Reload material property groups when model changes

The property groups would be unloaded when a model is detached,
and it would be loaded when the model is attached.
The problem was that the unload function was missing for the
MaterialBrowserModel.

Task-number: QDS-7515
Change-Id: I89064a78552c10228c0b18e42c1e0df4a92fb4a6
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.cpp

@@ -105,9 +105,7 @@ bool MaterialBrowserModel::loadPropertyGroups(const QString &path)
 {
     bool ok = true;
 
-    if (m_propertyGroupsObj.isEmpty()) {
     QFile matPropsFile(path);
-
     if (!matPropsFile.open(QIODevice::ReadOnly)) {
         qWarning("Couldn't open propertyGroups.json");
         ok = false;
@@ -122,7 +120,6 @@ bool MaterialBrowserModel::loadPropertyGroups(const QString &path)
             m_propertyGroupsObj = matPropsJsonDoc.object();
         }
     }
-    }
 
     m_defaultMaterialSections.clear();
     m_principledMaterialSections.clear();
@@ -134,12 +131,25 @@ bool MaterialBrowserModel::loadPropertyGroups(const QString &path)
         QStringList customMatSections = m_propertyGroupsObj.value("CustomMaterial").toObject().keys();
         if (customMatSections.size() > 1) // as of now custom material has only 1 section, so we don't add it
             m_customMaterialSections.append(customMatSections);
+    } else {
+        m_propertyGroupsObj = {};
     }
     emit materialSectionsChanged();
 
     return ok;
 }
 
+void MaterialBrowserModel::unloadPropertyGroups()
+{
+    if (!m_propertyGroupsObj.isEmpty()) {
+        m_propertyGroupsObj = {};
+        m_defaultMaterialSections.clear();
+        m_principledMaterialSections.clear();
+        m_customMaterialSections.clear();
+        emit materialSectionsChanged();
+    }
+}
+
 QHash<int, QByteArray> MaterialBrowserModel::roleNames() const
 {
     static const QHash<int, QByteArray> roles {

src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.h

@@ -80,6 +80,7 @@ public:
     int materialIndex(const ModelNode &material) const;
     ModelNode materialAt(int idx) const;
     bool loadPropertyGroups(const QString &path);
+    void unloadPropertyGroups();
 
     void resetModel();
 

src/plugins/qmldesigner/components/materialbrowser/materialbrowserview.cpp

@@ -336,6 +336,11 @@ void MaterialBrowserView::modelAboutToBeDetached(Model *model)
 {
     m_widget->materialBrowserModel()->setMaterials({}, m_hasQuick3DImport);
 
+    if (m_propertyGroupsLoaded) {
+        m_propertyGroupsLoaded = false;
+        m_widget->materialBrowserModel()->unloadPropertyGroups();
+    }
+
     AbstractView::modelAboutToBeDetached(model);
 }