Cleanup QtWidgets (tools) examples

Cleanup QtWidgets tools examples:
 - use member-init (clang-tidy)
 - fix includes/don't include QtWidgets globally
 - include own header first
 - use nullptr (clang-tidy)
 - avoid c-style casts
 - use QVector instead QList
 - use QItemDelegate instead QStyledItemDelegate

Change-Id: Ibe9440cdf711e5cc2138c054864edebe1fc95731
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

1 files changed, 3 insertions, 3 deletions

diff --git a/examples/widgets/tools/settingseditor/variantdelegate.h b/examples/widgets/tools/settingseditor/variantdelegate.h
index 7cd9fa9ee8..68f21fa3f6 100644
--- a/examples/widgets/tools/settingseditor/variantdelegate.h
+++ b/examples/widgets/tools/settingseditor/variantdelegate.h
@@ -51,15 +51,15 @@
 #ifndef VARIANTDELEGATE_H
 #define VARIANTDELEGATE_H
 
-#include <QItemDelegate>
+#include <QStyledItemDelegate>
 #include <QRegularExpression>
 
-class VariantDelegate : public QItemDelegate
+class VariantDelegate : public QStyledItemDelegate
 {
     Q_OBJECT
 
 public:
-    VariantDelegate(QObject *parent = 0);
+    VariantDelegate(QObject *parent = nullptr);
 
     void paint(QPainter *painter, const QStyleOptionViewItem &option,
                const QModelIndex &index) const override;