QmlDesigner: Add scene root material support to material editor/browser

If the scene root item is Material subclass, material library is not
created for the scene. Material editor and browser functionalities that
relate to having material library are disabled.
Material editor will always show the material that is the scene root.

Fixes: QDS-7374
Change-Id: Icd1c212c17b59e4a2caa6b3b4d7e615e68b21eb9
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

12 files changed, 116 insertions, 81 deletions

diff --git a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5informationnodeinstanceserver.cpp b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5informationnodeinstanceserver.cpp
index 365aca3cd3..dae4f975b4 100644
--- a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5informationnodeinstanceserver.cpp
+++ b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5informationnodeinstanceserver.cpp
@@ -342,24 +342,14 @@ void Qt5InformationNodeInstanceServer::resolveImportSupport()
 void Qt5InformationNodeInstanceServer::updateMaterialPreviewData(const QVector<PropertyValueContainer> &valueChanges)
 {
     const PropertyName matPrevPrefix("matPrev");
-    qint32 materialLibraryId = -1;
     for (const auto &container : valueChanges) {
-        if (container.name().startsWith(matPrevPrefix)) {
-            if (!hasInstanceForId(container.instanceId()))
-                continue;
-            if (materialLibraryId < 0) {
-                ServerNodeInstance instance = instanceForId(container.instanceId());
-                if (instance.id() == "__materialLibrary__")
-                    materialLibraryId = container.instanceId();
-            }
-            if (container.instanceId() == materialLibraryId) {
-                if (container.name() == "matPrevEnv")
-                    m_materialPreviewData.env = container.value().toString();
-                else if (container.name() == "matPrevEnvValue")
-                    m_materialPreviewData.envValue = container.value().toString();
-                else if (container.name() == "matPrevModel")
-                    m_materialPreviewData.model = container.value().toString();
-            }
+        if (container.instanceId() == 0) {
+            if (container.name() == "matPrevEnv")
+                m_materialPreviewData.env = container.value().toString();
+            else if (container.name() == "matPrevEnvValue")
+                m_materialPreviewData.envValue = container.value().toString();
+            else if (container.name() == "matPrevModel")
+                m_materialPreviewData.model = container.value().toString();
         }
     }
 }
diff --git a/share/qtcreator/qmldesigner/materialBrowserQmlSource/MaterialBrowser.qml b/share/qtcreator/qmldesigner/materialBrowserQmlSource/MaterialBrowser.qml
index bc8582d359..468b4fb424 100644
--- a/share/qtcreator/qmldesigner/materialBrowserQmlSource/MaterialBrowser.qml
+++ b/share/qtcreator/qmldesigner/materialBrowserQmlSource/MaterialBrowser.qml
@@ -67,8 +67,10 @@ Item {
         acceptedButtons: Qt.RightButton
 
         onClicked: {
-            root.currentMaterial = null
-            contextMenu.popup()
+            if (!materialBrowserModel.hasMaterialRoot) {
+                root.currentMaterial = null
+                contextMenu.popup()
+            }
         }
     }
 
@@ -162,6 +164,7 @@ Item {
 
         Row {
             width: root.width
+            enabled: !materialBrowserModel.hasMaterialRoot && materialBrowserModel.hasQuick3DImport
 
             SearchBox {
                 id: searchBox
@@ -186,22 +189,22 @@ Item {
             color: StudioTheme.Values.themeTextColor
             font.pixelSize: StudioTheme.Values.baseFontSize
             leftPadding: 10
-            visible: materialBrowserModel.hasQuick3DImport && materialBrowserModel.isEmpty && !searchBox.isEmpty()
+            visible: materialBrowserModel.hasQuick3DImport && materialBrowserModel.isEmpty
+                     && !searchBox.isEmpty() && !materialBrowserModel.hasMaterialRoot
         }
 
         Text {
-            text: qsTr("There are no materials in this project.<br>Select '<b>+</b>' to create one.")
-            textFormat: Text.RichText
-            color: StudioTheme.Values.themeTextColor
-            font.pixelSize: StudioTheme.Values.mediumFontSize
-            horizontalAlignment: Text.AlignHCenter
-            topPadding: 30
-            anchors.horizontalCenter: parent.horizontalCenter
-            visible: materialBrowserModel.hasQuick3DImport && materialBrowserModel.isEmpty && searchBox.isEmpty()
-        }
+            text: {
+                if (materialBrowserModel.hasMaterialRoot)
+                    qsTr("<b>Material Browser</b> is disabled inside a material component.")
+                else if (!materialBrowserModel.hasQuick3DImport)
+                    qsTr("To use <b>Material Browser</b>, first add the QtQuick3D module in the <b>Components</b> view.")
+                else if (materialBrowserModel.isEmpty && searchBox.isEmpty())
+                    qsTr("There are no materials in this project.<br>Select '<b>+</b>' to create one.")
+                else
+                    ""
+            }
 
-        Text {
-            text: qsTr("To use <b>Material Browser</b>, first add the QtQuick3D module in the <b>Components</b> view.");
             textFormat: Text.RichText
             color: StudioTheme.Values.themeTextColor
             font.pixelSize: StudioTheme.Values.mediumFontSize
@@ -209,8 +212,7 @@ Item {
             horizontalAlignment: Text.AlignHCenter
             wrapMode: Text.WordWrap
             width: root.width
-            anchors.horizontalCenter: parent.horizontalCenter
-            visible: !materialBrowserModel.hasQuick3DImport
+            visible: text !== ""
         }
 
         ScrollView {
diff --git a/share/qtcreator/qmldesigner/materialEditorQmlSources/MaterialEditorToolBar.qml b/share/qtcreator/qmldesigner/materialEditorQmlSources/MaterialEditorToolBar.qml
index ba980340fe..5d53bfc87d 100644
--- a/share/qtcreator/qmldesigner/materialEditorQmlSources/MaterialEditorToolBar.qml
+++ b/share/qtcreator/qmldesigner/materialEditorQmlSources/MaterialEditorToolBar.qml
@@ -50,7 +50,7 @@ Rectangle {
             normalColor: StudioTheme.Values.themeSectionHeadBackground
             iconSize: StudioTheme.Values.bigIconFontSize
             buttonSize: root.height
-            enabled: hasMaterial && hasModelSelection && hasQuick3DImport
+            enabled: hasMaterial && hasModelSelection && hasQuick3DImport && !hasMaterialRoot
             onClicked: root.toolBarAction(ToolBarAction.ApplyToSelected)
             tooltip: qsTr("Apply material to selected model.")
         }
@@ -61,7 +61,7 @@ Rectangle {
             normalColor: StudioTheme.Values.themeSectionHeadBackground
             iconSize: StudioTheme.Values.bigIconFontSize
             buttonSize: root.height
-            enabled: hasQuick3DImport
+            enabled: hasQuick3DImport && !hasMaterialRoot
             onClicked: root.toolBarAction(ToolBarAction.AddNewMaterial)
             tooltip: qsTr("Create new material.")
         }
@@ -72,7 +72,7 @@ Rectangle {
             normalColor: StudioTheme.Values.themeSectionHeadBackground
             iconSize: StudioTheme.Values.bigIconFontSize
             buttonSize: root.height
-            enabled: hasMaterial && hasQuick3DImport
+            enabled: hasMaterial && hasQuick3DImport && !hasMaterialRoot
             onClicked: root.toolBarAction(ToolBarAction.DeleteCurrentMaterial)
             tooltip: qsTr("Delete current material.")
         }
@@ -83,7 +83,7 @@ Rectangle {
             normalColor: StudioTheme.Values.themeSectionHeadBackground
             iconSize: StudioTheme.Values.bigIconFontSize
             buttonSize: root.height
-            enabled: hasMaterial && hasQuick3DImport
+            enabled: hasMaterial && hasQuick3DImport && !hasMaterialRoot
             onClicked: root.toolBarAction(ToolBarAction.OpenMaterialBrowser)
             tooltip: qsTr("Open material browser.")
         }
diff --git a/share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/HelperWidgets/SearchBox.qml b/share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/HelperWidgets/SearchBox.qml
index 8f0079249d..c50d2e1d68 100644
--- a/share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/HelperWidgets/SearchBox.qml
+++ b/share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/HelperWidgets/SearchBox.qml
@@ -136,7 +136,7 @@ Item {
             },
             State {
                 name: "hover"
-                when: searchFilterText.hovered && !searchFilterText.activeFocus
+                when: root.enabled && searchFilterText.hovered && !searchFilterText.activeFocus
                 PropertyChanges {
                     target: textFieldBackground
                     color: StudioTheme.Values.themeControlBackgroundHover
diff --git a/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.cpp b/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.cpp
index 2998cc38c8..78c25d2c2b 100644
--- a/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.cpp
+++ b/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.cpp
@@ -124,6 +124,20 @@ void MaterialBrowserModel::setHasModelSelection(bool b)
     emit hasModelSelectionChanged();
 }
 
+bool MaterialBrowserModel::hasMaterialRoot() const
+{
+    return m_hasMaterialRoot;
+}
+
+void MaterialBrowserModel::setHasMaterialRoot(bool b)
+{
+    if (m_hasMaterialRoot == b)
+        return;
+
+    m_hasMaterialRoot = b;
+    emit hasMaterialRootChanged();
+}
+
 TypeName MaterialBrowserModel::copiedMaterialType() const
 {
     return m_copiedMaterialType;
diff --git a/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.h b/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.h
index cb40ecd9d5..bafcdc1fa8 100644
--- a/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.h
+++ b/src/plugins/qmldesigner/components/materialbrowser/materialbrowsermodel.h
@@ -42,6 +42,7 @@ class MaterialBrowserModel : public QAbstractListModel
     Q_PROPERTY(int selectedIndex MEMBER m_selectedIndex NOTIFY selectedIndexChanged)
     Q_PROPERTY(bool hasQuick3DImport READ hasQuick3DImport WRITE setHasQuick3DImport NOTIFY hasQuick3DImportChanged)
     Q_PROPERTY(bool hasModelSelection READ hasModelSelection WRITE setHasModelSelection NOTIFY hasModelSelectionChanged)
+    Q_PROPERTY(bool hasMaterialRoot READ hasMaterialRoot WRITE setHasMaterialRoot NOTIFY hasMaterialRootChanged)
     Q_PROPERTY(TypeName copiedMaterialType READ copiedMaterialType WRITE setCopiedMaterialType NOTIFY copiedMaterialTypeChanged)
 
 public:
@@ -60,6 +61,9 @@ public:
     bool hasModelSelection() const;
     void setHasModelSelection(bool b);
 
+    bool hasMaterialRoot() const;
+    void setHasMaterialRoot(bool b);
+
     TypeName copiedMaterialType() const;
     void setCopiedMaterialType(const TypeName &matType);
 
@@ -88,6 +92,7 @@ signals:
     void isEmptyChanged();
     void hasQuick3DImportChanged();
     void hasModelSelectionChanged();
+    void hasMaterialRootChanged();
     void copiedMaterialTypeChanged();
     void selectedIndexChanged(int idx);
     void renameMaterialTriggered(const QmlDesigner::ModelNode &material, const QString &newName);
@@ -110,6 +115,7 @@ private:
     bool m_isEmpty = true;
     bool m_hasQuick3DImport = false;
     bool m_hasModelSelection = false;
+    bool m_hasMaterialRoot = false;
     TypeName m_copiedMaterialType;
 };
 
diff --git a/src/plugins/qmldesigner/components/materialbrowser/materialbrowserview.cpp b/src/plugins/qmldesigner/components/materialbrowser/materialbrowserview.cpp
index c8b788ea3a..51595656d5 100644
--- a/src/plugins/qmldesigner/components/materialbrowser/materialbrowserview.cpp
+++ b/src/plugins/qmldesigner/components/materialbrowser/materialbrowserview.cpp
@@ -127,6 +127,7 @@ void MaterialBrowserView::modelAttached(Model *model)
     AbstractView::modelAttached(model);
 
     m_widget->clearSearchFilter();
+    m_widget->materialBrowserModel()->setHasMaterialRoot(rootModelNode().isSubclassOf("QtQuick3D.Material"));
     m_hasQuick3DImport = model->hasImport("QtQuick3D");
 
     // Project load is already very busy and may even trigger puppet reset, so let's wait a moment
diff --git a/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.cpp b/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.cpp
index 435c531897..9323435db7 100644
--- a/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.cpp
+++ b/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.cpp
@@ -233,6 +233,20 @@ void MaterialEditorContextObject::setHasQuick3DImport(bool b)
     emit hasQuick3DImportChanged();
 }
 
+bool MaterialEditorContextObject::hasMaterialRoot() const
+{
+    return m_hasMaterialRoot;
+}
+
+void MaterialEditorContextObject::setHasMaterialRoot(bool b)
+{
+    if (b == m_hasMaterialRoot)
+        return;
+
+    m_hasMaterialRoot = b;
+    emit hasMaterialRootChanged();
+}
+
 bool MaterialEditorContextObject::hasModelSelection() const
 {
     return m_hasModelSelection;
diff --git a/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.h b/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.h
index 54d72171a5..ed1540d574 100644
--- a/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.h
+++ b/src/plugins/qmldesigner/components/materialeditor/materialeditorcontextobject.h
@@ -56,6 +56,7 @@ class MaterialEditorContextObject : public QObject
     Q_PROPERTY(bool hasActiveTimeline READ hasActiveTimeline NOTIFY hasActiveTimelineChanged)
     Q_PROPERTY(bool hasQuick3DImport READ hasQuick3DImport WRITE setHasQuick3DImport NOTIFY hasQuick3DImportChanged)
     Q_PROPERTY(bool hasModelSelection READ hasModelSelection WRITE setHasModelSelection NOTIFY hasModelSelectionChanged)
+    Q_PROPERTY(bool hasMaterialRoot READ hasMaterialRoot WRITE setHasMaterialRoot NOTIFY hasMaterialRootChanged)
 
     Q_PROPERTY(QQmlPropertyMap *backendValues READ backendValues WRITE setBackendValues NOTIFY backendValuesChanged)
 
@@ -105,6 +106,9 @@ public:
     bool hasQuick3DImport() const;
     void setHasQuick3DImport(bool b);
 
+    bool hasMaterialRoot() const;
+    void setHasMaterialRoot(bool b);
+
     bool hasModelSelection() const;
     void setHasModelSelection(bool b);
 
@@ -134,6 +138,7 @@ signals:
     void hasAliasExportChanged();
     void hasActiveTimelineChanged();
     void hasQuick3DImportChanged();
+    void hasMaterialRootChanged();
     void hasModelSelectionChanged();
 
 private:
@@ -155,6 +160,7 @@ private:
     bool m_aliasExport = false;
     bool m_hasActiveTimeline = false;
     bool m_hasQuick3DImport = false;
+    bool m_hasMaterialRoot = false;
     bool m_hasModelSelection = false;
 
     ModelNode m_selectedMaterial;
diff --git a/src/plugins/qmldesigner/components/materialeditor/materialeditorview.cpp b/src/plugins/qmldesigner/components/materialeditor/materialeditorview.cpp
index c0b766648b..295935e8ac 100644
--- a/src/plugins/qmldesigner/components/materialeditor/materialeditorview.cpp
+++ b/src/plugins/qmldesigner/components/materialeditor/materialeditorview.cpp
@@ -420,12 +420,15 @@ void MaterialEditorView::handleToolBarAction(int action)
         if (!model())
             break;
         executeInTransaction("MaterialEditorView:handleToolBarAction", [&] {
+            ModelNode matLib = materialLibraryNode();
+            if (!matLib.isValid())
+                return;
+
             NodeMetaInfo metaInfo = model()->metaInfo("QtQuick3D.DefaultMaterial");
             ModelNode newMatNode = createModelNode("QtQuick3D.DefaultMaterial", metaInfo.majorVersion(),
                                                                                 metaInfo.minorVersion());
             renameMaterial(newMatNode, "New Material");
-
-            materialLibraryNode().defaultNodeListProperty().reparentHere(newMatNode);
+            matLib.defaultNodeListProperty().reparentHere(newMatNode);
         });
         break;
     }
@@ -462,10 +465,8 @@ void MaterialEditorView::handlePreviewEnvChanged(const QString &envAndValue)
     PropertyName matPrevEnvValueAuxProp("matPrevEnvValue");
 
     auto renderPreviews = [=](const QString &auxEnv, const QString &auxValue) {
-        ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-        QTC_ASSERT(matLib.isValid(), return);
-        matLib.setAuxiliaryData(matPrevEnvAuxProp, auxEnv);
-        matLib.setAuxiliaryData(matPrevEnvValueAuxProp, auxValue);
+        rootModelNode().setAuxiliaryData(matPrevEnvAuxProp, auxEnv);
+        rootModelNode().setAuxiliaryData(matPrevEnvValueAuxProp, auxValue);
         QTimer::singleShot(0, this, &MaterialEditorView::requestPreviewRender);
         emitCustomNotification("refresh_material_browser", {});
     };
@@ -473,13 +474,11 @@ void MaterialEditorView::handlePreviewEnvChanged(const QString &envAndValue)
     if (env == "Color") {
         m_colorDialog.clear();
 
-        ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-        QTC_ASSERT(matLib.isValid(), return);
         // Store color to separate property to persist selection over non-color env changes
         PropertyName colorAuxProp("matPrevColor");
-        QString oldColor = matLib.auxiliaryData(colorAuxProp).toString();
-        QString oldEnv = matLib.auxiliaryData(matPrevEnvAuxProp).toString();
-        QString oldValue = matLib.auxiliaryData(matPrevEnvValueAuxProp).toString();
+        QString oldColor = rootModelNode().auxiliaryData(colorAuxProp).toString();
+        QString oldEnv = rootModelNode().auxiliaryData(matPrevEnvAuxProp).toString();
+        QString oldValue = rootModelNode().auxiliaryData(matPrevEnvValueAuxProp).toString();
 
         m_colorDialog = new QColorDialog(Core::ICore::dialogParent());
         m_colorDialog->setModal(true);
@@ -495,9 +494,7 @@ void MaterialEditorView::handlePreviewEnvChanged(const QString &envAndValue)
         QObject::connect(m_colorDialog, &QColorDialog::colorSelected,
                          m_colorDialog, [=](const QColor &color) {
             renderPreviews(env, color.name());
-            ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-            QTC_ASSERT(matLib.isValid(), return);
-            matLib.setAuxiliaryData(colorAuxProp, color.name());
+            rootModelNode().setAuxiliaryData(colorAuxProp, color.name());
         });
 
         QObject::connect(m_colorDialog, &QColorDialog::rejected,
@@ -519,9 +516,7 @@ void MaterialEditorView::handlePreviewModelChanged(const QString &modelStr)
     QTC_ASSERT(model(), return);
     QTC_ASSERT(model()->nodeInstanceView(), return);
 
-    ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-    QTC_ASSERT(matLib.isValid(), return);
-    matLib.setAuxiliaryData("matPrevModel", modelStr);
+    rootModelNode().setAuxiliaryData("matPrevModel", modelStr);
 
     QTimer::singleShot(0, this, &MaterialEditorView::requestPreviewRender);
     emitCustomNotification("refresh_material_browser", {});
@@ -570,6 +565,7 @@ void MaterialEditorView::setupQmlBackend()
 
     currentQmlBackend->widget()->installEventFilter(this);
     currentQmlBackend->contextObject()->setHasQuick3DImport(m_hasQuick3DImport);
+    currentQmlBackend->contextObject()->setHasMaterialRoot(m_hasMaterialRoot);
 
     m_stackedWidget->setCurrentWidget(currentQmlBackend->widget());
 
@@ -623,23 +619,20 @@ bool MaterialEditorView::noValidSelection() const
 void MaterialEditorView::initPreviewData()
 {
     if (model() && m_qmlBackEnd) {
-        ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-        if (matLib.isValid()) {
-            QString env = matLib.auxiliaryData("matPrevEnv").toString();
-            QString envValue = matLib.auxiliaryData("matPrevEnvValue").toString();
-            QString modelStr = matLib.auxiliaryData("matPrevModel").toString();
-            if (!envValue.isEmpty() && env != "Color" && env != "Default") {
-                env += '=';
-                env += envValue;
-            }
-            if (env.isEmpty())
-                env = "Default";
-            if (modelStr.isEmpty())
-                modelStr = "#Sphere";
-            QMetaObject::invokeMethod(m_qmlBackEnd->widget()->rootObject(),
-                                      "initPreviewData",
-                                      Q_ARG(QVariant, env), Q_ARG(QVariant, modelStr));
+        QString env = rootModelNode().auxiliaryData("matPrevEnv").toString();
+        QString envValue = rootModelNode().auxiliaryData("matPrevEnvValue").toString();
+        QString modelStr = rootModelNode().auxiliaryData("matPrevModel").toString();
+        if (!envValue.isEmpty() && env != "Color" && env != "Default") {
+            env += '=';
+            env += envValue;
         }
+        if (env.isEmpty())
+            env = "Default";
+        if (modelStr.isEmpty())
+            modelStr = "#Sphere";
+        QMetaObject::invokeMethod(m_qmlBackEnd->widget()->rootObject(),
+                                  "initPreviewData",
+                                  Q_ARG(QVariant, env), Q_ARG(QVariant, modelStr));
     }
 }
 
@@ -650,11 +643,15 @@ void MaterialEditorView::modelAttached(Model *model)
     m_locked = true;
 
     m_hasQuick3DImport = model->hasImport("QtQuick3D");
+    m_hasMaterialRoot = rootModelNode().isSubclassOf("QtQuick3D.Material");
 
-    // Creating the material library node on model attach causes errors as long as the type information
-    // not complete yet, so we keep checking until type info is complete.
-    if (m_hasQuick3DImport)
+    if (m_hasMaterialRoot) {
+        m_selectedMaterial = rootModelNode();
+    } else if (m_hasQuick3DImport) {
+        // Creating the material library node on model attach causes errors as long as the type
+        // information is not complete yet, so we keep checking until type info is complete.
         m_ensureMatLibTimer.start(500);
+    }
 
     if (!m_setupCompleted) {
         reloadQml();
@@ -868,6 +865,10 @@ void MaterialEditorView::duplicateMaterial(const ModelNode &material)
     QmlObjectNode sourceMat(material);
 
     executeInTransaction(__FUNCTION__, [&] {
+        ModelNode matLib = materialLibraryNode();
+        if (!matLib.isValid())
+            return;
+
         // create the duplicate material
         NodeMetaInfo metaInfo = model()->metaInfo(matType);
         QmlObjectNode duplicateMat = createModelNode(matType, metaInfo.majorVersion(), metaInfo.minorVersion());
@@ -889,7 +890,7 @@ void MaterialEditorView::duplicateMaterial(const ModelNode &material)
                 duplicateMat.setBindingProperty(prop.name(), prop.toBindingProperty().expression());
         }
 
-        materialLibraryNode().defaultNodeListProperty().reparentHere(duplicateMat);
+        matLib.defaultNodeListProperty().reparentHere(duplicateMat);
     });
 }
 
@@ -899,8 +900,10 @@ void MaterialEditorView::customNotification(const AbstractView *view, const QStr
     Q_UNUSED(view)
 
     if (identifier == "selected_material_changed") {
-        m_selectedMaterial = nodeList.first();
-        QTimer::singleShot(0, this, &MaterialEditorView::resetView);
+        if (!m_hasMaterialRoot) {
+            m_selectedMaterial = nodeList.first();
+            QTimer::singleShot(0, this, &MaterialEditorView::resetView);
+        }
     } else if (identifier == "apply_to_selected_triggered") {
         applyMaterialToSelectedModels(nodeList.first(), data.first().toBool());
     } else if (identifier == "rename_material") {
diff --git a/src/plugins/qmldesigner/components/materialeditor/materialeditorview.h b/src/plugins/qmldesigner/components/materialeditor/materialeditorview.h
index 1c52be87cf..cda537280f 100644
--- a/src/plugins/qmldesigner/components/materialeditor/materialeditorview.h
+++ b/src/plugins/qmldesigner/components/materialeditor/materialeditorview.h
@@ -131,6 +131,7 @@ private:
     bool m_locked = false;
     bool m_setupCompleted = false;
     bool m_hasQuick3DImport = false;
+    bool m_hasMaterialRoot = false;
 
     QPointer<QColorDialog> m_colorDialog;
 };
diff --git a/src/plugins/qmldesigner/designercore/model/abstractview.cpp b/src/plugins/qmldesigner/designercore/model/abstractview.cpp
index 3899d37d49..8bf0e4347f 100644
--- a/src/plugins/qmldesigner/designercore/model/abstractview.cpp
+++ b/src/plugins/qmldesigner/designercore/model/abstractview.cpp
@@ -834,7 +834,7 @@ void AbstractView::changeRootNodeType(const TypeName &type, int majorVersion, in
 void AbstractView::ensureMaterialLibraryNode()
 {
     ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-    if (matLib.isValid())
+    if (matLib.isValid() || rootModelNode().isSubclassOf("QtQuick3D.Material"))
         return;
 
     // Create material library node
@@ -863,13 +863,11 @@ void AbstractView::ensureMaterialLibraryNode()
 }
 
 // Returns ModelNode for project's material library.
+// Since this calls ensureMaterialLibraryNode(), it should only be called within a transaction.
 ModelNode AbstractView::materialLibraryNode()
 {
     ensureMaterialLibraryNode();
-
     ModelNode matLib = modelNodeForId(Constants::MATERIAL_LIB_ID);
-    QTC_ASSERT(matLib.isValid(), return {});
-
     return matLib;
 }