Add prompt_toolkit input hooks for wx

IPython/terminal/pt_inputhooks/wx.py

@@ -0,0 +1,148 b''
+"""Enable wxPython to be used interacively in prompt_toolkit
+"""
+from __future__ import absolute_import
+
+import sys
+import signal
+import time
+from timeit import default_timer as clock
+import wx
+
+
+def inputhook_wx1(context):
+    """Run the wx event loop by processing pending events only.
+
+    This approach seems to work, but its performance is not great as it
+    relies on having PyOS_InputHook called regularly.
+    """
+    try:
+        app = wx.GetApp()
+        if app is not None:
+            assert wx.Thread_IsMain()
+
+            # Make a temporary event loop and process system events until
+            # there are no more waiting, then allow idle events (which
+            # will also deal with pending or posted wx events.)
+            evtloop = wx.EventLoop()
+            ea = wx.EventLoopActivator(evtloop)
+            while evtloop.Pending():
+                evtloop.Dispatch()
+            app.ProcessIdle()
+            del ea
+    except KeyboardInterrupt:
+        pass
+    return 0
+
+class EventLoopTimer(wx.Timer):
+
+    def __init__(self, func):
+        self.func = func
+        wx.Timer.__init__(self)
+
+    def Notify(self):
+        self.func()
+
+class EventLoopRunner(object):
+
+    def Run(self, time, input_is_ready):
+        self.input_is_ready = input_is_ready
+        self.evtloop = wx.EventLoop()
+        self.timer = EventLoopTimer(self.check_stdin)
+        self.timer.Start(time)
+        self.evtloop.Run()
+
+    def check_stdin(self):
+        if self.input_is_ready():
+            self.timer.Stop()
+            self.evtloop.Exit()
+
+def inputhook_wx2(context):
+    """Run the wx event loop, polling for stdin.
+
+    This version runs the wx eventloop for an undetermined amount of time,
+    during which it periodically checks to see if anything is ready on
+    stdin.  If anything is ready on stdin, the event loop exits.
+
+    The argument to elr.Run controls how often the event loop looks at stdin.
+    This determines the responsiveness at the keyboard.  A setting of 1000
+    enables a user to type at most 1 char per second.  I have found that a
+    setting of 10 gives good keyboard response.  We can shorten it further,
+    but eventually performance would suffer from calling select/kbhit too
+    often.
+    """
+    try:
+        app = wx.GetApp()
+        if app is not None:
+            assert wx.Thread_IsMain()
+            elr = EventLoopRunner()
+            # As this time is made shorter, keyboard response improves, but idle
+            # CPU load goes up.  10 ms seems like a good compromise.
+            elr.Run(time=10,  # CHANGE time here to control polling interval
+                    input_is_ready=context.input_is_ready)
+    except KeyboardInterrupt:
+        pass
+    return 0
+
+def inputhook_wx3(context):
+    """Run the wx event loop by processing pending events only.
+
+    This is like inputhook_wx1, but it 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:
+        app = wx.GetApp()
+        if app is not None:
+            assert wx.Thread_IsMain()
+
+            # The import of wx on Linux sets the handler for signal.SIGINT
+            # to 0.  This is a bug in wx or gtk.  We fix by just setting it
+            # back to the Python default.
+            if not callable(signal.getsignal(signal.SIGINT)):
+                signal.signal(signal.SIGINT, signal.default_int_handler)
+
+            evtloop = wx.EventLoop()
+            ea = wx.EventLoopActivator(evtloop)
+            t = clock()
+            while not context.input_is_ready():
+                while evtloop.Pending():
+                    t = clock()
+                    evtloop.Dispatch()
+                app.ProcessIdle()
+                # 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 > 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)
+            del ea
+    except KeyboardInterrupt:
+        pass
+    return 0
+
+if sys.platform == 'darwin':
+    # On OSX, evtloop.Pending() always returns True, regardless of there being
+    # any events pending. As such we can't use implementations 1 or 3 of the
+    # inputhook as those depend on a pending/dispatch loop.
+    inputhook = inputhook_wx2
+else:
+    # This is our default implementation
+    inputhook = inputhook_wx3

IPython/terminal/pt_inputhooks/__init__.py

@@ -2,7 +2,7 b' import importlib'
 import os
 
 aliases = {
-    'qt4': 'qt'
+    'qt4': 'qt',
 }
 
 def get_inputhook_func(gui):

IPython/terminal/pt_inputhooks/gtk.py

@@ -35,6 +35,7 b' PyGTK input hook for prompt_toolkit.'
 Listens on the pipe prompt_toolkit sets up for a notification that it should
 return control to the terminal event loop.
 """
+from __future__ import absolute_import
 
 import gtk, gobject