Creating FileRef object from QString

[Plasty Grove]

You're right about FileRef taking only const char *, and yes
QStringToTString doesn't help. But in addition, the function doesn't work. I
don't know if it's with the new qt libraries (I'm using 4.5.2). I took a
look at the macro definition for the function and it looks outdated. viz.

#define QStringToTString(s) TagLib::String(s.utf8().data(),
TagLib::String::UTF8)

QString no longer has a utf8() function.

But there is one thing I took away from this function that seems to work in
addition to toAscii() and that's toUtf8().data().

For some reason toUtf8().constData() doesn't work, but toUtf8().data()
works.

i.e.

TagLib::FileRef tagFile(qstr.toUtf8().data());

Would this be a more preferable way to do it than toAscii()?

Thanks,
Plasty.

PS: I also noticed that both Qt and taglib support utf16, but I tried it and
it didn't work and also I don't know much about UTF.


2009/12/6 Lukáš Lalinský <lalinsky at gmail.com>

> On Sat, Dec 5, 2009 at 10:29 PM, Michael Pyne <mpyne at purinchu.net> wrote:
> > On Saturday 05 December 2009 15:25:13 Plasty Grove wrote:
> >> That makes sense, but even the following doesn't work:
> >>
> >> QString qstr = "/home/mydir/music/song.mp3";
> >> QByteArray qbArray = qstr.toLocal8Bit();
> >> const char* str = qbArray.constData();
> >> TagLib::FileRef tagFile(str);
> >>
> >> In this case, I've got a local object which stores the value returned by
> >> toLocal8Bit() and which is in scope when I'm using str. Does qbArray get
> >> destroyed whenever constData() is called on it? When I'm debugging, I
> can
> >> still see str holding a value when it goes to the next step.
> >
> > Perhaps an encoding issue if you don't use straight US-ASCII for your
> file
> > names? In that case if "local8Bit" is not the encoding Taglib is
> expecting
> > you'll get weirdness.
> >
> > The KDE JuK music manager uses taglib and has TString/QString conversion
> code
> > (and I'm sure Amarok has the same thing) if you want to see how those
> projects
> > do it.
>
> TagLib::String will not help in this case, because it also represents
> Unicode string, like QString. FileRef's filename parameter on
> non-Windows platforms is char*, so you need the actual encoded bytes.
> In Qt you can use QFile::encodeName(string) to encode the filename the
> same way Qt does it for file dialogs or other places that interact
> with the filesystem. This can still fail in some cases (different
> mounted filesystems using different encodings), but it's the best you
> can do if you store filenames as Unicode strings.
>
> --
> Lukas Lalinsky
> lalinsky at gmail.com
> _______________________________________________
> taglib-devel mailing list
> taglib-devel at kde.org
> https://mail.kde.org/mailman/listinfo/taglib-devel
>
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