+<p>The usage of wxPyBeginAllowThreads and wxPyEndAllowThreads has changed
+slightly. wxPyBeginAllowThreads now returns a boolean value that must
+be passed to the coresponding wxPyEndAllowThreads function call. This
+is to help do the RightThing when calls to these two functions are
+nested, or if calls to external code in other extension modules that
+are wrapped in the standard Py_(BEGIN|END)_ALLOW_THERADS may result in
+wx event handlers being called (such as during the call to
+os.startfile.)</p>
+</div>
+<div class="section" id="two-or-three-phase-create">
+<h1><a name="two-or-three-phase-create">Two (or Three!) Phase Create</a></h1>
+<p>If you use the Precreate/Create method of instantiating a window, (for
+example, to set an extended style flag, or for XRC handlers) then
+there is now a new method named PostCreate to help with transplanting
+the brain of the prewindow instance into the derived window instance.
+For example:</p>
+<pre class="literal-block">
+class MyDialog(wx.Dialog):
+ def __init__(self, parent, ID, title, pos, size, style):
+ pre = wx.PreDialog()
+ pre.SetExtraStyle(wx.DIALOG_EX_CONTEXTHELP)
+ pre.Create(parent, ID, title, pos, size, style)
+ self.PostCreate(pre)
+</pre>
+</div>
+<div class="section" id="sizers">
+<h1><a name="sizers">Sizers</a></h1>
+<p>The hack allowing the old "option" keyword parameter has been removed.
+If you use keyword args with wx.Sizer Add, Insert, or Prepend methods
+then you will need to use the <tt class="docutils literal"><span class="pre">proportion</span></tt> name instead of
+<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>
+<p>When adding a spacer to a sizer you now need to use a wx.Size or a
+2-integer sequence instead of separate width and height parameters.
+This was optionally allowed in 2.4, but now it is required. This
+allows for more consistency in how you add the various types of items
+to a sizer. The first parameter defines the item (instead of the
+possibily first two, depending on if you are doing a spacer or not,)
+and that item can either be a window, a sizer or a spacer (which can
+be a sequence or a wx.Size.) Removing the option for separate width
+and height parameters greatly simplified the wrapper code.</p>
+<p>The wx.GridBagSizer class (very similar to the RowColSizer in the
+library) has been added to C++ and wrapped for wxPython. It can also
+be used from XRC.</p>
+<p>You should not use AddWindow, AddSizer, AddSpacer (and similar for
+Insert, Prepend, and etc.) methods any longer. Just use Add and the
+wrappers will figure out what to do. <strong>[Changed in 2.5.2.x]</strong>
+AddWindow, AddSizer, AddSpacer and etc. will now issue a
+DeprecationWarning. <strong>[Changed in 2.5.4.x]</strong> These methods have now
+been undeprecated at the request of Riaan Booysen, the Boa Constructor
+team lead. They are now just simple compatibility aliases for Add,
+and etc.</p>
+<p><strong>[Changed in 2.5.2.x]</strong> The Sizers have had some fundamental internal
+changes in the 2.5.2.x release intended to make them do more of the
+"Right Thing" but also be as backwards compatible as possible.
+First a bit about how things used to work:</p>
+<blockquote>
+<ul class="simple">
+<li>The size that a window had when Add()ed to the sizer was assumed
+to be its minimal size, and that size would always be used by
+default when calculating layout size and positions, and the
+sizer itself would keep track of that minimal size.</li>
+<li>If the window item was added with the <tt class="docutils literal"><span class="pre">wx.ADJUST_MINSIZE</span></tt>
+flag then when layout was calculated the item's <tt class="docutils literal"><span class="pre">GetBestSize</span></tt>
+would be used to reset the minimal size that the sizer used.</li>
+</ul>
+</blockquote>
+<p>The main thrust of the new Sizer changes was to make behavior like
+<tt class="docutils literal"><span class="pre">wx.ADJUST_MINSIZE</span></tt> be the default, and also to push the tracking of
+the minimal size to the window itself (since it knows its own needs)
+instead of having the sizer take care of it. Consequently these
+changes were made:</p>
+<blockquote>
+<ul class="simple">
+<li>The <tt class="docutils literal"><span class="pre">wx.FIXED_MINSIZE</span></tt> flag was added to allow for the old
+behavior. When this flag is used the size a window has when
+added to the sizer will be treated as its minimal size and it
+will not be readjusted on each layout.</li>
+<li>The min size stored in <tt class="docutils literal"><span class="pre">wx.Window</span></tt> and settable with
+<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
+the sizer (if it was set) as the minimal size of the sizer item.
+If the min size was not set (or was only partially set) then the
+window's best size is fetched and it is used instead of (or
+blended with) the min size. <tt class="docutils literal"><span class="pre">wx.Window.GetBestFittingSize</span></tt>
+was added to facilitate getting the size to be used by the
+sizers.</li>
+<li>The best size of a window is cached so it doesn't need to
+recaculated on every layout. <tt class="docutils literal"><span class="pre">wx.Window.InvalidateBestSize</span></tt>
+was added and should be called (usually just internally in
+control methods) whenever something is done that would make the
+best size change.</li>
+<li>All wxControls were changed to set the minsize to what is passed
+to the constructor or Create method, and also to set the real
+size of the control to the blending of the min size and best
+size. <tt class="docutils literal"><span class="pre">wx.Window.SetBestFittingSize</span></tt> was added to help with
+this, although most controls don't need to call it directly
+because it is called indirectly via the <tt class="docutils literal"><span class="pre">SetInitialSize</span></tt>
+called in the base classes.</li>
+</ul>
+</blockquote>
+<p>At this time, the only situation known not to work the same as before
+is the following:</p>
+<pre class="literal-block">
+win = SomeWidget(parent)
+win.SetSize(SomeNonDefaultSize)
+sizer.Add(win)
+</pre>
+<p>In this case the old code would have used the new size as the minimum,
+but now the sizer will use the default size as the minimum rather than
+the size set later. It is an easy fix though, just move the
+specification of the size to the constructor (assuming that SomeWidget
+will set its minsize there like the rest of the controls do) or call
+<tt class="docutils literal"><span class="pre">SetMinSize</span></tt> instead of <tt class="docutils literal"><span class="pre">SetSize</span></tt>.</p>
+<p>In order to fit well with this new scheme of things, all wxControls or
+custom controls should do the following things. (Depending on how
+they are used you may also want to do the same thing for non-control
+custom windows.)</p>
+<blockquote>
+<ul>
+<li><p class="first">Either override or inherit a meaningful <tt class="docutils literal"><span class="pre">DoGetBestSize</span></tt> method
+that calculates whatever size is "best" for the control. Once
+that size is calculated then there should normally be a call to
+<tt class="docutils literal"><span class="pre">CacheBestSize</span></tt> to save it for later use, unless for some
+reason you want the best size to be recalculated on every
+layout.</p>
+<p>Note: In order to successfully override <tt class="docutils literal"><span class="pre">DoGetBestSize</span></tt> in
+Python the class needs to be derived from <tt class="docutils literal"><span class="pre">wx.PyWindow</span></tt>,
+<tt class="docutils literal"><span class="pre">wx.PyControl</span></tt>, or etc. If your class instead derives from
+one of the standard wx classes then just be sure that the min
+size gets explicitly set to what would have been the best size
+and things should work properly in almost all situations.</p>
+</li>
+<li><p class="first">Any method that changes the attributes of the control such that
+the best size will change should call <tt class="docutils literal"><span class="pre">InvalidateBestSize</span></tt> so
+it will be recalculated the next time it is needed.</p>
+</li>
+<li><p class="first">The control's constructor and/or Create method should ensure
+that the minsize is set to the size passed in, and that the
+control is sized to a blending of the min size and best size.
+This can be done by calling <tt class="docutils literal"><span class="pre">SetBestFittingSize</span></tt>.</p>
+</li>
+</ul>
+</blockquote>
+</div>
+<div class="section" id="platforminfo">
+<h1><a name="platforminfo">PlatformInfo</a></h1>
+<p>Added wx.PlatformInfo which is a tuple containing strings that
+describe the platform and build options of wxPython. This lets you
+know more about the build than just the __WXPORT__ value that
+wx.Platform contains, such as if it is a GTK2 build. For example,
+instead of:</p>
+<pre class="literal-block">
+if wx.Platform == "__WXGTK__":
+ ...
+</pre>
+<p>you should do this:</p>
+<pre class="literal-block">
+if "__WXGTK__" in wx.PlatformInfo:
+ ...
+</pre>
+<p>and you can specifically check for a wxGTK2 build by looking for
+"gtk2" in wx.PlatformInfo. Unicode builds are also detectable this
+way. If there are any other platform/toolkit/build flags that make
+sense to add to this tuple please let me know.</p>
+<p>BTW, wx.Platform will probably be deprecated in the future.</p>
+</div>
+<div class="section" id="activex">
+<h1><a name="activex">ActiveX</a></h1>
+<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
+extension module called wx.activex. It is very generic and dynamic
+and should allow hosting of arbitray ActiveX controls within your
+wxPython apps. So far I've tested it with IE, PDF, and Flash
+controls, (and there are new samples in the demo and also library
+modules supporting these.)</p>
+<p>The new wx.activex module contains a bunch of code, but the most
+important things to look at are ActiveXWindow and ActiveXEvent.
+ActiveXWindow derives from wxWindow and the constructor accepts a
+CLSID for the ActiveX Control that should be created. (There is also
+a CLSID class that can convert from a progID or a CLSID String.) The
+ActiveXWindow class simply adds methods that allow you to query some
+of the TypeInfo exposed by the ActiveX object, and also to get/set
+properties or call methods by name. The Python implementation
+automatically handles converting parameters and return values to/from
+the types expected by the ActiveX code as specified by the TypeInfo,
+(just bool, integers, floating point, strings and None/Empty so far,
+but more can be handled later.)</p>
+<p>That's pretty much all there is to the class, as I mentioned before it
+is very generic and dynamic. Very little is hard-coded and everything
+that is done with the actual ActiveX control is done at runtime and
+referenced by property or method name. Since Python is such a dynamic
+language this is a very good match. I thought for a while about doing
+some Python black-magic and making the specific methods/properties of
+the actual ActiveX control "appear" at runtime, but then decided that
+it would be better and more understandable to do it via subclassing.
+So there is a utility class in wx.activex that given an existing
+ActiveXWindow instance can generate a .py module containing a derived
+class with real methods and properties that do the Right Thing to
+reflect those calls to the real ActiveX control. There is also a
+script/tool module named genaxmodule that given a CLSID or progID and
+a class name, will generate the module for you. There are a few
+examples of the output of this tool in the wx.lib package, see
+iewin.py, pdfwin.py and flashwin.py.</p>
+<p>Currently the genaxmodule tool will tweak some of the names it
+generates, but this can be controled if you would like to do it
+differently by deriving your own class from GernerateAXModule,
+overriding some methods and then using this class from a tool like
+genaxmodule. [TODO: make specifying a new class on genaxmodule's
+command-line possible.] The current default behavior is that any
+event names that start with "On" will have the "On" dropped, property
+names are converted to all lower case, and if any name is a Python
+keyword it will have an underscore appended to it. GernerateAXModule
+does it's best when generating the code in the new module, but it can
+only be as good as the TypeInfo data available from the ActiveX
+control so sometimes some tweaking will be needed. For example, the
+IE web browser control defines the Flags parameter of the Navigate2
+method as required, but MSDN says it is optional.</p>
+<p>It is intended that this new wx.activex module will replace both the
+older version of Lindsay's code available in iewin.IEHtmlWindow, and
+also the wx.lib.activexwraper module. Probably the biggest
+differences you'll ecounter in migrating activexwrapper-based code
+(besides events working better without causing deadlocks) is that
+events are no longer caught by overriding methods in your derived
+class. Instead ActiveXWindow uses the wx event system and you bind
+handlers for the ActiveX events exactly the same way you do for any wx
+event. There is just one extra step needed and that is creating an
+event ID from the ActiveX event name, and if you use the genaxmodule
+tool then this extra step will be handled for you there. For example,
+for the StatusTextChange event in the IE web browser control, this
+code is generated for you:</p>
+<pre class="literal-block">
+wxEVT_StatusTextChange = wx.activex.RegisterActiveXEvent('StatusTextChange')
+EVT_StatusTextChange = wx.PyEventBinder(wxEVT_StatusTextChange, 1)
+</pre>
+<p>and you would use it in your code like this:</p>
+<pre class="literal-block">
+self.Bind(iewin.EVT_StatusTextChange, self.UpdateStatusText, self.ie)
+</pre>
+<p>When the event happens and your event handler function is called the
+event properties from the ActiveX control (if any) are converted to
+attributes of the event object passed to the handler. (Can you say
+'event' any more times in a single sentence? ;-) ) For example the
+StatusTextChange event will also send the text that should be put into
+the status line as an event parameter named "Text" and you can access
+it your handlers as an attribute of the event object like this:</p>
+<pre class="literal-block">
+def UpdateStatusText(self, evt):
+ self.SetStatusText(evt.Text)
+</pre>
+<p>Usually these event object attributes should be considered read-only,
+but some will be defined by the TypeInfo as output parameters. In
+those cases if you modify the event object's attribute then that value
+will be returned to the ActiveX control. For example, to prevent a
+new window from being opened by the IE web browser control you can do
+this in the handler for the iewin.EVT_NewWindow2 event:</p>
+<pre class="literal-block">
+def OnNewWindow2(self, evt):
+ evt.Cancel = True
+</pre>
+<p>So how do you know what methods, events and properties that an ActiveX
+control supports? There is a funciton in wx.activex named GetAXInfo
+that returns a printable summary of the TypeInfo from the ActiveX
+instance passed in. You can use this as an example of how to browse
+the TypeInfo provided, and there is also a copy of this function's
+output appended as a comment to the modules produced by the
+genaxmodule tool. Beyond that you'll need to consult the docs
+provided by the makers of the ActiveX control that you are using.</p>
+</div>
+<div class="section" id="png-images">
+<h1><a name="png-images">PNG Images</a></h1>
+<p>Prior to 2.5 the PNG image handler would convert all alpha channel
+information to a mask when the image was loaded. Pixels that were
+more than halfway transparent would be made fully transparent by the
+mask and the rest would be made fully opaque.</p>
+<p>In 2.5 the image handler has been updated to preserve the alpha
+channel and will now only create a mask when all the pixels in the
+image are either fully transparent or fully opaque. In addition, the
+wx.DC.DrawBitmap and wx.DC.Blit methods are able to correctly blend
+the pixels in the image with partially transparent alpha values.</p>
+<p>If you are using a PNG with an alpha channel but you need to have a
+wx.Mask like you automatically got in 2.4 then you can do one of the
+following:</p>
+<blockquote>
+<ul class="simple">
+<li>Edit the image and make all the partially transparent pixels be
+fully transparent.</li>
+<li>Use a different image type.</li>
+<li>Set a mask based on colour after you load the image.</li>
+</ul>
+</blockquote>
projects / wxWidgets.git / blobdiff