wxPython

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wxPython

• It rocks.

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What is wxPython?

• Python bindings over the wxWidgets C library
• Cross platform GUI (and non-GUI) framework
• Native look and feel backends
• GTK 1 2 (Linux, BSDs, etc.)
• Windows 98, 2000, XP, PocketPC, etc.
• Mac (OS 8.6, OS 9, OS X)
• Motif (for people who like writing ugly
  applications)
• X11(also ugly but it works)
• Various other non-complete ports (e.g. Palm)

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Hardcore imagery
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Why not just use...

• GTK-python?
• Weird look and feel on non-linux platforms (even
  with Wimp)
• GTK still immature on Windows
• PyQT?
• It's QT
• Tkinter?
• Non-native look-and-feel
• Complex layouts are difficult or impossible
• "Why the hell hasn't wxPython become the standard
  GUI for Python yet?" -- Eric S. Raymond

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Writing an application

• Import wx
• Create a wxApp instance (wx.PySimpleApp for
  convenience)
• Begin main event loop - MainLoop()
• Program ends after all top-level windows are gone

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Add a frame

• Derive a new class from wx.Frame
• Set some defaults (title, size, etc.)
• Add a panel child (otherwise ugly on MSW)
• Create an instance of this class

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Adding Menus and Statusbar

• Create a wx.Menu for each top-level menu
• Append(id, Name) the wx.Menu for each item in
  it
• Create a wx.MenuBar
• Append each menu to the menu bar.
• Call SetMenuBar()

• CreateStatusBar()
• SetStatusText(text, column)
• SetStatusWidths(...)

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Handling menu events

• Create a function to handle the event
• wx.EVT_MENU(self, id, handler) to bind
• More pythonic alternative Connect

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Adding extra controls and windows

• Controls are Windows
• Create as children of a pre-existing window
• wxPython supports absolute positioning and sizing
  (SetPosition() and SetSize()) but that's for
  chumps.
• Use Sizers instead.

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Sizers The Cat's Pajamas

• Confusing at first but powerful
• Learn to think about how controls can be nested
• wx.BoxSizer is most common (grid style sizers are
  also availible)
• Add(window/sizer, proportion, flags, border)
• It'll be easier if I show you...
• Nest sizers for sophisticated and powerful layouts

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Dialogs

• Modal dialogs won't let the user interact with
  the parent until the dialog is dismissed.
• wx.FileDialog lets you get a filename to open
  from or save to.

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Issues with wxPython

• Fundamental platform behavioral differences
• Windows users are rarely cool enough to have
  Python installed, let alone wxPython (py2exe
  helps)
• Not very pythonic (Wax looks promising)

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Choo choo!!