Respect build options in export dialogs (LMMS#3714)

* Respect build options in ExportProjectDialog

* Use QItem user data instead of hard ordering to identify export format in ExportProjectDialog

* For compatibility with QVariant, ExportFileFormats is now explicitly an int.

* Don't break out of format identifier loop prematurely in Song export.

include/ProjectRenderer.h

@@ -35,7 +35,7 @@ class ProjectRenderer : public QThread
 {
 	Q_OBJECT
 public:
-	enum ExportFileFormats
+	enum ExportFileFormats: int
 	{
 		WaveFile,
 		OggFile,

src/core/Song.cpp

@@ -1337,10 +1337,11 @@ void Song::exportProject( bool multiExport )
 		efd.setFileMode( FileDialog::AnyFile );
 		int idx = 0;
 		QStringList types;
-		while( ProjectRenderer::fileEncodeDevices[idx].m_fileFormat != ProjectRenderer::NumFileFormats &&
-		       ProjectRenderer::fileEncodeDevices[idx].isAvailable())
+		while( ProjectRenderer::fileEncodeDevices[idx].m_fileFormat != ProjectRenderer::NumFileFormats)
 		{
-			types << tr( ProjectRenderer::fileEncodeDevices[idx].m_description );
+			if(ProjectRenderer::fileEncodeDevices[idx].isAvailable()) {
+				types << tr(ProjectRenderer::fileEncodeDevices[idx].m_description);
+			}
 			++idx;
 		}
 		efd.setNameFilters( types );

src/gui/ExportProjectDialog.cpp

@@ -65,7 +65,9 @@ ExportProjectDialog::ExportProjectDialog( const QString & _file_name,
 
 			// add to combo box
 			fileFormatCB->addItem( ProjectRenderer::tr(
-				ProjectRenderer::fileEncodeDevices[i].m_description ) );
+				ProjectRenderer::fileEncodeDevices[i].m_description ),
+				QVariant(ProjectRenderer::fileEncodeDevices[i].m_fileFormat) // format tag; later used for identification
+			);
 
 			// if this is our extension, select it
 			if( QString::compare( renderExt, fileExt,
@@ -187,29 +189,16 @@ void ExportProjectDialog::startExport()
 }
 
 
-ProjectRenderer::ExportFileFormats convertIndexToExportFileFormat(int index)
-{
-	switch (index)
-	{
-	case 0:
-		return ProjectRenderer::WaveFile;
-	case 1:
-		return ProjectRenderer::OggFile;
-	case 2:
-		return ProjectRenderer::MP3File;
-	default:
-		Q_ASSERT(false);
-		break;
-	}
-
-	return ProjectRenderer::NumFileFormats;
-}
-
-
 void ExportProjectDialog::onFileFormatChanged(int index)
 {
-	ProjectRenderer::ExportFileFormats exportFormat =
-			convertIndexToExportFileFormat(index);
+	// Extract the format tag from the currently selected item,
+	// and adjust the UI properly.
+	QVariant format_tag = fileFormatCB->itemData(index);
+	bool successful_conversion = false;
+	auto exportFormat = static_cast<ProjectRenderer::ExportFileFormats>(
+		format_tag.toInt(&successful_conversion)
+	);
+	Q_ASSERT(successful_conversion);
 
 	bool stereoModeVisible = exportFormat == ProjectRenderer::MP3File;
 
@@ -236,28 +225,31 @@ void ExportProjectDialog::startBtnClicked()
 {
 	m_ft = ProjectRenderer::NumFileFormats;
 
+	//Get file format from current menu selection.
+	bool successful_conversion = false;
+	QVariant tag = fileFormatCB->itemData(fileFormatCB->currentIndex());
+	m_ft = static_cast<ProjectRenderer::ExportFileFormats>(tag.toInt(&successful_conversion));
+
+	if( !successful_conversion )
+	{
+		QMessageBox::information( this, tr( "Error" ),
+								  tr( "Error while determining file-encoder device. "
+										  "Please try to choose a different output "
+										  "format." ) );
+		reject();
+		return;
+	}
+
+	// Find proper file extension.
 	for( int i = 0; i < ProjectRenderer::NumFileFormats; ++i )
 	{
-		if( fileFormatCB->currentText() ==
-			ProjectRenderer::tr(
-				ProjectRenderer::fileEncodeDevices[i].m_description ) )
+		if (m_ft == ProjectRenderer::fileEncodeDevices[i].m_fileFormat)
 		{
-			m_ft = ProjectRenderer::fileEncodeDevices[i].m_fileFormat;
 			m_fileExtension = QString( QLatin1String( ProjectRenderer::fileEncodeDevices[i].m_extension ) );
 			break;
 		}
 	}
 
-	if( m_ft == ProjectRenderer::NumFileFormats )
-	{
-		QMessageBox::information( this, tr( "Error" ),
-			tr( "Error while determining file-encoder device. "
-				"Please try to choose a different output "
-							"format." ) );
-		reject();
-		return;
-	}
-
 	startButton->setEnabled( false );
 	progressBar->setEnabled( true );