Add support for pdb prompt

Note: pdbpp is not supported, it has lots of problems with unicode<-->str
conversion (either explicit or implicit).

docs/source/develop/segments.rst

@@ -469,6 +469,12 @@ Ipython
     Attribute ``prompt_count`` contains the so-called “history count” 
     (equivalent to ``\N`` in ``in_template``).
 
+Pdb
+---
+
+``pdb``
+    Currently active :py:class:`pdb.Pdb` instance.
+
 Segment class
 =============
 

docs/source/usage/other.rst

@@ -124,3 +124,30 @@ the used profile:
 
 IPython=0.11* is not supported and does not work. IPython<0.10 was not 
 tested (not installable by pip).
+
+PDB prompt
+==========
+
+To use Powerline with PDB prompt you need to use custom class. Inherit your 
+class from :py:class:`pdb.Pdb` and decorate it with 
+:py:func:`powerline.bindings.pdb.use_powerline_prompt`:
+
+.. code-block:: Python
+
+   import pdb
+
+   from powerline.bindings.pdb import use_powerline_prompt
+
+   @use_powerline_prompt
+   class MyPdb(pdb.Pdb):
+       pass
+
+   MyPdb.run('some.code.to.debug()')
+
+. Alternatively you may use
+
+.. code-block:: bash
+
+   python -mpowerline.bindings.pdb path/to/script.py
+
+just like you used ``python -m pdb``.

powerline/bindings/pdb/__init__.py

@@ -0,0 +1,54 @@
+# vim:fileencoding=utf-8:noet
+from __future__ import (unicode_literals, division, absolute_import, print_function)
+
+from powerline.pdb import PDBPowerline
+from powerline.lib.encoding import get_preferred_output_encoding
+
+
+def use_powerline_prompt(cls):
+	'''Decorator that installs powerline prompt to the class
+
+	:param pdb.Pdb cls:
+		Class that should be decorated.
+
+	:return:
+		``cls`` argument or a class derived from it. Latter is used to turn 
+		old-style classes into new-style classes.
+	'''
+	encoding = get_preferred_output_encoding()
+
+	@property
+	def prompt(self):
+		try:
+			powerline = self.powerline
+		except AttributeError:
+			powerline = PDBPowerline()
+			powerline.setup(self)
+			self.powerline = powerline
+		ret = powerline.render(side='left')
+		if not isinstance(ret, str):
+			# Python-2
+			ret = ret.encode(encoding)
+		return ret
+
+	@prompt.setter
+	def prompt(self, _):
+		pass
+
+	@prompt.deleter
+	def prompt(self):
+		pass
+
+	if not hasattr(cls, '__class__'):
+		# Old-style class: make it new-style or @property will not work.
+		old_cls = cls
+
+		class cls(cls, object):
+			__module__ = cls.__module__
+			__doc__ = cls.__doc__
+
+		cls.__name__ = old_cls.__name__
+
+	cls.prompt = prompt
+
+	return cls

powerline/bindings/pdb/__main__.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8:noet
+from __future__ import (unicode_literals, division, absolute_import, print_function)
+
+import pdb
+
+from powerline.bindings.pdb import use_powerline_prompt
+
+
+def main():
+	'''Run module as a script
+
+	Uses :py:func:`pdb.main` function directly, but prior to that it mocks 
+	:py:class:`pdb.Pdb` class with powerline-specific class instance.
+	'''
+	orig_pdb = pdb.Pdb
+
+	@use_powerline_prompt
+	class Pdb(pdb.Pdb, object):
+		def __init__(self):
+			orig_pdb.__init__(self)
+
+	pdb.Pdb = Pdb
+
+	return pdb.main()
+
+
+if __name__ == '__main__':
+	main()

powerline/config_files/config.json

@@ -12,6 +12,10 @@
 				"in2": "in2"
 			}
 		},
+		"pdb": {
+			"colorscheme": "default",
+			"theme": "default"
+		},
 		"shell": {
 			"colorscheme": "default",
 			"theme": "default",

powerline/config_files/themes/pdb/default.json

@@ -0,0 +1,21 @@
+{
+	"segments": {
+		"left": [
+			{
+				"function": "powerline.segments.common.env.virtualenv",
+				"priority": 10
+			},
+			{
+				"type": "string",
+				"contents": "In [",
+				"draw_soft_divider": false,
+				"highlight_groups": ["virtualenv"]
+			},
+			{
+				"type": "string",
+				"contents": "]",
+				"highlight_groups": ["virtualenv"]
+			}
+		]
+	}
+}

powerline/pdb.py

@@ -0,0 +1,19 @@
+# vim:fileencoding=utf-8:noet
+from __future__ import (unicode_literals, division, absolute_import, print_function)
+
+from powerline import Powerline
+
+
+class PDBPowerline(Powerline):
+	'''PDB-specific powerline bindings
+	'''
+	def init(self, **kwargs):
+		return super(PDBPowerline, self).init(
+			ext='pdb',
+			renderer_module='pdb',
+			**kwargs
+		)
+
+	def do_setup(self, pdb):
+		self.update_renderer()
+		self.renderer.set_pdb(pdb)

powerline/renderers/pdb.py

@@ -0,0 +1,34 @@
+# vim:fileencoding=utf-8:noet
+from __future__ import (unicode_literals, division, absolute_import, print_function)
+
+from powerline.renderers.shell.readline import ReadlineRenderer
+from powerline.renderer import Renderer
+
+
+class PDBRenderer(ReadlineRenderer):
+	'''PDB-specific powerline renderer
+	'''
+	pdb = None
+
+	def get_segment_info(self, segment_info, mode):
+		r = self.segment_info.copy()
+		r['pdb'] = self.pdb
+		return r
+
+	def set_pdb(self, pdb):
+		'''Record currently used :py:class:`pdb.Pdb` instance
+
+		Must be called before first calling :py:meth:`render` method.
+
+		:param pdb.Pdb pdb:
+			Used :py:class:`pdb.Pdb` instance. This instance will later be used 
+			by :py:meth:`get_segment_info` for patching :ref:`segment_info 
+			<dev-segments-info>` dictionary.
+		'''
+		self.pdb = pdb
+
+	def render(self, **kwargs):
+		return Renderer.render(self, **kwargs)
+
+
+renderer = PDBRenderer