Revamp SQL examples to C++11

Changed signals and slots to new syntax, used nullptr and replaced
foreach with new C++11 range based for loops.
Also fixed a few minor flaws.

Task-number: QTBUG-60633
Change-Id: Ice4030133971912f96752d9d84c638c70fd73e35
Reviewed-by: Jesus Fernandez <Jesus.Fernandez@qt.io>
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

6 files changed, 19 insertions, 16 deletions

diff --git a/examples/sql/sqlbrowser/browser.cpp b/examples/sql/sqlbrowser/browser.cpp
index d86c54404d..b05cf52099 100644
--- a/examples/sql/sqlbrowser/browser.cpp
+++ b/examples/sql/sqlbrowser/browser.cpp
@@ -165,11 +165,12 @@ void Browser::showTable(const QString &t)
     model->select();
     if (model->lastError().type() != QSqlError::NoError)
         emit statusMessage(model->lastError().text());
+
     table->setModel(model);
     table->setEditTriggers(QAbstractItemView::DoubleClicked|QAbstractItemView::EditKeyPressed);
+    connect(table->selectionModel(), &QItemSelectionModel::currentRowChanged,
+            this, &Browser::currentChanged);
 
-    connect(table->selectionModel(), SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
-            this, SLOT(currentChanged()));
     updateActions();
 }
 
@@ -189,7 +190,6 @@ void Browser::showMetaData(const QString &t)
     model->setHeaderData(5, Qt::Horizontal, "AutoValue");
     model->setHeaderData(6, Qt::Horizontal, "DefaultValue");
 
-
     for (int i = 0; i < rec.count(); ++i) {
         QSqlField fld = rec.field(i);
         model->setData(model->index(i, 0), fld.name());
diff --git a/examples/sql/sqlbrowser/browser.h b/examples/sql/sqlbrowser/browser.h
index fef410778b..3f98f487c3 100644
--- a/examples/sql/sqlbrowser/browser.h
+++ b/examples/sql/sqlbrowser/browser.h
@@ -65,7 +65,7 @@ class Browser: public QWidget, private Ui::Browser
 {
     Q_OBJECT
 public:
-    Browser(QWidget *parent = 0);
+    Browser(QWidget *parent = nullptr);
     virtual ~Browser();
 
     QSqlError addConnection(const QString &driver, const QString &dbName, const QString &host,
@@ -116,7 +116,9 @@ class CustomModel: public QSqlTableModel
 {
     Q_OBJECT
 public:
-    explicit CustomModel(QObject *parent = 0, QSqlDatabase db = QSqlDatabase()):QSqlTableModel(parent, db) {}
+    explicit CustomModel(QObject *parent = nullptr, QSqlDatabase db = QSqlDatabase())
+        : QSqlTableModel(parent, db) {}
+
     QVariant data(const QModelIndex &idx, int role) const override
     {
         if (role == Qt::BackgroundRole && isDirty(idx))
diff --git a/examples/sql/sqlbrowser/connectionwidget.cpp b/examples/sql/sqlbrowser/connectionwidget.cpp
index 888579c9af..658cfb77dc 100644
--- a/examples/sql/sqlbrowser/connectionwidget.cpp
+++ b/examples/sql/sqlbrowser/connectionwidget.cpp
@@ -63,8 +63,8 @@ ConnectionWidget::ConnectionWidget(QWidget *parent)
     tree->header()->setSectionResizeMode(QHeaderView::Stretch);
     QAction *refreshAction = new QAction(tr("Refresh"), tree);
     metaDataAction = new QAction(tr("Show Schema"), tree);
-    connect(refreshAction, SIGNAL(triggered()), SLOT(refresh()));
-    connect(metaDataAction, SIGNAL(triggered()), SLOT(showMetaData()));
+    connect(refreshAction, &QAction::triggered, this, &ConnectionWidget::refresh);
+    connect(metaDataAction, &QAction::triggered, this, &ConnectionWidget::showMetaData);
     tree->addAction(refreshAction);
     tree->addAction(metaDataAction);
     tree->setContextMenuPolicy(Qt::ActionsContextMenu);
@@ -146,7 +146,6 @@ void ConnectionWidget::setActive(QTreeWidgetItem *item)
 
 void ConnectionWidget::on_tree_itemActivated(QTreeWidgetItem *item, int /* column */)
 {
-
     if (!item)
         return;
 
diff --git a/examples/sql/sqlbrowser/connectionwidget.h b/examples/sql/sqlbrowser/connectionwidget.h
index 8b8e3a9a62..a805765f69 100644
--- a/examples/sql/sqlbrowser/connectionwidget.h
+++ b/examples/sql/sqlbrowser/connectionwidget.h
@@ -62,7 +62,7 @@ class ConnectionWidget: public QWidget
 {
     Q_OBJECT
 public:
-    ConnectionWidget(QWidget *parent = 0);
+    ConnectionWidget(QWidget *parent = nullptr);
     virtual ~ConnectionWidget();
 
     QSqlDatabase currentDatabase() const;
diff --git a/examples/sql/sqlbrowser/main.cpp b/examples/sql/sqlbrowser/main.cpp
index 002dbc3242..ea4649b68d 100644
--- a/examples/sql/sqlbrowser/main.cpp
+++ b/examples/sql/sqlbrowser/main.cpp
@@ -80,16 +80,18 @@ int main(int argc, char *argv[])
     mainWin.setCentralWidget(&browser);
 
     QMenu *fileMenu = mainWin.menuBar()->addMenu(QObject::tr("&File"));
-    fileMenu->addAction(QObject::tr("Add &Connection..."), &browser, SLOT(addConnection()));
+    fileMenu->addAction(QObject::tr("Add &Connection..."),
+            [&]() { browser.addConnection(); });
     fileMenu->addSeparator();
-    fileMenu->addAction(QObject::tr("&Quit"), &app, SLOT(quit()));
+    fileMenu->addAction(QObject::tr("&Quit"), []() { qApp->quit(); });
 
     QMenu *helpMenu = mainWin.menuBar()->addMenu(QObject::tr("&Help"));
-    helpMenu->addAction(QObject::tr("About"), &browser, SLOT(about()));
-    helpMenu->addAction(QObject::tr("About Qt"), qApp, SLOT(aboutQt()));
+    helpMenu->addAction(QObject::tr("About"), [&]() { browser.about(); });
+    helpMenu->addAction(QObject::tr("About Qt"), []() { qApp->aboutQt(); });
 
-    QObject::connect(&browser, SIGNAL(statusMessage(QString)),
-                     mainWin.statusBar(), SLOT(showMessage(QString)));
+    QObject::connect(&browser, &Browser::statusMessage, [&mainWin](const QString &text) {
+        mainWin.statusBar()->showMessage(text);
+    });
 
     addConnectionsFromCommandline(app.arguments(), &browser);
     mainWin.show();
diff --git a/examples/sql/sqlbrowser/qsqlconnectiondialog.h b/examples/sql/sqlbrowser/qsqlconnectiondialog.h
index d43955acdc..fc998d7ee9 100644
--- a/examples/sql/sqlbrowser/qsqlconnectiondialog.h
+++ b/examples/sql/sqlbrowser/qsqlconnectiondialog.h
@@ -60,7 +60,7 @@ class QSqlConnectionDialog: public QDialog
 {
     Q_OBJECT
 public:
-    QSqlConnectionDialog(QWidget *parent = 0);
+    QSqlConnectionDialog(QWidget *parent = nullptr);
     ~QSqlConnectionDialog();
 
     QString driverName() const;