make code work in the 'lightly hacked' and 'project aware' qmlscene

Author: pestophagous

src/app/gui_tests.cc

@@ -23,9 +23,13 @@ namespace
 constexpr char EXPECTED_FIRST_LOADED_FILE[] = "main.qml";
 } // namespace
 
-GuiTests::GuiTests( const QQmlApplicationEngine& engine )
+GuiTests::GuiTests( QQmlEngine& engine )
 {
-    connect( &engine, &QQmlApplicationEngine::objectCreated, [ = ]( QObject*, const QUrl& url ) {
+    const QQmlApplicationEngine* appEngine
+        = dynamic_cast<const QQmlApplicationEngine*>( &engine );
+    FASSERT( appEngine, "not null. downcast must succeed." );
+
+    connect( appEngine, &QQmlApplicationEngine::objectCreated, [ = ]( QObject*, const QUrl& url ) {
         FASSERT( url.fileName() == QString( EXPECTED_FIRST_LOADED_FILE ), "something must have changed in loading behavior of QQmlApplicationEngine" );
 
         // quit during next event-loop cycle

src/app/gui_tests.h

@@ -17,7 +17,7 @@ class GuiTests : public QObject
 {
     Q_OBJECT
 public:
-    explicit GuiTests( const QQmlApplicationEngine& qmlapp );
+    explicit GuiTests( QQmlEngine& qmlapp );
     ~GuiTests();
 
     GuiTests( const GuiTests& ) = delete;

src/app/main.cc

@@ -39,7 +39,7 @@ int main( int argc, char* argv[] )
     // QQuickStyle::setStyle( "Fusion" ); // <-- call setStyle after creating app (if style is needed)
 
     // ViewModels must OUTLIVE the qml engine, so create them first:
-    project::ViewModelCollection vms( app );
+    project::ViewModelCollection vms( app, false /*cliArgsOnlyParseThenSkipErrorHandling*/ );
 
     // For antialiasing: https://stackoverflow.com/a/49576756/10278
     // QSurfaceFormat format;

src/app/view_model_collection.cc

@@ -24,8 +24,8 @@ namespace project
 using str = std::string;
 
 // clang-format off
-ViewModelCollection::ViewModelCollection( const QCoreApplication& app )
-    : m_opts( std::make_unique<CliOptions>( app ) ),
+ViewModelCollection::ViewModelCollection( const QCoreApplication& app, bool cliArgsOnlyParseThenSkipErrorHandling )
+    : m_opts( std::make_unique<CliOptions>( app, cliArgsOnlyParseThenSkipErrorHandling ) ),
       m_eventFilter( std::make_unique<EventFilter>() ),
       m_qmlLogger( std::make_unique<QmlMessageInterceptor>( !m_opts->MaximumQtLogging() ) ),
       m_logging( std::make_unique<LoggingTags>( *m_opts ) )
@@ -44,7 +44,7 @@ const CliOptions& ViewModelCollection::Options() const
     return *m_opts;
 }
 
-void ViewModelCollection::ExportContextPropertiesToQml( QQmlApplicationEngine* engine )
+void ViewModelCollection::ExportContextPropertiesToQml( QQmlEngine* engine )
 {
     // Sort of a "silly" demo usage of project::Log<>
     Log( str( "rootContext" ), engine )->rootContext()->setContextProperty( "versionInfoBuildDateString", BUILD_ON_DATE );

src/app/view_model_collection.h

@@ -25,13 +25,13 @@ class QmlMessageInterceptor;
 class ViewModelCollection
 {
 public:
-    explicit ViewModelCollection( const QCoreApplication& app );
+    explicit ViewModelCollection( const QCoreApplication& app, bool cliArgsOnlyParseThenSkipErrorHandling );
     ~ViewModelCollection();
 
     ViewModelCollection( const ViewModelCollection& ) = delete;
     ViewModelCollection& operator=( const ViewModelCollection& ) = delete;
 
-    void ExportContextPropertiesToQml( QQmlApplicationEngine* engine );
+    void ExportContextPropertiesToQml( QQmlEngine* engine );
 
     void SetRootObject( QObject* object );
 

src/lib_app/cli_options.cc

@@ -15,7 +15,7 @@ constexpr char GUI_TEST_CLI_OPT[] = "guitest";
 constexpr char MAX_QT_LOGGING_CLI_OPT[] = "maxlogs";
 constexpr char COLOR_PALETTE_CLI_OPT[] = "colorpalette";
 
-CliOptions::CliOptions( const QCoreApplication& app )
+CliOptions::CliOptions( const QCoreApplication& app, bool stopAtParseOnly )
 {
     QCommandLineParser parser;
     parser.addHelpOption();
@@ -27,7 +27,27 @@ CliOptions::CliOptions( const QCoreApplication& app )
         { { "c", COLOR_PALETTE_CLI_OPT }, "show color palette to allow for on-the-fly color experiments" },
     } );
 
-    parser.process( app );
+    if( !stopAtParseOnly )
+    {
+        // The NOT-stop case is the full desktop application.
+        // This call to 'process' gives us parsing and type-checking and error
+        // reporting. (In other words, everything you would want in a full app.)
+        parser.process( app );
+    }
+    else
+    {
+        // The 'stopAtParseOnly' case is the case when this instance of
+        // CliOptions is part of our 'lightly hacked' and 'project aware'
+        // locally-built qmlscene.
+        //    We MUST NOT CALL QCommandLineParser::process IN THIS CASE, because
+        // it will prevent us from using the arguments that qmlscene accepts in
+        // its own 'main' function.
+        //    By calling 'parse' instead, we DO achieve the desired capture of
+        // our app-specific options. As a trade-off, we forgo the built-in
+        // type-checking and error reporting of QCommandLineParser::process
+        const QStringList arguments = QCoreApplication::arguments();
+        parser.parse( arguments );
+    }
 
     m_guiTests = parser.isSet( GUI_TEST_CLI_OPT );
     m_maximumQtLogs = parser.isSet( MAX_QT_LOGGING_CLI_OPT );

src/lib_app/cli_options.h

@@ -15,7 +15,7 @@ namespace project
 class CliOptions
 {
 public:
-    explicit CliOptions( const QCoreApplication& app );
+    explicit CliOptions( const QCoreApplication& app, bool stopAtParseOnly );
     ~CliOptions();
 
     CliOptions( const CliOptions& ) = delete;