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Diffstat (limited to 'Doc/faq/gui.rst')
| -rw-r--r-- | Doc/faq/gui.rst | 25 |
1 files changed, 3 insertions, 22 deletions
diff --git a/Doc/faq/gui.rst b/Doc/faq/gui.rst index f130d33..5122de1 100644 --- a/Doc/faq/gui.rst +++ b/Doc/faq/gui.rst @@ -139,30 +139,11 @@ might include the Tix libraries as well). Can I have Tk events handled while waiting for I/O? --------------------------------------------------- -Yes, and you don't even need threads! But you'll have to restructure your I/O +On platforms other than Windows, yes, and you don't even +need threads! But you'll have to restructure your I/O code a bit. Tk has the equivalent of Xt's :c:func:`XtAddInput()` call, which allows you to register a callback function which will be called from the Tk mainloop when -I/O is possible on a file descriptor. Here's what you need:: - - from Tkinter import tkinter - tkinter.createfilehandler(file, mask, callback) - -The file may be a Python file or socket object (actually, anything with a -fileno() method), or an integer file descriptor. The mask is one of the -constants tkinter.READABLE or tkinter.WRITABLE. The callback is called as -follows:: - - callback(file, mask) - -You must unregister the callback when you're done, using :: - - tkinter.deletefilehandler(file) - -Note: since you don't know *how many bytes* are available for reading, you can't -use the Python file object's read or readline methods, since these will insist -on reading a predefined number of bytes. For sockets, the :meth:`recv` or -:meth:`recvfrom` methods will work fine; for other files, use -``os.read(file.fileno(), maxbytecount)``. +I/O is possible on a file descriptor. See :ref:`tkinter-file-handlers`. I can't get key bindings to work in Tkinter: why? |