Use uniform_int_distribution for generating PINs

app/gui/PcView.qml

@@ -187,7 +187,7 @@ CenteredGridView {
                 }
                 else {
                     if (!model.busy) {
-                        var pin = ("0000" + Math.floor(Math.random() * 10000)).slice(-4)
+                        var pin = computerModel.generatePinString()
 
                         // Kick off pairing in the background
                         computerModel.pairComputer(index, pin)

app/gui/computermodel.cpp

@@ -2,6 +2,8 @@
 
 #include <QThreadPool>
 
+#include <random>
+
 ComputerModel::ComputerModel(QObject* object)
     : QAbstractListModel(object) {}
 
@@ -135,6 +137,16 @@ void ComputerModel::renameComputer(int computerIndex, QString name)
     m_ComputerManager->renameHost(m_Computers[computerIndex], name);
 }
 
+// TODO: Use QRandomGenerator when we drop Qt 5.9 support
+QString ComputerModel::generatePinString()
+{
+    std::uniform_int_distribution<int> dist(0, 9999);
+    std::random_device rd;
+    std::mt19937 engine(rd());
+
+    return QString::asprintf("%04u", dist(engine));
+}
+
 void ComputerModel::pairComputer(int computerIndex, QString pin)
 {
     Q_ASSERT(computerIndex < m_Computers.count());

app/gui/computermodel.h

@@ -31,6 +31,8 @@ public:
 
     Q_INVOKABLE void deleteComputer(int computerIndex);
 
+    Q_INVOKABLE QString generatePinString();
+
     Q_INVOKABLE void pairComputer(int computerIndex, QString pin);
 
     Q_INVOKABLE void wakeComputer(int computerIndex);