More improvements to the display system.

* Full PNG handling in the rich frontend.
* Sympy printer now can render to latex->png.

IPython/lib/latextools.py

@@ -0,0 +1,62 b''
+# -*- coding: utf-8 -*-
+"""Tools for handling LaTeX.
+
+Authors:
+
+* Brian Granger
+"""
+#-----------------------------------------------------------------------------
+# Copyright (c) 2010, IPython Development Team.
+#
+# Distributed under the terms of the Modified BSD License.
+#
+# The full license is in the file COPYING.txt, distributed with this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+from StringIO import StringIO
+from base64 import encodestring
+
+#-----------------------------------------------------------------------------
+# Tools
+#-----------------------------------------------------------------------------
+
+
+def latex_to_png(s, encode=True):
+    """Render a LaTeX string to PNG using matplotlib.mathtext.
+
+    Parameters
+    ----------
+    s : str
+        The raw string containing valid inline LaTeX.
+    encode : bool, optional
+        Should the PNG data bebase64 encoded to make it JSON'able.
+    """
+    from matplotlib import mathtext
+    
+    mt = mathtext.MathTextParser('bitmap')
+    f = StringIO()
+    mt.to_png(f, s, fontsize=12)
+    bin_data = f.getvalue()
+    if encode:
+        bin_data = encodestring(bin_data)
+    return bin_data
+
+_data_uri_template_png = """<img src="data:image/png;base64,%s" alt=%s />"""
+
+def latex_to_html(s, alt='image'):
+    """Render LaTeX to HTML with embedded PNG data using data URIs.
+
+    Parameters
+    ----------
+    s : str
+        The raw string containing valid inline LateX.
+    alt : str
+        The alt text to use for the HTML.
+    """
+    base64_data = latex_to_png(s, encode=True)
+    return _data_uri_template_png  % (base64_data, alt)
+

IPython/core/display.py

@@ -48,6 +48,17 b' def display(obj, include=None, exclude=None):'
     publish('IPython.core.display.display', format_dict)
 
 
+def display_pretty(obj):
+    """Display the pretty (default) representation of an object.
+
+    Parameters
+    ----------
+    obj : object
+        The Python object to display.
+    """
+    display(obj, include=['text/plain'])
+
+
 def display_html(obj):
     """Display the HTML representation of an object.
 

IPython/core/formatters.py

@@ -15,6 +15,10 b' Authors:'
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
 # Stdlib imports
 import abc
 # We must use StringIO, as cStringIO doesn't handle unicode properly.
@@ -259,6 +263,23 b' class BaseFormatter(Configurable):'
             self.deferred_printers[key] = func
         return oldfunc
 
+    def _in_deferred_types(self, cls):
+        """
+        Check if the given class is specified in the deferred type registry.
+
+        Returns the printer from the registry if it exists, and None if the
+        class is not in the registry. Successful matches will be moved to the
+        regular type registry for future use.
+        """
+        mod = getattr(cls, '__module__', None)
+        name = getattr(cls, '__name__', None)
+        key = (mod, name)
+        printer = None
+        if key in self.deferred_printers:
+            # Move the printer over to the regular registry.
+            printer = self.deferred_printers.pop(key)
+            self.type_printers[cls] = printer
+        return printer
 
 class PlainTextFormatter(BaseFormatter):
     """The default pretty-printer.

IPython/extensions/sympy_printing.py

@@ -14,7 +14,9 b' Authors:'
 # Imports
 #-----------------------------------------------------------------------------
 
-from sympy import pretty
+from IPython.lib.latextools import latex_to_png
+
+from sympy import pretty, latex
 
 #-----------------------------------------------------------------------------
 # Definitions of magic functions for use with IPython
@@ -30,6 +32,12 b' def print_basic_unicode(o, p, cycle):'
     p.text(out)
 
 
+def print_png(o):
+    """A funciton to display sympy expression using LaTex -> PNG."""
+    s = latex(o)
+    png = latex_to_png(s, encode=True)
+    return png
+
 _loaded = False
 
 
@@ -41,5 +49,9 b' def load_ipython_extension(ip):'
         plaintext_formatter.for_type_by_name(
             'sympy.core.basic', 'Basic', print_basic_unicode
         )
+        png_formatter = ip.display_formatter.formatters['image/png']
+        png_formatter.for_type_by_name(
+            'sympy.core.basic', 'Basic', print_png
+        )
         _loaded = True
 

IPython/frontend/qt/console/ipython_widget.py

@@ -210,6 +210,8 b' class IPythonWidget(FrontendWidget):'
             elif data.has_key('text/plain'):
                 text = data['text/plain']
                 self._append_plain_text(text)
+            # This newline seems to be needed for text and html output.
+            self._append_plain_text(u'\n')
 
     def _started_channels(self):
         """ Reimplemented to make a history request.

IPython/frontend/qt/console/rich_ipython_widget.py

@@ -1,6 +1,7 b''
 # System library imports
 import os
 import re
+from base64 import decodestring
 from PyQt4 import QtCore, QtGui
 
 # Local imports
@@ -74,6 +75,13 b' class RichIPythonWidget(IPythonWidget):'
                 # TODO: try/except this call.
                 self._append_svg(data['image/svg+xml'])
                 self._append_html(self.output_sep2)
+            elif data.has_key('image/png'):
+                self._append_plain_text(self.output_sep)
+                self._append_html(self._make_out_prompt(prompt_number))
+                # TODO: try/except these calls
+                png = decodestring(data['image/png'])
+                self._append_png(png)
+                self._append_html(self.output_sep2)
             else:
                 # Default back to the plain text representation.
                 return super(RichIPythonWidget, self)._handle_pyout(msg)
@@ -91,6 +99,12 b' class RichIPythonWidget(IPythonWidget):'
                 svg = data['image/svg+xml']
                 # TODO: try/except this call.
                 self._append_svg(svg)
+            elif data.has_key('image/png'):
+                # TODO: try/except these calls
+                # PNG data is base64 encoded as it passes over the network
+                # in a JSON structure so we decode it.
+                png = decodestring(data['image/png'])
+                self._append_png(png)
             else:
                 # Default back to the plain text representation.
                 return super(RichIPythonWidget, self)._handle_display_data(msg)
@@ -135,6 +149,21 b' class RichIPythonWidget(IPythonWidget):'
             cursor.insertImage(format)
             cursor.insertBlock()
 
+    def _append_png(self, png):
+        """ Append raw svg data to the widget.
+        """
+        try:
+            image = QtGui.QImage()
+            image.loadFromData(png, 'PNG')
+        except ValueError:
+            self._append_plain_text('Received invalid plot data.')
+        else:
+            format = self._add_image(image)
+            cursor = self._get_end_cursor()
+            cursor.insertBlock()
+            cursor.insertImage(format)
+            cursor.insertBlock()
+
     def _add_image(self, image):
         """ Adds the specified QImage to the document and returns a
             QTextImageFormat that references it.