Use static QCoreApplication::processEvents() w/o QApplication instance (

#1772)

Drop QApplication instance from VisualizationFrame

src/rviz/main.cpp

@@ -36,7 +36,6 @@ int main(int argc, char** argv)
   QApplication qapp(argc, argv);
 
   rviz::VisualizerApp vapp;
-  vapp.setApp(&qapp);
   if (vapp.init(argc, argv))
   {
     return qapp.exec();

src/rviz/visualization_frame.cpp

@@ -33,6 +33,7 @@
 #include <QAction>
 #include <QShortcut>
 #include <QApplication>
+#include <QCoreApplication>
 #include <QCloseEvent>
 #include <QDesktopServices>
 #include <QDockWidget>
@@ -103,7 +104,6 @@ namespace rviz
 {
 VisualizationFrame::VisualizationFrame(QWidget* parent)
   : QMainWindow(parent)
-  , app_(nullptr)
   , render_panel_(nullptr)
   , show_help_action_(nullptr)
   , preferences_(new Preferences())
@@ -166,7 +166,7 @@ VisualizationFrame::~VisualizationFrame()
 
 void VisualizationFrame::setApp(QApplication* app)
 {
-  app_ = app;
+  Q_UNUSED(app);
 }
 
 void VisualizationFrame::setStatus(const QString& message)
@@ -258,8 +258,7 @@ void VisualizationFrame::initialize(const QString& display_config_file)
 
   // Periodically process events for the splash screen.
   // See: http://doc.qt.io/qt-5/qsplashscreen.html#details
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   if (!ros::isInitialized())
   {
@@ -268,8 +267,7 @@ void VisualizationFrame::initialize(const QString& display_config_file)
   }
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   QWidget* central_widget = new QWidget(this);
   QHBoxLayout* central_layout = new QHBoxLayout;
@@ -305,40 +303,34 @@ void VisualizationFrame::initialize(const QString& display_config_file)
   central_widget->setLayout(central_layout);
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   initMenus();
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   initToolbars();
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   setCentralWidget(central_widget);
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   manager_ = new VisualizationManager(render_panel_, this);
   manager_->setHelpPath(help_path_);
   connect(manager_, SIGNAL(escapePressed()), this, SLOT(exitFullScreen()));
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   render_panel_->initialize(manager_->getSceneManager(), manager_);
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   ToolManager* tool_man = manager_->getToolManager();
 
@@ -351,8 +343,7 @@ void VisualizationFrame::initialize(const QString& display_config_file)
   manager_->initialize();
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   if (display_config_file != "")
   {
@@ -364,8 +355,7 @@ void VisualizationFrame::initialize(const QString& display_config_file)
   }
 
   // Periodically process events for the splash screen.
-  if (app_)
-    app_->processEvents();
+  QCoreApplication::processEvents();
 
   delete splash_;
   splash_ = nullptr;
@@ -759,7 +749,9 @@ bool VisualizationFrame::loadDisplayConfigHelper(const std::string& full_path, c
     dialog.reset(new LoadingDialog(this));
     dialog->show();
     connect(this, SIGNAL(statusUpdate(const QString&)), dialog.get(), SLOT(showMessage(const QString&)));
-    app_->processEvents(); // make the window correctly appear although running a long-term function
+
+    // make the window correctly appear although running a long-term function
+    QCoreApplication::processEvents();
   }
 
   YamlConfigReader reader;

src/rviz/visualization_frame.h

@@ -78,7 +78,7 @@ class RVIZ_EXPORT VisualizationFrame : public QMainWindow, public WindowManagerI
   VisualizationFrame(QWidget* parent = nullptr);
   ~VisualizationFrame() override;
 
-  void setApp(QApplication* app);
+  [[deprecated("setApp() not needed anymore")]] void setApp(QApplication* app);
 
   /** @brief Call this @e before initialize() to have it take effect. */
   void setShowChooseNewMaster(bool show);
@@ -328,8 +328,6 @@ protected Q_SLOTS:
 
   void hideDockImpl(Qt::DockWidgetArea area, bool hide);
 
-  QApplication* app_;
-
   RenderPanel* render_panel_;
 
   QAction* show_help_action_;

src/rviz/visualizer_app.cpp

@@ -100,13 +100,13 @@ bool reloadShaders(std_srvs::Empty::Request& /*unused*/, std_srvs::Empty::Respon
   return true;
 }
 
-VisualizerApp::VisualizerApp() : app_(nullptr), continue_timer_(nullptr), frame_(nullptr)
+VisualizerApp::VisualizerApp() : continue_timer_(nullptr), frame_(nullptr)
 {
 }
 
 void VisualizerApp::setApp(QApplication* app)
 {
-  app_ = app;
+  Q_UNUSED(app);
 }
 
 bool VisualizerApp::init(int argc, char** argv)
@@ -202,7 +202,6 @@ bool VisualizerApp::init(int argc, char** argv)
       RenderSystem::forceNoStereo();
 
     frame_ = new VisualizationFrame();
-    frame_->setApp(this->app_);
     if (!help_path.empty())
     {
       frame_->setHelpPath(QString::fromStdString(help_path));

src/rviz/visualizer_app.h

@@ -29,7 +29,6 @@
 #ifndef RVIZ_VISUALIZER_APP_H
 #define RVIZ_VISUALIZER_APP_H
 
-#include <QApplication>
 #include <QObject>
 
 #ifndef Q_MOC_RUN // See: https://bugreports.qt-project.org/browse/QTBUG-22829
@@ -38,6 +37,7 @@
 #include <rviz/SendFilePath.h>
 #endif
 
+class QApplication;
 class QTimer;
 
 namespace rviz
@@ -51,7 +51,7 @@ class RVIZ_EXPORT VisualizerApp : public QObject
   VisualizerApp();
   ~VisualizerApp() override;
 
-  void setApp(QApplication* app);
+  [[deprecated("setApp() not needed anymore")]] void setApp(QApplication* app);
 
   /** Start everything.  Pass in command line arguments.
    * @return false on failure, true on success. */
@@ -67,7 +67,6 @@ private Q_SLOTS:
   bool loadConfigDiscardingCallback(rviz::SendFilePathRequest& req, rviz::SendFilePathResponse& res);
   bool saveConfigCallback(rviz::SendFilePathRequest& req, rviz::SendFilePathResponse& res);
 
-  QApplication* app_;
   QTimer* continue_timer_;
   VisualizationFrame* frame_;
   ros::NodeHandlePtr nh_;