owTvQtWidgetShow refactoring

Summary

Refactoring owTvQtWidgetShow in order to optimize processing time such as described in #1778.

Rationale

This test loads all OTB-applications (one dynamic library per OTB-Application) and displays their GUI (loading of Qt dynamic-libraries). Since each OTB-applications command-line is already tested individually, this test only ensures that the GUI window could be displayed and, then, could be reduced to displaying only one OTB-Application : TestApplication.

Implementation Details

Classes and files

The test-driver https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb/blob/develop/Modules/Wrappers/QtWidget/test/otbWrapperQtWidgetShowWidget.cxx has been optimized as following :

• Direct parsing of command-line arguments and removal of needless copy into temporary container
• Removal of OTB-application listing
• Replacement of for-each OTB-application loop by single instantiation of TestApplication (Main improvement)
• Replacement of QDockWidget for otb::Wrapper::QtProgressReport by single Layout lowers Qt resources usage

Additional notes

The processing time of this test falls from 111.65s+ (fastest platform) to:

• 2.19s on hulk
• 7.21s on leod
• 13.07 on megatron

TestApplication could be reviewed and upgraded in order to include Qt widgets of all parameters.

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

---

Check before merging:

• All discussions are resolved
• At least 2 votes from core developers, no vote.
• The feature branch is (reasonably) up-to-date with the base branch
• Dashboard is green
• Copyright owner has signed the ORFEO ToolBox Contributor License Agreement

Modules/Wrappers/QtWidget/test/otbWrapperQtWidgetShowWidget.cxx

@@ -20,99 +20,133 @@
 
 
 #include <QtWidgets>
+
+
+#include "otbQtApplication.h"
 #include "otbWrapperApplicationRegistry.h"
 #include "otbWrapperQtWidgetView.h"
 #include "otbWrapperQtWidgetProgressReport.h"
 #include "itksys/SystemTools.hxx"
 
+
 using otb::Wrapper::Application;
 using otb::Wrapper::ApplicationRegistry;
+using otb::Wrapper::QtApplication;
 using otb::Wrapper::QtWidgetView;
 using otb::Wrapper::QtWidgetProgressReport;
 
 
-int otbWrapperQtWidgetShowWidget(int argc, char* argv[])
+struct static_finalizer
+{
+  ~static_finalizer()
+  {
+    ApplicationRegistry::CleanRegistry();
+  }
+};
+
+
+namespace
 {
-  QApplication qtApp(argc, argv);
+  static_finalizer finalizer;
+}
 
-  std::cout << "Usage : " << argv[0] << " [module_path]" << std::endl;
 
-  // Get the module path list
-  std::list<std::string> modulePathList;
-  if (argc > 1)
+int
+otbWrapperQtWidgetShowWidget( int argc, char* argv[] )
+{
+  std::cout << "Usage: " << argv[0] << " [module_path]" << std::endl;
+
+  // Register module-path list.
+  std::for_each(
+    // std::advance( std::begin( argv ) ),
+    // std::end( argv ),
+    argv + 1,
+    argv + argc,
+    []( auto module_path )
     {
-    std::copy(argv + 1, argv + argc, std::back_inserter(modulePathList));
+      ApplicationRegistry::AddApplicationPath( module_path );
+    }
+  );
 
-    // Load the path in the environment
-    std::list<std::string>::const_iterator it = modulePathList.begin();
-    while( it != modulePathList.end() )
+  {
+    // Create OTB-application.
+    Application::Pointer otb_application =
+      ApplicationRegistry::CreateApplication( "TestApplication" );
+
+    if( !otb_application )
       {
-      ApplicationRegistry::AddApplicationPath( *(it) );
-      ++it;
+      std::cerr << "Could not find application: 'TestApplication'" << std::endl;
+
+      return EXIT_FAILURE;
       }
-    }
 
-  bool result = true;
+    // Qt application.
+    QtApplication qt_app( argc, argv );
+
+    qt_app.setQuitOnLastWindowClosed( true );
+
+    // Qt main-window.
+    QMainWindow main_window; // Stack instance acts as a
+			     // scoped-pointer inside {}.
 
-  // Get list of available applications
-  std::vector<std::string> list = ApplicationRegistry::GetAvailableApplications();
-  for (std::vector<std::string>::const_iterator it = list.begin(); it != list.end(); ++it)
+    // OTB-Application GUI.
     {
-    std::cout << "Testing QtWidget for application "<< (*it) << " ..." << std::endl;
-    // Create module
-    Application::Pointer app = ApplicationRegistry::CreateApplication(*it);
-    if (app.IsNull())
+      QWidget * widget = new QWidget( &main_window );
       {
-      std::cerr << "Could not find application " << (*it) << std::endl;
-      result = false;
-      continue;
+        QVBoxLayout * layout = new QVBoxLayout( widget );
+	{
+	  // Create OTB-Application widget.
+	  //
+	  // SAT: QWidget should be created without parent when adding
+	  // into QLayout (because QLayout will take ownership of the
+	  // reference-counted pointer) but OTB API doesn't defined default nullptr
+	  // value such as in Qt.
+	  QtWidgetView * qwv = new QtWidgetView( otb_application, widget );
+
+	  // SAT: Should be automatically done in QtWidgetView().
+	  qwv->CreateGui();
+
+	  // Connect the view to main-window.
+	  QObject::connect(
+	    qwv, SIGNAL( QuitSignal() ),
+	    &main_window, SLOT( close() )
+	  );
+
+	  layout->addWidget( qwv );
+
+	  // Create OTB-Application progress-report.
+	  //
+	  // SAT: QWidget should be created without parent when adding
+	  // into QLayout (because QLayout will take ownership of the
+	  // reference-counted pointer) but OTB API doesn't defined default nullptr
+	  // value such as in Qt.
+	  QtWidgetProgressReport * qwpr =
+	    new QtWidgetProgressReport( qwv->GetModel(), widget );
+
+	  qwpr->SetApplication( otb_application );
+
+	  layout->addWidget( qwpr );
+	}
+        widget->setLayout( layout );
       }
-  
-    // MainWidget : that contains the view and any other widget
-    // (progress, logs...)
-    QMainWindow* mainWindow =  new QMainWindow();
-  
-    // Create GUI based on module
-    QtWidgetView* gui = new QtWidgetView(app, mainWindow);
-    gui->CreateGui();
-  
-    // Connect the View "Quit" signal, to the mainWindow close slot
-    QObject::connect(gui, &QtWidgetView::QuitSignal, mainWindow, &QMainWindow::close);
-  
-    // Create a progressReport object
-    QtWidgetProgressReport* progressReport =  new QtWidgetProgressReport(gui->GetModel(), mainWindow);
-    progressReport->SetApplication(app);
-  
-    // Create a dock widget containing the progress widget
-    QDockWidget* qdock = new QDockWidget("Progress Reporting ...", mainWindow);
-    qdock->setWidget(progressReport);
-  
-    // build the main window, central widget is the plugin view, other
-    // are docked widget (progress, logs...)
-    mainWindow->setCentralWidget(gui);
-    mainWindow->addDockWidget(Qt::BottomDockWidgetArea, qdock);
-  
+      main_window.setCentralWidget( widget );
+    }
+
     // Show the main window
-    mainWindow->show();
-  
-    QTimer::singleShot(1000, &qtApp, SLOT(quit()));
-  
+    main_window.show();
+
+    QTimer::singleShot( 1000, &qt_app, SLOT( quit() ) );
+
     // Start event processing loop
-    if (qtApp.exec())
+    if( qt_app.exec() )
       {
-      std::cerr << "Failed to show widget for application " << (*it) << std::endl;
-      result = false;
+      std::cerr
+    	<< "Failed to execute Qt event-loop for application 'TestApplication'"
+    	<< std::endl;
+
+      return EXIT_FAILURE;
       }
-    
-    // clean main window
-    if (mainWindow) delete mainWindow;
-    }
+  }
 
-  ApplicationRegistry::CleanRegistry();
-  
-  if (result)
-    {
-    return EXIT_SUCCESS;
-    }
-  return EXIT_FAILURE;
+  return EXIT_SUCCESS;
 }