Use signals/slots to prevent QObject lifetime issues

scwx-qt/source/scwx/qt/main/main_window.cpp

@@ -223,10 +223,18 @@ void MainWindow::on_actionOpen_triggered()
       {
          BOOST_LOG_TRIVIAL(info) << "Selected: " << file.toStdString();
 
-         manager::RadarProductManager::LoadFile(
-            file.toStdString(),
-            [=](std::shared_ptr<wsr88d::NexradFile> nexradFile)
+         std::shared_ptr<request::NexradFileRequest> request =
+            std::make_shared<request::NexradFileRequest>();
+
+         connect(
+            request.get(),
+            &request::NexradFileRequest::RequestComplete,
+            this,
+            [=](std::shared_ptr<request::NexradFileRequest> request)
             {
+               std::shared_ptr<wsr88d::NexradFile> nexradFile =
+                  request->nexrad_file();
+
                std::shared_ptr<wsr88d::Ar2vFile> level2File =
                   std::dynamic_pointer_cast<wsr88d::Ar2vFile>(nexradFile);
                std::shared_ptr<wsr88d::Level3File> level3File =
@@ -250,8 +258,9 @@ void MainWindow::on_actionOpen_triggered()
                   messageBox->setAttribute(Qt::WA_DeleteOnClose);
                   messageBox->open();
                }
-            },
-            this);
+            });
+
+         manager::RadarProductManager::LoadFile(file.toStdString(), request);
       });
 
    dialog->open();

scwx-qt/source/scwx/qt/manager/radar_product_manager.cpp

@@ -28,9 +28,8 @@ static const std::string logPrefix_ =
 typedef std::function<std::shared_ptr<wsr88d::NexradFile>()>
    CreateNexradFileFunction;
 
-static void LoadNexradFile(CreateNexradFileFunction load,
-                           FileLoadCompleteFunction onComplete,
-                           QObject*                 context);
+static void LoadNexradFile(CreateNexradFileFunction                    load,
+                           std::shared_ptr<request::NexradFileRequest> request);
 
 static constexpr uint32_t NUM_RADIAL_GATES_0_5_DEGREE =
    common::MAX_0_5_DEGREE_RADIALS * common::MAX_DATA_MOMENT_GATES;
@@ -210,33 +209,29 @@ void RadarProductManager::Initialize()
    p->initialized_ = true;
 }
 
-void RadarProductManager::LoadData(std::istream&            is,
-                                   FileLoadCompleteFunction onComplete,
-                                   QObject*                 context)
+void RadarProductManager::LoadData(
+   std::istream& is, std::shared_ptr<request::NexradFileRequest> request)
 {
    LoadNexradFile(
       [=, &is]() -> std::shared_ptr<wsr88d::NexradFile> {
          return wsr88d::NexradFileFactory::Create(is);
       },
-      onComplete,
-      context);
+      request);
 }
 
-void RadarProductManager::LoadFile(const std::string&       filename,
-                                   FileLoadCompleteFunction onComplete,
-                                   QObject*                 context)
+void RadarProductManager::LoadFile(
+   const std::string&                          filename,
+   std::shared_ptr<request::NexradFileRequest> request)
 {
    LoadNexradFile(
       [=]() -> std::shared_ptr<wsr88d::NexradFile> {
          return wsr88d::NexradFileFactory::Create(filename);
       },
-      onComplete,
-      context);
+      request);
 }
 
-static void LoadNexradFile(CreateNexradFileFunction load,
-                           FileLoadCompleteFunction onComplete,
-                           QObject*                 context)
+static void LoadNexradFile(CreateNexradFileFunction                    load,
+                           std::shared_ptr<request::NexradFileRequest> request)
 {
    scwx::util::async(
       [=]()
@@ -249,17 +244,10 @@ static void LoadNexradFile(CreateNexradFileFunction load,
 
          lock.unlock();
 
-         if (onComplete != nullptr)
+         if (request != nullptr)
          {
-            if (context == nullptr)
-            {
-               onComplete(nexradFile);
-            }
-            else
-            {
-               QMetaObject::invokeMethod(context,
-                                         [=]() { onComplete(nexradFile); });
-            }
+            request->set_nexrad_file(nexradFile);
+            emit request->RequestComplete(request);
          }
       });
 }

scwx-qt/source/scwx/qt/manager/radar_product_manager.hpp

@@ -2,6 +2,7 @@
 
 #include <scwx/common/types.hpp>
 #include <scwx/qt/config/radar_site.hpp>
+#include <scwx/qt/request/nexrad_file_request.hpp>
 #include <scwx/wsr88d/ar2v_file.hpp>
 #include <scwx/wsr88d/level3_file.hpp>
 
@@ -17,9 +18,6 @@ namespace qt
 namespace manager
 {
 
-typedef std::function<void(std::shared_ptr<wsr88d::NexradFile>)>
-   FileLoadCompleteFunction;
-
 class RadarProductManagerImpl;
 
 class RadarProductManager : public QObject
@@ -49,12 +47,12 @@ public:
    static std::shared_ptr<RadarProductManager>
    Instance(const std::string& radarSite);
 
-   static void LoadData(std::istream&            is,
-                        FileLoadCompleteFunction onComplete,
-                        QObject*                 context = nullptr);
-   static void LoadFile(const std::string&       filename,
-                        FileLoadCompleteFunction onComplete,
-                        QObject*                 context = nullptr);
+   static void
+   LoadData(std::istream&                               is,
+            std::shared_ptr<request::NexradFileRequest> request = nullptr);
+   static void
+   LoadFile(const std::string&                          filename,
+            std::shared_ptr<request::NexradFileRequest> request = nullptr);
 
 signals:
    void Level2DataLoaded();

scwx-qt/source/scwx/qt/request/nexrad_file_request.cpp

@@ -0,0 +1,44 @@
+#include <scwx/qt/request/nexrad_file_request.hpp>
+
+#include <boost/log/trivial.hpp>
+
+namespace scwx
+{
+namespace qt
+{
+namespace request
+{
+
+static const std::string logPrefix_ =
+   "[scwx::qt::request::nexrad_file_request] ";
+
+class NexradFileRequestImpl
+{
+public:
+   explicit NexradFileRequestImpl() : nexradFile_ {nullptr} {}
+
+   ~NexradFileRequestImpl() {}
+
+   std::shared_ptr<wsr88d::NexradFile> nexradFile_;
+};
+
+NexradFileRequest::NexradFileRequest() :
+    p(std::make_unique<NexradFileRequestImpl>())
+{
+}
+NexradFileRequest::~NexradFileRequest() = default;
+
+std::shared_ptr<wsr88d::NexradFile> NexradFileRequest::nexrad_file() const
+{
+   return p->nexradFile_;
+}
+
+void NexradFileRequest::set_nexrad_file(
+   std::shared_ptr<wsr88d::NexradFile> nexradFile)
+{
+   p->nexradFile_ = nexradFile;
+}
+
+} // namespace request
+} // namespace qt
+} // namespace scwx

scwx-qt/source/scwx/qt/request/nexrad_file_request.hpp

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <scwx/wsr88d/nexrad_file.hpp>
+
+#include <memory>
+
+#include <QObject>
+
+namespace scwx
+{
+namespace qt
+{
+namespace request
+{
+
+class NexradFileRequestImpl;
+
+class NexradFileRequest : public QObject
+{
+   Q_OBJECT
+
+public:
+   explicit NexradFileRequest();
+   ~NexradFileRequest();
+
+   std::shared_ptr<wsr88d::NexradFile> nexrad_file() const;
+
+   void set_nexrad_file(std::shared_ptr<wsr88d::NexradFile> nexradFile);
+
+private:
+   std::unique_ptr<NexradFileRequestImpl> p;
+
+signals:
+   void RequestComplete(std::shared_ptr<NexradFileRequest> request);
+};
+
+} // namespace request
+} // namespace qt
+} // namespace scwx