QmlDesigner.Model: adding isComponent to ModelNode

This function checks if the ModelNode is a Component or has a delegate
which is a Component.

Change-Id: I6bc92c3246b58eb04a5d37722e821dbed52147e5
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

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

@@ -184,6 +184,8 @@ public:
 
     NodeSourceType nodeSourceType() const;
 
+    bool isComponent() const;
+
 private: // functions
     Internal::InternalNodePointer internalNode() const;
 

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

@@ -984,4 +984,26 @@ ModelNode::NodeSourceType ModelNode::nodeSourceType() const
 
 }
 
+bool ModelNode::isComponent() const
+{
+    if (!isValid())
+        throw InvalidModelNodeException(__LINE__, __FUNCTION__, __FILE__);
+
+    if (metaInfo().isFileComponent())
+        return true;
+
+    if (nodeSourceType() == ModelNode::NodeWithComponentSource)
+        return true;
+
+    if (metaInfo().isView() && hasNodeProperty("delegate")) {
+        if (nodeProperty("delegate").modelNode().metaInfo().isFileComponent())
+            return true;
+
+        if (nodeProperty("delegate").modelNode().nodeSourceType() == ModelNode::NodeWithComponentSource)
+            return true;
+    }
+
+    return false;
+}
+
 }