qt: add ReadableTreeView

src/modules/interface/qt/widgets/ReadableTreeView.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <QTreeView>
+
+// Enables the tree view to send a signal when item dragging starts
+
+class ReadableTreeView : public QTreeView {
+public:
+    ReadableTreeView(QWidget *parent = nullptr) : QTreeView(parent) {}
+signals:
+    void itemDragStarted();
+protected:
+    void startDrag(Qt::DropActions acts) {
+        emit itemDragStarted();
+        
+        QAbstractItemView::startDrag(acts);
+    }
+private:
+    Q_OBJECT
+};