added elevator

src/store/modules/project.js

@@ -44,7 +44,8 @@ export default {
     contents_size_factor: 2, // factor to get the contents (grid) size proportional to windows
     contentTypes: ['visible', 'context', 'process', 'concept'],
     grid: { visible: [], context: [], process: [], concept: [] },
-    gridContentPlaced: {}
+    gridContentPlaced: {},
+    activeLevel: 'visibles'
   },
 
   // getters
@@ -94,6 +95,9 @@ export default {
         state.gridContentPlaced[c.type] = {}
       }
       state.gridContentPlaced[c.type][c.id] = p
+    },
+    setActiveLevel: (state, l) => {
+      state.activeLevel = l
     }
   },