enh: fix qr scanner issues and speed it up

src/backend/backend.cpp

@@ -217,9 +217,12 @@ void Backend::scanQrCode()
     m_qrScanner.reset(new QrScanner);
     connect(m_qrScanner.get(), &QrScanner::qrCodeScanned, this, [&](const QString &qrCode) {
         qDebug() << "QR code scanned:" << qrCode;
-        parseDesignViewerUrl(QUrl(qrCode));
         m_qrScanner.reset();
+        parseDesignViewerUrl(QUrl(qrCode));
     });
+
+    connect(m_qrScanner.get(), &QrScanner::windowClosed, this, [&]() { m_qrScanner.reset(); });
+
     m_qrScanner->scanQrCode();
 }
 

src/backend/backend.h

@@ -42,8 +42,8 @@ public:
 
 private:
     // Other members
-    std::unique_ptr<ProjectManager> m_projectManager;
-    std::unique_ptr<QrScanner> m_qrScanner;
+    QScopedPointer<ProjectManager> m_projectManager;
+    QScopedPointer<QrScanner> m_qrScanner;
 
     // DS Connector
     QScopedPointer<DesignStudioManager> m_dsManager;

src/backend/qrscanner.cpp

@@ -82,65 +82,54 @@ void QrScanner::openCamera()
     m_captureSession.reset(new QMediaCaptureSession(this));
     m_captureSession->setCamera(new QCamera(this));
     m_captureSession->setVideoOutput(new CustomVideoWidget);
-
     m_captureSession->camera()->setFocusMode(QCamera::FocusModeAuto);
 
-    CustomVideoWidget *videoWidget = qobject_cast<CustomVideoWidget *>(
-        m_captureSession->videoOutput());
+    m_videoWidget = qobject_cast<CustomVideoWidget *>(m_captureSession->videoOutput());
+    m_processing = 0;
+    ZXing::ReaderOptions readerOptions;
+    readerOptions.setTryRotate(false);
+    readerOptions.setTryHarder(false);
+    readerOptions.setTryInvert(false);
+    readerOptions.setDownscaleFactor(2);
 
     connect(m_captureSession->videoSink(),
             &QVideoSink::videoFrameChanged,
             this,
-            [&](const QVideoFrame &frame) {
-                static QAtomicInt i = 0;
-                static QAtomicInt running = 0;
-
-                if (i++ < 20 || running > 0) {
-                    return;
-                }
-
-                i = 0;
-
+            [&, readerOptions](const QVideoFrame &frame) {
                 if (!frame.isValid())
                     return;
 
+                if (!m_processing.testAndSetOrdered(0, 1)) {
+                    return; // Another task is already running
+                }
+
                 QtConcurrent::run([=] {
                     if (!m_captureSession)
                         return QList<Result>();
 
-                    // lock the thread so that only one barcode can be read at a time
-                    running++;
-
                     QElapsedTimer timer;
                     timer.start();
-                    QList<Result> results = ReadBarcodes(frame.toImage());
+                    QList<Result> results = ReadBarcodes(frame.toImage(), readerOptions);
                     qDebug() << "Barcode detection took" << timer.elapsed() << "ms";
 
+                    if (!results.size())
+                        m_processing = 0;
+
                     return results;
                 }).then([=](const QList<Result> &results) {
                     if (results.isEmpty() || !m_captureSession)
                         return;
 
-                    qDebug() << "Stopping camera";
-                    qobject_cast<CustomVideoWidget *>(m_captureSession->videoOutput())->close();
-                    qDebug() << "Camera stopped";
-
                     Result result = results.first();
 
                     qDebug() << "Text:   " << result.text();
                     qDebug() << "Format: " << result.format();
                     qDebug() << "Content:" << result.contentType();
+                    qDebug() << "Position:" << result.position().bottomLeft()
+                             << result.position().bottomRight() << result.position().topLeft()
+                             << result.position().topRight();
 
-                    // we have to use invokeMethod because we are in a different thread
-                    // then where the serviceConnector is created
-                    // QMetaObject::invokeMethod(this,
-                    //                           "parseDesignViewerUrl",
-                    //                           Qt::QueuedConnection,
-                    //                           Q_ARG(QUrl, result.text()));
                     emit qrCodeScanned(result.text());
-
-                    // release the lock so that another barcode can be read
-                    running--;
                 });
             });
 
@@ -155,15 +144,12 @@ void QrScanner::openCamera()
     });
 
     // stop camera when video widget is closed
-    connect(videoWidget, &CustomVideoWidget::closed, this, [&] {
-        qDebug() << "Video widget closed. Clearing capture session";
-        m_captureSession->camera()->stop();
-        m_captureSession->camera()->deleteLater();
-        m_captureSession->videoOutput()->deleteLater();
-        m_captureSession.clear();
+    connect(m_videoWidget, &CustomVideoWidget::closed, this, [&] {
+        qDebug() << "Video widget closed.";
+        emit windowClosed();
     });
 
-    videoWidget->setWindowFlags(Qt::Window | Qt::WindowStaysOnTopHint);
-    videoWidget->show();
+    m_videoWidget->setWindowFlags(Qt::Window | Qt::WindowStaysOnTopHint);
+    m_videoWidget->show();
     m_captureSession->camera()->start();
 }

src/backend/qrscanner.h

@@ -25,7 +25,9 @@
 
 #pragma once
 
+#include <QList>
 #include <QMediaCaptureSession>
+#include <QRect>
 #include <QVideoWidget>
 
 class CustomVideoWidget : public QVideoWidget
@@ -35,8 +37,8 @@ public:
     explicit CustomVideoWidget(QWidget *parent = nullptr)
         : QVideoWidget(parent)
     {}
-    ~CustomVideoWidget() override {}
 
+    ~CustomVideoWidget() override {}
     void closeEvent(QCloseEvent *) override { emit closed(); }
 
 signals:
@@ -52,9 +54,12 @@ public:
 
 private:
     QSharedPointer<QMediaCaptureSession> m_captureSession;
+    CustomVideoWidget *m_videoWidget;
+    QAtomicInt m_processing;
 
     void openCamera();
 
 signals:
     void qrCodeScanned(const QString &qrCode);
+    void windowClosed();
 };