further progress on export dialog

Implemented setting up and running the export thread with valid parameters,
transformation matrix and color processor.

app/dialog/export/export.h

@@ -4,6 +4,7 @@
 #include <QComboBox>
 #include <QDialog>
 #include <QLineEdit>
+#include <QProgressBar>
 
 #include "exportaudiotab.h"
 #include "exportcodec.h"
@@ -17,6 +18,9 @@ class ExportDialog : public QDialog
 public:
   ExportDialog(ViewerOutput* viewer_node, QWidget* parent = nullptr);
 
+public slots:
+  virtual void accept() override;
+
 private:
   void SetUpFormats();
   void LoadPresets();
@@ -40,6 +44,10 @@ private:
 
   double video_aspect_ratio_;
 
+  ColorManager* color_manager_;
+
+  QProgressBar* progress_bar_;
+
   enum Format {
     kFormatDNxHD,
     kFormatMatroska,
@@ -80,6 +88,8 @@ private slots:
 
   void UpdateViewerDimensions();
 
+  void ExporterIsDone();
+
 };
 
 #endif // EXPORTDIALOG_H