Itemviews: Cleanup examples

Cleanup some minor issues in the chart example:
 - remove unused members
 - use initializer list for members
 - pass a proper role to dataChanged()
 - honor roles parameter in PieView::dataChanged()
 - use nullptr instead 0
 - use new-style connect
 - fix indentation and other whitespaces

Change-Id: Idb212b07c006fe3ae31bee9cd9b1ba4d03043b5e
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

1 files changed, 6 insertions, 6 deletions

diff --git a/examples/widgets/tutorials/modelview/6_treeview/mainwindow.h b/examples/widgets/tutorials/modelview/6_treeview/mainwindow.h
index d625d5991d..65d9c18658 100644
--- a/examples/widgets/tutorials/modelview/6_treeview/mainwindow.h
+++ b/examples/widgets/tutorials/modelview/6_treeview/mainwindow.h
@@ -51,9 +51,9 @@
 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
-#include <QtWidgets/QMainWindow>
+#include <QMainWindow>
 
-QT_BEGIN_NAMESPACE // QT_BEGIN_NAMESPACE / QT_END_NAMESPACE are not needed in Qt user code
+QT_BEGIN_NAMESPACE
 class QTreeView; //forward declarations
 class QStandardItemModel;
 class QStandardItem;
@@ -66,11 +66,11 @@ class MainWindow : public QMainWindow
 private:
     QTreeView *treeView;
     QStandardItemModel *standardModel;
-    QList<QStandardItem *> prepareRow( const QString &first,
-                                       const QString &second,
-                                       const QString &third );
+    QList<QStandardItem *> prepareRow(const QString &first,
+                                      const QString &second,
+                                      const QString &third) const;
 public:
-    MainWindow(QWidget *parent = 0);
+    MainWindow(QWidget *parent = nullptr);
 };
 
 #endif // MAINWINDOW_H