Improved error handling when opening files

Software/PC_Application/Calibration/calkit.cpp

@@ -79,7 +79,11 @@ Calkit Calkit::fromFile(QString filename)
     }
 
     json j;
+    try {
         file >> j;
+    } catch (exception &e) {
+        throw runtime_error("JSON parsing error: " + string(e.what()));
+    }
     if(j.contains("SOLT")) {
         qDebug() << "JSON format detected";
         // calkit file uses json format, parse

Software/PC_Application/Calibration/calkitdialog.cpp

@@ -7,6 +7,7 @@
 #include <fstream>
 #include <touchstone.h>
 #include <QtGlobal>
+#include <QMessageBox>
 
 using namespace std;
 
@@ -119,7 +120,12 @@ CalkitDialog::CalkitDialog(Calkit &c, QWidget *parent) :
     connect(ui->buttonBox->button(QDialogButtonBox::Open), &QPushButton::clicked, [=](){
         auto filename = QFileDialog::getOpenFileName(this, "Open calibration kit coefficients", "", "Calibration kit files (*.calkit)", nullptr, QFileDialog::DontUseNativeDialog);
         if(filename.length() > 0) {
+            try {
                 ownKit = Calkit::fromFile(filename);
+            } catch (runtime_error e) {
+                QMessageBox::warning(nullptr, "Error", "The calibration kit file could not be parsed (" + QString(e.what()) + ")");
+                qWarning() << "Parsing of calibration kit failed while opening calibration file: " << e.what();
+            }
             updateEntries();
         }
     });

Software/PC_Application/appwindow.cpp

@@ -178,7 +178,12 @@ AppWindow::AppWindow(QWidget *parent)
             return;
         }
         nlohmann::json j;
+        try {
             file >> j;
+        } catch (exception &e) {
+            QMessageBox::warning(nullptr, "Error", "Failed to parse the setup file (" + QString(e.what()) + ")");
+            qWarning() << "Parsing of setup file failed: " << e.what();
+        }
         file.close();
         LoadSetup(j);
     });