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[wxWidgets.git] / wxPython / docs / MigrationGuide.html
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10 <body>
11 <div class="document" id="wxpython-2-6-migration-guide">
12 <h1 class="title">wxPython 2.6 Migration Guide</h1>
13 <p>This document will help explain some of the major changes in wxPython
14 2.6 since the 2.4 series and let you know what you need to do to adapt
15 your programs to those changes. Be sure to also check in the <a class="reference" href="CHANGES.html">CHANGES</a>
16 file like usual to see info about the not so major changes and other
17 things that have been added to wxPython.</p>
18 <div class="section" id="wxname-change">
19 <h1><a name="wxname-change">wxName Change</a></h1>
20 <p>The <strong>wxWindows</strong> project and library is now known as
21 <strong>wxWidgets</strong>. Please see <a class="reference" href="http://www.wxwidgets.org/name.htm">here</a> for more details.</p>
22 <p>This won't really affect wxPython all that much, other than the fact
23 that the wxwindows.org domain name has changed to wxwidgets.org,
24 so mail list, CVS, and etc. addresses have also changed. We're going
25 to try and smooth the transition as much as possible, but I wanted you
26 all to be aware of this change if you run into any issues.</p>
27 </div>
28 <div class="section" id="module-initialization">
29 <h1><a name="module-initialization">Module Initialization</a></h1>
30 <p>The import-startup-bootstrap process employed by wxPython was changed
31 such that wxWidgets and the underlying gui toolkit are <strong>not</strong>
32 initialized until the wx.App object is created (but before wx.App.OnInit
33 is called.) This was required because of some changes that were made
34 to the C++ wxApp class.</p>
35 <p>There are both benefits and potential problems with this change. The
36 benefits are that you can import wxPython without requiring access to
37 a GUI (for checking version numbers, etc.) and that in a
38 multi-threaded environment the thread that creates the app object will
39 now be the GUI thread instead of the one that imports wxPython. Some
40 potential problems are that the C++ side of the &quot;stock-objects&quot;
41 (wx.BLUE_PEN, wx.TheColourDatabase, etc.) are not initialized until
42 the wx.App object is created, so you should not use them until after
43 you have created your wx.App object. If you do then an exception will
44 be raised telling you that the C++ object has not been initialized
45 yet.</p>
46 <p>Also, you will probably not be able to do any kind of GUI or bitmap
47 operation unless you first have created an app object, (even on
48 Windows where most anything was possible before.)</p>
49 <p><strong>[Changed in 2.5.2.x]</strong> All the Window and GDI (pen, bitmap, etc.)
50 class constructors and also many toplevel functions and static methods
51 will now check that a wx.App object has already been created and will
52 raise a wx.PyNoAppError exception if not.</p>
53 </div>
54 <div class="section" id="swig-1-3">
55 <h1><a name="swig-1-3">SWIG 1.3</a></h1>
56 <p>wxPython is now using SWIG 1.3.x from CVS (with several of my own
57 customizations added that I hope to get folded back into the main SWIG
58 distribution.) This has some far reaching ramifications:</p>
59 <blockquote>
60 <p>All classes derive from object and so all are now &quot;new-style
61 classes.&quot; This also allows you to use mixin classes that are
62 new-style and to use properties, staticmethod, etc.</p>
63 <p>Public data members of the C++ classes are wrapped as Python
64 properties using property() instead of using
65 __getattr__/__setattr__ hacks like before. Normally you shouldn't
66 notice any difference, but if you were previously doing something
67 with __getattr__/__setattr__ in derived classes then you may have
68 to adjust things.</p>
69 <p>Static C++ methods are wrapped using the staticmethod() feature of
70 Python and so are accessible as ClassName.MethodName as expected.
71 They are still also available as top level functions named like
72 ClassName_MethodName as before.</p>
73 <p>The relationship between the wxFoo and wxFooPtr classes have
74 changed for the better. Specifically, all instances that you see
75 will be wx.Foo even if they are created internally using wx.FooPtr,
76 because wx.FooPtr.__init__ will change the instance's __class__ as
77 part of the initialization. If you have any code that checks
78 class type using something like isinstance(obj, wx.FooPtr) you will
79 need to change it to isinstance(obj, wx.Foo).</p>
80 </blockquote>
81 </div>
82 <div class="section" id="binding-events">
83 <h1><a name="binding-events">Binding Events</a></h1>
84 <p>All of the EVT_* functions are now instances of the wx.PyEventBinder
85 class. They have a __call__ method so they can still be used as
86 functions like before, but making them instances adds some
87 flexibility that I expect to take advantave of in the future.</p>
88 <p>wx.EvtHandler (the base class for wx.Window) now has a Bind method that
89 makes binding events to windows a little easier. Here is its
90 definition and docstring:</p>
91 <pre class="literal-block">
92 def Bind(self, event, handler, source=None, id=wxID_ANY, id2=wxID_ANY):
93 &quot;&quot;&quot;
94 Bind an event to an event handler.
95
96 event One of the EVT_* objects that specifies the
97 type of event to bind.
98
99 handler A callable object to be invoked when the event
100 is delivered to self. Pass None to disconnect an
101 event handler.
102
103 source Sometimes the event originates from a different window
104 than self, but you still want to catch it in self. (For
105 example, a button event delivered to a frame.) By
106 passing the source of the event, the event handling
107 system is able to differentiate between the same event
108 type from different controls.
109
110 id,id2 Used for menu IDs or for event types that require a
111 range of IDs
112
113 &quot;&quot;&quot;
114 </pre>
115 <p>Some examples of its use:</p>
116 <pre class="literal-block">
117 self.Bind(wx.EVT_SIZE, self.OnSize)
118 self.Bind(wx.EVT_BUTTON, self.OnButtonClick, theButton)
119 self.Bind(wx.EVT_MENU, self.OnExit, id=wx.ID_EXIT)
120 </pre>
121 <p>The wx.Menu methods that add items to a wx.Menu have been modified
122 such that they return a reference to the wx.MenuItem that was created.
123 Additionally menu items and toolbar items have been modified to
124 automatically generate a new ID if -1 is given, similar to using -1
125 with window classess. This means that you can create menu or toolbar
126 items and event bindings without having to predefine a unique menu ID,
127 although you still can use IDs just like before if you want. For
128 example, these are all equivallent other than their specific ID
129 values:</p>
130 <pre class="literal-block">
131 1.
132 item = menu.Append(-1, &quot;E&amp;xit&quot;, &quot;Terminate the App&quot;)
133 self.Bind(wx.EVT_MENU, self.OnExit, item)
134
135 2.
136 item = menu.Append(wx.ID_EXIT, &quot;E&amp;xit&quot;, &quot;Terminate the App&quot;)
137 self.Bind(wx.EVT_MENU, self.OnExit, item)
138
139 3.
140 menu.Append(wx.ID_EXIT, &quot;E&amp;xit&quot;, &quot;Terminate the App&quot;)
141 self.Bind(wx.EVT_MENU, self.OnExit, id=wx.ID_EXIT)
142 </pre>
143 <p>If you create your own custom event types and EVT_* functions, and you
144 want to be able to use them with the Bind method above then you should
145 change your EVT_* to be an instance of wx.PyEventBinder instead of a
146 function. For example, if you used to have something like this:</p>
147 <pre class="literal-block">
148 myCustomEventType = wxNewEventType()
149 def EVT_MY_CUSTOM_EVENT(win, id, func):
150 win.Connect(id, -1, myCustomEventType, func)
151 </pre>
152 <p>Change it like so:</p>
153 <pre class="literal-block">
154 myCustomEventType = wx.NewEventType()
155 EVT_MY_CUSTOM_EVENT = wx.PyEventBinder(myCustomEventType, 1)
156 </pre>
157 <p>The second parameter is an integer in [0, 1, 2] that specifies the
158 number of IDs that are needed to be passed to Connect.</p>
159 <p><strong>[Changed in 2.5.2.x]</strong> There is also an Unbind method added to
160 wx.EvtHandler that can be used to disconenct event handlers. It looks
161 like this:</p>
162 <pre class="literal-block">
163 def Unbind(self, event, source=None, id=wx.ID_ANY, id2=wx.ID_ANY):
164 &quot;&quot;&quot;
165 Disconencts the event handler binding for event from self.
166 Returns True if successful.
167 &quot;&quot;&quot;
168 </pre>
169 </div>
170 <div class="section" id="the-wx-namespace">
171 <h1><a name="the-wx-namespace">The wx Namespace</a></h1>
172 <p>The second phase of the wx Namespace Transition has begun. That means
173 that the real names of the classes and other symbols do not have the
174 'wx' prefix and the modules are located in a Python package named
175 wx. There is still a Python package named wxPython with modules
176 that have the names with the wx prefix for backwards compatibility.
177 Instead of dynamically changing the names at module load time like in
178 2.4, the compatibility modules are generated at build time and contain
179 assignment statements like this:</p>
180 <pre class="literal-block">
181 wxWindow = wx._core.Window
182 </pre>
183 <p>Don't let the &quot;_core&quot; in the name bother you. That and some other
184 modules are implementation details, and everything that was in the
185 wxPython.wx module before will still be in the wx package namespace
186 after this change. So from your code you would use it as wx.Window or
187 wxWindow if you import from the wxPython.wx module.</p>
188 <p>A few notes about how all of this was accomplished might be
189 interesting... SWIG is now run twice for each module that it is
190 generating code for. The first time it outputs an XML representaion
191 of the parse tree, which can be up to 20MB and 300K lines in size!
192 That XML is then run through a little Python script that creates a
193 file full of SWIG %rename directives that take the wx off of the
194 names, and also generates the Python compatibility file described
195 above that puts the wx back on the names. SWIG is then run a second
196 time to generate the C++ code to implement the extension module, and
197 uses the %rename directives that were generated in the first step.</p>
198 <p>Not every name is handled correctly (but the bulk of them are) and so
199 some work has to be done by hand, especially for the reverse-renamers.
200 So expect a few flaws here and there until everything gets sorted out.</p>
201 <p>In summary, the wx package and names without the &quot;wx&quot; prefix are now
202 the official form of the wxPython classes. For example:</p>
203 <pre class="literal-block">
204 import wx
205
206 class MyFrame(wx.Frame):
207 def __init__(self, parent, title):
208 wx.Frame.__init__(self, parent, -1, title)
209 p = wx.Panel(self, -1)
210 b = wx.Button(p, -1, &quot;Do It&quot;, (10,10))
211 self.Bind(wx.EVT_BUTTON, self.JustDoIt, b)
212
213 def JustDoIt(self, evt):
214 print &quot;It's done!&quot;
215
216 app = wx.PySimpleApp()
217 f = MyFrame(None, &quot;What's up?&quot;)
218 f.Show()
219 app.MainLoop()
220 </pre>
221 <p>You shouldn't need to migrate all your modules over to use the new
222 package and names right away as there are modules in place that try to
223 provide as much backwards compatibility of the names as possible. If
224 you rewrote the above sample using &quot;from wxPython.wx import * &quot;, the
225 old wxNames, and the old style of event binding it will still work
226 just fine.</p>
227 </div>
228 <div class="section" id="new-wx-dc-methods">
229 <h1><a name="new-wx-dc-methods">New wx.DC Methods</a></h1>
230 <p><strong>[Changed in 2.5.2.x]</strong> In wxPython 2.5.1.5 there was a new
231 implementation of the wx.DC Draw and other methods that broke
232 backwards compatibility in the name of consistency. That change has
233 been reverted and the wx.DC Draw methods with 2.4 compatible
234 signatures have been restored. In addition a new set of methods have
235 been added that take wx.Point and/or wx.Size parameters instead of
236 separate integer parameters. The Draw and etc. methods now available
237 in the wx.DC class are:</p>
238 <pre class="literal-block">
239 FloodFill(self, x, y, colour, style = wx.FLOOD_SURFACE)
240 FoodFillPoint(self, pt, colour, style = wx.FLOOD_SURFACE)
241
242 GetPixel(self, x,y)
243 GetPixelPoint(self, pt)
244
245 DrawLine(self, x1, y1, x2, y2)
246 DrawLinePoint(self, pt1, pt2)
247
248 CrossHair(self, x, y)
249 CrossHairPoint(self, pt)
250
251 DrawArc(self, x1, y1, x2, y2, xc, yc)
252 DrawArcPoint(self, pt1, pt2, centre)
253
254 DrawCheckMark(self, x, y, width, height)
255 DrawCheckMarkRect(self, rect)
256
257 DrawEllipticArc(self, x, y, w, h, sa, ea)
258 DrawEllipticArcPointSize(self, pt, sz, sa, ea)
259
260 DrawPoint(self, x, y)
261 DrawPointPoint(self, pt)
262
263 DrawRectangle(self, x, y, width, height)
264 DrawRectangleRect(self, rect)
265 DrawRectanglePointSize(self, pt, sz)
266
267 DrawRoundedRectangle(self, x, y, width, height, radius)
268 DrawRoundedRectangleRect(self, r, radius)
269 DrawRoundedRectanglePointSize(self, pt, sz, radius)
270
271 DrawCircle(self, x, y, radius)
272 DrawCirclePoint(self, pt, radius)
273
274 DrawEllipse(self, x, y, width, height)
275 DrawEllipseRect(self, rect)
276 DrawEllipsePointSize(self, pt, sz)
277
278 DrawIcon(self, icon, x, y)
279 DrawIconPoint(self, icon, pt)
280
281 DrawBitmap(self, bmp, x, y, useMask = False)
282 DrawBitmapPoint(self, bmp, pt, useMask = False)
283
284 DrawText(self, text, x, y)
285 DrawTextPoint(self, text, pt)
286
287 DrawRotatedText(self, text, x, y, angle)
288 DrawRotatedTextPoint(self, text, pt, angle)
289
290 bool Blit(self, xdest, ydest, width, height, sourceDC, xsrc, ysrc,
291 rop = wx.COPY, useMask = False, xsrcMask = -1, ysrcMask = -1)
292 BlitPointSize(self, destPt, sz, sourceDC, srcPt, rop = wx.COPY,
293 useMask = False, srcPtMask = wxDefaultPosition)
294
295
296 SetClippingRegion(self, x, y, width, height)
297 SetClippingRegionPointSize(self, pt, sz)
298 SetClippingRegionAsRegion(self, region)
299 SetClippingRect(self, rect)
300 </pre>
301 </div>
302 <div class="section" id="building-extending-and-embedding-wxpython">
303 <h1><a name="building-extending-and-embedding-wxpython">Building, Extending and Embedding wxPython</a></h1>
304 <p>wxPython's setup.py script now expects to use existing libraries for
305 the contribs (gizmos, stc, xrc, etc.) rather than building local
306 copies of them. If you build your own copies of wxPython please be
307 aware that you now need to also build the stc, xrc, animate and gizmos
308 libraries in addition to the main wx lib.</p>
309 <p>The wxPython.h and other header files are now in
310 .../wxPython/include/wx/wxPython instead of in wxPython/src. You
311 should include it via the &quot;wx/wxPython/wxPython.h&quot; path and add
312 .../wxPython/include to your list of include paths. On OSX and
313 unix-like systems the wxPython headers are installed to the same place
314 that the wxWidgets headers are installed, so if you are building
315 wxPython compatible extensions on those platforms then your include
316 path should already be set properly.</p>
317 <p>If you are also using SWIG for your extension then you'll need to
318 adapt how the wxPython .i files are imported into your .i files. See
319 the wxPython sources for examples. Your modules will need to at least
320 <tt class="docutils literal"><span class="pre">%import</span> <span class="pre">core.i</span></tt>, and possibly others if you need the definition of
321 other classes. Since you will need them to build your modules using
322 SWIG, the main wxPython .i files are also installed with the wxPython
323 headers in an i_files sibdirectory. It should be enough to pass a
324 -I/pathname on the command line for SWIG to find the files.</p>
325 <p>The bulk of wxPython's setup.py has been moved to another module,
326 wx/build/config.py. This module will be installed as part of wxPython
327 so 3rd party modules that wish to use the same setup/configuration
328 code can do so simply by importing this module from their own setup.py
329 scripts using <tt class="docutils literal"><span class="pre">import</span> <span class="pre">wx.build.config</span></tt>.</p>
330 <p>You no longer need to call wxClassInfo::CleanUpClasses() and
331 wxClassInfo::InitializeClasses() in your extensions or when embedding
332 wxPython.</p>
333 <p>The usage of wxPyBeginAllowThreads and wxPyEndAllowThreads has changed
334 slightly. wxPyBeginAllowThreads now returns a boolean value that must
335 be passed to the coresponding wxPyEndAllowThreads function call. This
336 is to help do the RightThing when calls to these two functions are
337 nested, or if calls to external code in other extension modules that
338 are wrapped in the standard Py_(BEGIN|END)_ALLOW_THERADS may result in
339 wx event handlers being called (such as during the call to
340 os.startfile.)</p>
341 </div>
342 <div class="section" id="two-or-three-phase-create">
343 <h1><a name="two-or-three-phase-create">Two (or Three!) Phase Create</a></h1>
344 <p>If you use the Precreate/Create method of instantiating a window, (for
345 example, to set an extended style flag, or for XRC handlers) then
346 there is now a new method named PostCreate to help with transplanting
347 the brain of the prewindow instance into the derived window instance.
348 For example:</p>
349 <pre class="literal-block">
350 class MyDialog(wx.Dialog):
351 def __init__(self, parent, ID, title, pos, size, style):
352 pre = wx.PreDialog()
353 pre.SetExtraStyle(wx.DIALOG_EX_CONTEXTHELP)
354 pre.Create(parent, ID, title, pos, size, style)
355 self.PostCreate(pre)
356 </pre>
357 </div>
358 <div class="section" id="sizers">
359 <h1><a name="sizers">Sizers</a></h1>
360 <p>The hack allowing the old &quot;option&quot; keyword parameter has been removed.
361 If you use keyword args with wx.Sizer Add, Insert, or Prepend methods
362 then you will need to use the <tt class="docutils literal"><span class="pre">proportion</span></tt> name instead of
363 <tt class="docutils literal"><span class="pre">option</span></tt>. (The <tt class="docutils literal"><span class="pre">proportion</span></tt> keyword was also allowed in 2.4.2.4.)</p>
364 <p>When adding a spacer to a sizer you now need to use a wx.Size or a
365 2-integer sequence instead of separate width and height parameters.
366 This was optionally allowed in 2.4, but now it is required. This
367 allows for more consistency in how you add the various types of items
368 to a sizer. The first parameter defines the item (instead of the
369 possibily first two, depending on if you are doing a spacer or not,)
370 and that item can either be a window, a sizer or a spacer (which can
371 be a sequence or a wx.Size.) Removing the option for separate width
372 and height parameters greatly simplified the wrapper code.</p>
373 <p>The wx.GridBagSizer class (very similar to the RowColSizer in the
374 library) has been added to C++ and wrapped for wxPython. It can also
375 be used from XRC.</p>
376 <p>You should not use AddWindow, AddSizer, AddSpacer (and similar for
377 Insert, Prepend, and etc.) methods any longer. Just use Add and the
378 wrappers will figure out what to do. <strong>[Changed in 2.5.2.x]</strong>
379 AddWindow, AddSizer, AddSpacer and etc. will now issue a
380 DeprecationWarning. <strong>[Changed in 2.5.4.x]</strong> These methods have now
381 been undeprecated at the request of Riaan Booysen, the Boa Constructor
382 team lead. They are now just simple compatibility aliases for Add,
383 and etc.</p>
384 <p><strong>[Changed in 2.5.2.x]</strong> The Sizers have had some fundamental internal
385 changes in the 2.5.2.x release intended to make them do more of the
386 &quot;Right Thing&quot; but also be as backwards compatible as possible.
387 First a bit about how things used to work:</p>
388 <blockquote>
389 <ul class="simple">
390 <li>The size that a window had when Add()ed to the sizer was assumed
391 to be its minimal size, and that size would always be used by
392 default when calculating layout size and positions, and the
393 sizer itself would keep track of that minimal size.</li>
394 <li>If the window item was added with the <tt class="docutils literal"><span class="pre">wx.ADJUST_MINSIZE</span></tt>
395 flag then when layout was calculated the item's <tt class="docutils literal"><span class="pre">GetBestSize</span></tt>
396 would be used to reset the minimal size that the sizer used.</li>
397 </ul>
398 </blockquote>
399 <p>The main thrust of the new Sizer changes was to make behavior like
400 <tt class="docutils literal"><span class="pre">wx.ADJUST_MINSIZE</span></tt> be the default, and also to push the tracking of
401 the minimal size to the window itself (since it knows its own needs)
402 instead of having the sizer take care of it. Consequently these
403 changes were made:</p>
404 <blockquote>
405 <ul class="simple">
406 <li>The <tt class="docutils literal"><span class="pre">wx.FIXED_MINSIZE</span></tt> flag was added to allow for the old
407 behavior. When this flag is used the size a window has when
408 added to the sizer will be treated as its minimal size and it
409 will not be readjusted on each layout.</li>
410 <li>The min size stored in <tt class="docutils literal"><span class="pre">wx.Window</span></tt> and settable with
411 <tt class="docutils literal"><span class="pre">SetSizeHints</span></tt> or <tt class="docutils literal"><span class="pre">SetMinSize</span></tt> will by default be used by
412 the sizer (if it was set) as the minimal size of the sizer item.
413 If the min size was not set (or was only partially set) then the
414 window's best size is fetched and it is used instead of (or
415 blended with) the min size. <tt class="docutils literal"><span class="pre">wx.Window.GetBestFittingSize</span></tt>
416 was added to facilitate getting the size to be used by the
417 sizers.</li>
418 <li>The best size of a window is cached so it doesn't need to
419 recaculated on every layout. <tt class="docutils literal"><span class="pre">wx.Window.InvalidateBestSize</span></tt>
420 was added and should be called (usually just internally in
421 control methods) whenever something is done that would make the
422 best size change.</li>
423 <li>All wxControls were changed to set the minsize to what is passed
424 to the constructor or Create method, and also to set the real
425 size of the control to the blending of the min size and best
426 size. <tt class="docutils literal"><span class="pre">wx.Window.SetBestFittingSize</span></tt> was added to help with
427 this, although most controls don't need to call it directly
428 because it is called indirectly via the <tt class="docutils literal"><span class="pre">SetInitialSize</span></tt>
429 called in the base classes.</li>
430 </ul>
431 </blockquote>
432 <p>At this time, the only situation known not to work the same as before
433 is the following:</p>
434 <pre class="literal-block">
435 win = SomeWidget(parent)
436 win.SetSize(SomeNonDefaultSize)
437 sizer.Add(win)
438 </pre>
439 <p>In this case the old code would have used the new size as the minimum,
440 but now the sizer will use the default size as the minimum rather than
441 the size set later. It is an easy fix though, just move the
442 specification of the size to the constructor (assuming that SomeWidget
443 will set its minsize there like the rest of the controls do) or call
444 <tt class="docutils literal"><span class="pre">SetMinSize</span></tt> instead of <tt class="docutils literal"><span class="pre">SetSize</span></tt>.</p>
445 <p>In order to fit well with this new scheme of things, all wxControls or
446 custom controls should do the following things. (Depending on how
447 they are used you may also want to do the same thing for non-control
448 custom windows.)</p>
449 <blockquote>
450 <ul>
451 <li><p class="first">Either override or inherit a meaningful <tt class="docutils literal"><span class="pre">DoGetBestSize</span></tt> method
452 that calculates whatever size is &quot;best&quot; for the control. Once
453 that size is calculated then there should normally be a call to
454 <tt class="docutils literal"><span class="pre">CacheBestSize</span></tt> to save it for later use, unless for some
455 reason you want the best size to be recalculated on every
456 layout.</p>
457 <p>Note: In order to successfully override <tt class="docutils literal"><span class="pre">DoGetBestSize</span></tt> in
458 Python the class needs to be derived from <tt class="docutils literal"><span class="pre">wx.PyWindow</span></tt>,
459 <tt class="docutils literal"><span class="pre">wx.PyControl</span></tt>, or etc. If your class instead derives from
460 one of the standard wx classes then just be sure that the min
461 size gets explicitly set to what would have been the best size
462 and things should work properly in almost all situations.</p>
463 </li>
464 <li><p class="first">Any method that changes the attributes of the control such that
465 the best size will change should call <tt class="docutils literal"><span class="pre">InvalidateBestSize</span></tt> so
466 it will be recalculated the next time it is needed.</p>
467 </li>
468 <li><p class="first">The control's constructor and/or Create method should ensure
469 that the minsize is set to the size passed in, and that the
470 control is sized to a blending of the min size and best size.
471 This can be done by calling <tt class="docutils literal"><span class="pre">SetBestFittingSize</span></tt>.</p>
472 </li>
473 </ul>
474 </blockquote>
475 </div>
476 <div class="section" id="platforminfo">
477 <h1><a name="platforminfo">PlatformInfo</a></h1>
478 <p>Added wx.PlatformInfo which is a tuple containing strings that
479 describe the platform and build options of wxPython. This lets you
480 know more about the build than just the __WXPORT__ value that
481 wx.Platform contains, such as if it is a GTK2 build. For example,
482 instead of:</p>
483 <pre class="literal-block">
484 if wx.Platform == &quot;__WXGTK__&quot;:
485 ...
486 </pre>
487 <p>you should do this:</p>
488 <pre class="literal-block">
489 if &quot;__WXGTK__&quot; in wx.PlatformInfo:
490 ...
491 </pre>
492 <p>and you can specifically check for a wxGTK2 build by looking for
493 &quot;gtk2&quot; in wx.PlatformInfo. Unicode builds are also detectable this
494 way. If there are any other platform/toolkit/build flags that make
495 sense to add to this tuple please let me know.</p>
496 <p>BTW, wx.Platform will probably be deprecated in the future.</p>
497 </div>
498 <div class="section" id="activex">
499 <h1><a name="activex">ActiveX</a></h1>
500 <p>Lindsay Mathieson's newest <a class="reference" href="http://members.optusnet.com.au/~blackpaw1/wxactivex.html">wxActiveX</a> class has been wrapped into a new
501 extension module called wx.activex. It is very generic and dynamic
502 and should allow hosting of arbitray ActiveX controls within your
503 wxPython apps. So far I've tested it with IE, PDF, and Flash
504 controls, (and there are new samples in the demo and also library
505 modules supporting these.)</p>
506 <p>The new wx.activex module contains a bunch of code, but the most
507 important things to look at are ActiveXWindow and ActiveXEvent.
508 ActiveXWindow derives from wxWindow and the constructor accepts a
509 CLSID for the ActiveX Control that should be created. (There is also
510 a CLSID class that can convert from a progID or a CLSID String.) The
511 ActiveXWindow class simply adds methods that allow you to query some
512 of the TypeInfo exposed by the ActiveX object, and also to get/set
513 properties or call methods by name. The Python implementation
514 automatically handles converting parameters and return values to/from
515 the types expected by the ActiveX code as specified by the TypeInfo,
516 (just bool, integers, floating point, strings and None/Empty so far,
517 but more can be handled later.)</p>
518 <p>That's pretty much all there is to the class, as I mentioned before it
519 is very generic and dynamic. Very little is hard-coded and everything
520 that is done with the actual ActiveX control is done at runtime and
521 referenced by property or method name. Since Python is such a dynamic
522 language this is a very good match. I thought for a while about doing
523 some Python black-magic and making the specific methods/properties of
524 the actual ActiveX control &quot;appear&quot; at runtime, but then decided that
525 it would be better and more understandable to do it via subclassing.
526 So there is a utility class in wx.activex that given an existing
527 ActiveXWindow instance can generate a .py module containing a derived
528 class with real methods and properties that do the Right Thing to
529 reflect those calls to the real ActiveX control. There is also a
530 script/tool module named genaxmodule that given a CLSID or progID and
531 a class name, will generate the module for you. There are a few
532 examples of the output of this tool in the wx.lib package, see
533 iewin.py, pdfwin.py and flashwin.py.</p>
534 <p>Currently the genaxmodule tool will tweak some of the names it
535 generates, but this can be controled if you would like to do it
536 differently by deriving your own class from GernerateAXModule,
537 overriding some methods and then using this class from a tool like
538 genaxmodule. [TODO: make specifying a new class on genaxmodule's
539 command-line possible.] The current default behavior is that any
540 event names that start with &quot;On&quot; will have the &quot;On&quot; dropped, property
541 names are converted to all lower case, and if any name is a Python
542 keyword it will have an underscore appended to it. GernerateAXModule
543 does it's best when generating the code in the new module, but it can
544 only be as good as the TypeInfo data available from the ActiveX
545 control so sometimes some tweaking will be needed. For example, the
546 IE web browser control defines the Flags parameter of the Navigate2
547 method as required, but MSDN says it is optional.</p>
548 <p>It is intended that this new wx.activex module will replace both the
549 older version of Lindsay's code available in iewin.IEHtmlWindow, and
550 also the wx.lib.activexwraper module. Probably the biggest
551 differences you'll ecounter in migrating activexwrapper-based code
552 (besides events working better without causing deadlocks) is that
553 events are no longer caught by overriding methods in your derived
554 class. Instead ActiveXWindow uses the wx event system and you bind
555 handlers for the ActiveX events exactly the same way you do for any wx
556 event. There is just one extra step needed and that is creating an
557 event ID from the ActiveX event name, and if you use the genaxmodule
558 tool then this extra step will be handled for you there. For example,
559 for the StatusTextChange event in the IE web browser control, this
560 code is generated for you:</p>
561 <pre class="literal-block">
562 wxEVT_StatusTextChange = wx.activex.RegisterActiveXEvent('StatusTextChange')
563 EVT_StatusTextChange = wx.PyEventBinder(wxEVT_StatusTextChange, 1)
564 </pre>
565 <p>and you would use it in your code like this:</p>
566 <pre class="literal-block">
567 self.Bind(iewin.EVT_StatusTextChange, self.UpdateStatusText, self.ie)
568 </pre>
569 <p>When the event happens and your event handler function is called the
570 event properties from the ActiveX control (if any) are converted to
571 attributes of the event object passed to the handler. (Can you say
572 'event' any more times in a single sentence? ;-) ) For example the
573 StatusTextChange event will also send the text that should be put into
574 the status line as an event parameter named &quot;Text&quot; and you can access
575 it your handlers as an attribute of the event object like this:</p>
576 <pre class="literal-block">
577 def UpdateStatusText(self, evt):
578 self.SetStatusText(evt.Text)
579 </pre>
580 <p>Usually these event object attributes should be considered read-only,
581 but some will be defined by the TypeInfo as output parameters. In
582 those cases if you modify the event object's attribute then that value
583 will be returned to the ActiveX control. For example, to prevent a
584 new window from being opened by the IE web browser control you can do
585 this in the handler for the iewin.EVT_NewWindow2 event:</p>
586 <pre class="literal-block">
587 def OnNewWindow2(self, evt):
588 evt.Cancel = True
589 </pre>
590 <p>So how do you know what methods, events and properties that an ActiveX
591 control supports? There is a funciton in wx.activex named GetAXInfo
592 that returns a printable summary of the TypeInfo from the ActiveX
593 instance passed in. You can use this as an example of how to browse
594 the TypeInfo provided, and there is also a copy of this function's
595 output appended as a comment to the modules produced by the
596 genaxmodule tool. Beyond that you'll need to consult the docs
597 provided by the makers of the ActiveX control that you are using.</p>
598 </div>
599 <div class="section" id="png-images">
600 <h1><a name="png-images">PNG Images</a></h1>
601 <p>Prior to 2.5 the PNG image handler would convert all alpha channel
602 information to a mask when the image was loaded. Pixels that were
603 more than halfway transparent would be made fully transparent by the
604 mask and the rest would be made fully opaque.</p>
605 <p>In 2.5 the image handler has been updated to preserve the alpha
606 channel and will now only create a mask when all the pixels in the
607 image are either fully transparent or fully opaque. In addition, the
608 wx.DC.DrawBitmap and wx.DC.Blit methods are able to correctly blend
609 the pixels in the image with partially transparent alpha values.</p>
610 <p>If you are using a PNG with an alpha channel but you need to have a
611 wx.Mask like you automatically got in 2.4 then you can do one of the
612 following:</p>
613 <blockquote>
614 <ul class="simple">
615 <li>Edit the image and make all the partially transparent pixels be
616 fully transparent.</li>
617 <li>Use a different image type.</li>
618 <li>Set a mask based on colour after you load the image.</li>
619 </ul>
620 </blockquote>
621 </div>
622 <div class="section" id="ogl-is-dead-long-live-ogl">
623 <h1><a name="ogl-is-dead-long-live-ogl">OGL is dead! LONG LIVE OGL!</a></h1>
624 <p><strong>[Changed in 2.5.2.x]</strong></p>
625 <p>The wx.ogl module was deprecated in version 2.5.2 in favor of the new
626 Python port of the OGL library located at wx.lib.ogl contributed by
627 Pierre Hjälm. Starting in version 2.5.5 the old ogl is no longer
628 being built in the distributed binaries, however the source code is
629 still in the source tree so people can built it themselves if desired.</p>
630 <p>The reason this changes was done was to greatly extend the life of OGL
631 within wxPython by making it more easily maintainable and less prone
632 to getting rusty as there seems to be less and less interest in
633 maintaining the C++ version.</p>
634 <p>There are only a few known compatibility issues at this time. First
635 is the location of OGL. The old version was located in the
636 wx.ogl module, and the new version is in the wx.lib.ogl package. So
637 this just means that to start using the new version you need to adjust
638 your imports. So if your code currently has something like this:</p>
639 <pre class="literal-block">
640 import wx
641 import wx.ogl as ogl
642 </pre>
643 <p>Then just change it to this:</p>
644 <pre class="literal-block">
645 import wx
646 import wx.lib.ogl as ogl
647 </pre>
648 <p>The other compatibility issue deals with removing a wart in the
649 original API that was necessary in order to allow overloaded methods
650 in derived classes to call the same method in the base class when
651 using the old SWIG. Instead dedaling with the wart you can now just
652 call the base class method like you woudl for any other Python class.
653 For example, if you had to do something like this previously:</p>
654 <pre class="literal-block">
655 class MyDividedShape(ogl.DividedShape):
656 ...
657 def OnSizingEndDragLeft(self, pt, x, y, keys, attch):
658 self.base_OnSizingEndDragLeft(pt, x, y, keys, attch)
659 ...
660 </pre>
661 <p>You will need to change it to be like this:</p>
662 <pre class="literal-block">
663 class MyDividedShape(ogl.DividedShape):
664 ...
665 def OnSizingEndDragLeft(self, pt, x, y, keys, attch):
666 ogl.DividedShape.OnSizingEndDragLeft(self, pt, x, y, keys, attch)
667 ...
668 </pre>
669 </div>
670 <div class="section" id="obsolete-modules">
671 <h1><a name="obsolete-modules">Obsolete Modules</a></h1>
672 <p>Instead of over a dozen separate extension modules linked together
673 into a single extension module, the &quot;core&quot; module is now just a few
674 extensions that are linked independently, and then merged together
675 later into the main namespace via Python code.</p>
676 <p>Because of the above and also because of the way the new SWIG works,
677 the &quot;internal&quot; module names have changed, but you shouldn't have been
678 using them anyway so it shouldn't bother you. ;-) In case you were
679 erroneously using them in 2.4, here are the internal extension modules
680 that no longer exist:</p>
681 <blockquote>
682 <ul class="simple">
683 <li>clip_dnd</li>
684 <li>cmndlgs</li>
685 <li>controls</li>
686 <li>controls2</li>
687 <li>events</li>
688 <li>filesys</li>
689 <li>fonts</li>
690 <li>frames</li>
691 <li>gdi</li>
692 <li>image</li>
693 <li>mdi</li>
694 <li>misc</li>
695 <li>misc2</li>
696 <li>printfw</li>
697 <li>sizers</li>
698 <li>stattool</li>
699 <li>streams</li>
700 <li>utils</li>
701 <li>windows</li>
702 <li>windows2</li>
703 <li>windows3</li>
704 </ul>
705 </blockquote>
706 <p>They have been replaced by the following, but please remember that
707 these are just &quot;implementation details&quot; and you should really be using
708 the objects in these modules only via the wx or wxPython.wx packages:</p>
709 <blockquote>
710 <ul class="simple">
711 <li>_core</li>
712 <li>_gdi</li>
713 <li>_windows</li>
714 <li>_controls</li>
715 <li>_misc</li>
716 </ul>
717 </blockquote>
718 <p>The help module no longer exists and the classes therein are now part
719 of the core module imported with wxPython.wx or the wx package.</p>
720 </div>
721 <div class="section" id="wx-taskbaricon">
722 <h1><a name="wx-taskbaricon">wx.TaskBarIcon</a></h1>
723 <p><strong>[Changed in 2.5.3.x]</strong></p>
724 <p>wx.TaskbarIcon now works on all three platforms, although for wxGTK it
725 depends on support from the Window Manager. On OS X the icon replaces
726 the application's icon on the dock and when you right click on it the
727 app's default popup menu is merged with the wx.TaskBarIcon's menu.
728 Because of how it is implemented on the Mac using the Dock most of the
729 TaskBarIcon events will _not_ be emitted on that platform, but since
730 98% of the time you simply want to display an icon and have a popup
731 menu it shouldn't be much of a problem. You can still use the other
732 events on the other platforms, you'll just want to be sure that you
733 can do everything you want via the menu too.</p>
734 <p>Since popping up a menu is the most common thing to do with a
735 TaskBarIcon the class has some new built in functionality to
736 facilitate that. To use the TaskBarIcon in this new way, simply
737 derive a new class from TaskBarIcon and implement a CreatePopupMenu
738 method that creates and returns the menu. That's all there is to it,
739 besides binding event handlers for the menu items of course. Take a
740 look at the DemoTaskBarIcon class in the demo/Main.py module for an
741 example.</p>
742 <p><strong>NOTE</strong>: Unfortunately due to being able to support virtualizing
743 CreatePopupMenu the C++ TaskBarIcon instance now holds a reference to
744 the Python instance, and so you will need to explicitly Destroy() your
745 TaskBarIcon instance when you are done with it. (Like you do with
746 wx.Dialogs.) If you don't destroy it then wxWidgets will assume that
747 you want the app to keep running with just the icon in the task bar
748 and the MainLoop will not exit.</p>
749 </div>
750 <div class="section" id="version-number-change">
751 <h1><a name="version-number-change">Version Number Change</a></h1>
752 <p><strong>[Changed in 2.5.3.x]</strong></p>
753 <p>Starting with 2.5.3.0 the Unicode versions of wxPython will no longer
754 have a 'u' appended to the fourth component of the version number.
755 Please check for the presence of &quot;unicode&quot; in the <cite>wx.PlatformInfo</cite>
756 tuple instead. (This tuple of strings has been available since the
757 first 2.5 version.) For example:</p>
758 <pre class="literal-block">
759 if &quot;unicode&quot; in wx.PlatformInfo:
760 # do whatever
761 ...
762 </pre>
763 </div>
764 <div class="section" id="multi-version-installs">
765 <h1><a name="multi-version-installs">Multi-Version Installs</a></h1>
766 <p><strong>[Changed in 2.5.3.x]</strong></p>
767 <p>Starting with 2.5.3.0 the wx and wxPython package directories will be
768 installed in a subdirectory of the site-packages directory, instead of
769 directly in site-packages. This is done to help facilitate having
770 multiple versions of wxPython installed side-by-side. Why would you
771 want to do this? One possible scenario is you have an app that
772 requires wxPython 2.4 but you want to use the newest 2.5 to do your
773 own development with. Or perhaps you want to be able to test your app
774 with several different versions of wxPython to ensure compatibility.
775 Before everyone panics, rest asured that if you only install one
776 version of wxPython then you should notice no difference in how things
777 work.</p>
778 <p>In addition to installing wxPython into a &quot;versioned&quot; subdirectory of
779 site-packages, a file named <cite>wx.pth</cite> is optionally installed that will
780 contain the name of the versioned subdirectory. This will cause that
781 subdirectory to be automatically added to the sys.path and so doing an
782 &quot;import wx&quot; will find the package in the subdirectory like it would
783 have if it was still located directly in site-packages. I say
784 &quot;optionally&quot; above because that is how you can control which install
785 of wxPython is the default one. Which ever version installs the
786 wx.pth file will be the one that is imported with a plain &quot;import wx&quot;
787 statement. Of course you can always manipulate that by editing the
788 wx.pth file, or by setting PYTHONPATH in the environment, or by the
789 method described in the next paragraph.</p>
790 <p>Finally, a new module named wxversion.py is installed to the
791 site-packages directory. It can be used to manipulate the sys.path at
792 runtime so your applications can select which version of wxPython they
793 would like to to have imported. You use it like this:</p>
794 <pre class="literal-block">
795 import wxversion
796 wxversion.select(&quot;2.4&quot;)
797 import wx
798 </pre>
799 <p>Then even though a 2.5 version of wxPython may be the default the
800 application that does the above the first time that wx is imported
801 will actually get a 2.4 version. <strong>NOTE:</strong> There isn't actually a 2.4
802 version of wxPython that supports this, but there will be.</p>
803 <p>Please see this wiki page for more details, HowTo's and FAQ's:
804 <a class="reference" href="http://wiki.wxpython.org/index.cgi/MultiVersionInstalls">http://wiki.wxpython.org/index.cgi/MultiVersionInstalls</a></p>
805 </div>
806 <div class="section" id="miscellaneous-stuff">
807 <h1><a name="miscellaneous-stuff">Miscellaneous Stuff</a></h1>
808 <p>wxPyDefaultPosition and wxPyDefaultSize are gone. Use the
809 wxDefaultPosition and wxDefaultSize objects instead.</p>
810 <p>Similarly, the wxSystemSettings backwards compatibiility aliases for
811 GetSystemColour, GetSystemFont and GetSystemMetric have also gone into
812 the bit-bucket. Use GetColour, GetFont and GetMetric instead.</p>
813 <p>Use the Python True/False constants instead of the true, TRUE, false,
814 FALSE that used to be provided with wxPython.</p>
815 <p>Use None instead of the ancient and should have been removed a long
816 time ago wx.NULL alias.</p>
817 <p>wx.TreeCtrl.GetFirstChild no longer needs to be passed the cookie
818 variable as the 2nd parameter. It still returns it though, for use
819 with GetNextChild.</p>
820 <p>The wx.NO_FULL_REPAINT_ON_RESIZE style is now the default style for
821 all windows. The name still exists for compatibility, but it is set
822 to zero. If you want to disable the setting (so it matches the old
823 default) then you need to use the new wx.FULL_REPAINT_ON_RESIZE style
824 flag otherwise only the freshly exposed areas of the window will be
825 refreshed.</p>
826 <p>wxPyTypeCast has been removed. Since we've had the OOR (Original
827 Object Return) for a couple years now there should be no need to use
828 wxPyTypeCast at all.</p>
829 <p>If you use the old wxPython package and wxPython.wx namespace then
830 there are compatibility aliases for much of the above items.</p>
831 <p>The wxWave class has been renamed to wxSound, and now has a slightly
832 different API.</p>
833 <p>Before Python 2.3 it was possible to pass a floating point object as a
834 parameter to a function that expected an integer, and the
835 PyArg_ParseTuple family of functions would automatically convert to
836 integer by truncating the fractional portion of the number. With
837 Python 2.3 that behavior was deprecated and a deprecation warning is
838 raised when you pass a floating point value, (for example, calling
839 wx.DC.DrawLine with floats for the position and size,) and lots of
840 developers using wxPython had to scramble to change their code to call
841 int() before calling wxPython methods. Recent changes in SWIG have
842 moved the conversion out of PyArg_ParseTuple to custom code that SWIG
843 generates. Since the default conversion fragment was a little too
844 strict and didn't generate a very meaningful exception when it failed,
845 I decided to use a custom fragment instead, and it turned out that
846 it's very easy to allow floats to be converted again just like they
847 used to be. So, in a nutshell, any numeric type that can be
848 converted to an integer is now legal to be passed to SWIG wrapped
849 functions in wxPython for parameters that are expecting an integer.
850 If the object is not already an integer then it will be asked to
851 convert itself to one. A similar conversion fragment is in place for
852 parameters that expect floating point values.</p>
853 <p><strong>[Changed in 2.5.2.x]</strong> The MaskedEditCtrl modules have been moved
854 to their own sub-package, wx.lib.masked. See the docstrings and demo
855 for changes in capabilities, usage, etc.</p>
856 <p><strong>[Changed in 2.5.2.x]</strong> wx.MaskColour constructor has been deprecated
857 and will raise a DeprecationWarning if used. The main wx.Mask
858 constructor has been modified to be compatible with wx.MaskColour so
859 you should use it instead.</p>
860 <p><strong>[Changed in 2.5.2.x]</strong> In wx.TextCtrls that have the
861 wx.TE_PROCESS_TAB style the TAB key will be treated like an ordinary
862 character and will not cause any tab traversal navigation at all. If
863 you use this style but would still like to have the normal tab
864 traversal take place then you should send your own
865 wx.NavigationKeyEvent from the wx.EVT_KEY_DOWN handler. There is a
866 new Navigate method in the wx.Window class to help send the event and
867 it is used something like this:</p>
868 <pre class="literal-block">
869 flags = wx.NavigationKeyEvent.IsForward
870 if event.ShiftDown():
871 flags = wx.NavigationKeyEvent.IsBackward
872 if event.ControlDown():
873 flags |= wx.NavigationKeyEvent.WinChange
874 self.Navigate(flags)
875 </pre>
876 </div>
877 </div>
878 </body>
879 </html>