Add hasModelChildren property to delegates with QAbstractItemModel model type.

Also add some helper function to VisualDataModel:
- VisualDataModel::modelIndex(int) returns a QModelIndex which can be
  assigned to VisualDataModel::rootIndex
- VisualDataModel::parentModelIndex() returns a QModelIndex which can
  be assigned to VisualDataModel::rootIndex

2 files changed, 71 insertions, 39 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativevisualitemmodel.cpp b/src/declarative/graphicsitems/qdeclarativevisualitemmodel.cpp
index 207232d..7fa8cc4 100644
--- a/src/declarative/graphicsitems/qdeclarativevisualitemmodel.cpp
+++ b/src/declarative/graphicsitems/qdeclarativevisualitemmodel.cpp
@@ -262,6 +262,7 @@ public:
                 }
                 if (m_roles.count() == 1)
                     m_roleNames.insert("modelData", m_roles.at(0));
+                m_roleNames.insert("hasModelChildren", 0);
             } else if (m_listAccessor) {
                 m_roleNames.insert("modelData", 0);
                 if (m_listAccessor->type() == QDeclarativeListAccessor::Instance) {
@@ -473,11 +474,16 @@ QVariant QDeclarativeVisualDataModelDataMetaObject::initialValue(int propId)
         }
     } else if (model->m_abstractItemModel) {
         model->ensureRoles();
-        QHash<QByteArray,int>::const_iterator it = model->m_roleNames.find(propName);
-        if (it != model->m_roleNames.end()) {
-            roleToProp.insert(*it, propId);
+        if (propName == "hasModelChildren") {
             QModelIndex index = model->m_abstractItemModel->index(data->m_index, 0, model->m_root);
-            return model->m_abstractItemModel->data(index, *it);
+            return model->m_abstractItemModel->hasChildren(index);
+        } else {
+            QHash<QByteArray,int>::const_iterator it = model->m_roleNames.find(propName);
+            if (it != model->m_roleNames.end()) {
+                roleToProp.insert(*it, propId);
+                QModelIndex index = model->m_abstractItemModel->index(data->m_index, 0, model->m_root);
+                return model->m_abstractItemModel->data(index, *it);
+            }
         }
     }
     Q_ASSERT(!"Can never be reached");
@@ -784,34 +790,13 @@ void QDeclarativeVisualDataModel::setDelegate(QDeclarativeComponent *delegate)
     \qmlproperty QModelIndex VisualDataModel::rootIndex
 
     QAbstractItemModel provides a heirachical tree of data, whereas
-    QML only operates on list data. rootIndex allows the children of
+    QML only operates on list data.  \c rootIndex allows the children of
     any node in a QAbstractItemModel to be provided by this model.
 
     This property only affects models of type QAbstractItemModel.
 
     \code
     // main.cpp
-    Q_DECLARE_METATYPE(QModelIndex)
-
-    class MyModel : public QDirModel
-    {
-        Q_OBJECT
-    public:
-        MyModel(QDeclarativeContext *ctxt) : QDirModel(), context(ctxt) {
-            QHash<int,QByteArray> roles = roleNames();
-            roles.insert(FilePathRole, "path");
-            setRoleNames(roles);
-            context->setContextProperty("myModel", this);
-            context->setContextProperty("myRoot", QVariant::fromValue(index(0,0,QModelIndex())));
-        }
-
-        Q_INVOKABLE void setRoot(const QString &path) {
-            QModelIndex root = index(path);
-            context->setContextProperty("myRoot", QVariant::fromValue(root));
-        }
-
-        QDeclarativeContext *context;
-    };
 
     int main(int argc, char ** argv)
     {
@@ -819,7 +804,8 @@ void QDeclarativeVisualDataModel::setDelegate(QDeclarativeComponent *delegate)
 
         QDeclarativeView view;
 
-        MyModel model(view.rootContext());
+        QDirModel model;
+        view.rootContext()->setContextProperty("myModel", &model);
 
         view.setSource(QUrl("qrc:view.qml"));
         view.show();
@@ -835,18 +821,18 @@ void QDeclarativeVisualDataModel::setDelegate(QDeclarativeComponent *delegate)
     import Qt 4.7
 
     ListView {
+        id: view
         width: 200
         height: 200
         model: VisualDataModel {
             model: myModel
-            rootIndex: myRoot
             delegate: Component {
                 Rectangle {
-                    height: 25; width: 100
-                    Text { text: path }
+                    height: 25; width: 200
+                    Text { text: filePath }
                     MouseArea {
                         anchors.fill: parent;
-                        onClicked: myModel.setRoot(path)
+                        onClicked: if (hasModelChildren) view.model.rootIndex = view.model.modelIndex(index)
                     }
                 }
             }
@@ -854,19 +840,21 @@ void QDeclarativeVisualDataModel::setDelegate(QDeclarativeComponent *delegate)
     }
     \endcode
 
+    \sa modelIndex(), parentModelIndex()
 */
-QModelIndex QDeclarativeVisualDataModel::rootIndex() const
+QVariant QDeclarativeVisualDataModel::rootIndex() const
 {
     Q_D(const QDeclarativeVisualDataModel);
-    return d->m_root;
+    return QVariant::fromValue(d->m_root);
 }
 
-void QDeclarativeVisualDataModel::setRootIndex(const QModelIndex &root)
+void QDeclarativeVisualDataModel::setRootIndex(const QVariant &root)
 {
     Q_D(QDeclarativeVisualDataModel);
-    if (d->m_root != root) {
+    QModelIndex modelIndex = qvariant_cast<QModelIndex>(root);
+    if (d->m_root != modelIndex) {
         int oldCount = d->modelCount();
-        d->m_root = root;
+        d->m_root = modelIndex;
         int newCount = d->modelCount();
         if (d->m_delegate && oldCount)
             emit itemsRemoved(0, oldCount);
@@ -878,6 +866,47 @@ void QDeclarativeVisualDataModel::setRootIndex(const QModelIndex &root)
     }
 }
 
+
+/*!
+    \qmlmethod QModelIndex VisualDataModel::modelIndex(int index)
+
+    QAbstractItemModel provides a heirachical tree of data, whereas
+    QML only operates on list data.  This function assists in using
+    tree models in QML.
+
+    Returns a QModelIndex for the specified index.
+    This value can be assigned to rootIndex.
+
+    \sa rootIndex
+*/
+QVariant QDeclarativeVisualDataModel::modelIndex(int idx) const
+{
+    Q_D(const QDeclarativeVisualDataModel);
+    if (d->m_abstractItemModel)
+        return QVariant::fromValue(d->m_abstractItemModel->index(idx, 0, d->m_root));
+    return QVariant::fromValue(QModelIndex());
+}
+
+/*!
+    \qmlmethod QModelIndex VisualDataModel::parentModelIndex()
+
+    QAbstractItemModel provides a heirachical tree of data, whereas
+    QML only operates on list data.  This function assists in using
+    tree models in QML.
+
+    Returns a QModelIndex for the parent of the current rootIndex.
+    This value can be assigned to rootIndex.
+
+    \sa rootIndex
+*/
+QVariant QDeclarativeVisualDataModel::parentModelIndex() const
+{
+    Q_D(const QDeclarativeVisualDataModel);
+    if (d->m_abstractItemModel)
+        return QVariant::fromValue(d->m_abstractItemModel->parent(d->m_root));
+    return QVariant::fromValue(QModelIndex());
+}
+
 QString QDeclarativeVisualDataModel::part() const
 {
     Q_D(const QDeclarativeVisualDataModel);
diff --git a/src/declarative/graphicsitems/qdeclarativevisualitemmodel_p.h b/src/declarative/graphicsitems/qdeclarativevisualitemmodel_p.h
index d34bcaf..0a9173f 100644
--- a/src/declarative/graphicsitems/qdeclarativevisualitemmodel_p.h
+++ b/src/declarative/graphicsitems/qdeclarativevisualitemmodel_p.h
@@ -150,7 +150,7 @@ class Q_DECLARATIVE_EXPORT QDeclarativeVisualDataModel : public QDeclarativeVisu
     Q_PROPERTY(QDeclarativeComponent *delegate READ delegate WRITE setDelegate)
     Q_PROPERTY(QString part READ part WRITE setPart)
     Q_PROPERTY(QObject *parts READ parts CONSTANT)
-    Q_PROPERTY(QModelIndex rootIndex READ rootIndex WRITE setRootIndex NOTIFY rootIndexChanged)
+    Q_PROPERTY(QVariant rootIndex READ rootIndex WRITE setRootIndex NOTIFY rootIndexChanged)
     Q_CLASSINFO("DefaultProperty", "delegate")
 public:
     QDeclarativeVisualDataModel();
@@ -163,8 +163,11 @@ public:
     QDeclarativeComponent *delegate() const;
     void setDelegate(QDeclarativeComponent *);
 
-    QModelIndex rootIndex() const;
-    void setRootIndex(const QModelIndex &root);
+    QVariant rootIndex() const;
+    void setRootIndex(const QVariant &root);
+
+    Q_INVOKABLE QVariant modelIndex(int idx) const;
+    Q_INVOKABLE QVariant parentModelIndex() const;
 
     QString part() const;
     void setPart(const QString &);