ENH: Add continuation prompts

IPython/frontend/linefrontendbase.py

@@ -295,6 +295,17 b' class LineFrontEndBase(FrontEndBase):'
         self.write(prompt)
 
 
+    def continuation_prompt(self):
+        """Returns the current continuation prompt.
+        Overridden to generate a continuation prompt matching the length of the
+        current prompt."""
+        
+        # FIXME: This is a bad hack.. I need to find a way to use the 'Prompt2'
+        # class in IPython/kernel/prompts.py. Basically, I am trying to get the
+        # length of the current prompt ("In ['number']").
+        return ("."*(5+len(str(self.last_result['number']))) + ':')
+ 
+
     def execute_command(self, command, hidden=False):
         """ Execute a command, not only in the model, but also in the
             view, if any.
@@ -310,14 +321,19 b' class LineFrontEndBase(FrontEndBase):'
             buffer.
         """
         current_buffer = self.input_buffer
-        cleaned_buffer = self.prefilter_input(current_buffer)
+        # XXX: This string replace is ugly, but there should be no way it
+        # fails.
+        prompt_less_buffer = re.sub('^' + self.continuation_prompt(),
+                '', current_buffer).replace('\n' + self.continuation_prompt(),
+                                            '\n')
+        cleaned_buffer = self.prefilter_input(prompt_less_buffer)
         if self.is_complete(cleaned_buffer):
             self.execute(cleaned_buffer, raw_string=current_buffer)
         else:
-            self.input_buffer += self._get_indent_string(
-                                                current_buffer[:-1])
+            self.input_buffer += self.continuation_prompt() + \
+                  self._get_indent_string(prompt_less_buffer[:-1])
             if len(current_buffer.split('\n')) == 2:
-                self.input_buffer += '\t\t'
+                self.input_buffer += '\t'
             if current_buffer[:-1].split('\n')[-1].rstrip().endswith(':'):
                 self.input_buffer += '\t'
 

IPython/frontend/prefilterfrontend.py

@@ -24,6 +24,7 b' __docformat__ = "restructuredtext en"'
 import sys
 import pydoc
 import os
+import re
 import __builtin__
 
 from IPython.ipmaker import make_IPython
@@ -113,9 +114,9 b' class PrefilterFrontEnd(LineFrontEndBase):'
 
 
         if not 'banner' in kwargs and self.banner is None:
-            self.banner = self.ipython0.BANNER + """
-This is the wx frontend, by Gael Varoquaux. This is EXPERIMENTAL code."""
+            self.banner = self.ipython0.BANNER
 
+        # FIXME: __init__ and start should be two different steps
         self.start()
 
     #--------------------------------------------------------------------------
@@ -182,7 +183,9 b' This is the wx frontend, by Gael Varoquaux. This is EXPERIMENTAL code."""'
     def complete(self, line):
         # FIXME: This should be factored out in the linefrontendbase
         # method.
+        word = self._get_completion_text(line)
         word = line.split('\n')[-1].split(' ')[-1]
+        print 'Completion', word
         completions = self.ipython0.complete(word)
         # FIXME: The proper sort should be done in the complete method.
         key = lambda x: x.replace('_', '')
@@ -255,3 +258,18 b' This is the wx frontend, by Gael Varoquaux. This is EXPERIMENTAL code."""'
         """
         self.ipython0.atexit_operations()
 
+
+    def _get_completion_text(self, line):
+        """ Returns the text to be completed by breaking the line at specified
+        delimiters.
+        """
+        # Break at: spaces, '=', all parentheses (except if balanced).
+        # FIXME2: In the future, we need to make the implementation similar to
+        # that in the 'pyreadline' module (modes/basemode.py) where we break at
+        # each delimiter and try to complete the residual line, until we get a
+        # successful list of completions.
+        expression = '\s|=|,|:|\((?!.*\))|\[(?!.*\])|\{(?!.*\})' 
+        complete_sep = re.compile(expression)
+        text = complete_sep.split(line)[-1]
+        return text
+

IPython/frontend/wx/console_widget.py

@@ -216,6 +216,16 b' class ConsoleWidget(editwindow.EditWindow):'
         """
         return self.GetSize()[0]/self.GetCharWidth()
 
+
+    def clear_screen(self):
+        """ Empty completely the widget.
+        """
+        self.ClearAll()
+        self.new_prompt(self.input_prompt_template.substitute(
+                                number=(self.last_result['number'] + 1)))
+
+
+
     #--------------------------------------------------------------------------
     # EditWindow API
     #--------------------------------------------------------------------------
@@ -391,15 +401,16 b' class ConsoleWidget(editwindow.EditWindow):'
                 catched = True
 
             elif event.KeyCode in (wx.WXK_LEFT, wx.WXK_BACK):
-                if self.GetCurrentPos() > self.current_prompt_pos:
+                if not self._keep_cursor_in_buffer():
                     event.Skip()
                 catched = True
 
             if skip and not catched:
                 # Put the cursor back in the edit region
-                if self.GetCurrentPos() < self.current_prompt_pos:
-                    self.GotoPos(self.current_prompt_pos)
-                else:
+                if not self._keep_cursor_in_buffer():
+                    if (self.GetCurrentPos() == self.GetLength()
+                                and event.KeyCode == wx.WXK_DELETE):
+                        pass
                     event.Skip()
 
         return catched
@@ -408,9 +419,44 b' class ConsoleWidget(editwindow.EditWindow):'
     def _on_key_up(self, event, skip=True):
         """ If cursor is outside the editing region, put it back.
         """
-        event.Skip()
-        if self.GetCurrentPos() < self.current_prompt_pos:
+        if skip:
+            event.Skip()
+        self._keep_cursor_in_buffer()
+
+
+    def _keep_cursor_in_buffer(self):
+        """ Checks if the cursor is where it is allowed to be. If not,
+            put it back.
+
+            Returns
+            -------
+            cursor_moved: Boolean
+                whether or not the cursor was moved by this routine.
+
+            Notes
+            ------
+                WARNING: This does proper checks only for horizontal
+                movements.
+        """
+        current_pos  = self.GetCurrentPos()
+        if  current_pos < self.current_prompt_pos:
             self.GotoPos(self.current_prompt_pos)
+            return True
+        line, line_pos = self.GetCurLine()
+        # Jump the continuation prompt
+        continuation_prompt = self.continuation_prompt()
+        if ( line.startswith(continuation_prompt)
+                     and line_pos < len(continuation_prompt)+1):
+            if line_pos < 2:
+                # We are at the beginning of the line, trying to move
+                # forward: jump forward.
+                self.GotoPos(current_pos + 1 +
+                                    len(continuation_prompt) - line_pos)
+            else:
+                # Jump back up
+                self.GotoPos(self.GetLineEndPosition(self.GetCurrentLine()-1))
+            return True
+        return False
 
 
 

IPython/frontend/wx/wx_frontend.py

@@ -485,6 +485,12 b' class WxController(ConsoleWidget, PrefilterFrontEnd):'
             wx.CallAfter(self._popup_completion, create=True)
         else:
             ConsoleWidget._on_key_up(self, event, skip=skip)
+        if (self.input_buffer.split('\n')[-1] == self.continuation_prompt()
+                        and self._input_state == 'readline'):
+            # Make sure the continuation_prompt is followed by a whitespace
+            position = self.GetCurrentPos()
+            self.input_buffer += ' '
+            self.GotoPos(position)
 
 
     def _on_enter(self):