ResourcesProvider: added isLocal() method

Added isLocal() method for returning whether according provider class
provides local resources or not (will allow a download option for
non-local resources later).

Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>

include/local_resources_provider.h

@@ -51,6 +51,11 @@ public:
 	virtual QByteArray fetchData( const ResourcesItem * _item,
 						int _maxSize = -1 ) const;
 
+	virtual bool isLocal( void ) const
+	{
+		return true;
+	}
+
 
 private slots:
 	void addDirectory( const QString & _path );

include/resources_provider.h

@@ -45,6 +45,9 @@ public:
 	virtual int dataSize( const ResourcesItem * _item ) const = 0;
 	virtual QByteArray fetchData( const ResourcesItem * _item,
 					int _maxSize = -1 ) const = 0;
+	// return wether this provider provides local resources
+	virtual bool isLocal( void ) const = 0;
+
 	virtual bool cacheDatabase( void ) const
 	{
 		return true;

include/unified_resources_provider.h

@@ -64,6 +64,11 @@ public:
 		return QByteArray();
 	}
 
+	virtual bool isLocal( void ) const
+	{
+		return false;
+	}
+
 	virtual bool cacheDatabase( void ) const
 	{
 		return false;

include/web_resources_provider.h

@@ -58,6 +58,11 @@ public:
 	virtual QByteArray fetchData( const ResourcesItem * _item,
 					int _maxSize = -1 ) const;
 
+	virtual bool isLocal( void ) const
+	{
+		return false;
+	}
+
 
 private slots:
 	void finishDownload( int _id, bool );