aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/Twisted/py2/twisted/internet/wxreactor.py
blob: ae24c599e1b21968b58c973f8c28904533d9c7d1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
This module provides wxPython event loop support for Twisted.

In order to use this support, simply do the following::

    |  from twisted.internet import wxreactor
    |  wxreactor.install()

Then, when your root wxApp has been created::

    | from twisted.internet import reactor
    | reactor.registerWxApp(yourApp)
    | reactor.run()

Then use twisted.internet APIs as usual. Stop the event loop using
reactor.stop(), not yourApp.ExitMainLoop().

IMPORTANT: tests will fail when run under this reactor. This is
expected and probably does not reflect on the reactor's ability to run
real applications.
"""

try:
    from queue import Empty, Queue
except ImportError:
    from Queue import Empty, Queue

try:
    from wx import PySimpleApp as wxPySimpleApp, CallAfter as wxCallAfter, \
         Timer as wxTimer
except ImportError:
    # older version of wxPython:
    from wxPython.wx import wxPySimpleApp, wxCallAfter, wxTimer

from twisted.python import log, runtime
from twisted.internet import _threadedselect


class ProcessEventsTimer(wxTimer):
    """
    Timer that tells wx to process pending events.

    This is necessary on macOS, probably due to a bug in wx, if we want
    wxCallAfters to be handled when modal dialogs, menus, etc.  are open.
    """
    def __init__(self, wxapp):
        wxTimer.__init__(self)
        self.wxapp = wxapp
    

    def Notify(self):
        """
        Called repeatedly by wx event loop.
        """
        self.wxapp.ProcessPendingEvents()



class WxReactor(_threadedselect.ThreadedSelectReactor):
    """
    wxPython reactor.

    wxPython drives the event loop, select() runs in a thread.
    """

    _stopping = False

    def registerWxApp(self, wxapp):
        """
        Register wxApp instance with the reactor.
        """
        self.wxapp = wxapp


    def _installSignalHandlersAgain(self):
        """
        wx sometimes removes our own signal handlers, so re-add them.
        """
        try:
            # make _handleSignals happy:
            import signal
            signal.signal(signal.SIGINT, signal.default_int_handler)
        except ImportError:
            return
        self._handleSignals()


    def stop(self):
        """
        Stop the reactor.
        """
        if self._stopping:
            return
        self._stopping = True
        _threadedselect.ThreadedSelectReactor.stop(self)


    def _runInMainThread(self, f):
        """
        Schedule function to run in main wx/Twisted thread.

        Called by the select() thread.
        """
        if hasattr(self, "wxapp"):
            wxCallAfter(f)
        else:
            # wx shutdown but twisted hasn't
            self._postQueue.put(f)


    def _stopWx(self):
        """
        Stop the wx event loop if it hasn't already been stopped.

        Called during Twisted event loop shutdown.
        """
        if hasattr(self, "wxapp"):
            self.wxapp.ExitMainLoop()


    def run(self, installSignalHandlers=True):
        """
        Start the reactor.
        """
        self._postQueue = Queue()
        if not hasattr(self, "wxapp"):
            log.msg("registerWxApp() was not called on reactor, "
                    "registering my own wxApp instance.")
            self.registerWxApp(wxPySimpleApp())

        # start select() thread:
        self.interleave(self._runInMainThread,
                        installSignalHandlers=installSignalHandlers)
        if installSignalHandlers:
            self.callLater(0, self._installSignalHandlersAgain)

        # add cleanup events:
        self.addSystemEventTrigger("after", "shutdown", self._stopWx)
        self.addSystemEventTrigger("after", "shutdown",
                                   lambda: self._postQueue.put(None))

        # On macOS, work around wx bug by starting timer to ensure
        # wxCallAfter calls are always processed. We don't wake up as
        # often as we could since that uses too much CPU.
        if runtime.platform.isMacOSX():
            t = ProcessEventsTimer(self.wxapp)
            t.Start(2) # wake up every 2ms

        self.wxapp.MainLoop()
        wxapp = self.wxapp
        del self.wxapp

        if not self._stopping:
            # wx event loop exited without reactor.stop() being
            # called.  At this point events from select() thread will
            # be added to _postQueue, but some may still be waiting
            # unprocessed in wx, thus the ProcessPendingEvents()
            # below.
            self.stop()
            wxapp.ProcessPendingEvents() # deal with any queued wxCallAfters
            while 1:
                try:
                    f = self._postQueue.get(timeout=0.01)
                except Empty:
                    continue
                else:
                    if f is None:
                        break
                    try:
                        f()
                    except:
                        log.err()


def install():
    """
    Configure the twisted mainloop to be run inside the wxPython mainloop.
    """
    reactor = WxReactor()
    from twisted.internet.main import installReactor
    installReactor(reactor)
    return reactor


__all__ = ['install']