Re: opening unknown file types in external applications

[Daniel J Sebald]

On 04/23/2013 04:06 PM, John W. Eaton wrote:
> On 04/23/2013 02:58 PM, Torsten wrote:
>
> > This one should do the job:
> >
> > QDesktopServices::openUrl (
> > QUrl::fromLocalFile ( const QString& localFile )
> > );
>
> OK, that works great to open files with their default applications,
> but what's the best way to recognize the files that should be opened
> in the Octave GUI's built-in editor?
>
> I don't see a general way to override the default editor or disable
> editing of text files so that openURL will return some kind of "sorry,
> I don't know how to open that file" status so that we can handle them
> internally in Octave. So it seems that we need to recognize the files
> we want to handle first, then call openURL. But nothing that I can
> think of (lists of filename patterns, binary vs. ASCII text, the Unix
> file program) really seems like a complete or reliable solution.
>
> Any ideas?

The description for the QDesktopServices object sounds like the feature 
to use, but it sure is skimpy as far as class members.  When I think of 
desktop services I think of the printer manager, etc.  That must not be 
the case.

There is a sample program that shows how to filter by extension and 
create menu groups:

http://qt-project.org/doc/qt-4.8/demos-embedded-desktopservices.html
http://qt-project.org/doc/qt-4.8/demos-embedded-desktopservices-contenttab-cpp.html

There is this method that will accept "file" as a scheme:

void QDesktopServices::setUrlHandler ( "file", QObject * receiver, const 
char * method )

"Sets the handler for the given scheme to be the handler method provided 
by the receiver object."

I'm not sure what that means though.  Can one write a method that will 
check the file name extension and if not of interest call the normal 
system openUrl()?

Dan