Cleanup QtWidgets (widgets) examples

Cleanup QtWidgets widgets 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

Change-Id: Ib56bb507eb2ef885f1ddc664050d3c7af92adb70
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

2 files changed, 28 insertions, 23 deletions

diff --git a/examples/widgets/widgets/windowflags/controllerwindow.cpp b/examples/widgets/widgets/windowflags/controllerwindow.cpp
index e2abad89f4..0e9a916988 100644
--- a/examples/widgets/widgets/windowflags/controllerwindow.cpp
+++ b/examples/widgets/widgets/windowflags/controllerwindow.cpp
@@ -48,10 +48,15 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
-
 #include "controllerwindow.h"
 
+#include <QCheckBox>
+#include <QCoreApplication>
+#include <QGroupBox>
+#include <QHBoxLayout>
+#include <QPushButton>
+#include <QRadioButton>
+
 //! [0]
 ControllerWindow::ControllerWindow(QWidget *parent)
     : QWidget(parent)
@@ -63,7 +68,7 @@ ControllerWindow::ControllerWindow(QWidget *parent)
 
     quitButton = new QPushButton(tr("&Quit"));
     connect(quitButton, &QPushButton::clicked,
-            qApp, &QApplication::quit);
+            qApp, &QCoreApplication::quit);
 
     QHBoxLayout *bottomLayout = new QHBoxLayout;
     bottomLayout->addStretch();
@@ -83,26 +88,25 @@ ControllerWindow::ControllerWindow(QWidget *parent)
 //! [1]
 void ControllerWindow::updatePreview()
 {
-    Qt::WindowFlags flags = 0;
+    Qt::WindowFlags flags;
 
-    if (windowRadioButton->isChecked()) {
+    if (windowRadioButton->isChecked())
         flags = Qt::Window;
-    } else if (dialogRadioButton->isChecked()) {
+    else if (dialogRadioButton->isChecked())
         flags = Qt::Dialog;
-    } else if (sheetRadioButton->isChecked()) {
+    else if (sheetRadioButton->isChecked())
         flags = Qt::Sheet;
-    } else if (drawerRadioButton->isChecked()) {
+    else if (drawerRadioButton->isChecked())
         flags = Qt::Drawer;
-    } else if (popupRadioButton->isChecked()) {
+    else if (popupRadioButton->isChecked())
         flags = Qt::Popup;
-    } else if (toolRadioButton->isChecked()) {
+    else if (toolRadioButton->isChecked())
         flags = Qt::Tool;
-    } else if (toolTipRadioButton->isChecked()) {
+    else if (toolTipRadioButton->isChecked())
         flags = Qt::ToolTip;
-    } else if (splashScreenRadioButton->isChecked()) {
+    else if (splashScreenRadioButton->isChecked())
         flags = Qt::SplashScreen;
 //! [1] //! [2]
-    }
 //! [2] //! [3]
 
     if (msWindowsFixedSizeDialogCheckBox->isChecked())
diff --git a/examples/widgets/widgets/windowflags/previewwindow.cpp b/examples/widgets/widgets/windowflags/previewwindow.cpp
index 8773dccb05..d7ebed7b3c 100644
--- a/examples/widgets/widgets/windowflags/previewwindow.cpp
+++ b/examples/widgets/widgets/windowflags/previewwindow.cpp
@@ -50,7 +50,9 @@
 
 #include "previewwindow.h"
 
-#include <QtWidgets>
+#include <QPushButton>
+#include <QTextEdit>
+#include <QVBoxLayout>
 
 //! [0]
 PreviewWindow::PreviewWindow(QWidget *parent)
@@ -81,23 +83,22 @@ void PreviewWindow::setWindowFlags(Qt::WindowFlags flags)
     QString text;
 
     Qt::WindowFlags type = (flags & Qt::WindowType_Mask);
-    if (type == Qt::Window) {
+    if (type == Qt::Window)
         text = "Qt::Window";
-    } else if (type == Qt::Dialog) {
+    else if (type == Qt::Dialog)
         text = "Qt::Dialog";
-    } else if (type == Qt::Sheet) {
+    else if (type == Qt::Sheet)
         text = "Qt::Sheet";
-    } else if (type == Qt::Drawer) {
+    else if (type == Qt::Drawer)
         text = "Qt::Drawer";
-    } else if (type == Qt::Popup) {
+    else if (type == Qt::Popup)
         text = "Qt::Popup";
-    } else if (type == Qt::Tool) {
+    else if (type == Qt::Tool)
         text = "Qt::Tool";
-    } else if (type == Qt::ToolTip) {
+    else if (type == Qt::ToolTip)
         text = "Qt::ToolTip";
-    } else if (type == Qt::SplashScreen) {
+    else if (type == Qt::SplashScreen)
         text = "Qt::SplashScreen";
-    }
 
     if (flags & Qt::MSWindowsFixedSizeDialogHint)
         text += "\n| Qt::MSWindowsFixedSizeDialogHint";