain_text(item['data'])
-            else:
-                # Add other payload types here!
-                pass
-        else:
-            super(RichIPythonWidget, self)._process_execute_ok(msg)
+            return super(RichIPythonWidget, self)._process_execute_ok(msg)
 
     #---------------------------------------------------------------------------
     # 'RichIPythonWidget' protected interface