ui: stop timer if PairingQRWidget is hidden (#25671)

selfdrive/ui/qt/widgets/prime.cc

@@ -18,21 +18,23 @@
 using qrcodegen::QrCode;
 
 PairingQRWidget::PairingQRWidget(QWidget* parent) : QWidget(parent) {
-  QTimer* timer = new QTimer(this);
-  timer->start(5 * 60 * 1000);
+  timer = new QTimer(this);
   connect(timer, &QTimer::timeout, this, &PairingQRWidget::refresh);
 }
 
 void PairingQRWidget::showEvent(QShowEvent *event) {
   refresh();
+  timer->start(5 * 60 * 1000);
+}
+
+void PairingQRWidget::hideEvent(QHideEvent *event) {
+  timer->stop();
 }
 
 void PairingQRWidget::refresh() {
-  if (isVisible()) {
   QString pairToken = CommaApi::create_jwt({{"pair", true}});
   QString qrString = "https://connect.comma.ai/?pair=" + pairToken;
   this->updateQrCode(qrString);
-  }
 }
 
 void PairingQRWidget::updateQrCode(const QString &text) {

selfdrive/ui/qt/widgets/prime.h

@@ -25,8 +25,10 @@ public:
 
 private:
   QPixmap img;
+  QTimer *timer;
   void updateQrCode(const QString &text);
   void showEvent(QShowEvent *event) override;
+  void hideEvent(QHideEvent *event) override;
 
 private slots:
   void refresh();