Merge branch 'pyglet' by Nicolas Rougier, with minor fixes.

This adds pyglet event loop integration with a new 'pyglet' option for
the --gui flag and %gui magic.  The internal implementation is fairly
similar to the one for Wx integration.

IPython/frontend/terminal/ipapp.py

@@ -229,8 +229,8 @@ def _quick_changed(self, name, old, new):
             self.load_config_file = lambda *a, **kw: None
             self.ignore_old_config=True
 
-    gui = CaselessStrEnum(('qt','wx','gtk'), config=True,
-        help="Enable GUI event loop integration ('qt', 'wx', 'gtk')."
+    gui = CaselessStrEnum(('qt','wx','gtk', 'pyglet'), config=True,
+        help="Enable GUI event loop integration ('qt', 'wx', 'gtk', 'pyglet')."
     )
     pylab = CaselessStrEnum(['tk', 'qt', 'wx', 'gtk', 'osx', 'auto'],
         config=True,

IPython/lib/__init__.py

@@ -19,6 +19,7 @@
     enable_gtk, disable_gtk,
     enable_qt4, disable_qt4,
     enable_tk, disable_tk,
+    enable_pyglet, disable_pyglet,
     set_inputhook, clear_inputhook,
     current_gui
 )

IPython/lib/inputhook.py

@@ -29,6 +29,7 @@
 GUI_GTK = 'gtk'
 GUI_TK = 'tk'
 GUI_OSX = 'osx'
+GUI_PYGLET = 'pyglet'
 
 #-----------------------------------------------------------------------------
 # Utility classes
@@ -283,6 +284,39 @@ def disable_tk(self):
         """
         self.clear_inputhook()
 
+
+
+    def enable_pyglet(self, app=None):
+        """Enable event loop integration with pyglet.
+
+        Parameters
+        ----------
+        app : ignored
+           Ignored, it's only a placeholder to keep the call signature of all
+           gui activation methods consistent, which simplifies the logic of
+           supporting magics.
+
+        Notes
+        -----
+        This methods sets the ``PyOS_InputHook`` for pyglet, which allows
+        pyglet to integrate with terminal based applications like
+        IPython.
+
+        """
+        import pyglet
+        from IPython.lib.inputhookpyglet import inputhook_pyglet
+        self.set_inputhook(inputhook_pyglet)
+        self._current_gui = GUI_PYGLET
+        return app
+
+    def disable_pyglet(self):
+        """Disable event loop integration with pyglet.
+
+        This merely sets PyOS_InputHook to NULL.
+        """
+        self.clear_inputhook()
+
+
     def current_gui(self):
         """Return a string indicating the currently active GUI or None."""
         return self._current_gui
@@ -297,6 +331,8 @@ def current_gui(self):
 disable_gtk = inputhook_manager.disable_gtk
 enable_tk = inputhook_manager.enable_tk
 disable_tk = inputhook_manager.disable_tk
+enable_pyglet = inputhook_manager.enable_pyglet
+disable_pyglet = inputhook_manager.disable_pyglet
 clear_inputhook = inputhook_manager.clear_inputhook
 set_inputhook = inputhook_manager.set_inputhook
 current_gui = inputhook_manager.current_gui
@@ -334,7 +370,9 @@ def enable_gui(gui=None, app=None):
             GUI_GTK: enable_gtk,
             GUI_WX: enable_wx,
             GUI_QT: enable_qt4, # qt3 not supported
-            GUI_QT4: enable_qt4 }
+            GUI_QT4: enable_qt4,
+            GUI_PYGLET: enable_pyglet,
+            }
     try:
         gui_hook = guis[gui]
     except KeyError:

IPython/lib/inputhookpyglet.py

@@ -0,0 +1,115 @@
+# encoding: utf-8
+"""
+Enable pyglet to be used interacive by setting PyOS_InputHook.
+
+Authors
+-------
+
+* Nicolas P. Rougier
+* Fernando Perez
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2009  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import os
+import signal
+import sys
+import time
+from timeit import default_timer as clock
+import pyglet
+
+#-----------------------------------------------------------------------------
+# Platform-dependent imports and functions
+#-----------------------------------------------------------------------------
+
+if os.name == 'posix':
+    import select
+
+    def stdin_ready():
+        infds, outfds, erfds = select.select([sys.stdin],[],[],0)
+        if infds:
+            return True
+        else:
+            return False
+
+elif sys.platform == 'win32':
+    import msvcrt
+
+    def stdin_ready():
+        return msvcrt.kbhit()
+
+
+# On linux only, window.flip() has a bug that causes an AttributeError on
+# window close.  For details, see:
+# http://groups.google.com/group/pyglet-users/browse_thread/thread/47c1aab9aa4a3d23/c22f9e819826799e?#c22f9e819826799e
+
+if sys.platform.startswith('linux'):
+    def flip(window):
+        try:
+            window.flip()
+        except AttributeError:
+            pass
+else:
+    def flip(window):
+        window.flip()
+
+#-----------------------------------------------------------------------------
+# Code
+#-----------------------------------------------------------------------------
+
+def inputhook_pyglet():
+    """Run the pyglet event loop by processing pending events only.
+    
+    This keeps processing pending events until stdin is ready.  After
+    processing all pending events, a call to time.sleep is inserted.  This is
+    needed, otherwise, CPU usage is at 100%.  This sleep time should be tuned
+    though for best performance.
+    """
+    # We need to protect against a user pressing Control-C when IPython is
+    # idle and this is running. We trap KeyboardInterrupt and pass.
+    try:
+        t = clock()
+        while not stdin_ready():
+            pyglet.clock.tick()
+            for window in pyglet.app.windows:
+                window.switch_to()
+                window.dispatch_events()
+                window.dispatch_event('on_draw')
+                flip(window)
+
+            # We need to sleep at this point to keep the idle CPU load
+            # low.  However, if sleep to long, GUI response is poor.  As 
+            # a compromise, we watch how often GUI events are being processed
+            # and switch between a short and long sleep time.  Here are some
+            # stats useful in helping to tune this.
+            # time    CPU load
+            # 0.001   13%
+            # 0.005   3%
+            # 0.01    1.5%
+            # 0.05    0.5%
+            used_time = clock() - t
+            if used_time > 5*60.0:
+                # print 'Sleep for 5 s'  # dbg
+                time.sleep(5.0)
+            elif used_time > 10.0:
+                # print 'Sleep for 1 s'  # dbg
+                time.sleep(1.0)
+            elif used_time > 0.1:
+                # Few GUI events coming in, so we can sleep longer
+                # print 'Sleep for 0.05 s'  # dbg
+                time.sleep(0.05)
+            else:
+                # Many GUI events coming in, so sleep only very little
+                time.sleep(0.001)
+    except KeyboardInterrupt:
+        pass
+    return 0

docs/examples/lib/gui-pyglet.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+"""Simple pyglet example to manually test event loop integration.
+
+This is meant to run tests manually in ipython as:
+
+In [5]: %gui pyglet
+
+In [6]: %run gui-pyglet.py
+"""
+
+import pyglet
+
+
+window = pyglet.window.Window()
+label = pyglet.text.Label('Hello, world',
+                          font_name='Times New Roman',
+                          font_size=36,
+                          x=window.width//2, y=window.height//2,
+                          anchor_x='center', anchor_y='center')
+@window.event
+def on_close():
+    window.close()
+
+@window.event
+def on_draw():
+    window.clear()
+    label.draw()
+
+try:
+    from IPython.lib.inputhook import enable_pyglet
+    enable_pyglet()
+except ImportError:
+    pyglet.app.run()