cabana: catch exceptions thrown from opendbc (#27242)

* catch exceptions thrown from opendbc

* Update tools/cabana/mainwin.cc

Co-authored-by: Cameron Clough <cameronjclough@gmail.com>

* Update tools/cabana/mainwin.cc

Co-authored-by: Cameron Clough <cameronjclough@gmail.com>

* show error line in detailed text

---------

Co-authored-by: Cameron Clough <cameronjclough@gmail.com>
old-commit-hash: 95fc84e0b7

tools/cabana/dbcmanager.cc

@@ -13,10 +13,16 @@ void DBCManager::open(const QString &dbc_file_name) {
   initMsgMap();
 }
 
-void DBCManager::open(const QString &name, const QString &content) {
+bool DBCManager::open(const QString &name, const QString &content, QString *error) {
+  try {
     std::istringstream stream(content.toStdString());
     dbc = const_cast<DBC *>(dbc_parse_from_stream(name.toStdString(), stream));
     initMsgMap();
+    return true;
+  } catch (std::exception &e) {
+    if (error) *error = e.what();
+  }
+  return false;
 }
 
 void DBCManager::initMsgMap() {

tools/cabana/dbcmanager.h

@@ -22,7 +22,7 @@ public:
   ~DBCManager();
 
   void open(const QString &dbc_file_name);
-  void open(const QString &name, const QString &content);
+  bool open(const QString &name, const QString &content, QString *error = nullptr);
   QString generateDBC();
   void addSignal(const QString &id, const Signal &sig);
   void updateSignal(const QString &id, const QString &sig_name, const Signal &sig);

tools/cabana/mainwin.cc

@@ -220,9 +220,16 @@ void MainWindow::loadFile(const QString &fn) {
     QFile file(fn);
     if (file.open(QIODevice::ReadOnly)) {
       auto dbc_name = QFileInfo(fn).baseName();
-      dbc()->open(dbc_name, file.readAll());
+      QString error;
+      bool ret = dbc()->open(dbc_name, file.readAll(), &error);
+      if (ret) {
         setCurrentFile(fn);
         statusBar()->showMessage(tr("DBC File %1 loaded").arg(fn), 2000);
+      } else {
+        QMessageBox msg_box(QMessageBox::Warning, tr("Failed to load DBC file"), tr("Failed to parse DBC file %1").arg(fn));
+        msg_box.setDetailedText(error);
+        msg_box.exec();
+      }
     }
   }
 }
@@ -251,11 +258,16 @@ void MainWindow::loadDBCFromOpendbc(const QString &name) {
 void MainWindow::loadDBCFromClipboard() {
   remindSaveChanges();
   QString dbc_str = QGuiApplication::clipboard()->text();
-  dbc()->open("from_clipboard.dbc", dbc_str);
-  if (dbc()->messages().size() > 0) {
+  QString error;
+  bool ret = dbc()->open("clipboard", dbc_str, &error);
+  if (ret && dbc()->messages().size() > 0) {
     QMessageBox::information(this, tr("Load From Clipboard"), tr("DBC Successfully Loaded!"));
   } else {
-    QMessageBox::warning(this, tr("Load From Clipboard"), tr("Failed to parse dbc from clipboard!\nMake sure that you paste the text with correct format."));
+    QMessageBox msg_box(QMessageBox::Warning, tr("Failed to load DBC from clipboard"), tr("Make sure that you paste the text with correct format."));
+    if (!error.isEmpty()) {
+      msg_box.setDetailedText(error);
+    }
+    msg_box.exec();
   }
 }