Add some drag'n'drop utils to work with TableMimeData

apps/opencs/CMakeLists.txt

@@ -70,7 +70,7 @@ opencs_units (view/world
 opencs_units_noqt (view/world
     subviews enumdelegate vartypedelegate recordstatusdelegate idtypedelegate datadisplaydelegate
     scripthighlighter idvalidator dialoguecreator physicssystem idcompletiondelegate
-    colordelegate
+    colordelegate dragdroputils
     )
 
 opencs_units (view/widget

apps/opencs/view/world/dragdroputils.cpp

@@ -0,0 +1,26 @@
+#include "dragdroputils.hpp"
+
+#include <QDropEvent>
+
+#include "../../model/world/tablemimedata.hpp"
+
+const CSMWorld::TableMimeData *CSVWorld::DragDropUtils::getTableMimeData(const QDropEvent &event)
+{
+    return dynamic_cast<const CSMWorld::TableMimeData *>(event.mimeData());
+}
+
+bool CSVWorld::DragDropUtils::canAcceptData(const QDropEvent &event, CSMWorld::ColumnBase::Display type)
+{
+    const CSMWorld::TableMimeData *data = getTableMimeData(event);
+    return data != NULL && data->holdsType(type);
+}
+
+CSMWorld::UniversalId CSVWorld::DragDropUtils::getAcceptedData(const QDropEvent &event, 
+                                                               CSMWorld::ColumnBase::Display type)
+{
+    if (canAcceptData(event, type))
+    {
+        return getTableMimeData(event)->returnMatching(type);
+    }
+    return CSMWorld::UniversalId::Type_None;
+}

apps/opencs/view/world/dragdroputils.hpp

@@ -0,0 +1,30 @@
+#ifndef CSV_WORLD_DRAGDROPUTILS_HPP
+#define CSV_WORLD_DRAGDROPUTILS_HPP
+
+#include "../../model/world/columnbase.hpp"
+
+class QDropEvent;
+
+namespace CSMWorld
+{
+    class TableMimeData;
+    class UniversalId;
+}
+
+namespace CSVWorld
+{
+    class DragDropUtils
+    {
+        public:
+            static const CSMWorld::TableMimeData *getTableMimeData(const QDropEvent &event);
+
+            static bool canAcceptData(const QDropEvent &event, CSMWorld::ColumnBase::Display type);
+            ///< Checks whether the \a event contains a valid CSMWorld::TableMimeData that holds the \a type
+
+            static CSMWorld::UniversalId getAcceptedData(const QDropEvent &event, CSMWorld::ColumnBase::Display type);
+            ///< Gets the accepted data from the \a event using the \a type
+            ///< \return Type_None if the \a event data doesn't holds the \a type
+    };
+}
+
+#endif