Add fast mimetype accessor for use by Konqueror when checking for media device icons

This relates to Bug 699
(cherry picked from commit a21cb20628)

kio/kio/kfileitem.cpp

@@ -47,8 +47,13 @@
 #include <krun.h>
 
 class KFileItem::KFileItemPrivate {
+	public:
+		KFileItemPrivate() : commentCached(false) {}
+
 	public:
 		TQString iconName;
+		TQString comment;
+		bool commentCached;
 };
 
 KFileItem::KFileItem( const KIO::UDSEntry& _entry, const KURL& _url,
@@ -239,8 +244,9 @@ void KFileItem::readUDSEntry( bool _urlIsDirectory )
         break;
 
       case KIO::UDS_ICON_NAME:
-        if ( !d )
+        if ( !d ) {
           d = new KFileItemPrivate();
+        }
         d->iconName = (*it).m_str;
         break;
 
@@ -279,6 +285,11 @@ void KFileItem::refresh()
 
 void KFileItem::refreshMimeType()
 {
+  if ( d ) {
+    d->iconName = TQString::null;
+    d->comment = TQString::null;
+    d->commentCached = false;
+  }
   m_pMimeType = 0L;
   init( false ); // Will determine the mimetype
 }
@@ -510,6 +521,16 @@ TQString KFileItem::mimetype() const
   return that->determineMimeType()->name();
 }
 
+TQString KFileItem::mimetypeFast() const
+{
+  if (isMimeTypeKnown()) {
+    return mimetype();
+  }
+  else {
+    return m_pMimeType->name();
+  }
+}
+
 KMimeType::Ptr KFileItem::determineMimeType()
 {
   if ( !m_pMimeType || !m_bMimeTypeKnown )
@@ -535,6 +556,8 @@ bool KFileItem::isMimeTypeKnown() const
 
 TQString KFileItem::mimeComment()
 {
+	if (d && (d->commentCached)) return d->comment;
+
 	KMimeType::Ptr mType = determineMimeType();
 	
 	bool isLocalURL;
@@ -542,10 +565,19 @@ TQString KFileItem::mimeComment()
 	
 	TQString comment = mType->comment( url, isLocalURL );
 	//kdDebug() << "finding comment for " << url.url() << " : " << m_pMimeType->name() << endl;
-  if (!comment.isEmpty())
-    return comment;
-  else
-    return mType->name();
+	if ( !d ) {
+		d = new KFileItemPrivate();
+	}
+	if (!comment.isEmpty()) {
+        	d->comment = comment;
+        	d->commentCached = true;
+	}
+	else {
+		d->comment = mType->name();
+		d->commentCached = true;
+	}
+
+	return d->comment;
 }
 
 TQString KFileItem::iconName()
@@ -556,7 +588,11 @@ TQString KFileItem::iconName()
   KURL url = mostLocalURL(isLocalURL);
 
   //kdDebug() << "finding icon for " << url.url() << " : " << m_pMimeType->name() << endl;
-  return determineMimeType()->icon(url, isLocalURL);
+  if ( !d ) {
+    d = new KFileItemPrivate();
+  }
+  d->iconName = determineMimeType()->icon(url, isLocalURL);
+  return d->iconName;
 }
 
 int KFileItem::overlays() const
@@ -745,12 +781,18 @@ TQString KFileItem::getStatusBarInfo()
 
   if ( m_bLink )
   {
-      TQString comment = determineMimeType()->comment( m_url, m_bIsLocalURL );
+      if ( !d ) {
+        d = new KFileItemPrivate();
+      }
+      if (!d->commentCached) {
+        d->comment = determineMimeType()->comment( m_url, m_bIsLocalURL );
+        d->commentCached = true;
+      }
       TQString tmp;
-      if ( comment.isEmpty() )
+      if ( d->comment.isEmpty() )
         tmp = i18n ( "Symbolic Link" );
       else
-        tmp = i18n("%1 (Link)").arg(comment);
+        tmp = i18n("%1 (Link)").arg(d->comment);
       text += "->";
       text += linkDest();
       text += "  ";
@@ -921,8 +963,9 @@ void KFileItem::assign( const KFileItem & item )
     determineMimeType();
 
     if ( item.d ) {
-        if ( !d )
+        if ( !d ) {
             d = new KFileItemPrivate;
+        }
         d->iconName = item.d->iconName;
     } else {
         delete d;
@@ -951,8 +994,11 @@ void KFileItem::setUDSEntry( const KIO::UDSEntry& _entry, const KURL& _url,
   m_guessedMimeType = TQString::null;
   m_metaInfo = KFileMetaInfo();
 
-  if ( d )
+  if ( d ) {
     d->iconName = TQString::null;
+    d->comment = TQString::null;
+    d->commentCached = false;
+  }
 
   readUDSEntry( _urlIsDirectory );
   init( _determineMimeTypeOnDemand );

kio/kio/kfileitem.h

@@ -312,6 +312,14 @@ public:
    */
   TQString mimetype() const;
 
+  /**
+   * Returns the mimetype of the file item.
+   * If @p _determineMimeTypeOnDemand was used in the constructor, this will return
+   * the mimetype as fast as possible at the expense of accuracy.
+   * @return the fast mime type of the file
+   */
+  TQString mimetypeFast() const;
+
   /**
    * Returns the mimetype of the file item.
    * If _determineMimeTypeOnDemand was used in the constructor, this will determine