QmlDesigner: Add lock functionality to navigator

* Update icon font and change related theme and constants files
* Add locked column to Navigator
* Add auxiliary property "locked"
* Integrate locked feature into the following components:
  * Transition Editor
  * Connection Editor
  * Form Editor
  * Text Editor
  * Timeline
  * Navigator
  * State Editor

Task-number: QDS-826
Change-Id: Ibf3ae96e0d5daeb1ab00279b94df5aaabe75e0bb
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/StudioTheme/InternalConstants.qml

@@ -98,33 +98,37 @@ QtObject {
     readonly property string idAliasOff: "\u005B"
     readonly property string idAliasOn: "\u005C"
     readonly property string listView: "\u005D"
-    readonly property string mergeCells: "\u005E"
+    readonly property string lockOff: "\u005E"
-    readonly property string minus: "\u005F"
+    readonly property string lockOn: "\u005F"
-    readonly property string plus: "\u0060"
+    readonly property string mergeCells: "\u0060"
-    readonly property string redo: "\u0061"
+    readonly property string minus: "\u0061"
-    readonly property string splitColumns: "\u0062"
+    readonly property string plus: "\u0062"
-    readonly property string splitRows: "\u0063"
+    readonly property string redo: "\u0063"
-    readonly property string startNode: "\u0064"
+    readonly property string splitColumns: "\u0064"
-    readonly property string testIcon: "\u0065"
+    readonly property string splitRows: "\u0065"
-    readonly property string textAlignBottom: "\u0066"
+    readonly property string startNode: "\u0066"
-    readonly property string textAlignCenter: "\u0067"
+    readonly property string testIcon: "\u0067"
-    readonly property string textAlignLeft: "\u0068"
+    readonly property string textAlignBottom: "\u0068"
-    readonly property string textAlignMiddle: "\u0069"
+    readonly property string textAlignCenter: "\u0069"
-    readonly property string textAlignRight: "\u006A"
+    readonly property string textAlignLeft: "\u006A"
-    readonly property string textAlignTop: "\u006B"
+    readonly property string textAlignMiddle: "\u006B"
-    readonly property string textBulletList: "\u006C"
+    readonly property string textAlignRight: "\u006C"
-    readonly property string textFullJustification: "\u006D"
+    readonly property string textAlignTop: "\u006D"
-    readonly property string textNumberedList: "\u006E"
+    readonly property string textBulletList: "\u006E"
-    readonly property string tickIcon: "\u006F"
+    readonly property string textFullJustification: "\u006F"
-    readonly property string triState: "\u0070"
+    readonly property string textNumberedList: "\u0070"
-    readonly property string undo: "\u0071"
+    readonly property string tickIcon: "\u0071"
-    readonly property string upDownIcon: "\u0072"
+    readonly property string triState: "\u0072"
-    readonly property string upDownSquare2: "\u0073"
+    readonly property string undo: "\u0073"
-    readonly property string wildcard: "\u0074"
+    readonly property string upDownIcon: "\u0074"
-    readonly property string zoomAll: "\u0075"
+    readonly property string upDownSquare2: "\u0075"
-    readonly property string zoomIn: "\u0076"
+    readonly property string visibilityOff: "\u0076"
-    readonly property string zoomOut: "\u0077"
+    readonly property string visibilityOn: "\u0077"
-    readonly property string zoomSelection: "\u0078"
+    readonly property string wildcard: "\u0078"
+    readonly property string zoomAll: "\u0079"
+    readonly property string zoomIn: "\u007A"
+    readonly property string zoomOut: "\u007B"
+    readonly property string zoomSelection: "\u007C"
 
     readonly property font iconFont: Qt.font({
                                                  "family": controlIcons.name,

src/plugins/qmldesigner/components/componentcore/designeractionmanager.cpp

@@ -347,11 +347,11 @@ public:
                     && !selectionContext().currentSingleSelectedNode().isRootNode()
                     && selectionContext().currentSingleSelectedNode().hasParentProperty()) {
 
-                ActionTemplate *selectionAction = new ActionTemplate(QString(), &ModelNodeOperations::select);
-                selectionAction->setParent(menu());
-
                 parentNode = selectionContext().currentSingleSelectedNode().parentProperty().parentModelNode();
 
+                if (!ModelNode::isThisOrAncestorLocked(parentNode)) {
+                    ActionTemplate *selectionAction = new ActionTemplate(QString(), &ModelNodeOperations::select);
+                    selectionAction->setParent(menu());
                     selectionAction->setText(QString(QT_TRANSLATE_NOOP("QmlDesignerContextMenu", "Select parent: %1")).arg(
                                                  captionForModelNode(parentNode)));
 
@@ -361,11 +361,13 @@ public:
 
                     menu()->addAction(selectionAction);
                 }
-            foreach (const ModelNode &node, selectionContext().view()->allModelNodes()) {
+            }
+            for (const ModelNode &node : selectionContext().view()->allModelNodes()) {
                 if (node != selectionContext().currentSingleSelectedNode()
                         && node != parentNode
                         && contains(node, selectionContext().scenePosition())
-                        && !node.isRootNode()) {
+                        && !node.isRootNode()
+                        && !ModelNode::isThisOrAncestorLocked(node)) {
                     selectionContext().setTargetNode(node);
                     QString what = QString(QT_TRANSLATE_NOOP("QmlDesignerContextMenu", "Select: %1")).arg(captionForModelNode(node));
                     ActionTemplate *selectionAction = new ActionTemplate(what, &ModelNodeOperations::select);
@@ -377,6 +379,9 @@ public:
                     menu()->addAction(selectionAction);
                 }
             }
+
+            if (menu()->isEmpty())
+                action()->setEnabled(false);
         }
     }
 };

src/plugins/qmldesigner/components/componentcore/theme.h

@@ -107,6 +107,8 @@ public:
         idAliasOff,
         idAliasOn,
         listView,
+        lockOff,
+        lockOn,
         mergeCells,
         minus,
         plus,
@@ -129,6 +131,8 @@ public:
         undo,
         upDownIcon,
         upDownSquare2,
+        visibilityOff,
+        visibilityOn,
         wildcard,
         zoomAll,
         zoomIn,

src/plugins/qmldesigner/components/connectioneditor/connectionmodel.cpp

@@ -75,6 +75,23 @@ ConnectionModel::ConnectionModel(ConnectionView *parent)
     connect(this, &QStandardItemModel::dataChanged, this, &ConnectionModel::handleDataChanged);
 }
 
+Qt::ItemFlags ConnectionModel::flags(const QModelIndex &modelIndex) const
+{
+    if (!modelIndex.isValid())
+        return Qt::ItemIsEnabled;
+
+    if (!m_connectionView || !m_connectionView->model())
+        return Qt::ItemIsEnabled;
+
+    const int internalId = data(index(modelIndex.row(), TargetModelNodeRow), UserRoles::InternalIdRole).toInt();
+    ModelNode modelNode = m_connectionView->modelNodeForInternalId(internalId);
+
+    if (modelNode.isValid() && ModelNode::isThisOrAncestorLocked(modelNode))
+        return Qt::ItemIsEnabled;
+
+    return Qt::ItemIsSelectable | Qt::ItemIsEditable | Qt::ItemIsEnabled;
+}
+
 void ConnectionModel::resetModel()
 {
     beginResetModel();
@@ -82,7 +99,7 @@ void ConnectionModel::resetModel()
     setHorizontalHeaderLabels(QStringList({ tr("Target"), tr("Signal Handler"), tr("Action") }));
 
     if (connectionView()->isAttached()) {
-        for (const ModelNode modelNode : connectionView()->allModelNodes())
+        for (const ModelNode &modelNode : connectionView()->allModelNodes())
             addModelNode(modelNode);
     }
 
@@ -94,8 +111,8 @@ void ConnectionModel::resetModel()
 
 SignalHandlerProperty ConnectionModel::signalHandlerPropertyForRow(int rowNumber) const
 {
-    const int internalId = data(index(rowNumber, TargetModelNodeRow), Qt::UserRole + 1).toInt();
+    const int internalId = data(index(rowNumber, TargetModelNodeRow), UserRoles::InternalIdRole).toInt();
-    const QString targetPropertyName = data(index(rowNumber, TargetModelNodeRow), Qt::UserRole + 2).toString();
+    const QString targetPropertyName = data(index(rowNumber, TargetModelNodeRow), UserRoles::TargetPropertyNameRole).toString();
 
     ModelNode modelNode = connectionView()->modelNodeForInternalId(internalId);
     if (modelNode.isValid())
@@ -256,8 +273,8 @@ void ConnectionModel::updateTargetNode(int rowNumber)
 
 void ConnectionModel::updateCustomData(QStandardItem *item, const SignalHandlerProperty &signalHandlerProperty)
 {
-    item->setData(signalHandlerProperty.parentModelNode().internalId(), Qt::UserRole + 1);
+    item->setData(signalHandlerProperty.parentModelNode().internalId(), UserRoles::InternalIdRole);
-    item->setData(signalHandlerProperty.name(), Qt::UserRole + 2);
+    item->setData(signalHandlerProperty.name(), UserRoles::TargetPropertyNameRole);
 }
 
 ModelNode ConnectionModel::getTargetNodeForConnection(const ModelNode &connection) const

src/plugins/qmldesigner/components/connectioneditor/connectionmodel.h

@@ -48,7 +48,14 @@ public:
         TargetPropertyNameRow = 1,
         SourceRow = 2
     };
+    enum UserRoles {
+        InternalIdRole = Qt::UserRole + 1,
+        TargetPropertyNameRole
+    };
     ConnectionModel(ConnectionView *parent = nullptr);
+
+    Qt::ItemFlags flags(const QModelIndex &modelIndex) const override;
+
     void resetModel();
     SignalHandlerProperty signalHandlerPropertyForRow(int rowNumber) const;
     ConnectionView *connectionView() const;

src/plugins/qmldesigner/components/connectioneditor/connectionview.cpp

@@ -36,6 +36,8 @@
 #include <variantproperty.h>
 #include <signalhandlerproperty.h>
 
+#include <QTableView>
+
 namespace QmlDesigner {
 
 namespace  Internal {
@@ -162,6 +164,33 @@ void ConnectionView::selectedNodesChanged(const QList<ModelNode> & selectedNodeL
         emit connectionViewWidget()->setEnabledAddButton(selectedNodeList.count() == 1);
 }
 
+void ConnectionView::auxiliaryDataChanged(const ModelNode &node,
+                                          const PropertyName &name,
+                                          const QVariant &data)
+{
+    Q_UNUSED(node)
+
+    // Check if the auxiliary data is actually the locked property or if it is unlocked
+    if (name != QmlDesigner::lockedProperty || !data.toBool())
+        return;
+
+    QItemSelectionModel *selectionModel = connectionTableView()->selectionModel();
+    if (!selectionModel->hasSelection())
+        return;
+
+    QModelIndex modelIndex = selectionModel->currentIndex();
+    if (!modelIndex.isValid() || !model())
+        return;
+
+    const int internalId = connectionModel()->data(connectionModel()->index(modelIndex.row(),
+                                                                            ConnectionModel::TargetModelNodeRow),
+                                                   ConnectionModel::UserRoles::InternalIdRole).toInt();
+    ModelNode modelNode = modelNodeForInternalId(internalId);
+
+    if (modelNode.isValid() && ModelNode::isThisOrAncestorLocked(modelNode))
+        selectionModel->clearSelection();
+}
+
 void ConnectionView::importsChanged(const QList<Import> & /*addedImports*/, const QList<Import> & /*removedImports*/)
 {
     backendModel()->resetModel();

src/plugins/qmldesigner/components/connectioneditor/connectionview.h

@@ -69,6 +69,7 @@ public:
 
     void selectedNodesChanged(const QList<ModelNode> &selectedNodeList,
                               const QList<ModelNode> &lastSelectedNodeList) override;
+    void auxiliaryDataChanged(const ModelNode &node, const PropertyName &name, const QVariant &data) override;
 
     void importsChanged(const QList<Import> &addedImports, const QList<Import> &removedImports) override;
 

src/plugins/qmldesigner/components/formeditor/abstractformeditortool.cpp

@@ -189,7 +189,7 @@ FormEditorItem *AbstractFormEditorTool::topMovableFormEditorItem(const QList<QGr
 FormEditorItem* AbstractFormEditorTool::nearestFormEditorItem(const QPointF &point, const QList<QGraphicsItem*> &itemList)
 {
     FormEditorItem* nearestItem = nullptr;
-    foreach (QGraphicsItem *item, itemList) {
+    for (QGraphicsItem *item : itemList) {
         FormEditorItem *formEditorItem = FormEditorItem::fromQGraphicsItem(item);
 
         if (formEditorItem && formEditorItem->flowHitTest(point))
@@ -201,6 +201,9 @@ FormEditorItem* AbstractFormEditorTool::nearestFormEditorItem(const QPointF &poi
         if (formEditorItem->parentItem() && !formEditorItem->parentItem()->isContentVisible())
             continue;
 
+        if (formEditorItem && ModelNode::isThisOrAncestorLocked(formEditorItem->qmlItemNode().modelNode()))
+            continue;
+
         if (!nearestItem)
             nearestItem = formEditorItem;
         else if (formEditorItem->selectionWeigth(point, 1) < nearestItem->selectionWeigth(point, 0))

src/plugins/qmldesigner/components/formeditor/dragtool.cpp

@@ -250,7 +250,6 @@ void DragTool::dropEvent(const QList<QGraphicsItem *> &/*itemList*/, QGraphicsSc
         if (m_dragNode.isValid())
             view()->setSelectedModelNode(m_dragNode);
 
-
         m_dragNode = QmlItemNode();
 
         view()->changeToSelectionTool();

src/plugins/qmldesigner/components/formeditor/rubberbandselectionmanipulator.cpp

@@ -93,7 +93,7 @@ void RubberBandSelectionManipulator::select(SelectionType selectionType)
     QList<QGraphicsItem *> itemList = m_editorView->scene()->items(m_selectionRectangleElement.rect(), Qt::IntersectsItemBoundingRect);
     QList<QmlItemNode> newNodeList;
 
-    foreach (QGraphicsItem* item, itemList)
+    for (QGraphicsItem *item : itemList)
     {
         FormEditorItem *formEditorItem = FormEditorItem::fromQGraphicsItem(item);
 

src/plugins/qmldesigner/components/integration/designdocument.cpp

@@ -49,6 +49,7 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/idocument.h>
 #include <coreplugin/editormanager/editormanager.h>
+#include <utils/algorithm.h>
 
 #include <qmljs/qmljsmodelmanagerinterface.h>
 
@@ -57,6 +58,7 @@
 #include <QDebug>
 
 #include <QApplication>
+#include <QMessageBox>
 #include <QPlainTextEdit>
 #include <QRandomGenerator>
 
@@ -375,9 +377,41 @@ void DesignDocument::deleteSelected()
     if (!currentModel())
         return;
 
+    QStringList lockedNodes;
+    for (const ModelNode &modelNode : view()->selectedModelNodes()) {
+        for (const ModelNode &node : modelNode.allSubModelNodesAndThisNode()) {
+            if (node.isValid() && !node.isRootNode() && node.locked())
+                lockedNodes.push_back(node.id());
+        }
+    }
+
+    if (!lockedNodes.empty()) {
+        Utils::sort(lockedNodes);
+        QString detailedText = QString("<b>" + tr("Locked items:") + "</b><br>");
+
+        for (const auto &id : qAsConst(lockedNodes))
+            detailedText.append("- " + id + "<br>");
+
+        detailedText.chop(QString("<br>").size());
+
+        QMessageBox msgBox;
+        msgBox.setTextFormat(Qt::RichText);
+        msgBox.setIcon(QMessageBox::Question);
+        msgBox.setWindowTitle(tr("Delete/Cut Item"));
+        msgBox.setText(QString(tr("Deleting or cutting this item will modify locked items.") + "<br><br>%1")
+                               .arg(detailedText));
+        msgBox.setInformativeText(tr("Do you want to continue by removing the item (Delete) or removing it and copying it to the clipboard (Cut)?"));
+        msgBox.setStandardButtons(QMessageBox::Ok | QMessageBox::Cancel);
+        msgBox.setDefaultButton(QMessageBox::Ok);
+
+        if (msgBox.exec() == QMessageBox::Cancel)
+            return;
+    }
+
     rewriterView()->executeInTransaction("DesignDocument::deleteSelected", [this](){
         QList<ModelNode> toDelete = view()->selectedModelNodes();
-        foreach (ModelNode node, toDelete) {
+
+        for (ModelNode node : toDelete) {
             if (node.isValid() && !node.isRootNode() && QmlObjectNode::isValidQmlObjectNode(node))
                 QmlObjectNode(node).destroy();
         }

src/plugins/qmldesigner/components/navigator/navigatortreemodel.cpp

@@ -203,7 +203,7 @@ QVariant NavigatorTreeModel::data(const QModelIndex &index, int role) const
     if (role == ItemIsVisibleRole) // independent of column
         return m_view->isNodeInvisible(modelNode) ? Qt::Unchecked : Qt::Checked;
 
-    if (index.column() == 0) {
+    if (index.column() == ColumnType::Name) {
         if (role == Qt::DisplayRole) {
             return modelNode.displayName();
         } else if (role == Qt::DecorationRole) {
@@ -240,18 +240,24 @@ QVariant NavigatorTreeModel::data(const QModelIndex &index, int role) const
         } else if (role == ModelNodeRole) {
             return QVariant::fromValue<ModelNode>(modelNode);
         }
-    } else if (index.column() == 1) { //export
+    } else if (index.column() == ColumnType::Alias) { // export
         if (role == Qt::CheckStateRole)
             return currentQmlObjectNode.isAliasExported() ? Qt::Checked : Qt::Unchecked;
         else if (role == Qt::ToolTipRole)
             return tr("Toggles whether this item is exported as an "
                       "alias property of the root item.");
-    } else if (index.column() == 2) { //visible
+    } else if (index.column() == ColumnType::Visibility) { // visible
         if (role == Qt::CheckStateRole)
             return m_view->isNodeInvisible(modelNode) ? Qt::Unchecked : Qt::Checked;
         else if (role == Qt::ToolTipRole)
             return tr("Toggles the visibility of this item in the form editor.\n"
                       "This is independent of the visibility property in QML.");
+    } else if (index.column() == ColumnType::Lock) { // lock
+        if (role == Qt::CheckStateRole)
+            return modelNode.locked() ? Qt::Checked : Qt::Unchecked;
+        else if (role == Qt::ToolTipRole)
+            return tr("Toggles whether this item is locked.\n"
+                      "Locked items can't be modified or selected.");
     }
 
     return QVariant();
@@ -259,7 +265,16 @@ QVariant NavigatorTreeModel::data(const QModelIndex &index, int role) const
 
 Qt::ItemFlags NavigatorTreeModel::flags(const QModelIndex &index) const
 {
-    if (index.column() == 0)
+    if (index.column() == ColumnType::Alias
+        || index.column() == ColumnType::Visibility
+        || index.column() == ColumnType::Lock)
+        return Qt::ItemIsEnabled | Qt::ItemIsUserCheckable | Qt::ItemNeverHasChildren;
+
+    const ModelNode modelNode = modelNodeForIndex(index);
+    if (ModelNode::isThisOrAncestorLocked(modelNode))
+        return Qt::NoItemFlags;
+
+    if (index.column() == ColumnType::Name)
         return Qt::ItemIsEditable | Qt::ItemIsDropEnabled | Qt::ItemIsDragEnabled | Qt::ItemIsSelectable | Qt::ItemIsEnabled;
 
     return Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsUserCheckable
@@ -378,7 +393,7 @@ int NavigatorTreeModel::columnCount(const QModelIndex &parent) const
     if (parent.column() > 0)
         return 0;
 
-    return 3;
+    return ColumnType::Count;
 }
 
 ModelNode NavigatorTreeModel::modelNodeForIndex(const QModelIndex &index) const
@@ -792,11 +807,13 @@ Qt::DropActions NavigatorTreeModel::supportedDragActions() const
 bool NavigatorTreeModel::setData(const QModelIndex &index, const QVariant &value, int role)
 {
     ModelNode modelNode = modelNodeForIndex(index);
-    if (index.column() == 1 && role == Qt::CheckStateRole) {
+    if (index.column() == ColumnType::Alias && role == Qt::CheckStateRole) {
         QTC_ASSERT(m_view, return false);
         m_view->handleChangedExport(modelNode, value.toInt() != 0);
-    } else if (index.column() == 2 && role == Qt::CheckStateRole) {
+    } else if (index.column() == ColumnType::Visibility && role == Qt::CheckStateRole) {
         QmlVisualNode(modelNode).setVisibilityOverride(value.toInt() == 0);
+    } else if (index.column() == ColumnType::Lock && role == Qt::CheckStateRole) {
+        modelNode.setLocked(value.toInt() != 0);
     }
 
     return true;
@@ -806,7 +823,7 @@ void NavigatorTreeModel::notifyDataChanged(const ModelNode &modelNode)
 {
     const QModelIndex index = indexForModelNode(modelNode);
     const QAbstractItemModel *model = index.model();
-    const QModelIndex sibling = model ? model->sibling(index.row(), 2, index) : QModelIndex();
+    const QModelIndex sibling = model ? model->sibling(index.row(), ColumnType::Count - 1, index) : QModelIndex();
     emit dataChanged(index, sibling);
 }
 

src/plugins/qmldesigner/components/navigator/navigatortreemodel.h

@@ -49,6 +49,14 @@ class NavigatorTreeModel : public QAbstractItemModel, public NavigatorModelInter
 
 public:
 
+    enum ColumnType {
+        Name = 0,
+        Alias,
+        Visibility,
+        Lock,
+        Count
+    };
+
     explicit NavigatorTreeModel(QObject *parent = nullptr);
     ~NavigatorTreeModel() override;
 

src/plugins/qmldesigner/components/navigator/navigatorview.cpp

@@ -41,6 +41,7 @@
 #include <qmlitemnode.h>
 #include <rewritingexception.h>
 #include <nodeinstanceview.h>
+#include <theme.h>
 
 #include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/icore.h>
@@ -48,6 +49,7 @@
 #include <utils/algorithm.h>
 #include <utils/icon.h>
 #include <utils/utilsicons.h>
+#include <utils/stylehelper.h>
 
 #include <QHeaderView>
 #include <QTimer>
@@ -138,13 +140,14 @@ void NavigatorView::modelAttached(Model *model)
 
     QTreeView *treeView = treeWidget();
 
-    treeView->header()->setSectionResizeMode(0, QHeaderView::Stretch);
+    treeView->header()->setSectionResizeMode(NavigatorTreeModel::ColumnType::Name, QHeaderView::Stretch);
-    treeView->header()->resizeSection(1,26);
+    treeView->header()->resizeSection(NavigatorTreeModel::ColumnType::Alias, 26);
+    treeView->header()->resizeSection(NavigatorTreeModel::ColumnType::Visibility, 26);
+    treeView->header()->resizeSection(NavigatorTreeModel::ColumnType::Lock, 26);
     treeView->setIndentation(20);
 
     m_currentModelInterface->setFilter(false);
 
-
     QTimer::singleShot(0, this, [this, treeView]() {
         m_currentModelInterface->setFilter(
                     DesignerSettings::getValue(DesignerSettingsKey::NAVIGATOR_SHOW_ONLY_VISIBLE_ITEMS).toBool());
@@ -166,10 +169,6 @@ void NavigatorView::modelAttached(Model *model)
             }
         }
     });
-
-#ifdef _LOCK_ITEMS_
-    treeView->header()->resizeSection(2,20);
-#endif
 }
 
 void NavigatorView::modelAboutToBeDetached(Model *model)
@@ -332,9 +331,12 @@ void NavigatorView::nodeTypeChanged(const ModelNode &modelNode, const TypeName &
 }
 
 void NavigatorView::auxiliaryDataChanged(const ModelNode &modelNode,
-                                         const PropertyName & /*name*/,
+                                         const PropertyName &name,
-                                         const QVariant & /*data*/)
+                                         const QVariant &data)
 {
+    Q_UNUSED(name)
+    Q_UNUSED(data)
+
     m_currentModelInterface->notifyDataChanged(modelNode);
 }
 
@@ -613,33 +615,50 @@ void NavigatorView::setupWidget()
     connect(m_widget.data(), &NavigatorWidget::reverseOrderToggled, this, &NavigatorView::reverseOrderToggled);
 
 #ifndef QMLDESIGNER_TEST
+    const QString fontName = "qtds_propertyIconFont.ttf";
+
+    const QIcon visibilityOnIcon =
+            Utils::StyleHelper::getIconFromIconFont(fontName,
+                                                    Theme::getIconUnicode(Theme::Icon::visibilityOn),
+                                                    28, 28, QColor(Qt::white));
+    const QIcon visibilityOffIcon =
+            Utils::StyleHelper::getIconFromIconFont(fontName,
+                                                    Theme::getIconUnicode(Theme::Icon::visibilityOff),
+                                                    28, 28, QColor(Qt::white));
+
+    const QIcon aliasOnIcon =
+            Utils::StyleHelper::getIconFromIconFont(fontName,
+                                                    Theme::getIconUnicode(Theme::Icon::idAliasOn),
+                                                    28, 28, QColor(Qt::red));
+    const QIcon aliasOffIcon =
+            Utils::StyleHelper::getIconFromIconFont(fontName,
+                                                    Theme::getIconUnicode(Theme::Icon::idAliasOff),
+                                                    28, 28, QColor(Qt::white));
+
+    const QIcon lockOnIcon =
+            Utils::StyleHelper::getIconFromIconFont(fontName,
+                                                    Theme::getIconUnicode(Theme::Icon::lockOn),
+                                                    28, 28, QColor(Qt::white));
+    const QIcon lockOffIcon =
+            Utils::StyleHelper::getIconFromIconFont(fontName,
+                                                    Theme::getIconUnicode(Theme::Icon::lockOff),
+                                                    28, 28, QColor(Qt::white));
+
     auto idDelegate = new NameItemDelegate(this);
-    IconCheckboxItemDelegate *showDelegate =
-            new IconCheckboxItemDelegate(this,
-                                         Utils::Icons::EYE_OPEN_TOOLBAR.icon(),
-                                         Utils::Icons::EYE_CLOSED_TOOLBAR.icon());
 
-    IconCheckboxItemDelegate *exportDelegate =
+    IconCheckboxItemDelegate *visibilityDelegate =
-            new IconCheckboxItemDelegate(this,
+            new IconCheckboxItemDelegate(this, visibilityOnIcon, visibilityOffIcon);
-                                         Icons::EXPORT_CHECKED.icon(),
+
-                                         Icons::EXPORT_UNCHECKED.icon());
+    IconCheckboxItemDelegate *aliasDelegate =
+            new IconCheckboxItemDelegate(this, aliasOnIcon, aliasOffIcon);
 
-#ifdef _LOCK_ITEMS_
     IconCheckboxItemDelegate *lockDelegate =
-            new IconCheckboxItemDelegate(this,
+            new IconCheckboxItemDelegate(this, lockOnIcon, lockOffIcon);
-                                         Utils::Icons::LOCKED_TOOLBAR.icon(),
-                                         Utils::Icons::UNLOCKED_TOOLBAR.icon());
-#endif
 
-
+    treeWidget()->setItemDelegateForColumn(NavigatorTreeModel::ColumnType::Name, idDelegate);
-    treeWidget()->setItemDelegateForColumn(0, idDelegate);
+    treeWidget()->setItemDelegateForColumn(NavigatorTreeModel::ColumnType::Alias, aliasDelegate);
-#ifdef _LOCK_ITEMS_
+    treeWidget()->setItemDelegateForColumn(NavigatorTreeModel::ColumnType::Visibility, visibilityDelegate);
-    treeWidget()->setItemDelegateForColumn(1,lockDelegate);
+    treeWidget()->setItemDelegateForColumn(NavigatorTreeModel::ColumnType::Lock, lockDelegate);
-    treeWidget()->setItemDelegateForColumn(2,showDelegate);
-#else
-    treeWidget()->setItemDelegateForColumn(1, exportDelegate);
-    treeWidget()->setItemDelegateForColumn(2, showDelegate);
-#endif
 
 #endif //QMLDESIGNER_TEST
 }

src/plugins/qmldesigner/components/navigator/navigatorwidget.cpp

@@ -92,7 +92,6 @@ QList<QToolButton *> NavigatorWidget::createToolBarWidgets()
 {
     QList<QToolButton *> buttons;
 
-
     auto button = new QToolButton();
     button->setIcon(Icons::ARROW_LEFT.icon());
     button->setToolTip(tr("Become last sibling of parent (CTRL + Left)."));
@@ -180,7 +179,6 @@ void NavigatorWidget::enableNavigator()
     m_treeView->setEnabled(true);
 }
 
-
 NavigatorView *NavigatorWidget::navigatorView() const
 {
     return m_navigatorView.data();

src/plugins/qmldesigner/components/stateseditor/stateseditorview.cpp

@@ -30,6 +30,7 @@
 
 #include <QDebug>
 #include <QRegularExpression>
+#include <QMessageBox>
 #include <cmath>
 #include <memory>
 
@@ -42,6 +43,7 @@
 #include <qmlitemnode.h>
 #include <qmlstate.h>
 #include <annotationeditor/annotationeditor.h>
+#include <utils/algorithm.h>
 
 
 namespace QmlDesigner {
@@ -92,6 +94,41 @@ void StatesEditorView::removeState(int nodeId)
         if (nodeId > 0 && hasModelNodeForInternalId(nodeId)) {
             ModelNode stateNode(modelNodeForInternalId(nodeId));
             Q_ASSERT(stateNode.metaInfo().isSubclassOf("QtQuick.State"));
+
+            QmlModelState modelState(stateNode);
+            if (modelState.isValid()) {
+                QStringList lockedTargets;
+                const auto propertyChanges = modelState.propertyChanges();
+                for (const QmlPropertyChanges &change : propertyChanges) {
+                    const ModelNode target = change.target();
+                    if (target.locked())
+                        lockedTargets.push_back(target.id());
+                }
+
+                if (!lockedTargets.empty()) {
+                    Utils::sort(lockedTargets);
+                    QString detailedText = QString("<b>" + tr("Locked items:") + "</b><br>");
+
+                    for (const auto &id : qAsConst(lockedTargets))
+                        detailedText.append("- " + id + "<br>");
+
+                    detailedText.chop(QString("<br>").size());
+
+                    QMessageBox msgBox;
+                    msgBox.setTextFormat(Qt::RichText);
+                    msgBox.setIcon(QMessageBox::Question);
+                    msgBox.setWindowTitle(tr("Remove State"));
+                    msgBox.setText(QString(tr("Removing this state will modify locked items.") + "<br><br>%1")
+                                           .arg(detailedText));
+                    msgBox.setInformativeText(tr("Do you want to continue by removing the state?"));
+                    msgBox.setStandardButtons(QMessageBox::Ok | QMessageBox::Cancel);
+                    msgBox.setDefaultButton(QMessageBox::Ok);
+
+                    if (msgBox.exec() == QMessageBox::Cancel)
+                        return;
+                }
+            }
+
             NodeListProperty parentProperty = stateNode.parentProperty().toNodeListProperty();
 
             if (parentProperty.count() <= 1) {
@@ -104,7 +141,6 @@ void StatesEditorView::removeState(int nodeId)
                     setCurrentState(parentProperty.at(index - 1));
             }
 
-
             stateNode.destroy();
         }
     }  catch (const RewritingException &e) {

src/plugins/qmldesigner/components/timelineeditor/timelinegraphicsscene.cpp

@@ -428,6 +428,18 @@ void TimelineGraphicsScene::invalidateKeyframesForTarget(const ModelNode &target
         TimelineSectionItem::updateFramesForTarget(child, target);
 }
 
+void TimelineGraphicsScene::invalidateHeightForTarget(const ModelNode &target)
+{
+    if (!target.isValid())
+        return;
+
+    const auto children = m_layout->childItems();
+    for (auto child : children)
+        TimelineSectionItem::updateHeightForTarget(child, target);
+
+    invalidateLayout();
+}
+
 void TimelineGraphicsScene::invalidateScene()
 {
     ModelNode node = timelineView()->modelNodeForId(

src/plugins/qmldesigner/components/timelineeditor/timelinegraphicsscene.h

@@ -158,6 +158,7 @@ public:
 
     void invalidateSectionForTarget(const ModelNode &modelNode);
     void invalidateKeyframesForTarget(const ModelNode &modelNode);
+    void invalidateHeightForTarget(const ModelNode &modelNode);
 
     void invalidateScene();
     void invalidateScrollbar() override;

src/plugins/qmldesigner/components/timelineeditor/timelinemovableabstractitem.cpp

@@ -156,4 +156,9 @@ TimelineFrameHandle *TimelineMovableAbstractItem::asTimelineFrameHandle()
     return nullptr;
 }
 
+bool TimelineMovableAbstractItem::isLocked() const
+{
+    return false;
+}
+
 } // namespace QmlDesigner

src/plugins/qmldesigner/components/timelineeditor/timelinemovableabstractitem.h

@@ -69,6 +69,8 @@ public:
     virtual TimelineKeyframeItem *asTimelineKeyframeItem();
     virtual TimelineFrameHandle *asTimelineFrameHandle();
 
+    virtual bool isLocked() const;
+
 protected:
     int scrollOffset() const;
     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;

src/plugins/qmldesigner/components/timelineeditor/timelinemovetool.cpp

@@ -70,6 +70,9 @@ void TimelineMoveTool::mousePressEvent(TimelineMovableAbstractItem *item,
 {
     Q_UNUSED(item)
 
+    if (currentItem() && currentItem()->isLocked())
+        return;
+
     if (auto *current = currentItem()->asTimelineKeyframeItem()) {
         const qreal sourceFrame = qRound(current->mapFromSceneToFrame(current->rect().center().x()));
         const qreal targetFrame = qRound(current->mapFromSceneToFrame(event->scenePos().x()));
@@ -85,6 +88,9 @@ void TimelineMoveTool::mouseMoveEvent(TimelineMovableAbstractItem *item,
     if (!currentItem())
         return;
 
+    if (currentItem()->isLocked())
+        return;
+
     if (auto *current = currentItem()->asTimelineKeyframeItem()) {
         // prevent dragging if deselecting a keyframe (Ctrl+click and drag a selected keyframe)
         if (!current->highlighted())

src/plugins/qmldesigner/components/timelineeditor/timelinesectionitem.cpp

@@ -171,6 +171,17 @@ void TimelineSectionItem::updateFramesForTarget(QGraphicsItem *item, const Model
     }
 }
 
+void TimelineSectionItem::updateHeightForTarget(QGraphicsItem *item, const ModelNode &target)
+{
+    if (!target.isValid())
+        return;
+
+    if (auto sectionItem = qgraphicsitem_cast<TimelineSectionItem *>(item)) {
+        if (sectionItem->targetNode() == target)
+            sectionItem->updateHeight();
+    }
+}
+
 void TimelineSectionItem::moveAllFrames(qreal offset)
 {
     if (m_timeline.isValid())
@@ -313,6 +324,7 @@ void TimelineSectionItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
 
     if (event->button() == Qt::LeftButton) {
         event->accept();
+        if (!ModelNode::isThisOrAncestorLocked(m_targetNode))
             toggleCollapsed();
     }
 }
@@ -345,6 +357,7 @@ void TimelineSectionItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
         if (m_targetNode.isValid())
             m_targetNode.view()->setSelectedModelNode(m_targetNode);
     } else {
+        if (!ModelNode::isThisOrAncestorLocked(m_targetNode))
             toggleCollapsed();
     }
     update();
@@ -414,6 +427,12 @@ void TimelineSectionItem::updateFrames()
     update();
 }
 
+void TimelineSectionItem::updateHeight()
+{
+    invalidateHeight();
+    update();
+}
+
 void TimelineSectionItem::invalidateHeight()
 {
     int height = 0;
@@ -464,7 +483,8 @@ void TimelineSectionItem::invalidateFrames()
 
 bool TimelineSectionItem::collapsed() const
 {
-    return m_targetNode.isValid() && !m_targetNode.hasAuxiliaryData("timeline_expanded");
+    return m_targetNode.isValid()
+            && (!m_targetNode.hasAuxiliaryData("timeline_expanded") || m_targetNode.locked());
 }
 
 void TimelineSectionItem::createPropertyItems()
@@ -845,6 +865,11 @@ void TimelineBarItem::commitPosition(const QPointF & /*point*/)
     m_oldRect = QRectF();
 }
 
+bool TimelineBarItem::isLocked() const
+{
+    return sectionItem()->targetNode().isValid() && sectionItem()->targetNode().locked();
+}
+
 void TimelineBarItem::scrollOffsetChanged()
 {
     sectionItem()->invalidateBar();
@@ -904,7 +929,9 @@ void TimelineBarItem::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
     const auto p = event->pos();
 
     QRectF left, right;
-    if (handleRects(rect(), left, right)) {
+    if (isLocked() && rect().contains(p)) {
+        setCursor(QCursor(Qt::ForbiddenCursor));
+    } else if (handleRects(rect(), left, right)) {
         if (left.contains(p) || right.contains(p)) {
             if (cursor().shape() != Qt::SizeHorCursor)
                 setCursor(QCursor(Qt::SizeHorCursor));
@@ -920,6 +947,9 @@ void TimelineBarItem::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
 
 void TimelineBarItem::contextMenuEvent(QGraphicsSceneContextMenuEvent* event)
 {
+    if (isLocked())
+        return;
+
     QMenu menu;
     QAction* overrideColor = menu.addAction(tr("Override Color"));
 

src/plugins/qmldesigner/components/timelineeditor/timelinesectionitem.h

@@ -50,6 +50,8 @@ public:
     void itemMoved(const QPointF &start, const QPointF &end) override;
     void commitPosition(const QPointF &point) override;
 
+    bool isLocked() const override;
+
 protected:
     void scrollOffsetChanged() override;
     void paint(QPainter *painter,
@@ -100,6 +102,7 @@ public:
     static void updateData(QGraphicsItem *item);
     static void updateDataForTarget(QGraphicsItem *item, const ModelNode &target, bool *b);
     static void updateFramesForTarget(QGraphicsItem *item, const ModelNode &target);
+    static void updateHeightForTarget(QGraphicsItem *item, const ModelNode &target);
 
     void moveAllFrames(qreal offset);
     void scaleAllFrames(qreal scale);
@@ -121,6 +124,7 @@ protected:
 private:
     void updateData();
     void updateFrames();
+    void updateHeight();
     void invalidateHeight();
     void invalidateProperties();
     void invalidateFrames();

src/plugins/qmldesigner/components/timelineeditor/timelineview.cpp

@@ -236,6 +236,18 @@ void TimelineView::selectedNodesChanged(const QList<ModelNode> & /*selectedNodeL
         m_timelineWidget->graphicsScene()->update();
 }
 
+void TimelineView::auxiliaryDataChanged(const ModelNode &modelNode,
+                                        const PropertyName &name,
+                                        const QVariant &data)
+{
+    if (name == QmlDesigner::lockedProperty && data.toBool() && modelNode.isValid()) {
+        for (const auto &node : modelNode.allSubModelNodesAndThisNode()) {
+            if (node.hasAuxiliaryData("timeline_expanded"))
+                m_timelineWidget->graphicsScene()->invalidateHeightForTarget(node);
+        }
+    }
+}
+
 void TimelineView::propertiesAboutToBeRemoved(const QList<AbstractProperty> &propertyList)
 {
     for (const auto &property : propertyList) {

src/plugins/qmldesigner/components/timelineeditor/timelineview.h

@@ -62,6 +62,9 @@ public:
                                   PropertyChangeFlags propertyChange) override;
     void selectedNodesChanged(const QList<ModelNode> &selectedNodeList,
                               const QList<ModelNode> &lastSelectedNodeList) override;
+    void auxiliaryDataChanged(const ModelNode &node,
+                              const PropertyName &name,
+                              const QVariant &data) override;
 
     void propertiesAboutToBeRemoved(const QList<AbstractProperty> &propertyList) override;
     void propertiesRemoved(const QList<AbstractProperty> &propertyList) override;

src/plugins/qmldesigner/components/transitioneditor/transitioneditorgraphicsscene.cpp

@@ -218,7 +218,7 @@ void TransitionEditorGraphicsScene::invalidateSectionForTarget(const ModelNode &
 
     const QList<QGraphicsItem *> items = m_layout->childItems();
     for (auto child : items)
-        TimelineSectionItem::updateDataForTarget(child, target, &found);
+        TransitionEditorSectionItem::updateDataForTarget(child, target, &found);
 
     if (!found)
         invalidateScene();
@@ -227,6 +227,18 @@ void TransitionEditorGraphicsScene::invalidateSectionForTarget(const ModelNode &
     invalidateLayout();
 }
 
+void TransitionEditorGraphicsScene::invalidateHeightForTarget(const ModelNode &target)
+{
+    if (!target.isValid())
+        return;
+
+    const auto children = m_layout->childItems();
+    for (auto child : children)
+        TransitionEditorSectionItem::updateHeightForTarget(child, target);
+
+    invalidateLayout();
+}
+
 void TransitionEditorGraphicsScene::invalidateScene()
 {
     invalidateScrollbar();

src/plugins/qmldesigner/components/transitioneditor/transitioneditorgraphicsscene.h

@@ -93,6 +93,7 @@ public:
     void setRulerScaling(int scaling);
 
     void invalidateSectionForTarget(const ModelNode &modelNode);
+    void invalidateHeightForTarget(const ModelNode &modelNode);
 
     void invalidateScene();
     void invalidateCurrentValues();

src/plugins/qmldesigner/components/transitioneditor/transitioneditorsectionitem.cpp

@@ -196,6 +196,17 @@ void TransitionEditorSectionItem::updateData(QGraphicsItem *item)
         sectionItem->updateData();
 }
 
+void TransitionEditorSectionItem::updateHeightForTarget(QGraphicsItem *item, const ModelNode &target)
+{
+    if (!target.isValid())
+        return;
+
+    if (auto sectionItem = qgraphicsitem_cast<TransitionEditorSectionItem *>(item)) {
+        if (sectionItem->targetNode() == target)
+            sectionItem->updateHeight();
+    }
+}
+
 void TransitionEditorSectionItem::invalidateBar(QGraphicsItem *item)
 {
     if (auto sectionItem = qgraphicsitem_cast<TransitionEditorSectionItem *>(item))
@@ -360,6 +371,7 @@ void TransitionEditorSectionItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent
 
     if (event->button() == Qt::LeftButton) {
         event->accept();
+        if (!ModelNode::isThisOrAncestorLocked(m_targetNode))
             toggleCollapsed();
     }
 }
@@ -392,6 +404,7 @@ void TransitionEditorSectionItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *ev
         if (m_targetNode.isValid())
             m_targetNode.view()->setSelectedModelNode(m_targetNode);
     } else {
+        if (!ModelNode::isThisOrAncestorLocked(m_targetNode))
             toggleCollapsed();
     }
     update();
@@ -417,6 +430,12 @@ void TransitionEditorSectionItem::updateData()
     update();
 }
 
+void TransitionEditorSectionItem::updateHeight()
+{
+    invalidateHeight();
+    update();
+}
+
 const QList<QGraphicsItem *> TransitionEditorSectionItem::propertyItems() const
 {
     QList<QGraphicsItem *> list;
@@ -488,7 +507,8 @@ void TransitionEditorSectionItem::invalidateProperties()
 
 bool TransitionEditorSectionItem::collapsed() const
 {
-    return m_targetNode.isValid() && !m_targetNode.hasAuxiliaryData("timeline_expanded");
+    return m_targetNode.isValid()
+            && (!m_targetNode.hasAuxiliaryData("transition_expanded") || m_targetNode.locked());
 }
 
 qreal TransitionEditorSectionItem::rulerWidth() const
@@ -501,9 +521,9 @@ void TransitionEditorSectionItem::toggleCollapsed()
     QTC_ASSERT(m_targetNode.isValid(), return );
 
     if (collapsed())
-        m_targetNode.setAuxiliaryData("timeline_expanded", true);
+        m_targetNode.setAuxiliaryData("transition_expanded", true);
     else
-        m_targetNode.removeAuxiliaryData("timeline_expanded");
+        m_targetNode.removeAuxiliaryData("transition_expanded");
 
     invalidateHeight();
 }
@@ -592,6 +612,11 @@ void TransitionEditorBarItem::commitPosition(const QPointF & /*point*/)
     scrollOffsetChanged();
 }
 
+bool TransitionEditorBarItem::isLocked() const
+{
+    return sectionItem() && sectionItem()->targetNode().isValid() && sectionItem()->targetNode().locked();
+}
+
 void TransitionEditorBarItem::scrollOffsetChanged()
 {
     if (sectionItem())
@@ -637,7 +662,9 @@ void TransitionEditorBarItem::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
     const auto p = event->pos();
 
     QRectF left, right;
-    if (handleRects(rect(), left, right)) {
+    if (isLocked() && rect().contains(p)) {
+        setCursor(QCursor(Qt::ForbiddenCursor));
+    } else if (handleRects(rect(), left, right)) {
         if (left.contains(p) || right.contains(p)) {
             if (cursor().shape() != Qt::SizeHorCursor)
                 setCursor(QCursor(Qt::SizeHorCursor));

src/plugins/qmldesigner/components/transitioneditor/transitioneditorsectionitem.h

@@ -54,6 +54,8 @@ public:
     void itemMoved(const QPointF &start, const QPointF &end) override;
     void commitPosition(const QPointF &point) override;
 
+    bool isLocked() const override;
+
 protected:
     void scrollOffsetChanged() override;
     void paint(QPainter *painter,
@@ -106,6 +108,7 @@ public:
     static void updateData(QGraphicsItem *item);
     static void invalidateBar(QGraphicsItem *item);
     static void updateDataForTarget(QGraphicsItem *item, const ModelNode &target, bool *b);
+    static void updateHeightForTarget(QGraphicsItem *item, const ModelNode &target);
 
     void moveAllDurations(qreal offset);
     void scaleAllDurations(qreal scale);
@@ -125,6 +128,7 @@ protected:
     void contextMenuEvent(QGraphicsSceneContextMenuEvent *event) override;
 
 private:
+    void updateHeight();
     void invalidateHeight();
     void invalidateProperties();
     bool collapsed() const;

src/plugins/qmldesigner/components/transitioneditor/transitioneditorview.cpp

@@ -142,6 +142,18 @@ void TransitionEditorView::selectedNodesChanged(const QList<ModelNode> & /*selec
 
 }
 
+void TransitionEditorView::auxiliaryDataChanged(const ModelNode &modelNode,
+                                                const PropertyName &name,
+                                                const QVariant &data)
+{
+    if (name == QmlDesigner::lockedProperty && data.toBool() && modelNode.isValid()) {
+        for (const auto &node : modelNode.allSubModelNodesAndThisNode()) {
+            if (node.hasAuxiliaryData("transition_expanded"))
+                m_transitionEditorWidget->graphicsScene()->invalidateHeightForTarget(node);
+        }
+    }
+}
+
 void TransitionEditorView::propertiesAboutToBeRemoved(
     const QList<AbstractProperty> & /*propertyList */)
 {

src/plugins/qmldesigner/components/transitioneditor/transitioneditorview.h

@@ -60,6 +60,9 @@ public:
                                   PropertyChangeFlags propertyChange) override;
     void selectedNodesChanged(const QList<ModelNode> &selectedNodeList,
                               const QList<ModelNode> &lastSelectedNodeList) override;
+    void auxiliaryDataChanged(const ModelNode &node,
+                              const PropertyName &name,
+                              const QVariant &data) override;
 
     void propertiesAboutToBeRemoved(const QList<AbstractProperty> &propertyList) override;
     void propertiesRemoved(const QList<AbstractProperty> &propertyList) override;

src/plugins/qmldesigner/designercore/include/abstractview.h

@@ -147,6 +147,7 @@ public:
 
     void setSelectedModelNodes(const QList<ModelNode> &selectedNodeList);
     void setSelectedModelNode(const ModelNode &modelNode);
+
     void selectModelNode(const ModelNode &node);
     void deselectModelNode(const ModelNode &node);
     void clearSelectedModelNodes();

src/plugins/qmldesigner/designercore/include/modelnode.h

@@ -65,6 +65,8 @@ QMLDESIGNERCORE_EXPORT QList<Internal::InternalNodePointer> toInternalNodeList(c
 
 using PropertyListType = QList<QPair<PropertyName, QVariant> >;
 
+static const PropertyName lockedProperty = {("locked")};
+
 class QMLDESIGNERCORE_EXPORT ModelNode
 {
     friend QMLDESIGNERCORE_EXPORT bool operator ==(const ModelNode &firstNode, const ModelNode &secondNode);
@@ -216,6 +218,11 @@ public:
     void setGlobalStatus(const GlobalAnnotationStatus &status);
     void removeGlobalStatus();
 
+    bool locked() const;
+    void setLocked(bool value);
+
+    static bool isThisOrAncestorLocked(const ModelNode &node);
+
     qint32 internalId() const;
 
     void setNodeSource(const QString&);
@@ -241,6 +248,8 @@ public:
 private: // functions
     Internal::InternalNodePointer internalNode() const;
 
+    void removeLocked();
+    bool hasLocked() const;
 
 private: // variables
     Internal::InternalNodePointer m_internalNode;

src/plugins/qmldesigner/designercore/instances/nodeinstanceview.cpp

@@ -534,11 +534,11 @@ void NodeInstanceView::auxiliaryDataChanged(const ModelNode &node,
                                             const PropertyName &name,
                                             const QVariant &value)
 {
-    if (((node.isRootNode() && (name == "width" || name == "height")) || name == "invisible")
+    if (((node.isRootNode() && (name == "width" || name == "height")) || name == "invisible" || name == "locked")
             || name.endsWith(PropertyName("@NodeInstance"))) {
         if (hasInstanceForModelNode(node)) {
             NodeInstance instance = instanceForModelNode(node);
-            if (value.isValid() || name == "invisible") {
+            if (value.isValid() || name == "invisible" || name == "locked") {
                 PropertyValueContainer container{instance.instanceId(), name, value, TypeName()};
                 m_nodeInstanceServer->changeAuxiliaryValues({{container}});
             } else {

src/plugins/qmldesigner/designercore/model/abstractview.cpp

@@ -35,6 +35,7 @@
 #ifndef QMLDESIGNER_TEST
 #include <qmldesignerplugin.h>
 #include <viewmanager.h>
+#include <nodeabstractproperty.h>
 #endif
 
 #include <coreplugin/helpmanager.h>
@@ -397,7 +398,7 @@ QList<ModelNode> AbstractView::toModelNodeList(const QList<Internal::InternalNod
 QList<ModelNode> toModelNodeList(const QList<Internal::InternalNode::Pointer> &nodeList, AbstractView *view)
 {
     QList<ModelNode> newNodeList;
-    foreach (const Internal::InternalNode::Pointer &node, nodeList)
+    for (const Internal::InternalNode::Pointer &node : nodeList)
         newNodeList.append(ModelNode(node, view->model(), view));
 
     return newNodeList;
@@ -406,7 +407,7 @@ QList<ModelNode> toModelNodeList(const QList<Internal::InternalNode::Pointer> &n
 QList<Internal::InternalNode::Pointer> toInternalNodeList(const QList<ModelNode> &nodeList)
 {
     QList<Internal::InternalNode::Pointer> newNodeList;
-    foreach (const ModelNode &node, nodeList)
+    for (const ModelNode &node : nodeList)
         newNodeList.append(node.internalNode());
 
     return newNodeList;
@@ -414,15 +415,26 @@ QList<Internal::InternalNode::Pointer> toInternalNodeList(const QList<ModelNode>
 
 /*!
     Sets the list of nodes to the actual selected nodes specified by
-    \a selectedNodeList.
+    \a selectedNodeList if the node or its ancestors are not locked.
 */
 void AbstractView::setSelectedModelNodes(const QList<ModelNode> &selectedNodeList)
 {
-    model()->d->setSelectedNodes(toInternalNodeList(selectedNodeList));
+    QList<ModelNode> unlockedNodes;
+
+    for (const auto &modelNode : selectedNodeList) {
+        if (!ModelNode::isThisOrAncestorLocked(modelNode))
+            unlockedNodes.push_back(modelNode);
+    }
+
+    model()->d->setSelectedNodes(toInternalNodeList(unlockedNodes));
 }
 
 void AbstractView::setSelectedModelNode(const ModelNode &modelNode)
 {
+    if (ModelNode::isThisOrAncestorLocked(modelNode)) {
+        clearSelectedModelNodes();
+        return;
+    }
     setSelectedModelNodes({modelNode});
 }
 

src/plugins/qmldesigner/designercore/model/modelnode.cpp

@@ -1228,6 +1228,53 @@ void ModelNode::removeGlobalStatus()
     }
 }
 
+bool ModelNode::locked() const
+{
+    if (hasLocked())
+        return auxiliaryData(lockedProperty).toBool();
+
+    return false;
+}
+
+bool ModelNode::hasLocked() const
+{
+    return hasAuxiliaryData(lockedProperty);
+}
+
+void ModelNode::setLocked(bool value)
+{
+    setAuxiliaryData(lockedProperty, value);
+
+    if (value) {
+        // Remove newly locked node and all its descendants from potential selection
+        for (ModelNode node : allSubModelNodesAndThisNode()) {
+            node.deselectNode();
+            node.removeAuxiliaryData("timeline_expanded");
+            node.removeAuxiliaryData("transition_expanded");
+        }
+    }
+}
+
+void ModelNode::removeLocked()
+{
+    if (hasLocked())
+        removeAuxiliaryData(lockedProperty);
+}
+
+bool ModelNode::isThisOrAncestorLocked(const ModelNode &node)
+{
+    if (!node.isValid())
+        return false;
+
+    if (node.locked())
+        return true;
+
+    if (node.isRootNode() || !node.hasParentProperty())
+        return false;
+
+    return isThisOrAncestorLocked(node.parentProperty().parentModelNode());
+}
+
 void  ModelNode::setScriptFunctions(const QStringList &scriptFunctionList)
 {
     model()->d->setScriptFunctions(internalNode(), scriptFunctionList);