Add the ASS sub document and the ASS tree

Also add views for the ASS tree in read only mode for now

src/UI/VivyDocumentView.cc

@@ -7,6 +7,7 @@
 #include <QHeaderView>
 #include <QTreeView>
 #include <QVBoxLayout>
+#include <QTableView>
 
 using namespace Vivy;
 
@@ -76,6 +77,24 @@ VivyDocumentView::loadVideoView() noexcept
 void
 VivyDocumentView::loadAssView() noexcept
 {
+    if (assLines)
+        delDockWidget(&assLines);
+
+    if (document->checkDocumentCapabilities(VivyDocument::Capabilities::AssAble)) {
+        assModel.reset(new AssLinesModel(document->getAssSubDocument()->getLines()));
+        assLines         = new QDockWidget("ASS Lines", this);
+        QTableView *view = new QTableView(assLines);
+        view->setModel(assModel.get());
+        view->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);
+        view->horizontalHeader()->setStretchLastSection(true);
+        view->verticalHeader()->setVisible(true);
+        view->setSelectionMode(QAbstractItemView::ExtendedSelection);
+        assLines->setWidget(view);
+        assLines->setFeatures(QDockWidget::DockWidgetMovable | QDockWidget::DockWidgetClosable);
+        assLines->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea |
+                                  Qt::BottomDockWidgetArea);
+        addDockWidget(Qt::BottomDockWidgetArea, assLines, Qt::Vertical);
+    }
 }
 
 void