Change almost all other uses of qrand() to QRandomGenerator

The vast majority is actually switched to QRandomGenerator::bounded(),
which gives a mostly uniform distribution over the [0, bound)
range. There are very few floating point cases left, as many of those
that did use floating point did not need to, after all. (I did leave
some that were too ugly for me to understand)

This commit also found a couple of calls to rand() instead of qrand().

This commit does not include changes to SSL code that continues to use
qrand() (job for someone else):
  src/network/ssl/qsslkey_qt.cpp
  src/network/ssl/qsslsocket_mac.cpp
  tests/auto/network/ssl/qsslsocket/tst_qsslsocket.cpp

Change-Id: Icd0e0d4b27cb4e5eb892fffd14b5285d43f4afbf
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

29 files changed, 57 insertions, 68 deletions

diff --git a/examples/widgets/animation/animatedtiles/main.cpp b/examples/widgets/animation/animatedtiles/main.cpp
index 0511fe8162..89b5b67f8a 100644
--- a/examples/widgets/animation/animatedtiles/main.cpp
+++ b/examples/widgets/animation/animatedtiles/main.cpp
@@ -50,6 +50,7 @@
 
 #include <QtWidgets>
 #include <QtCore/qmath.h>
+#include <QtCore/qrandom.h>
 #include <QtCore/qstate.h>
 
 class Pixmap : public QObject, public QGraphicsPixmapItem
@@ -202,8 +203,8 @@ int main(int argc, char **argv)
 
         // Random
         randomState->assignProperty(item, "pos",
-                                        QPointF(-250 + qrand() % 500,
-                                                -250 + qrand() % 500));
+                                        QPointF(-250 + QRandomGenerator::global()->bounded(500),
+                                                -250 + QRandomGenerator::global()->bounded(500)));
 
         // Tiled
         tiledState->assignProperty(item, "pos",
diff --git a/examples/widgets/animation/moveblocks/main.cpp b/examples/widgets/animation/moveblocks/main.cpp
index a9b95808a5..6d17696108 100644
--- a/examples/widgets/animation/moveblocks/main.cpp
+++ b/examples/widgets/animation/moveblocks/main.cpp
@@ -125,7 +125,7 @@ public:
     void onEntry(QEvent *) override
     {
         int n;
-        while ((n = (qrand() % m_stateCount + 1)) == m_lastIndex)
+        while ((n = QRandomGenerator::global()->bounded(m_stateCount) + 1) == m_lastIndex)
         { }
         m_lastIndex = n;
         machine()->postEvent(new StateSwitchEvent(n));
@@ -323,8 +323,6 @@ int main(int argc, char **argv)
     window.resize(300, 300);
     window.show();
 
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
-
     return app.exec();
 }
 
diff --git a/examples/widgets/animation/stickman/lifecycle.cpp b/examples/widgets/animation/stickman/lifecycle.cpp
index 253af22b2d..dbe9a299b4 100644
--- a/examples/widgets/animation/stickman/lifecycle.cpp
+++ b/examples/widgets/animation/stickman/lifecycle.cpp
@@ -91,13 +91,12 @@ public:
         : QEventTransition(this, QEvent::Timer)
     {
         setTargetState(target);
-        qsrand((uint)QDateTime::currentSecsSinceEpoch());
         startTimer(1000);
     }
 
     bool eventTest(QEvent *e) override
     {
-        return QEventTransition::eventTest(e) && ((qrand() % 50) == 0);
+        return QEventTransition::eventTest(e) && QRandomGenerator::global()->bounded(50) == 0;
     }
 };
 //! [4]
diff --git a/examples/widgets/animation/sub-attaq/main.cpp b/examples/widgets/animation/sub-attaq/main.cpp
index f65ca7be18..9b28d8c40f 100644
--- a/examples/widgets/animation/sub-attaq/main.cpp
+++ b/examples/widgets/animation/sub-attaq/main.cpp
@@ -57,8 +57,6 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
     Q_INIT_RESOURCE(subattaq);
 
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
-
     MainWindow w;
     w.show();
 
diff --git a/examples/widgets/animation/sub-attaq/states.cpp b/examples/widgets/animation/sub-attaq/states.cpp
index 21cff048e7..e19704db7b 100644
--- a/examples/widgets/animation/sub-attaq/states.cpp
+++ b/examples/widgets/animation/sub-attaq/states.cpp
@@ -64,6 +64,7 @@
 #include <QtCore/QStateMachine>
 #include <QtWidgets/QKeyEventTransition>
 #include <QtCore/QFinalState>
+#include <QtCore/QRandomGenerator>
 
 PlayState::PlayState(GraphicsScene *scene, QState *parent)
     : QState(parent),
@@ -193,12 +194,12 @@ void LevelState::initializeLevel()
         for (int j = 0; j < subContent.second; ++j ) {
             SubMarine *sub = new SubMarine(submarineDesc.type, submarineDesc.name, submarineDesc.points);
             scene->addItem(sub);
-            int random = (qrand() % 15 + 1);
+            int random = QRandomGenerator::global()->bounded(15) + 1;
             qreal x = random == 13 || random == 5 ? 0 : scene->width() - sub->size().width();
-            qreal y = scene->height() -(qrand() % 150 + 1) - sub->size().height();
+            qreal y = scene->height() -(QRandomGenerator::global()->bounded(150) + 1) - sub->size().height();
             sub->setPos(x,y);
             sub->setCurrentDirection(x == 0 ? SubMarine::Right : SubMarine::Left);
-            sub->setCurrentSpeed(qrand() % 3 + 1);
+            sub->setCurrentSpeed(QRandomGenerator::global()->bounded(3) + 1);
         }
     }
 }
diff --git a/examples/widgets/animation/sub-attaq/submarine_p.h b/examples/widgets/animation/sub-attaq/submarine_p.h
index b8d5532962..698b4b494f 100644
--- a/examples/widgets/animation/sub-attaq/submarine_p.h
+++ b/examples/widgets/animation/sub-attaq/submarine_p.h
@@ -69,6 +69,7 @@
 
 //Qt
 #include <QtCore/QPropertyAnimation>
+#include <QtCore/QRandomGenerator>
 #include <QtWidgets/QGraphicsScene>
 
 //This state is describing when the boat is moving right
@@ -88,8 +89,8 @@ public:
 protected slots:
     void onAnimationMovementValueChanged(const QVariant &)
     {
-        if (qrand() % 200 + 1 == 3)
-            submarine->launchTorpedo(qrand() % 3 + 1);
+        if (QRandomGenerator::global()->bounded(200) + 1 == 3)
+            submarine->launchTorpedo(QRandomGenerator::global()->bounded(3) + 1);
     }
 
 protected:
diff --git a/examples/widgets/doc/src/collidingmice-example.qdoc b/examples/widgets/doc/src/collidingmice-example.qdoc
index 02417ba521..535057bb6a 100644
--- a/examples/widgets/doc/src/collidingmice-example.qdoc
+++ b/examples/widgets/doc/src/collidingmice-example.qdoc
@@ -80,8 +80,7 @@
     \snippet graphicsview/collidingmice/mouse.cpp 0
 
     To calculate the various components of the mouse's color, we use
-    the global qrand() function which is a thread-safe version of the
-    standard C++ rand() function.
+    \l QRandomGenerator.
 
     Then we call the \l {QGraphicsItem::setRotation()}{setRotation()} function
     inherited from QGraphicsItem. Items live in their own local
@@ -178,12 +177,7 @@
 
     \snippet graphicsview/collidingmice/main.cpp 0
 
-    First, we create an application object and call the global
-    qsrand() function to specify the seed used to generate a new
-    random number sequence of pseudo random integers with the
-    previously mentioned qrand() function.
-
-    Then it is time to create the scene:
+    First, we create an application object and create the scene:
 
     \snippet graphicsview/collidingmice/main.cpp 1
 
diff --git a/examples/widgets/doc/src/dragdroprobot.qdoc b/examples/widgets/doc/src/dragdroprobot.qdoc
index ac221ec5f9..f74b898e1b 100644
--- a/examples/widgets/doc/src/dragdroprobot.qdoc
+++ b/examples/widgets/doc/src/dragdroprobot.qdoc
@@ -257,7 +257,7 @@
     \snippet graphicsview/dragdroprobot/coloritem.cpp 0
 
     \c ColorItem's constructor assigns an opaque random color to its color
-    member by making use of qrand(). For improved usability, it assigns a
+    member by making use of \l QRandomGenerator. For improved usability, it assigns a
     tooltip that provides a useful hint to the user, and it also sets a
     suitable cursor. This ensures that the cursor will chance to
     Qt::OpenHandCursor when the mouse pointer hovers over the item.
diff --git a/examples/widgets/doc/src/elasticnodes.qdoc b/examples/widgets/doc/src/elasticnodes.qdoc
index 09ac891b24..65e1195121 100644
--- a/examples/widgets/doc/src/elasticnodes.qdoc
+++ b/examples/widgets/doc/src/elasticnodes.qdoc
@@ -424,9 +424,8 @@
     \section1 The main() Function
 
     In contrast to the complexity of the rest of this example, the \c main()
-    function is very simple: We create a QApplication instance, seed the
-    randomizer using qsrand(), and then create and show an instance of \c
-    GraphWidget. Because all nodes in the grid are moved initially, the \c
-    GraphWidget timer will start immediately after control has returned to the
-    event loop.
+    function is very simple: We create a QApplication instance, then create and
+    show an instance of \c GraphWidget. Because all nodes in the grid are moved
+    initially, the \c GraphWidget timer will start immediately after control
+    has returned to the event loop.
 */
diff --git a/examples/widgets/draganddrop/puzzle/mainwindow.cpp b/examples/widgets/draganddrop/puzzle/mainwindow.cpp
index 1914519c68..98a7cd4265 100644
--- a/examples/widgets/draganddrop/puzzle/mainwindow.cpp
+++ b/examples/widgets/draganddrop/puzzle/mainwindow.cpp
@@ -122,10 +122,8 @@ void MainWindow::setupPuzzle()
         }
     }
 
-    qsrand(QCursor::pos().x() ^ QCursor::pos().y());
-
     for (int i = 0; i < piecesList->count(); ++i) {
-        if (int(2.0*qrand()/(RAND_MAX+1.0)) == 1) {
+        if (QRandomGenerator::global()->bounded(2) == 1) {
             QListWidgetItem *item = piecesList->takeItem(i);
             piecesList->insertItem(0, item);
         }
diff --git a/examples/widgets/graphicsview/boxes/qtbox.cpp b/examples/widgets/graphicsview/boxes/qtbox.cpp
index 9a19985fac..3a184dd0b6 100644
--- a/examples/widgets/graphicsview/boxes/qtbox.cpp
+++ b/examples/widgets/graphicsview/boxes/qtbox.cpp
@@ -414,7 +414,7 @@ void QtBox::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWi
 
 CircleItem::CircleItem(int size, int x, int y) : ItemBase(size, x, y)
 {
-     m_color = QColor::fromHsv(rand() % 360, 255, 255);
+     m_color = QColor::fromHsv(QRandomGenerator::global()->bounded(360), 255, 255);
 }
 
 void CircleItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
diff --git a/examples/widgets/graphicsview/boxes/scene.cpp b/examples/widgets/graphicsview/boxes/scene.cpp
index 31b9553c75..f51cad99ac 100644
--- a/examples/widgets/graphicsview/boxes/scene.cpp
+++ b/examples/widgets/graphicsview/boxes/scene.cpp
@@ -50,6 +50,7 @@
 
 #include <QDebug>
 #include "scene.h"
+#include <QtCore/QRandomGenerator>
 #include <QtGui/qmatrix4x4.h>
 #include <QtGui/qvector3d.h>
 #include <qmath.h>
@@ -1072,13 +1073,16 @@ void Scene::newItem(ItemDialog::ItemType type)
     QSize size = sceneRect().size().toSize();
     switch (type) {
     case ItemDialog::QtBoxItem:
-        addItem(new QtBox(64, rand() % (size.width() - 64) + 32, rand() % (size.height() - 64) + 32));
+        addItem(new QtBox(64, QRandomGenerator::global()->bounded(size.width() - 64) + 32,
+                          QRandomGenerator::global()->bounded(size.height() - 64) + 32));
         break;
     case ItemDialog::CircleItem:
-        addItem(new CircleItem(64, rand() % (size.width() - 64) + 32, rand() % (size.height() - 64) + 32));
+        addItem(new CircleItem(64, QRandomGenerator::global()->bounded(size.width() - 64) + 32,
+                               QRandomGenerator::global()->bounded(size.height() - 64) + 32));
         break;
     case ItemDialog::SquareItem:
-        addItem(new SquareItem(64, rand() % (size.width() - 64) + 32, rand() % (size.height() - 64) + 32));
+        addItem(new SquareItem(64, QRandomGenerator::global()->bounded(size.width() - 64) + 32,
+                               QRandomGenerator::global()->bounded(size.height() - 64) + 32));
         break;
     default:
         break;
diff --git a/examples/widgets/graphicsview/collidingmice/main.cpp b/examples/widgets/graphicsview/collidingmice/main.cpp
index a0659b9bc1..91aee70b86 100644
--- a/examples/widgets/graphicsview/collidingmice/main.cpp
+++ b/examples/widgets/graphicsview/collidingmice/main.cpp
@@ -60,7 +60,6 @@ static const int MouseCount = 7;
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
-    qsrand(QTime(0, 0, 0).secsTo(QTime::currentTime()));
 //! [0]
 
 //! [1]
diff --git a/examples/widgets/graphicsview/collidingmice/mouse.cpp b/examples/widgets/graphicsview/collidingmice/mouse.cpp
index 298e4aae64..14f887f6e3 100644
--- a/examples/widgets/graphicsview/collidingmice/mouse.cpp
+++ b/examples/widgets/graphicsview/collidingmice/mouse.cpp
@@ -52,6 +52,7 @@
 
 #include <QGraphicsScene>
 #include <QPainter>
+#include <QRandomGenerator>
 #include <QStyleOption>
 #include <qmath.h>
 
@@ -70,9 +71,9 @@ static qreal normalizeAngle(qreal angle)
 //! [0]
 Mouse::Mouse()
     : angle(0), speed(0), mouseEyeDirection(0),
-      color(qrand() % 256, qrand() % 256, qrand() % 256)
+      color(QRandomGenerator::global()->bounded(256), QRandomGenerator::global()->bounded(256), QRandomGenerator::global()->bounded(256))
 {
-    setRotation(qrand() % (360 * 16));
+    setRotation(QRandomGenerator::global()->bounded(360 * 16));
 }
 //! [0]
 
@@ -185,16 +186,16 @@ void Mouse::advance(int step)
 
     // Add some random movement
 //! [10]
-    if (dangerMice.size() > 1 && (qrand() % 10) == 0) {
-        if (qrand() % 1)
-            angle += (qrand() % 100) / 500.0;
+    if (dangerMice.size() > 1 && QRandomGenerator::global()->bounded(10) == 0) {
+        if (QRandomGenerator::global()->bounded(1))
+            angle += QRandomGenerator::global()->bounded(1 / 500.0);
         else
-            angle -= (qrand() % 100) / 500.0;
+            angle -= QRandomGenerator::global()->bounded(1 / 500.0);
     }
 //! [10]
 
 //! [11]
-    speed += (-50 + qrand() % 100) / 100.0;
+    speed += (-50 + QRandomGenerator::global()->bounded(100)) / 100.0;
 
     qreal dx = ::sin(angle) * 10;
     mouseEyeDirection = (qAbs(dx / 5) < 1) ? 0 : dx / 5;
diff --git a/examples/widgets/graphicsview/dragdroprobot/coloritem.cpp b/examples/widgets/graphicsview/dragdroprobot/coloritem.cpp
index 64a715d31f..262e18a317 100644
--- a/examples/widgets/graphicsview/dragdroprobot/coloritem.cpp
+++ b/examples/widgets/graphicsview/dragdroprobot/coloritem.cpp
@@ -54,7 +54,7 @@
 
 //! [0]
 ColorItem::ColorItem()
-    : color(qrand() % 256, qrand() % 256, qrand() % 256)
+    : color(QRandomGenerator::global()->bounded(256), QRandomGenerator::global()->bounded(256), QRandomGenerator::global()->bounded(256))
 {
     setToolTip(QString("QColor(%1, %2, %3)\n%4")
               .arg(color.red()).arg(color.green()).arg(color.blue())
@@ -107,7 +107,7 @@ void ColorItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 
 //! [6]
     static int n = 0;
-    if (n++ > 2 && (qrand() % 3) == 0) {
+    if (n++ > 2 && QRandomGenerator::global()->bounded(3) == 0) {
         QImage image(":/images/head.png");
         mime->setImageData(image);
 
diff --git a/examples/widgets/graphicsview/dragdroprobot/main.cpp b/examples/widgets/graphicsview/dragdroprobot/main.cpp
index 20cec92d26..045e184569 100644
--- a/examples/widgets/graphicsview/dragdroprobot/main.cpp
+++ b/examples/widgets/graphicsview/dragdroprobot/main.cpp
@@ -73,7 +73,6 @@ int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
 
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
 //! [0]
 //! [1]
     QGraphicsScene scene(-200, -200, 400, 400);
diff --git a/examples/widgets/graphicsview/elasticnodes/graphwidget.cpp b/examples/widgets/graphicsview/elasticnodes/graphwidget.cpp
index 844c8f8aac..4259aab803 100644
--- a/examples/widgets/graphicsview/elasticnodes/graphwidget.cpp
+++ b/examples/widgets/graphicsview/elasticnodes/graphwidget.cpp
@@ -55,6 +55,7 @@
 #include <math.h>
 
 #include <QKeyEvent>
+#include <QRandomGenerator>
 
 //! [0]
 GraphWidget::GraphWidget(QWidget *parent)
@@ -247,7 +248,7 @@ void GraphWidget::shuffle()
 {
     foreach (QGraphicsItem *item, scene()->items()) {
         if (qgraphicsitem_cast<Node *>(item))
-            item->setPos(-150 + qrand() % 300, -150 + qrand() % 300);
+            item->setPos(-150 + QRandomGenerator::global()->bounded(300), -150 + QRandomGenerator::global()->bounded(300));
     }
 }
 
diff --git a/examples/widgets/graphicsview/elasticnodes/main.cpp b/examples/widgets/graphicsview/elasticnodes/main.cpp
index 75cc4b0f69..1e372a9f6d 100644
--- a/examples/widgets/graphicsview/elasticnodes/main.cpp
+++ b/examples/widgets/graphicsview/elasticnodes/main.cpp
@@ -57,7 +57,6 @@
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
 
     GraphWidget *widget = new GraphWidget;
 
diff --git a/examples/widgets/itemviews/puzzle/mainwindow.cpp b/examples/widgets/itemviews/puzzle/mainwindow.cpp
index 8ee5cf659e..d598dc9017 100644
--- a/examples/widgets/itemviews/puzzle/mainwindow.cpp
+++ b/examples/widgets/itemviews/puzzle/mainwindow.cpp
@@ -114,8 +114,6 @@ void MainWindow::setupPuzzle()
         (puzzleImage.height() - size) / 2, size, size).scaled(puzzleWidget->imageSize(),
             puzzleWidget->imageSize(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
 
-    qsrand(QCursor::pos().x() ^ QCursor::pos().y());
-
     model->addPieces(puzzleImage);
     puzzleWidget->clear();
 }
diff --git a/examples/widgets/itemviews/puzzle/piecesmodel.cpp b/examples/widgets/itemviews/puzzle/piecesmodel.cpp
index 0fbf0cdcc2..f0649d3776 100644
--- a/examples/widgets/itemviews/puzzle/piecesmodel.cpp
+++ b/examples/widgets/itemviews/puzzle/piecesmodel.cpp
@@ -52,6 +52,7 @@
 
 #include <QIcon>
 #include <QMimeData>
+#include <QRandomGenerator>
 
 PiecesModel::PiecesModel(int pieceSize, QObject *parent)
     : QAbstractListModel(parent), m_PieceSize(pieceSize)
@@ -77,7 +78,7 @@ QVariant PiecesModel::data(const QModelIndex &index, int role) const
 void PiecesModel::addPiece(const QPixmap &pixmap, const QPoint &location)
 {
     int row;
-    if (int(2.0 * qrand() / (RAND_MAX + 1.0)) == 1)
+    if (QRandomGenerator::global()->bounded(2) == 1)
         row = 0;
     else
         row = pixmaps.size();
diff --git a/examples/widgets/mainwindows/mainwindow/toolbar.cpp b/examples/widgets/mainwindows/mainwindow/toolbar.cpp
index 97152a64a3..814cfc7f4d 100644
--- a/examples/widgets/mainwindows/mainwindow/toolbar.cpp
+++ b/examples/widgets/mainwindows/mainwindow/toolbar.cpp
@@ -50,6 +50,8 @@
 
 #include "toolbar.h"
 
+#include <QRandomGenerator>
+
 #include <QMainWindow>
 #include <QMenu>
 #include <QPainter>
@@ -257,7 +259,7 @@ void ToolBar::randomize()
     QList<QAction *> randomized;
     QList<QAction *> actions = this->actions();
     while (!actions.isEmpty()) {
-        QAction *action = actions.takeAt(rand() % actions.size());
+        QAction *action = actions.takeAt(QRandomGenerator::global()->bounded(actions.size()));
         randomized.append(action);
     }
     clear();
diff --git a/examples/widgets/statemachine/rogue/window.cpp b/examples/widgets/statemachine/rogue/window.cpp
index 428d4c3af6..3515138382 100644
--- a/examples/widgets/statemachine/rogue/window.cpp
+++ b/examples/widgets/statemachine/rogue/window.cpp
@@ -248,11 +248,9 @@ void Window::movePlayer(Direction direction)
 
 void Window::setupMap()
 {
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
-
     for (int x = 0; x < WIDTH; ++x)
         for (int y = 0; y < HEIGHT; ++y) {
-        if (x == 0 || x == WIDTH - 1 || y == 0 || y == HEIGHT - 1 || qrand() % 40 == 0)
+        if (x == 0 || x == WIDTH - 1 || y == 0 || y == HEIGHT - 1 || QRandomGenerator::global()->bounded(40) == 0)
             map[x][y] = '#';
         else
             map[x][y] = '.';
diff --git a/examples/widgets/tools/plugandpaint/plugins/basictools/basictoolsplugin.cpp b/examples/widgets/tools/plugandpaint/plugins/basictools/basictoolsplugin.cpp
index 740d007d44..92620ddd8c 100644
--- a/examples/widgets/tools/plugandpaint/plugins/basictools/basictoolsplugin.cpp
+++ b/examples/widgets/tools/plugandpaint/plugins/basictools/basictoolsplugin.cpp
@@ -101,7 +101,7 @@ QRect BasicToolsPlugin::mouseMove(const QString &brush, QPainter &painter,
                                 thickness, thickness);
         }
     } else if (brush == tr("Random Letters")) {
-        QChar ch('A' + (qrand() % 26));
+        QChar ch(QRandomGenerator::global()->bounded('A', 'Z' + 1));
 
         QFont biggerFont = painter.font();
         biggerFont.setBold(true);
diff --git a/examples/widgets/tools/undo/mainwindow.cpp b/examples/widgets/tools/undo/mainwindow.cpp
index aa570caa80..5976163f3f 100644
--- a/examples/widgets/tools/undo/mainwindow.cpp
+++ b/examples/widgets/tools/undo/mainwindow.cpp
@@ -52,6 +52,7 @@
 #include <QUndoStack>
 #include <QFileDialog>
 #include <QMessageBox>
+#include <QRandomGenerator>
 #include <QTextStream>
 #include <QToolButton>
 #include "document.h"
@@ -321,7 +322,7 @@ void MainWindow::newDocument()
 
 static QColor randomColor()
 {
-    int r = (int) (3.0*(rand()/(RAND_MAX + 1.0)));
+    int r = QRandomGenerator::global()->bounded(3);
     switch (r) {
         case 0:
             return Qt::red;
@@ -337,10 +338,10 @@ static QRect randomRect(const QSize &s)
 {
     QSize min = Shape::minSize;
 
-    int left = (int) ((0.0 + s.width() - min.width())*(rand()/(RAND_MAX + 1.0)));
-    int top = (int) ((0.0 + s.height() - min.height())*(rand()/(RAND_MAX + 1.0)));
-    int width = (int) ((0.0 + s.width() - left - min.width())*(rand()/(RAND_MAX + 1.0))) + min.width();
-    int height = (int) ((0.0 + s.height() - top - min.height())*(rand()/(RAND_MAX + 1.0))) + min.height();
+    int left = (int) ((0.0 + s.width() - min.width())*(QRandomGenerator::global()->bounded(1.0)));
+    int top = (int) ((0.0 + s.height() - min.height())*(QRandomGenerator::global()->bounded(1.0)));
+    int width = (int) ((0.0 + s.width() - left - min.width())*(QRandomGenerator::global()->bounded(1.0))) + min.width();
+    int height = (int) ((0.0 + s.height() - top - min.height())*(QRandomGenerator::global()->bounded(1.0))) + min.height();
 
     return QRect(left, top, width, height);
 }
diff --git a/examples/widgets/tools/undoframework/diagramitem.cpp b/examples/widgets/tools/undoframework/diagramitem.cpp
index 754baa2377..723645c9b2 100644
--- a/examples/widgets/tools/undoframework/diagramitem.cpp
+++ b/examples/widgets/tools/undoframework/diagramitem.cpp
@@ -65,8 +65,7 @@ DiagramItem::DiagramItem(DiagramType diagramType, QGraphicsItem *item)
         setPolygon(trianglePolygon);
     }
 
-    QColor color(static_cast<int>(qrand()) % 256,
-        static_cast<int>(qrand()) % 256, static_cast<int>(qrand()) % 256);
+    QColor color(QRandomGenerator::global()->bounded(256), QRandomGenerator::global()->bounded(256), QRandomGenerator::global()->bounded(256));
     QBrush brush(color);
     setBrush(brush);
     setFlag(QGraphicsItem::ItemIsSelectable);
diff --git a/examples/widgets/widgets/tetrix/main.cpp b/examples/widgets/widgets/tetrix/main.cpp
index 886e94de7c..2698190e76 100644
--- a/examples/widgets/widgets/tetrix/main.cpp
+++ b/examples/widgets/widgets/tetrix/main.cpp
@@ -59,6 +59,5 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
     TetrixWindow window;
     window.show();
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
     return app.exec();
 }
diff --git a/examples/widgets/widgets/tetrix/tetrixpiece.cpp b/examples/widgets/widgets/tetrix/tetrixpiece.cpp
index 69e1733ac4..3d8fa86860 100644
--- a/examples/widgets/widgets/tetrix/tetrixpiece.cpp
+++ b/examples/widgets/widgets/tetrix/tetrixpiece.cpp
@@ -57,7 +57,7 @@
 //! [0]
 void TetrixPiece::setRandomShape()
 {
-    setShape(TetrixShape(qrand() % 7 + 1));
+    setShape(TetrixShape(QRandomGenerator::global()->bounded(7) + 1));
 }
 //! [0]
 
diff --git a/examples/widgets/widgets/tooltips/main.cpp b/examples/widgets/widgets/tooltips/main.cpp
index 3c64a33a4c..8276b3dc8d 100644
--- a/examples/widgets/widgets/tooltips/main.cpp
+++ b/examples/widgets/widgets/tooltips/main.cpp
@@ -57,7 +57,6 @@ int main(int argc, char *argv[])
     Q_INIT_RESOURCE(tooltips);
 
     QApplication app(argc, argv);
-    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
     SortingBox sortingBox;
     sortingBox.show();
     return app.exec();
diff --git a/examples/widgets/widgets/tooltips/sortingbox.cpp b/examples/widgets/widgets/tooltips/sortingbox.cpp
index c15fdcf95b..4769a30c64 100644
--- a/examples/widgets/widgets/tooltips/sortingbox.cpp
+++ b/examples/widgets/widgets/tooltips/sortingbox.cpp
@@ -292,7 +292,7 @@ QPoint SortingBox::initialItemPosition(const QPainterPath &path)
 //! [24]
 QPoint SortingBox::randomItemPosition()
 {
-    return QPoint(qrand() % (width() - 120), qrand() % (height() - 120));
+    return QPoint(QRandomGenerator::global()->bounded(width() - 120), QRandomGenerator::global()->bounded(height() - 120));
 }
 //! [24]
 
@@ -306,6 +306,6 @@ QColor SortingBox::initialItemColor()
 //! [26]
 QColor SortingBox::randomItemColor()
 {
-    return QColor::fromHsv(qrand() % 256, 255, 190);
+    return QColor::fromHsv(QRandomGenerator::global()->bounded(256), 255, 190);
 }
 //! [26]