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	11	<div class="document" id="wxpython-2-5-migration-guide">
	12	<h1 class="title">wxPython 2.5 Migration Guide</h1>
	13	<p>This document will help explain some of the major changes in wxPython
	14	2.5 and let you know what you need to do to adapt your programs to
	15	those changes. Be sure to also check in the CHANGES.txt file like
	16	usual to see info about the not so major changes and other things that
	17	have been added to wxPython.</p>
	18	<div class="section" id="module-initialization">
	19	<h1><a name="module-initialization">Module Initialization</a></h1>
	20	<p>The import-startup-bootstrap process employed by wxPython was changed
	21	such that wxWindows and the underlying gui toolkit are <strong>not</strong>
	22	initialized until the wx.App object is created (but before wx.App.OnInit
	23	is called.) This was required because of some changes that were made
	24	to the C++ wxApp class.</p>
	25	<p>There are both benefits and potential problems with this change. The
	26	benefits are that you can import wxPython without requiring access to
	27	a GUI (for checking version numbers, etc.) and that in a
	28	multi-threaded environment the thread that creates the app object will
	29	now be the GUI thread instead of the one that imports wxPython. Some
	30	potential problems are that the C++ side of the "stock-objects"
	31	(wx.BLUE_PEN, wx.TheColourDatabase, etc.) are not initialized until
	32	the wx.App object is created, so you should not use them until after
	33	you have created your wx.App object. If you do then an exception will
	34	be raised telling you that the C++ object has not bene initialized
	35	yet.</p>
	36	<p>Also, you will probably not be able to do any kind of GUI or bitmap
	37	operation unless you first have created an app object, (even on
	38	Windows where most anything was possible before.)</p>
	39	</div>
	40	<div class="section" id="swig-1-3">
	41	<h1><a name="swig-1-3">SWIG 1.3</a></h1>
	42	<p>wxPython is now using SWIG 1.3.x from CVS (with several of my own
	43	customizations added that I hope to get folded back into the main SWIG
	44	distribution.) This has some far reaching ramifications:</p>
	45	<blockquote>
	46	<p>All classes derive from object and so all are now "new-style
	47	classes"</p>
	48	<p>Public data members of the C++ classes are wrapped as Python
	49	properties using property() instead of using __getattr__/__setattr__
	50	like before. Normally you shouldn't notice any difference, but if
	51	you were previously doing something with __getattr__/__setattr__
	52	in derived classes then you may have to adjust things.</p>
	53	<p>Static C++ methods are wrapped using the staticmethod()
	54	feature of Python and so are accessible as ClassName.MethodName
	55	as expected. They are still available as top level functions
	56	ClassName_MethodName as before.</p>
	57	<p>The relationship between the wxFoo and wxFooPtr classes have
	58	changed for the better. Specifically, all instances that you see
	59	will be wxFoo even if they are created internally using wxFooPtr,
	60	because wxFooPtr.__init__ will change the instance's __class__ as
	61	part of the initialization. If you have any code that checks
	62	class type using something like isinstance(obj, wxFooPtr) you will
	63	need to change it to isinstance(obj, wxFoo).</p>
	64	</blockquote>
	65	</div>
	66	<div class="section" id="binding-events">
	67	<h1><a name="binding-events">Binding Events</a></h1>
	68	<p>All of the EVT_* functions are now instances of the wx.PyEventBinder
	69	class. They have a __call__ method so they can still be used as
	70	functions like before, but making them instances adds some
	71	flexibility.</p>
	72	<p>wx.EvtHandler (the base class for wx.Window) now has a Bind method that
	73	makes binding events to windows a little easier. Here is its
	74	definition and docstring:</p>
	75	<pre class="literal-block">
	76	def Bind(self, event, handler, source=None, id=wxID_ANY, id2=wxID_ANY):
	77	"""
	78	Bind an event to an event handler.
	79
	80	event One of the EVT_* objects that specifies the
	81	type of event to bind.
	82
	83	handler A callable object to be invoked when the event
	84	is delivered to self. Pass None to disconnect an
	85	event handler.
	86
	87	source Sometimes the event originates from a different window
	88	than self, but you still want to catch it in self. (For
	89	example, a button event delivered to a frame.) By
	90	passing the source of the event, the event handling
	91	system is able to differentiate between the same event
	92	type from different controls.
	93
	94	id,id2 Used for menu IDs or for event types that require a
	95	range of IDs
	96
	97	"""
	98	</pre>
	99	<p>Some examples of its use:</p>
	100	<pre class="literal-block">
	101	self.Bind(wx.EVT_SIZE, self.OnSize)
	102	self.Bind(wx.EVT_BUTTON, self.OnButtonClick, theButton)
	103	self.Bind(wx.EVT_MENU, self.OnExit, id=ID_EXIT)
	104	</pre>
	105	<p>I hope to be able to remove the need for using IDs even for menu
	106	events too...</p>
	107	<p>If you create your own custom event types and EVT_* functions, and you
	108	want to be able to use them with the Bind method above then you should
	109	change your EVT_* to be an instance of wxPyEventBinder instead of a
	110	function. If you used to have something like this:</p>
	111	<pre class="literal-block">
	112	myCustomEventType = wxNewEventType()
	113	def EVT_MY_CUSTOM_EVENT(win, id, func):
	114	win.Connect(id, -1, myCustomEventType, func)
	115	</pre>
	116	<p>Change it like so:</p>
	117	<pre class="literal-block">
	118	myCustomEventType = wx.NewEventType()
	119	EVT_MY_CUSTOM_EVENT = wx.PyEventBinder(myCustomEventType, 1)
	120	</pre>
	121	<p>The second parameter is an integer in [0, 1, 2] that specifies the
	122	number of IDs that are needed to be passed to Connect.</p>
	123	</div>
	124	<div class="section" id="the-wx-namespace">
	125	<h1><a name="the-wx-namespace">The wx Namespace</a></h1>
	126	<p>The second phase of the wx Namespace Transition has begun. That means
	127	that the real names of the classes and other symbols do not have the
	128	'wx' prefix and the modules are located in a Python package named
	129	wx. There is still a Python package named wxPython with modules
	130	that have the names with the wx prefix for backwards compatibility.
	131	Instead of dynamically changing the names at module load time like in
	132	2.4, the compatibility modules are generated at build time and contain
	133	assignment statements like this:</p>
	134	<pre class="literal-block">
	135	wxWindow = wx.core.Window
	136	</pre>
	137	<p>Don't let the "core" in the name bother you. That and some other
	138	modules are implementation details, and everything that was in the
	139	wxPython.wx module before will still be in the wx package namespace
	140	after this change. So from your code you would use it as wx.Window.</p>
	141	<p>A few notes about how all of this was accomplished might be
	142	interesting... SWIG is now run twice for each module that it is
	143	generating code for. The first time it outputs an XML representaion
	144	of the parse tree, which can be up to 20MB and 300K lines in size!
	145	That XML is then run through a little Python script that creates a
	146	file full of SWIG %rename directives that take the wx off of the
	147	names, and also generates the Python compatibility file described
	148	above that puts the wx back on the names. SWIG is then run a second
	149	time to generate the C++ code to implement the extension module, and
	150	uses the %rename directives that were generated in the first step.</p>
	151	<p>Not every name is handled correctly (but the bulk of them are) and so
	152	some work has to be done by hand, especially for the reverse-renamers.
	153	So expect a few flaws here and there until everything gets sorted out.</p>
	154	<p>In summary, the wx package and names without the "wx" prefix are now
	155	the official form of the wxPython classes. For example:</p>
	156	<pre class="literal-block">
	157	import wx
	158
	159	class MyFrame(wx.Frame):
	160	def __init__(self, parent, title):
	161	wx.Frame.__init__(self, parent, -1, title)
	162	p = wx.Panel(self, -1)
	163	b = wx.Button(p, -1, "Do It", (10,10))
	164	self.Bind(wx.EVT_BUTTON, self.JustDoIt, b)
	165
	166	def JustDoIt(self, evt):
	167	print "It's done!"
	168
	169	app = wx.PySimpleApp()
	170	f = MyFrame(None, "What's up?")
	171	f.Show()
	172	app.MainLoop()
	173	</pre>
	174	<p>You shouldn't need to migrate all your modules over to use the new
	175	package and names right away as there are modules in place that try to
	176	provide as much backwards compatibility of the names as possible. If
	177	you rewrote the above sample using "from wxPython.wx import * ", the
	178	old wxNames, and the old style of event binding it will still work
	179	just fine.</p>
	180	</div>
	181	<div class="section" id="new-wx-dc-methods">
	182	<h1><a name="new-wx-dc-methods">New wx.DC Methods</a></h1>
	183	<p>Many of the Draw methods of wx.DC have alternate forms in C++ that take
	184	wxPoint or wxSize parameters (let's call these <em>Type A</em>) instead of
	185	the individual x, y, width, height, etc. parameters (and we'll call
	186	these <em>Type B</em>). In the rest of the library I normally made the <em>Type
	187	A</em> forms of the methods be the default method with the "normal" name,
	188	and had renamed the <em>Type B</em> forms of the methods to some similar
	189	name. For example in wx.Window we have these Python methods:</p>
	190	<pre class="literal-block">
	191	SetSize(size) # Type A
	192	SetSizeWH(width, height) # Type B
	193	</pre>
	194	<p>For various reasons the new <em>Type A</em> methods in wx.DC were never added
	195	and the existing <em>Type B</em> methods were never renamed. Now that lots
	196	of other things are also changing in wxPython it has been decided that
	197	it is a good time to also do the method renaming in wx.DC too in order
	198	to be consistent with the rest of the library. The methods in wx.DC
	199	that are affected are listed here:</p>
	200	<pre class="literal-block">
	201	FloodFillXY(x, y, colour, style = wx.FLOOD_SURFACE)
	202	FloodFill(point, colour, style = wx.FLOOD_SURFACE)
	203
	204	GetPixelXY(x, y)
	205	GetPixel(point)
	206
	207	DrawLineXY(x1, y1, x2, y2)
	208	DrawLine(point1, point2)
	209
	210	CrossHairXY(x, y)
	211	CrossHair(point)
	212
	213	DrawArcXY(x1, y1, x2, y2, xc, yc)
	214	DrawArc(point1, point2, center)
	215
	216	DrawCheckMarkXY(x, y, width, height)
	217	DrawCheckMark(rect)
	218
	219	DrawEllipticArcXY(x, y, w, h, start_angle, end_angle)
	220	DrawEllipticArc(point, size, start_angle, end_angle)
	221
	222	DrawPointXY(x, y)
	223	DrawPoint(point)
	224
	225	DrawRectangleXY(x, y, width, height)
	226	DrawRectangle(point, size)
	227	DrawRectangleRect(rect)
	228
	229	DrawRoundedRectangleXY(x, y, width, height, radius)
	230	DrawRoundedRectangle(point, size, radius)
	231	DrawRoundedRectangleRect(rect, radius)
	232
	233	DrawCircleXY(x, y, radius)
	234	DrawCircle(point, radius)
	235
	236	DrawEllipseXY(x, y, width, height)
	237	DrawEllipse(point, size)
	238	DrawEllipseRect(rect)
	239
	240	DrawIconXY(icon, x, y)
	241	DrawIcon(icon, point)
	242
	243	DrawBitmapXY(bmp, x, y, useMask = FALSE)
	244	DrawBitmap(bmp, point, useMask = FALSE)
	245
	246	DrawTextXY(text, x, y)
	247	DrawText(text, point)
	248
	249	DrawRotatedTextXY(text, x, y, angle)
	250	DrawRotatedText(text, point, angle)
	251
	252
	253	BlitXY(xdest, ydest, width, height, sourceDC, xsrc, ysrc,
	254	rop = wxCOPY, useMask = FALSE, xsrcMask = -1, ysrcMask = -1)
	255	Blit(destPt, size, sourceDC, srcPt,
	256	rop = wxCOPY, useMask = FALSE, srcPtMask = wx.DefaultPosition)
	257
	258	SetClippingRegionXY(x, y, width, height)
	259	SetClippingRegion(point, size)
	260	SetClippingRect(rect)
	261	SetClippingRegionAsRegion(region);
	262	</pre>
	263	<p>If you have code that draws on a DC you <strong>will</strong> get errors because of
	264	these changes, but it should be easy to fix the code. You can either
	265	change the name of the <em>Type B</em> method called to the names shown
	266	above, or just add parentheses around the parameters as needed to turn
	267	them into tuples and let the SWIG typemaps turn them into the wx.Point
	268	or wx.Size object that is expected. Then you will be calling the new
	269	<em>Type A</em> method. For example, if you had this code before:</p>
	270	<pre class="literal-block">
	271	dc.DrawRectangle(x, y, width, height)
	272	</pre>
	273	<p>You could either continue to use the <em>Type B</em> method bu changing the
	274	name to DrawRectabgleXY, or just change it to the new <em>Type A</em> by
	275	adding some parentheses like this:</p>
	276	<pre class="literal-block">
	277	dc.DrawRectangle((x, y), (width, height))
	278	</pre>
	279	<p>Or if you were already using a point and size:</p>
	280	<pre class="literal-block">
	281	dc.DrawRectangle(p.x, p.y, s.width, s.height)
	282	</pre>
	283	<p>Then you can just simplify it like this:</p>
	284	<pre class="literal-block">
	285	dc.DrawRectangle(p, s)
	286	</pre>
	287	</div>
	288	<div class="section" id="building-extending-and-embedding-wxpython">
	289	<h1><a name="building-extending-and-embedding-wxpython">Building, Extending and Embedding wxPython</a></h1>
	290	<p>wxPython's setup.py script now expects to use existing libraries for
	291	the contribs (gizmos, stc, xrc, etc.) rather than building local
	292	copies of them. If you build your own copies of wxPython please be
	293	aware that you now need to also build the ogl, stc, xrc, and gizmos
	294	libraries in addition to the main wx lib. [[TODO: update the
	295	BUILD.*.txt files too!]]</p>
	296	<p>The wxPython.h and other header files are now in
	297	.../wxPython/include/wx/wxPython instead of in wxPython/src. You should
	298	include it via the "wx/wxPython/wxPython.h" path and add
	299	.../wxPython/include to your list of include paths. [[TODO: Install
	300	these headers on Linux...]]</p>
	301	<p>You no longer need to call wxClassInfo::CleanUpClasses() and
	302	wxClassInfo::InitializeClasses() in your extensions or when embedding
	303	wxPython.</p>
	304	</div>
	305	<div class="section" id="two-or-three-phase-create">
	306	<h1><a name="two-or-three-phase-create">Two (or Three!) Phase Create</a></h1>
	307	<p>If you use the Precreate/Create method of instantiating a window, (for
	308	example, to set an extended style flag, or for XRC handlers) then
	309	there is now a new method named PostCreate to help with transplanting
	310	the brain of the prewindow instance into the derived window instance.
	311	For example:</p>
	312	<pre class="literal-block">
	313	class MyDialog(wx.Dialog):
	314	def __init__(self, parent, ID, title, pos, size, style):
	315	pre = wx.PreDialog()
	316	pre.SetExtraStyle(wx.DIALOG_EX_CONTEXTHELP)
	317	pre.Create(parent, ID, title, pos, size, style)
	318	self.PostCreate(pre)
	319	</pre>
	320	</div>
	321	<div class="section" id="sizers">
	322	<h1><a name="sizers">Sizers</a></h1>
	323	<p>The hack allowing the old "option" keyword parameter has been
	324	removed. If you use keyworkd args with wxSizer Add, Insert, or
	325	Prepend then you will need to use the "proportion" name instead of
	326	"option".</p>
	327	<p>When adding a spacer to a sizer you now need to use a wxSize or a
	328	2-integer sequence instead of separate width and height parameters.</p>
	329	<p>The wxGridBagSizer class (very similar to the RowColSizer in the
	330	library) has been added to C++ and wrapped for wxPython. It can also
	331	be used from XRC.</p>
	332	<p>You should not use AddWindow, AddSizer, AddSpacer (and similar for
	333	Insert, Prepend, and etc.) methods any longer. Just use Add and the
	334	wrappers will figure out what to do.</p>
	335	</div>
	336	<div class="section" id="other-stuff">
	337	<h1><a name="other-stuff">Other Stuff</a></h1>
	338	<p>Instead of over a dozen separate extension modules linked together
	339	into a single extension module, the "core" module is now just a few
	340	extensions that are linked independently, and then merged together
	341	later into the main namespace via Python code.</p>
	342	<p>Because of the above, the "internal" module names have changed, but
	343	you shouldn't have been using them anyway so it shouldn't bother
	344	you. ;-)</p>
	345	<p>The wxPython.help module no longer exists and the classes therein are
	346	now part of the core module imported with wxPython.wx or the wx
	347	package.</p>
	348	<p>wxPyDefaultPosition and wxPyDefaultSize are gone. Use the
	349	wxDefaultPosition and wxDefaultSize objects instead.</p>
	350	<p>Similarly, the wxSystemSettings backwards compatibiility aliases for
	351	GetSystemColour, GetSystemFont and GetSystemMetric have also gone into
	352	the bit-bucket. Use GetColour, GetFont and GetMetric instead.</p>
	353	<p>The wx.NO_FULL_REPAINT_ON_RESIZE style is now the default style for
	354	all windows. The name still exists for compatibility, but it is set
	355	to zero. If you want to disable the setting (so it matches the old
	356	default) then you need to use the new wx.FULL_REPAINT_ON_RESIZE style
	357	flag otherwise only the freshly exposed areas of the window will be
	358	refreshed.</p>
	359	<p>wxPyTypeCast has been removed. Since we've had the OOR (Original
	360	Object Return) for a couple years now there should be no need to use
	361	wxPyTypeCast at all.</p>
	362	</div>
	363	</div>
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