QmlDesigner: Add hint to set a property of the parent

This allows to do this in hints:

Hints {
   setParentProperty: "layer.enabled: true"
}

This will always set layer.enabled to true on the parent
if an item of this type is added. This is required for
adding effects from the item library.

Change-Id: Ic9600e0bbcde11df8d060d4a7ad05b4a590c8bea
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

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

@@ -70,6 +70,7 @@ public:
     bool visibleInNavigator() const;
     bool visibleInLibrary() const;
     QString forceNonDefaultProperty() const;
+    QPair<QString, QVariant> setParentProperty() const;
 
     QHash<QString, QString> hints() const;
     static NodeHints fromModelNode(const ModelNode &modelNode);

src/plugins/qmldesigner/designercore/metainfo/nodehints.cpp

@@ -259,6 +259,37 @@ QString NodeHints::forceNonDefaultProperty() const
     return Internal::evaluateExpression(expression, modelNode(), ModelNode()).toString();
 }
 
+QVariant parseValue(const QString &string)
+{
+    if (string == "true")
+        return true;
+    if (string == "false")
+        return false;
+    bool ok = false;
+    double d = string.toDouble(&ok);
+    if (ok)
+        return d;
+
+    return string;
+}
+
+QPair<QString, QVariant> NodeHints::setParentProperty() const
+{
+    const QString expression = m_hints.value("setParentProperty");
+
+    if (expression.isEmpty())
+        return {};
+
+    const QString str = Internal::evaluateExpression(expression, modelNode(), ModelNode()).toString();
+
+    QStringList list = str.split(":");
+
+    if (list.count() != 2)
+        return {};
+
+    return qMakePair(list.first().trimmed(), parseValue(list.last().trimmed()));
+}
+
 QHash<QString, QString> NodeHints::hints() const
 {
     return m_hints;

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

@@ -259,6 +259,8 @@ QmlObjectNode QmlVisualNode::createQmlObjectNode(AbstractView *view,
 {
     QmlObjectNode newQmlObjectNode;
 
+    NodeHints hints = NodeHints::fromItemLibraryEntry(itemLibraryEntry);
+
     auto createNodeFunc = [=, &newQmlObjectNode, &parentProperty]() {
         NodeMetaInfo metaInfo = view->model()->metaInfo(itemLibraryEntry.typeName());
 
@@ -310,6 +312,14 @@ QmlObjectNode QmlVisualNode::createQmlObjectNode(AbstractView *view,
 
     Q_ASSERT(newQmlObjectNode.isValid());
 
+    if (!hints.setParentProperty().first.isEmpty() && parentProperty.isValid()) {
+        ModelNode parent = parentProperty.parentModelNode();
+        const PropertyName property = hints.setParentProperty().first.toUtf8();
+        const QVariant value = hints.setParentProperty().second;
+
+        parent.variantProperty(property).setValue(value);
+    }
+
     return newQmlObjectNode;
 }