add DataEngine::setModel

examples/dataengines/sourcesOnRequest/sourcesOnRequest.cpp

@@ -64,13 +64,12 @@ 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 (!model(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);
+        setModel(source, m);
     }
 
     // as we successfully set up the source, return true
@@ -96,9 +95,8 @@ bool SourcesOnRequestEngine::updateSourceEvent(const QString &source)
     const int updateCount = containerForSource(source)->data().value("Update Count").toInt() + 1;
     setData(source, "Update Count", updateCount);
 
-    Plasma::DataContainer *s = containerForSource(source);
+    QStandardItemModel *m = qobject_cast<QStandardItemModel *>(model(source));
-    QStandardItemModel *m = qobject_cast<QStandardItemModel *>(s->model());
+    if (m) {
-    if (s->model()) {
         m->clear();
         m->appendRow(new QStandardItem(QString("Item1, update %1").arg(updateCount)));
         m->appendRow(new QStandardItem(QString("Item2, update %1").arg(updateCount)));

src/plasma/dataengine.cpp

@@ -21,6 +21,7 @@
 #include "private/dataengine_p.h"
 #include "private/datacontainer_p.h"
 
+#include <QAbstractItemModel>
 #include <QQueue>
 #include <QTimer>
 #include <QTime>
@@ -227,6 +228,32 @@ void DataEngine::removeData(const QString &source, const QString &key)
     }
 }
 
+void DataEngine::setModel(const QString &source, QAbstractItemModel *model)
+{
+    if (model) {
+        setData(source, "HasModel", true);
+    } else {
+        removeData(source, "HasModel");
+    }
+
+    Plasma::DataContainer *s = containerForSource(source);
+
+    if (s) {
+        s->setModel(model);
+    }
+}
+
+QAbstractItemModel *DataEngine::model(const QString &source)
+{
+    Plasma::DataContainer *s = containerForSource(source);
+
+    if (s) {
+        return s->model();
+    } else {
+        return 0;
+    }
+}
+
 void DataEngine::addSource(DataContainer *source)
 {
     if (d->sources.contains(source->objectName())) {

src/plasma/dataengine.h

@@ -31,6 +31,8 @@
 #include <plasma/plasma.h>
 #include <plasma/service.h>
 
+class QAbstractItemModel;
+
 namespace Plasma
 {
 
@@ -306,6 +308,27 @@ Types::NoAlignment) const;
          **/
         void removeData(const QString &source, const QString &key);
 
+        /**
+         * Associates a model to a data source. If the source
+         * doesn't exist then it is created. The source will have the key "HasModel" to easily indicate there is a model present.
+         *
+         * The ownership of the model is transferred to the DataContainer,
+         * so the model will be deletd when a new one is set or when the
+         * DataContainer itself is deleted. As the DataContainer, it will be
+         * deleted when there won't be any
+         * visualization associated to this source.
+         *
+         * @param source the name of the data source
+         * @param model the model instance
+         */
+        void setModel(const QString &source, QAbstractItemModel *model);
+
+        /**
+         * @return The model associated to a source if any. The ownership of the model stays with the DataContainer.
+         *         Returns 0 if there isn't any model associated or if the source doesn't exists.
+         */
+        QAbstractItemModel *model(const QString &source);
+
         /**
          * Adds an already constructed data source. The DataEngine takes
          * ownership of the DataContainer object. The objectName of the source