| :tocdepth: 2 |
| |
| ========================== |
| Graphic User Interface FAQ |
| ========================== |
| |
| .. contents:: |
| |
| General GUI Questions |
| ===================== |
| |
| What platform-independent GUI toolkits exist for Python? |
| ======================================================== |
| |
| Depending on what platform(s) you are aiming at, there are several. |
| |
| .. XXX check links |
| |
| Tkinter |
| ------- |
| |
| Standard builds of Python include an object-oriented interface to the Tcl/Tk |
| widget set, called Tkinter. This is probably the easiest to install and use. |
| For more info about Tk, including pointers to the source, see the Tcl/Tk home |
| page at http://www.tcl.tk. Tcl/Tk is fully portable to the MacOS, Windows, and |
| Unix platforms. |
| |
| wxWindows |
| --------- |
| |
| wxWidgets (http://www.wxwidgets.org) is a free, portable GUI class |
| library written in C++ that provides a native look and feel on a |
| number of platforms, with Windows, MacOS X, GTK, X11, all listed as |
| current stable targets. Language bindings are available for a number |
| of languages including Python, Perl, Ruby, etc. |
| |
| wxPython (http://www.wxpython.org) is the Python binding for |
| wxwidgets. While it often lags slightly behind the official wxWidgets |
| releases, it also offers a number of features via pure Python |
| extensions that are not available in other language bindings. There |
| is an active wxPython user and developer community. |
| |
| Both wxWidgets and wxPython are free, open source, software with |
| permissive licences that allow their use in commercial products as |
| well as in freeware or shareware. |
| |
| Qt |
| --- |
| |
| There are bindings available for the Qt toolkit (`PyQt |
| <http://www.riverbankcomputing.co.uk/software/pyqt/>`_) and for KDE (PyKDE). If |
| you're writing open source software, you don't need to pay for PyQt, but if you |
| want to write proprietary applications, you must buy a PyQt license from |
| `Riverbank Computing <http://www.riverbankcomputing.co.uk>`_ and (up to Qt 4.4; |
| Qt 4.5 upwards is licensed under the LGPL license) a Qt license from `Trolltech |
| <http://www.trolltech.com>`_. |
| |
| Gtk+ |
| ---- |
| |
| PyGtk bindings for the `Gtk+ toolkit <http://www.gtk.org>`_ have been |
| implemented by by James Henstridge; see ftp://ftp.gtk.org/pub/gtk/python/. |
| |
| FLTK |
| ---- |
| |
| Python bindings for `the FLTK toolkit <http://www.fltk.org>`_, a simple yet |
| powerful and mature cross-platform windowing system, are available from `the |
| PyFLTK project <http://pyfltk.sourceforge.net>`_. |
| |
| |
| FOX |
| ---- |
| |
| A wrapper for `the FOX toolkit <http://www.fox-toolkit.org/>`_ called `FXpy |
| <http://fxpy.sourceforge.net/>`_ is available. FOX supports both Unix variants |
| and Windows. |
| |
| |
| OpenGL |
| ------ |
| |
| For OpenGL bindings, see `PyOpenGL <http://pyopengl.sourceforge.net>`_. |
| |
| |
| What platform-specific GUI toolkits exist for Python? |
| ======================================================== |
| |
| `The Mac port <http://python.org/download/mac>`_ by Jack Jansen has a rich and |
| ever-growing set of modules that support the native Mac toolbox calls. The port |
| includes support for MacOS9 and MacOS X's Carbon libraries. By installing the |
| `PyObjc Objective-C bridge <http://pyobjc.sourceforge.net>`_, Python programs |
| can use MacOS X's Cocoa libraries. See the documentation that comes with the Mac |
| port. |
| |
| :ref:`Pythonwin <windows-faq>` by Mark Hammond includes an interface to the |
| Microsoft Foundation Classes and a Python programming environment using it |
| that's written mostly in Python. |
| |
| |
| Tkinter questions |
| ================= |
| |
| How do I freeze Tkinter applications? |
| ------------------------------------- |
| |
| Freeze is a tool to create stand-alone applications. When freezing Tkinter |
| applications, the applications will not be truly stand-alone, as the application |
| will still need the Tcl and Tk libraries. |
| |
| One solution is to ship the application with the tcl and tk libraries, and point |
| to them at run-time using the :envvar:`TCL_LIBRARY` and :envvar:`TK_LIBRARY` |
| environment variables. |
| |
| To get truly stand-alone applications, the Tcl scripts that form the library |
| have to be integrated into the application as well. One tool supporting that is |
| SAM (stand-alone modules), which is part of the Tix distribution |
| (http://tix.mne.com). Build Tix with SAM enabled, perform the appropriate call |
| to Tclsam_init etc inside Python's Modules/tkappinit.c, and link with libtclsam |
| and libtksam (you 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 |
| code a bit. Tk has the equivalent of Xt's 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 can't get key bindings to work in Tkinter: why? |
| ------------------------------------------------- |
| |
| An often-heard complaint is that event handlers bound to events with the |
| :meth:`bind` method don't get handled even when the appropriate key is pressed. |
| |
| The most common cause is that the widget to which the binding applies doesn't |
| have "keyboard focus". Check out the Tk documentation for the focus command. |
| Usually a widget is given the keyboard focus by clicking in it (but not for |
| labels; see the takefocus option). |
| |
| |
| |