[Qt-interest] Force file extension with QFileDialog::getSaveFileName?

[Eric Clark]

> -----Original Message-----
> From: qt-interest-bounces+eclark=ara.com at qt.nokia.com [mailto:qt-
> interest-bounces+eclark=ara.com at qt.nokia.com] On Behalf Of Eric Clark
> Sent: Wednesday, June 22, 2011 12:13 PM
> To: Qt Interest (qt-interest at trolltech.com)
> Subject: Re: [Qt-interest] Force file extension with
> QFileDialog::getSaveFileName?
> 
> 
> 
> > -----Original Message-----
> > From: qt-interest-bounces+eclark=ara.com at qt.nokia.com [mailto:qt-
> > interest-bounces+eclark=ara.com at qt.nokia.com] On Behalf Of Constantin
> > Makshin
> > Sent: Wednesday, June 22, 2011 12:03 PM
> > To: Qt Interest
> > Subject: Re: [Qt-interest] Force file extension with
> > QFileDialog::getSaveFileName?
> >
> > I don't want to insult anyone, but there's a problem with the way
> > those who expect setDefaultSuffix() to affect getSaveFileName() think.
> > There's simply no logic in that — getSaveFileName() is a *static*
> > function, so there's no way it can access non-static object members
> > (just because static functions don't have any object to work with) set
> > by setDefaultSuffix(). It's not specific to Qt or even C++, it's the way static
> functions work in any programming language.
> > I apologize if that sounds too rude.
> 
> It is only rude because you did not pay attention to everything that was said
> in the thread. Both David and I are fully aware of the fact that the function is
> only to be used with an instance of the dialog and not the static functions.
> Please pay attention to the whole thread next time before you go trying to
> explain how we don’t understand static functions in any language.

Ok, so I looked back through the thread and it looks as though David was still using the static function even after creating an instance. I tried to tell him to use an instance, but he was still calling the static function. Therefore, what I said was incorrect in that David was not aware of the static function call problem. But, I did try to set him straight... :)

> 
> David made an attempt to use the setDefaultSuffix function with an instance
> of the QFileDialog class, not the static function getSaveFileName, and it still
> does not do what the documentation says it should. So, if you want to help
> please don’t just show up in the middle of it without knowledge of
> everything that was going on. Or at least read the whole thread before you
> respond.
> 
> Thanks,
> Eric
> 
> >
> > As for the question about default extension in getSaveFileName(), in
> > my application I call it this way:
> >
> > QString fileName = QFileDialog::getSaveFileName(this, tr("Save
> > Technique"), m_technique->fileName(), MainWindow::tr("Production
> > Techniques XML (*.ptx *.ptxml);;All Files (*.*)"));
> >
> > And if the user doesn't change the filter and doesn't explicitly
> > specify any file extension, "ptx" is added automatically. I.e. if the
> > user types "somefile" into the file name box, fileName will be equal
> > to "somefile.ptx". And this works correctly at least on Windows and
> > GNU/Linux with KDE (once I asked a friend to test the application on
> > Mac OS X and didn't get any complaints related to default extension, but
> there was no thorough testing on that platform).
> >
> > On Wednesday, June 22, 2011 03:35:17 PM David Doria wrote:
> > > > Guys, nothing is wrong with the docu ;) The setDefaultSuffix
> > > > method only
> > has an impact on a QFileDialog *instance*, but the OP was calling the
> > *static* method which triggers the creation of a *native* file dialog,
> > which might or might not add the suffix by itself already. On Mac the
> > extension is added depending on the current filter, if  the filter
> > happens to be unique (e.g. "PNG (*.png)" as opposed to "Images (*.png,
> > *.jpg, *.bmp)"), on Windows not quite sure, KDE/Gnome native file
> > dialogs apparently don't auto-suffix your filename.
> > > >
> > > > That said, I am not even sure whether setDefaultSuffix() has an
> > > > impact on
> > the *native* file dialog - might be that Qt expands the filename
> > accordingly in "post production" (after the native dialog has returned).
> > > >
> > > > It works for sure with the Qt file dialog, but that one has
> > > > several
> > limitations and disadvantages. One being that the suffix cannot be
> > auto- applied depending on the selected filter (if you want to save
> > under multiple file formats, for instance, and the filter would
> > specify the format such as "Template" or "Document"). Only one suffix
> > can be supplied with setAutoSuffix.
> > > >
> > > > Cheers, Oliver
> > >
> > > Hi Oliver, they set me straight on making an instance of the dialog
> > > right away :)
> > >
> > > I'm not sure I follow the rest of what you said? Would you mind
> > > taking a look? The example has commented out an attempt with a
> > > static method (which apparently everyone agrees should not work),
> > > another commented section shows the attempt with setDefaultSuffix,
> > > and the uncommented section shows the manual method:
> > >
> > >
> >
> http://programmingexamples.net/index.php?title=Qt/Widgets/FileDialogDe
> > > faultSuffix
> > >
> > > Again the documentation says "This property specifies a string that
> > > will be added to the filename if it has no suffix already." and I'm
> > > just not seeing that happen.
> > >
> > > Thanks,
> > >
> > > David
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