[KPhotoAlbum] Problems with the context menu in image view

[Robert Krawitz]

On Fri, 10 Sep 2010 19:47:42 -0400, Robert Krawitz wrote:
> A couple of problems I've found related in a general sense to the
> context menu in image view:
>
> 1) Invoke External Progam is *extremely* slow.  The first time I use
>    it on a fresh session, it takes several minutes (!) to pop up the
>    list of programs.  It appears the culprit is this, in
>    MainWindow/ExternalPopup.cpp:
>
>         // Fetch set of offers
>         OfferType offers;
>         if ( which == 0 )
>             offers = appInfos( QStringList() << current->fileName(DB::AbsolutePath) );
>         else
>             offers = appInfos( imageList );
>
>    appInfos(), in turn, calls mimeTypes(), which then does this:
>
> QString MainWindow::ExternalPopup::mimeType( const QString& file )
> {
>     return KFileItem( KFileItem::Unknown, KFileItem::Unknown, KUrl(file) ).mimetype();
> }

This is much faster (basically instantaneous).  It assumes that
everything with the same file extension has the same mime type.

With millions of images this might be a bit of a bottleneck...but
there are probably a lot of other issues up around there.  We could
save a little by reusing the offers for All Selected Items with Copy
and Open, but I leave that as an exercise for the reader.

Index: ExternalPopup.cpp
===================================================================
--- ExternalPopup.cpp	(revision 1173991)
+++ ExternalPopup.cpp	(working copy)
@@ -166,14 +166,21 @@
 
 QString MainWindow::ExternalPopup::mimeType( const QString& file )
 {
-    return KFileItem( KFileItem::Unknown, KFileItem::Unknown, KUrl(file) ).mimetype();
+    return KMimeType::findByPath(file, 0, true)->name();
 }
 
 Utilities::StringSet MainWindow::ExternalPopup::mimeTypes( const QStringList& files )
 {
     StringSet res;
+    StringSet extensions;
     for( QStringList::ConstIterator fileIt = files.begin(); fileIt != files.end(); ++fileIt ) {
-        res.insert( mimeType( *fileIt ) );
+	QString baseFileName = *fileIt;
+	int extStart = baseFileName.lastIndexOf(QChar::fromLatin1('.'));
+	baseFileName.remove(0, extStart);
+	if (! extensions.contains(baseFileName)) {
+	    res.insert( mimeType( *fileIt ) );
+	    extensions.insert( baseFileName );
+	}
     }
     return res;
 }