make use of the model embedding

examples/dataengines/sourcesOnRequest/sourcesOnRequest.cpp

@@ -27,9 +27,12 @@
 
 #include <Plasma/DataContainer>
 
+#include <QStandardItemModel>
+
 /*
  This DataEngine shows how to created sources on demand as they are requested
  and update them on visualization-requested update intervals.
+ It also shows how to bind and arbitrary QAbstractItemModel to a source
 */
 
 SourcesOnRequestEngine::SourcesOnRequestEngine(QObject *parent, const QVariantList &args)
@@ -61,6 +64,15 @@ bool SourcesOnRequestEngine::sourceRequestEvent(const QString &source)
     // expects. So ALWAYS key the new data by the source string as below:
     setData(source, "Update Count", 0);
 
+    Plasma::DataContainer *s = containerForSource(source);
+    if (!s->model()) {
+        QStandardItemModel *m = new QStandardItemModel;
+        m->appendRow(new QStandardItem("Item1, first update"));
+        m->appendRow(new QStandardItem("Item2, first update"));
+        m->appendRow(new QStandardItem("Item3, first update"));
+        s->setModel(m);
+    }
+
     // as we successfully set up the source, return true
     return true;
 }
@@ -81,7 +93,17 @@ bool SourcesOnRequestEngine::updateSourceEvent(const QString &source)
     // sourceRequestEvent, however, this will result in expected behavior: visualizations
     // connected to the sources which have setData called for them will be notified
     // of these changes.
-    setData(source, "Update Count", containerForSource(source)->data().value("Update Count").toInt() + 1);
+    const int updateCount = containerForSource(source)->data().value("Update Count").toInt() + 1;
+    setData(source, "Update Count", updateCount);
+
+    Plasma::DataContainer *s = containerForSource(source);
+    if (!s->model()) {
+        QStandardItemModel *m = new QStandardItemModel;
+        m->appendRow(new QStandardItem("Item1, update " + updateCount));
+        m->appendRow(new QStandardItem("Item2, update " + updateCount));
+        m->appendRow(new QStandardItem("Item3, update " + updateCount));
+        s->setModel(m);
+    }
 
     // Since we updated the source immediately here, we need to return true so the DataEngine
     // knows to continue with the update notification for visualizations.

src/plasma/datacontainer.cpp

@@ -77,6 +77,11 @@ void DataContainer::setModel(QAbstractItemModel *model)
     emit modelChanged(objectName(), model);
 }
 
+QAbstractItemModel *DataContainer::model()
+{
+    return d->model.data();
+}
+
 void DataContainer::removeAllData()
 {
     if (d->data.isEmpty()) {

src/plasma/datacontainer.h

@@ -121,6 +121,11 @@ class PLASMA_EXPORT DataContainer : public QObject
          */
         void setModel(QAbstractItemModel *model);
 
+        /**
+         * @return the model owned by this DataSource
+         */
+        QAbstractItemModel *model();
+
         /**
          * @return true if the visualization is currently connected
          */