Refactoring document handling

The document handling in the qml designer was complicated source
code, which was initially intended for a non creator application.
To integrate new views it has to be changed and cleaned up. This
is the first major step in that direction.

Change-Id: Ie26f0aad7a03946d18bdb4c0759b246c5439d922
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>

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

@@ -34,6 +34,7 @@
 #include <nodemetainfo.h>
 #include <nodeabstractproperty.h>
 #include <QStandardItemModel>
+#include <QAbstractItemView>
 
 // silence gcc warnings about unused parameters
 
@@ -46,8 +47,6 @@ ComponentView::ComponentView(QObject *parent)
 {
 }
 
-
-
 void ComponentView::nodeAboutToBeRemoved(const ModelNode &removedNode)
 {
     removeSingleNodeFromList(removedNode);
@@ -74,6 +73,11 @@ void ComponentView::setComponentNode(const ModelNode &node)
     m_componentAction->setCurrentIndex(indexForNode(node));
 }
 
+QWidget *ComponentView::widget()
+{
+    return 0;
+}
+
 void ComponentView::appendWholeDocumentAsComponent()
 {
     QStandardItem *item = new QStandardItem(tr("whole document"));
@@ -110,7 +114,6 @@ void ComponentView::modelAttached(Model *model)
 
     AbstractView::modelAttached(model);
 
-    Q_ASSERT(model->masterModel());
     appendWholeDocumentAsComponent();
     searchForComponentAndAddToList(rootModelNode());