[PyQt] PyQt4 question

[Phil Thompson]

On Sunday 27 May 2007 1:10 pm, Detlev Offenbach wrote:
> On Sonntag, 27. Mai 2007, Phil Thompson wrote:
> > On Sunday 27 May 2007 12:37 pm, Detlev Offenbach wrote:
> > > On Sonntag, 27. Mai 2007, Phil Thompson wrote:
> > > > On Sunday 27 May 2007 11:50 am, Detlev Offenbach wrote:
> > > > > On Sonntag, 27. Mai 2007, Phil Thompson wrote:
> > > > > > On Saturday 26 May 2007 9:07 pm, Detlev Offenbach wrote:
> > > > > > > On Samstag, 26. Mai 2007, Phil Thompson wrote:
> > > > > > > > On Saturday 26 May 2007 7:58 pm, Detlev Offenbach wrote:
> > > > > > > > > On Samstag, 26. Mai 2007, Phil Thompson wrote:
> > > > > > > > > > On Saturday 26 May 2007 4:52 pm, Detlev Offenbach wrote:
> > > > > > > > > > > Hi,
> > > > > > > > > > >
> > > > > > > > > > > is there a PyQt equivalent to
> > > > > > > > > > > "qobject_cast<T*>(object)"?
> > > > > > > > > >
> > > > > > > > > > sip.cast()?
> > > > > > > > > >
> > > > > > > > > > But it shouldn't be necessary if the sub-class conversion
> > > > > > > > > > code has been properly implemented.
> > > > > > > > >
> > > > > > > > > How do I do that. I haven't wrapped complicated stuff like
> > > > > > > > > this so far. The situation is as follows. I have the
> > > > > > > > > following code:
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > self.plugins.extend(self.designer.pluginManager().instances
> > > > > > > > >() ) for plugin in self.plugins:
> > > > > > > > >             if isinstance(plugin,
> > > > > > > > > QDesignerFormEditorPluginInterface): if not
> > > > > > > > > plugin.isInitialized(): plugin.initialze(self.designer)
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > "self.designer.pluginManager().instances()" returns a list
> > > > > > > > > of QObject. The first if statement shall check, wether the
> > > > > > > > > returned QObject is of type
> > > > > > > > > QDesignerFormEditorPluginInterface. In C++ you would do it
> > > > > > > > > with code like
> > > > > > > > >
> > > > > > > > > if (
> > > > > > > > > (qobject_cast<QDesignerFormEditorPluginInterface*>(plugin))
> > > > > > > > > )
> > > > > > > > >
> > > > > > > > > How can the problem be solved with PyQt4 and Python?
> > > > > > > > >
> > > > > > > > > Note: self.designer.pluginManager() returns an object of
> > > > > > > > > type QDesignerPluginManager.
> > > > > > > >
> > > > > > > > The wrapper for QDesignerFormEditorPluginInterface must
> > > > > > > > define some %ConvertToSubClassCode which will use RTTI
> > > > > > > > provided by the instance to identify the right Python type
> > > > > > > > object. See how PyQt does it for QObject and QEvent. If the
> > > > > > > > instance doesn't provide any RTTI then you're stuck.
> > > > > > >
> > > > > > > Mustn't the %ConvertToSubClassCode go into the more general
> > > > > > > class (e.g. QObject)?
> > > > > >
> > > > > > No - just in a QObject sub-class in the module.
> > > > > >
> > > > > > > Is there a way to extend the QObject wrapper?
> > > > > >
> > > > > > That's what sip does under the covers.
> > > > >
> > > > > I am stuck at the moment due to my lack of sip know how. Below is
> > > > > the wrapper code in question. How does the %ConvertToSubClassCode
> > > > > have to be?
> > > > >
> > > > > -------------------------------------------------------------------
> > > > >-- -- -- -- - class QDesignerFormEditorPluginInterface
> > > > > {
> > > > >
> > > > > %TypeHeaderCode
> > > > > #include <abstractformeditorplugin.h>
> > > > > %End
> > > > >
> > > > > public:
> > > > >     virtual ~QDesignerFormEditorPluginInterface();
> > > > >
> > > > >     virtual bool isInitialized() const = 0;
> > > > >     virtual void initialize(QDesignerFormEditorInterface *core) =
> > > > > 0; virtual QAction *action() const = 0;
> > > > >
> > > > >     virtual QDesignerFormEditorInterface *core() const = 0;
> > > > > };
> > > > > -------------------------------------------------------------------
> > > > >-- -- -- --
> > > >
> > > > What RTTI is available for the code to determine what the class
> > > > really is? I can't see anything that is obviously suitable - in which
> > > > case you are stuck.
> > >
> > > In a C++ program one would do it with this statement
> > >
> > > qobject_cast<QDesignerFormEditorPluginInterface*>(object)
> > >
> > > where object is a pointer to a QObject. If the conversion code would be
> > > in QObject.sip, one could probably use the inherits() method of
> > > QObject.
> >
> > So that's what you put in your conversion code in your
> > QDesignerFormEditorPluginInterface class.
>
> I tried that before I posted to this list, but it didn't work. Phil, can
> you give a little help?

Post what you tried.

Phil