BACKEND: Add the vivy document's class with its view class

src/AudioVisualizer.h

 #ifndef VIVY_AUDIOVISUALIZER_H
 #define VIVY_AUDIOVISUALIZER_H
 
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
 #include "TimingView.hpp"
 #include <QWidget>
 

src/DialogHelp.h

 #ifndef VIVY_DIALOGHELP_H
 #define VIVY_DIALOGHELP_H
 
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
 #include <QMessageBox>
 #include <QWidget>
 

src/MainWindow.cc

@@ -3,6 +3,7 @@
 #include "MainWindow.h"
 #include "AudioUtils.h"
 #include "DialogHelp.h"
+#include "VivyDocumentView.h"
 
 #include <iostream>
 #include <cstring>

src/MainWindow.h

 #ifndef VIVY_MAINWINDOW_H
 #define VIVY_MAINWINDOW_H
 
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
 #include "AudioVisualizer.h"
 #include <QMainWindow>
 

src/TimingBar.h

 #ifndef VIVY_TIMING_BAR_H
 #define VIVY_TIMING_BAR_H
 
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
 #include <QWidget>
 #include <QGraphicsItem>
 #include <QGraphicsLineItem>

src/TimingView.hpp

 #ifndef VIVY_TIMING_VIEW_H
 #define VIVY_TIMING_VIEW_H
 
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
 #include "TimingBar.h"
 #include "TimingScene.hpp"
 

src/VivyDocument.h

+#ifndef VIVY_DOCUMENT_H
+#define VIVY_DOCUMENT_H
+
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
+class VivyDocument {
+    /* The document name */
+    const char *name;
+
+    /* Links to other files, they're not embeded inside the vivy file */
+    const char *audioFile;
+    const char *videoFile;
+    const char *assFile;
+};
+
+#endif // VIVY_DOCUMENT_H

src/VivyDocumentView.h

+#ifndef VIVY_DOCUMENTVIEW_H
+#define VIVY_DOCUMENTVIEW_H
+
+#ifndef __cplusplus
+#error "This is a C++ header"
+#endif
+
+#include "VivyDocument.h"
+#include "AudioVisualizer.h"
+
+#include <QWidget>
+
+class VivyDocumentView final : public QWidget {
+    Q_OBJECT
+
+private:
+    VivyDocument *document;
+    AudioVisualizer *visualizer;
+};
+
+#endif // VIVY_DOCUMENTVIEW_H