Return status when opening .dot file (even in python thread)

Author: joern274

plugins/dot_viewer/deps/QGVCore/QGVScene.cpp

@@ -81,6 +81,8 @@ QGVScene::QGVScene(QObject *parent)
 
 QGVScene::~QGVScene()
 {
+    for (QGraphicsItem* item : items())
+        item->setSelected(false);
     gvFreeLayout(_context->context(), _graph->graph());
     agclose(_graph->graph());
     gvFreeContext(_context->context());

plugins/dot_viewer/include/dot_viewer/dot_viewer.h

@@ -59,6 +59,7 @@ namespace hal
         static DotViewer* getDotviewerInstance();
         QString filename() const { return mFilename; }
         QString creatorPlugin() const { return mCreatorPlugin; }
+        bool loadDotFile(const QString& fileName, const QString& creator = QString());
 
     public Q_SLOTS:
         void handleOpenInputFileByName(const QString& fileName, const QString& creator = QString());
@@ -84,7 +85,7 @@ namespace hal
         Q_OBJECT
     public:
         DotViewerCallFromTread(QObject* parent = nullptr) : QObject(parent) {;}
-        void emitOpenInputFileByName(DotViewer* callee, QString filename, QString plugin);
+        bool openInputFileByName(DotViewer* callee, QString filename, QString plugin);
     Q_SIGNALS:
         void callOpenInputFileByName(QString filename, QString plugin);
     };

plugins/dot_viewer/include/dot_viewer/interaction/solve_fsm_interaction.h

@@ -37,6 +37,7 @@ namespace hal {
         Q_OBJECT
     public:
         SolveFsmInteraction(QGVScene* parent);
+        ~SolveFsmInteraction();
 
         void registerNode(QGVNode* node) override;
         void registerEdge(QGVEdge* edge) override;

plugins/dot_viewer/python/python_bindings.cpp

@@ -82,18 +82,19 @@ namespace hal
 
         m.def(
             "load_dot_file",
-            [](const std::filesystem::path& path, const std::string& creator_plugin = "") {
+            [](const std::filesystem::path& path, const std::string& creator_plugin = "") -> bool {
                 QString qfilename = QString::fromStdString(path.string());
                 QString qcreator  = QString::fromStdString(creator_plugin);
                 DotViewer* dv     = DotViewer::getDotviewerInstance();
                 if (dv)
                 {
-                    dv->handleOpenInputFileByName(qfilename, qcreator);
+                    return dv->loadDotFile(qfilename, qcreator);
                 }
                 else
                 {
                     log_error("python_context", "Cannot find dot viewer instance.");
                 }
+                return false;
             },
             py::arg("path"),
             py::arg("creator_plugin") = std::string(),
@@ -102,6 +103,8 @@ namespace hal
 
             :param pathlib.Path path: The path to the ``.dot`` file.
             :param str creator_plugin: The name of plugin that created the ``.dot`` file. Will try to detect from content or query by popup if empty.
+            :returns: True on success, false otherwise.
+            :rtype: bool
         )");
 
 #ifndef PYBIND11_MODULE

plugins/dot_viewer/src/dot_viewer.cpp

@@ -97,21 +97,25 @@ namespace hal
         void DotViewer::handleOpenInputFileDialog()
         {
             QString filename = QFileDialog::getOpenFileName(this, "Open dot file", ".", "Dot files (*.dot);;All files (*)");
-            if (!filename.isEmpty()) handleOpenInputFileByName(filename);
+            if (!filename.isEmpty()) loadDotFile(filename);
         }
 
         void DotViewer::handleOpenInputFileByName(const QString& fileName, const QString &creator)
+        {
+            loadDotFile(fileName,creator);
+        }
+
+        bool DotViewer::loadDotFile(const QString& fileName, const QString &creator)
         {
             if (dynamic_cast<PythonThread*>(QThread::currentThread()))
             {
                 // call from differnt thread, we cannot create GUI objects directly
                 DotViewerCallFromTread* dvcft = new DotViewerCallFromTread;
-                dvcft->emitOpenInputFileByName(this, fileName, creator);
+                bool retval = dvcft->openInputFileByName(this, fileName, creator);
                 delete dvcft;
-                return;
+                return retval;
             }
 
-            mFilename = fileName;
             mCreatorPlugin = creator;
 
             const char* halComment = "\"created by HAL plugin ";
@@ -121,9 +125,17 @@ namespace hal
             mDotGraphicsView->setScene(mDotScene);
             toDispose->deleteLater();
 
-            if (fileName.isEmpty()) return;
+            if (fileName.isEmpty()) {
+                log_warning("dot_viewer", "Cannot load dot file, no file name provided");
+                return false;
+            }
             QFile ff(fileName);
-            if (!ff.open(QIODevice::ReadOnly)) return;
+            if (!ff.open(QIODevice::ReadOnly)) {
+                log_warning("dot_viewer", "An error occurred loading dot file '{}'", fileName.toStdString());
+                return false;
+            }
+
+            mFilename = fileName;
             QByteArray dotfileContent = ff.readAll();
 
             // Determine plugin name to construct correct interaction class
@@ -163,6 +175,7 @@ namespace hal
 
             // interact might be nullptr but that is OK (no interactions in this case)
             mDotScene->loadLayout(dotfileContent, interact);
+            return true;
         }
 
         void DotViewer::handleColorSelect()
@@ -195,11 +208,12 @@ namespace hal
             }
         }
 
-        void DotViewerCallFromTread::emitOpenInputFileByName(DotViewer* callee, QString filename, QString plugin)
+        bool DotViewerCallFromTread::openInputFileByName(DotViewer* callee, QString filename, QString plugin)
         {
-            if (!callee) return;
+            if (!callee) return false;
             connect(this, &DotViewerCallFromTread::callOpenInputFileByName, callee, &DotViewer::handleOpenInputFileByName, Qt::BlockingQueuedConnection);
             Q_EMIT callOpenInputFileByName(filename, plugin);
             disconnect(this, &DotViewerCallFromTread::callOpenInputFileByName, callee, &DotViewer::handleOpenInputFileByName);
+            return (callee->filename() == filename); // callee will not store filename upon load error
         }
 }  // namespace hal

plugins/dot_viewer/src/dot_viewer_factory.cpp

@@ -20,7 +20,7 @@ namespace hal {
     ExternalContentWidget* DotViewerFactory::contentFactory() const
     {
         DotViewer* dv = new DotViewer(name());
-        if (!mFilename.isEmpty()) dv->handleOpenInputFileByName(mFilename, mCreator);
+        if (!mFilename.isEmpty()) dv->loadDotFile(mFilename, mCreator);
         return dv;
     }
 
@@ -85,6 +85,6 @@ namespace hal {
         if (!dv) return;
 
         if (!mFilename.isEmpty())
-            dv->handleOpenInputFileByName(mFilename, mCreator);
+            dv->loadDotFile(mFilename, mCreator);
     }
 }

plugins/dot_viewer/src/gui_extension_dot_viewer.cpp

@@ -38,7 +38,7 @@ namespace hal {
         if (loadClicked)
         {
             DotViewer* dv = DotViewer::getDotviewerInstance();
-            if (dv) dv->handleOpenInputFileByName(filename,plugin);
+            if (dv) dv->loadDotFile(filename,plugin);
         }
     }
 

plugins/dot_viewer/src/interaction/solve_fsm_interaction.cpp

@@ -32,6 +32,12 @@ namespace hal {
         connect(parent, &QGraphicsScene::changed, this, &SolveFsmInteraction::handleSceneChanged);
     }
 
+    SolveFsmInteraction::~SolveFsmInteraction()
+    {
+        std::cerr << "SolveFsmInteraction::~SolveFsmInteraction()" << std::endl;
+    }
+
+
     void SolveFsmInteraction::handleSceneChanged(const QList<QRectF>& changedArea)
     {
         Q_UNUSED(changedArea);