sidebar: Left key jumps to parent and activates it

src/widget/wlibrarysidebar.cpp

@@ -208,6 +208,19 @@ void WLibrarySidebar::keyPressEvent(QKeyEvent* event) {
     //    // encoder click via "GoToItem"
     //    qDebug() << "GoToItem";
     //    TODO(xxx) decide what todo here instead of in librarycontrol
+    } else if (event->key() == Qt::Key_Left) {
+        QTreeView::keyPressEvent(event);
+        // If this is a child item jump to its parent and activate it
+        auto selModel = selectionModel();
+        QModelIndexList selectedRows = selModel->selectedRows();
+        if (selectedRows.size() > 0) {
+            QModelIndex parentIndex = selectedRows.at(0).parent();
+            if (parentIndex.isValid()) {
+                selectIndex(parentIndex);
+                emit pressed(parentIndex);
+            }
+            return;
+        }
     }
 
     // Fall through to default handler.