DataEngine::isEmpty() for shawn

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=738136

dataengine.cpp

@@ -425,6 +425,11 @@ bool DataEngine::isValid() const
     return d->valid;
 }
 
+bool DataEngine::isEmpty() const
+{
+    return d->sources.count() > 0;
+}
+
 void DataEngine::setValid(bool valid)
 {
     d->valid = valid;

dataengine.h

@@ -181,6 +181,12 @@ class PLASMA_EXPORT DataEngine : public QObject
          **/
         bool isValid() const;
 
+        /**
+         * Returns true if the data engine is empty, which is to say that it has no
+         * data sources currently.
+         */
+        bool isEmpty() const;
+
         /**
          * Sets the icon for this data engine
          **/