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, 7 insertions, 10 deletions

diff --git a/examples/widgets/tools/undoframework/diagramscene.cpp b/examples/widgets/tools/undoframework/diagramscene.cpp
index 63aad97cb1..65909ab6cb 100644
--- a/examples/widgets/tools/undoframework/diagramscene.cpp
+++ b/examples/widgets/tools/undoframework/diagramscene.cpp
@@ -48,27 +48,24 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
-
 #include "diagramscene.h"
 #include "diagramitem.h"
 
+#include <QGraphicsSceneMouseEvent>
+
 DiagramScene::DiagramScene(QObject *parent)
     : QGraphicsScene(parent)
-{
-    movingItem = 0;
-}
+{}
 
 void DiagramScene::mousePressEvent(QGraphicsSceneMouseEvent *event)
 {
     QPointF mousePos(event->buttonDownScenePos(Qt::LeftButton).x(),
                      event->buttonDownScenePos(Qt::LeftButton).y());
     const QList<QGraphicsItem *> itemList = items(mousePos);
-    movingItem = itemList.isEmpty() ? 0 : itemList.first();
+    movingItem = itemList.isEmpty() ? nullptr : itemList.first();
 
-    if (movingItem != 0 && event->button() == Qt::LeftButton) {
+    if (movingItem != nullptr && event->button() == Qt::LeftButton)
         oldPos = movingItem->pos();
-    }
 
     clearSelection();
     QGraphicsScene::mousePressEvent(event);
@@ -76,11 +73,11 @@ void DiagramScene::mousePressEvent(QGraphicsSceneMouseEvent *event)
 
 void DiagramScene::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 {
-    if (movingItem != 0 && event->button() == Qt::LeftButton) {
+    if (movingItem != nullptr && event->button() == Qt::LeftButton) {
         if (oldPos != movingItem->pos())
             emit itemMoved(qgraphicsitem_cast<DiagramItem *>(movingItem),
                            oldPos);
-        movingItem = 0;
+        movingItem = nullptr;
     }
     QGraphicsScene::mouseReleaseEvent(event);
 }