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, 5 insertions, 5 deletions

diff --git a/examples/widgets/tutorials/modelview/4_headers/main.cpp b/examples/widgets/tutorials/modelview/4_headers/main.cpp
index 82d493345d..90a8c6e894 100644
--- a/examples/widgets/tutorials/modelview/4_headers/main.cpp
+++ b/examples/widgets/tutorials/modelview/4_headers/main.cpp
@@ -48,16 +48,16 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets/QApplication>
-#include <QtWidgets/QTableView>
+#include <QApplication>
+#include <QTableView>
 #include "mymodel.h"
 
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
     QTableView tableView;
-    MyModel myModel(0);
-    tableView.setModel( &myModel );
+    MyModel myModel;
+    tableView.setModel(&myModel);
     tableView.show();
     return a.exec();
-}
\ No newline at end of file
+}