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1============================
2wxPython 2.5 Migration Guide
3============================
4
5This document will help explain some of the major changes in wxPython
62.5 and let you know what you need to do to adapt your programs to
7those changes. Be sure to also check in the CHANGES.txt file like
8usual to see info about the not so major changes and other things that
9have been added to wxPython.
10
11
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12wxName Change
13-------------
14
15The **wxWindows** project and library is now known as
16**wxWidgets**. Please see here_ for more details.
17
18.. _here: http://www.wxwindows.org/name.htm
19
20This won't really affect wxPython all that much, other than the fact
21that the wxwindows.org domain name will be changing to wxwidgets.org,
22so mail list, CVS, and etc. addresses will be changing. We're going
23to try and smooth the transition as much as possible, but I wanted you
24all to be aware of this change if you run into any issues.
25
26
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27
28Module Initialization
29---------------------
30
31The import-startup-bootstrap process employed by wxPython was changed
e8a71fa0 32such that wxWidgets and the underlying gui toolkit are **not**
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33initialized until the wx.App object is created (but before wx.App.OnInit
34is called.) This was required because of some changes that were made
35to the C++ wxApp class.
36
37There are both benefits and potential problems with this change. The
38benefits are that you can import wxPython without requiring access to
39a GUI (for checking version numbers, etc.) and that in a
40multi-threaded environment the thread that creates the app object will
41now be the GUI thread instead of the one that imports wxPython. Some
42potential problems are that the C++ side of the "stock-objects"
43(wx.BLUE_PEN, wx.TheColourDatabase, etc.) are not initialized until
44the wx.App object is created, so you should not use them until after
61563ef3 45you have created your wx.App object. If you do then an exception will
cb2d8b77 46be raised telling you that the C++ object has not been initialized
61563ef3 47yet.
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48
49Also, you will probably not be able to do any kind of GUI or bitmap
50operation unless you first have created an app object, (even on
51Windows where most anything was possible before.)
52
53
54
55SWIG 1.3
56--------
57
58wxPython is now using SWIG 1.3.x from CVS (with several of my own
59customizations added that I hope to get folded back into the main SWIG
60distribution.) This has some far reaching ramifications:
61
62 All classes derive from object and so all are now "new-style
63 classes"
64
65 Public data members of the C++ classes are wrapped as Python
66 properties using property() instead of using __getattr__/__setattr__
67 like before. Normally you shouldn't notice any difference, but if
68 you were previously doing something with __getattr__/__setattr__
69 in derived classes then you may have to adjust things.
70
71 Static C++ methods are wrapped using the staticmethod()
72 feature of Python and so are accessible as ClassName.MethodName
73 as expected. They are still available as top level functions
74 ClassName_MethodName as before.
75
76 The relationship between the wxFoo and wxFooPtr classes have
77 changed for the better. Specifically, all instances that you see
78 will be wxFoo even if they are created internally using wxFooPtr,
79 because wxFooPtr.__init__ will change the instance's __class__ as
80 part of the initialization. If you have any code that checks
81 class type using something like isinstance(obj, wxFooPtr) you will
82 need to change it to isinstance(obj, wxFoo).
83
84
85
86Binding Events
87--------------
88
89All of the EVT_* functions are now instances of the wx.PyEventBinder
90class. They have a __call__ method so they can still be used as
91functions like before, but making them instances adds some
92flexibility.
93
94wx.EvtHandler (the base class for wx.Window) now has a Bind method that
95makes binding events to windows a little easier. Here is its
96definition and docstring::
97
98 def Bind(self, event, handler, source=None, id=wxID_ANY, id2=wxID_ANY):
99 """
100 Bind an event to an event handler.
101
102 event One of the EVT_* objects that specifies the
103 type of event to bind.
104
105 handler A callable object to be invoked when the event
106 is delivered to self. Pass None to disconnect an
107 event handler.
108
109 source Sometimes the event originates from a different window
110 than self, but you still want to catch it in self. (For
111 example, a button event delivered to a frame.) By
112 passing the source of the event, the event handling
113 system is able to differentiate between the same event
114 type from different controls.
115
116 id,id2 Used for menu IDs or for event types that require a
117 range of IDs
118
119 """
120
121Some examples of its use::
122
123 self.Bind(wx.EVT_SIZE, self.OnSize)
124 self.Bind(wx.EVT_BUTTON, self.OnButtonClick, theButton)
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125 self.Bind(wx.EVT_MENU, self.OnExit, id=wx.ID_EXIT)
126
127
128The wx.Menu methods that add items to a wx.Menu have been modified
129such that they return a reference to the wx.MenuItem that was created.
130Additionally menu items and toolbar items have been modified to
131automatically generate a new ID if -1 is given, similar to using -1
132with window classess. This means that you can create menu or toolbar
133items and event bindings without having to predefine a unique menu ID,
134although you still can use IDs just like before if you want. For
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135example, these are all equivallent other than their specific ID
136values::
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137
138 1.
139 item = menu.Append(-1, "E&xit", "Terminate the App")
140 self.Bind(wx.EVT_MENU, self.OnExit, item)
141
142 2.
143 item = menu.Append(wx.ID_EXIT, "E&xit", "Terminate the App")
144 self.Bind(wx.EVT_MENU, self.OnExit, item)
d14a1e28 145
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146 3.
147 menu.Append(wx.ID_EXIT, "E&xit", "Terminate the App")
148 self.Bind(wx.EVT_MENU, self.OnExit, id=wx.ID_EXIT)
149
150
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151If you create your own custom event types and EVT_* functions, and you
152want to be able to use them with the Bind method above then you should
153change your EVT_* to be an instance of wxPyEventBinder instead of a
154function. If you used to have something like this::
155
156 myCustomEventType = wxNewEventType()
157 def EVT_MY_CUSTOM_EVENT(win, id, func):
158 win.Connect(id, -1, myCustomEventType, func)
159
160
161Change it like so::
162
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163 myCustomEventType = wx.NewEventType()
164 EVT_MY_CUSTOM_EVENT = wx.PyEventBinder(myCustomEventType, 1)
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165
166The second parameter is an integer in [0, 1, 2] that specifies the
167number of IDs that are needed to be passed to Connect.
168
169
170
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171
172
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173The wx Namespace
174----------------
175
176The second phase of the wx Namespace Transition has begun. That means
177that the real names of the classes and other symbols do not have the
178'wx' prefix and the modules are located in a Python package named
179wx. There is still a Python package named wxPython with modules
180that have the names with the wx prefix for backwards compatibility.
181Instead of dynamically changing the names at module load time like in
1822.4, the compatibility modules are generated at build time and contain
183assignment statements like this::
184
185 wxWindow = wx.core.Window
186
187Don't let the "core" in the name bother you. That and some other
188modules are implementation details, and everything that was in the
189wxPython.wx module before will still be in the wx package namespace
190after this change. So from your code you would use it as wx.Window.
191
192A few notes about how all of this was accomplished might be
193interesting... SWIG is now run twice for each module that it is
194generating code for. The first time it outputs an XML representaion
195of the parse tree, which can be up to 20MB and 300K lines in size!
196That XML is then run through a little Python script that creates a
197file full of SWIG %rename directives that take the wx off of the
198names, and also generates the Python compatibility file described
199above that puts the wx back on the names. SWIG is then run a second
200time to generate the C++ code to implement the extension module, and
201uses the %rename directives that were generated in the first step.
202
203Not every name is handled correctly (but the bulk of them are) and so
204some work has to be done by hand, especially for the reverse-renamers.
205So expect a few flaws here and there until everything gets sorted out.
206
207In summary, the wx package and names without the "wx" prefix are now
208the official form of the wxPython classes. For example::
209
210 import wx
211
212 class MyFrame(wx.Frame):
213 def __init__(self, parent, title):
214 wx.Frame.__init__(self, parent, -1, title)
215 p = wx.Panel(self, -1)
216 b = wx.Button(p, -1, "Do It", (10,10))
217 self.Bind(wx.EVT_BUTTON, self.JustDoIt, b)
218
219 def JustDoIt(self, evt):
220 print "It's done!"
221
222 app = wx.PySimpleApp()
223 f = MyFrame(None, "What's up?")
224 f.Show()
225 app.MainLoop()
226
227You shouldn't need to migrate all your modules over to use the new
228package and names right away as there are modules in place that try to
229provide as much backwards compatibility of the names as possible. If
82a074ce 230you rewrote the above sample using "from wxPython.wx import * ", the
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231old wxNames, and the old style of event binding it will still work
232just fine.
233
234
235
236
237New wx.DC Methods
238-----------------
239
240Many of the Draw methods of wx.DC have alternate forms in C++ that take
241wxPoint or wxSize parameters (let's call these *Type A*) instead of
242the individual x, y, width, height, etc. parameters (and we'll call
243these *Type B*). In the rest of the library I normally made the *Type
244A* forms of the methods be the default method with the "normal" name,
245and had renamed the *Type B* forms of the methods to some similar
246name. For example in wx.Window we have these Python methods::
247
248 SetSize(size) # Type A
249 SetSizeWH(width, height) # Type B
250
251
252For various reasons the new *Type A* methods in wx.DC were never added
253and the existing *Type B* methods were never renamed. Now that lots
254of other things are also changing in wxPython it has been decided that
255it is a good time to also do the method renaming in wx.DC too in order
256to be consistent with the rest of the library. The methods in wx.DC
257that are affected are listed here::
258
259 FloodFillXY(x, y, colour, style = wx.FLOOD_SURFACE)
260 FloodFill(point, colour, style = wx.FLOOD_SURFACE)
261
262 GetPixelXY(x, y)
263 GetPixel(point)
264
265 DrawLineXY(x1, y1, x2, y2)
266 DrawLine(point1, point2)
267
268 CrossHairXY(x, y)
269 CrossHair(point)
270
271 DrawArcXY(x1, y1, x2, y2, xc, yc)
272 DrawArc(point1, point2, center)
273
274 DrawCheckMarkXY(x, y, width, height)
275 DrawCheckMark(rect)
276
277 DrawEllipticArcXY(x, y, w, h, start_angle, end_angle)
278 DrawEllipticArc(point, size, start_angle, end_angle)
279
280 DrawPointXY(x, y)
281 DrawPoint(point)
282
283 DrawRectangleXY(x, y, width, height)
284 DrawRectangle(point, size)
285 DrawRectangleRect(rect)
286
287 DrawRoundedRectangleXY(x, y, width, height, radius)
288 DrawRoundedRectangle(point, size, radius)
289 DrawRoundedRectangleRect(rect, radius)
290
291 DrawCircleXY(x, y, radius)
292 DrawCircle(point, radius)
293
294 DrawEllipseXY(x, y, width, height)
295 DrawEllipse(point, size)
296 DrawEllipseRect(rect)
297
298 DrawIconXY(icon, x, y)
299 DrawIcon(icon, point)
300
301 DrawBitmapXY(bmp, x, y, useMask = FALSE)
302 DrawBitmap(bmp, point, useMask = FALSE)
303
304 DrawTextXY(text, x, y)
305 DrawText(text, point)
306
307 DrawRotatedTextXY(text, x, y, angle)
308 DrawRotatedText(text, point, angle)
309
310
311 BlitXY(xdest, ydest, width, height, sourceDC, xsrc, ysrc,
312 rop = wxCOPY, useMask = FALSE, xsrcMask = -1, ysrcMask = -1)
313 Blit(destPt, size, sourceDC, srcPt,
314 rop = wxCOPY, useMask = FALSE, srcPtMask = wx.DefaultPosition)
315
82a074ce 316 SetClippingRegionXY(x, y, width, height)
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317 SetClippingRegion(point, size)
318 SetClippingRect(rect)
319 SetClippingRegionAsRegion(region);
320
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322If you have code that draws on a DC and you are using the new wx
323namespace then you **will** get errors because of these changes, but
324it should be easy to fix the code. You can either change the name of
325the *Type B* method called to the names shown above, or just add
326parentheses around the parameters as needed to turn them into tuples
327and let the SWIG typemaps turn them into the wx.Point or wx.Size
328object that is expected. Then you will be calling the new *Type A*
329method. For example, if you had this code before::
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330
331 dc.DrawRectangle(x, y, width, height)
332
333You could either continue to use the *Type B* method bu changing the
334name to DrawRectabgleXY, or just change it to the new *Type A* by
335adding some parentheses like this::
336
337 dc.DrawRectangle((x, y), (width, height))
338
339Or if you were already using a point and size::
340
341 dc.DrawRectangle(p.x, p.y, s.width, s.height)
342
343Then you can just simplify it like this::
344
345 dc.DrawRectangle(p, s)
346
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347Now before you start yelling and screaming at me for breaking all your
348code, take note that I said above "...using the new wx namespace..."
349That's because if you are still importing from wxPython.wx then there
350are some classes defined there with Draw and etc. methods that have
3512.4 compatible signatures. However if/when the old wxPython.wx
352namespace is removed then these classes will be removed too so you
e75fd8a4 353should plan on migrating to the new namespace and new DC Draw methods
4942342c 354before that time.
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355
356
357
358Building, Extending and Embedding wxPython
359------------------------------------------
360
361wxPython's setup.py script now expects to use existing libraries for
362the contribs (gizmos, stc, xrc, etc.) rather than building local
363copies of them. If you build your own copies of wxPython please be
364aware that you now need to also build the ogl, stc, xrc, and gizmos
365libraries in addition to the main wx lib. [[TODO: update the
366BUILD.*.txt files too!]]
367
368The wxPython.h and other header files are now in
369.../wxPython/include/wx/wxPython instead of in wxPython/src. You should
370include it via the "wx/wxPython/wxPython.h" path and add
371.../wxPython/include to your list of include paths. [[TODO: Install
372these headers on Linux...]]
373
374You no longer need to call wxClassInfo::CleanUpClasses() and
375wxClassInfo::InitializeClasses() in your extensions or when embedding
376wxPython.
377
378
379
380
381Two (or Three!) Phase Create
382----------------------------
383
384If you use the Precreate/Create method of instantiating a window, (for
385example, to set an extended style flag, or for XRC handlers) then
386there is now a new method named PostCreate to help with transplanting
387the brain of the prewindow instance into the derived window instance.
388For example::
389
390 class MyDialog(wx.Dialog):
391 def __init__(self, parent, ID, title, pos, size, style):
392 pre = wx.PreDialog()
393 pre.SetExtraStyle(wx.DIALOG_EX_CONTEXTHELP)
394 pre.Create(parent, ID, title, pos, size, style)
395 self.PostCreate(pre)
396
397
398
399Sizers
400------
401
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402The hack allowing the old "option" keyword parameter has been removed.
403If you use keyworkd args with wxSizer Add, Insert, or Prepend methods
404then you will need to use the "proportion" name instead of "option".
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405
406When adding a spacer to a sizer you now need to use a wxSize or a
4072-integer sequence instead of separate width and height parameters.
408
409The wxGridBagSizer class (very similar to the RowColSizer in the
410library) has been added to C++ and wrapped for wxPython. It can also
411be used from XRC.
412
413You should not use AddWindow, AddSizer, AddSpacer (and similar for
414Insert, Prepend, and etc.) methods any longer. Just use Add and the
415wrappers will figure out what to do.
416
417
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418PlatformInfo
419------------
420
421Added wx.PlatformInfo which is a tuple containing strings that
422describe the platform and build options of wxPython. This lets you
423know more about the build than just the __WXPORT__ value that
424wx.Platform contains, such as if it is a GTK2 build. For example,
425instead of::
426
427 if wx.Platform == "__WXGTK__":
428 ...
429
430you should do this::
431
432 if "__WXGTK__" in wx.PlatformInfo:
433 ...
434
435and you can specifically check for a wxGTK2 build by looking for
436"gtk2" in wx.PlatformInfo. Unicode builds are also detectable this
437way. If there are any other platform/toolkit/build flags that make
438sense to add to this tuple please let me know.
439
440BTW, wx.Platform will probably be deprecated in the future.
441
442
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444ActiveX
445-------
446
447Lindsay Mathieson's newest wxActiveX_ class has been wrapped into a new
448extension module called wx.activex. It is very generic and dynamic
449and should allow hosting of arbitray ActiveX controls within your
450wxPython apps. So far I've tested it with IE, PDF, and Flash
451controls, (and there are new samples in the demo and also library
452modules supporting these.)
453
454.. _wxActiveX: http://members.optusnet.com.au/~blackpaw1/wxactivex.html
455
456The new wx.activex module contains a bunch of code, but the most
457important things to look at are ActiveXWindow and ActiveXEvent.
458ActiveXWindow derives from wxWindow and the constructor accepts a
459CLSID for the ActiveX Control that should be created. (There is also
460a CLSID class that can convert from a progID or a CLSID String.) The
461ActiveXWindow class simply adds methods that allow you to query some
462of the TypeInfo exposed by the ActiveX object, and also to get/set
463properties or call methods by name. The Python implementation
464automatically handles converting parameters and return values to/from
465the types expected by the ActiveX code as specified by the TypeInfo,
466(just bool, integers, floating point, strings and None/Empty so far,
467but more can be handled later.)
468
469That's pretty much all there is to the class, as I mentioned before it
470is very generic and dynamic. Very little is hard-coded and everything
471that is done with the actual ActiveX control is done at runtime and
472referenced by property or method name. Since Python is such a dynamic
473language this is a very good match. I thought for a while about doing
474some Python black-magic and making the specific methods/properties of
475the actual ActiveX control "appear" at runtime, but then decided that
476it would be better and more understandable to do it via subclassing.
477So there is a utility class in wx.activex that given an existing
478ActiveXWindow instance can generate a .py module containing a derived
479class with real methods and properties that do the Right Thing to
480reflect those calls to the real ActiveX control. There is also a
481script/tool module named genaxmodule that given a CLSID or progID and
482a class name, will generate the module for you. There are a few
483examples of the output of this tool in the wx.lib package. See
484iewin.py, pdfwin.py and flashwin.py.
485
486Currently the genaxmodule tool will tweak some of the names it
487generates, but this can be controled if you would like to do it
488differently by deriving your own class from GernerateAXModule,
489overriding some methods and then using this class from a tool like
490genaxmodule. [TODO: make specifying a new class on genaxmodule's
491command-line possible.] The current default behavior is that any
492event names that start with "On" will have the "On" dropped, property
493names are converted to all lower case, and if any name is a Python
494keyword it will have an underscore appended to it. GernerateAXModule
495does it's best when generating the code in the new module, but it can
496only be as good as the TypeInfo data available from the ActiveX
497control so sometimes some tweaking will be needed. For example, the
498IE web browser control defines the Flags parameter of the Navigate2
499method as required, but MSDN says it is optional.
500
501It is intended that this new wx.activex module will replace both the
502older version of Lindsay's code available in iewin.IEHtmlWindow, and
503also the wx.lib.activexwraper module. Probably the biggest
504differences you'l ecounted in migrating activexwrapper-based code
505(besides events working better without causing deadlocks) is that
506events are no longer caught by overriding methods in your derived
507class. Instead ActiveXWindow uses the wx event system and you bind
508handlers for the ActiveX events exactly the same way you do for any wx
509event. There is just one extra step needed and that is creating an
510event ID from the ActiveX event name, and if you use the genaxmodule
511tool then this extra step will be handled for you there. For example,
512for the StatusTextChange event in the IE web browser control, this
513code is generated for you::
514
515 wxEVT_StatusTextChange = wx.activex.RegisterActiveXEvent('StatusTextChange')
516 EVT_StatusTextChange = wx.PyEventBinder(wxEVT_StatusTextChange, 1)
517
518and you would use it in your code like this::
519
520 self.Bind(iewin.EVT_StatusTextChange, self.UpdateStatusText, self.ie)
521
522When the event happens and your event handler function is called the
523event properties from the ActiveX control (if any) are converted to
524attributes of the event object passed to the handler. (Can you say
525'event' any more times in a single sentence? ;-) ) For example the
526StatusTextChange event will also send the text that should be put into
527the status line as an event parameter named "Text" and you can access
528it your handlers as an attribute of the evnt object like this::
529
530 def UpdateStatusText(self, evt):
531 self.SetStatusText(evt.Text)
532
533These event object attributes should be considered read-only since
534support for output parameters on the events is not yet implemented.
535But that could/should change in the future.
536
537So how do you know what methods, events and properties that am ActiveX
538control supports? There is a funciton in wx.activex named GetAXInfo
539that returns a printable summary of the TypeInfo from the ActiveX
540instance passed in. You can use this as an example of how to browse
541the TypeInfo provided, and there is also a copy of this function's
542output appended as a comment to the modules produced by the
543genaxmodule tool. Beyond that you'll need to consult the docs
544provided by the makers of the ActiveX control that you are using.
545
546
547
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548Other Stuff
549-----------
550
551Instead of over a dozen separate extension modules linked together
552into a single extension module, the "core" module is now just a few
553extensions that are linked independently, and then merged together
554later into the main namespace via Python code.
555
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556Because of the above and also because of the way the new SWIG works,
557the "internal" module names have changed, but you shouldn't have been
558using them anyway so it shouldn't bother you. ;-)
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560The help module no longer exists and the classes therein are now part
561of the core module imported with wxPython.wx or the wx package.
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562
563wxPyDefaultPosition and wxPyDefaultSize are gone. Use the
564wxDefaultPosition and wxDefaultSize objects instead.
565
566Similarly, the wxSystemSettings backwards compatibiility aliases for
567GetSystemColour, GetSystemFont and GetSystemMetric have also gone into
568the bit-bucket. Use GetColour, GetFont and GetMetric instead.
569
570
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571The wx.NO_FULL_REPAINT_ON_RESIZE style is now the default style for
572all windows. The name still exists for compatibility, but it is set
573to zero. If you want to disable the setting (so it matches the old
574default) then you need to use the new wx.FULL_REPAINT_ON_RESIZE style
575flag otherwise only the freshly exposed areas of the window will be
576refreshed.
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578wxPyTypeCast has been removed. Since we've had the OOR (Original
579Object Return) for a couple years now there should be no need to use
580wxPyTypeCast at all.
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582If you use the old wxPython package and wxPython.wx namespace then
583there are compatibility aliases for much of the above items.
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584
585The wxWave class has been renamed to wxSound, and now has a slightly
586different API.
ce32c85b 587
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