more refactoring

static/js/drag_and_drop.js

@@ -0,0 +1,62 @@
+const dragAndDropSetup = {
+    autoExpandMS: 600,
+    draggable: { // modify default jQuery draggable options
+        zIndex: 1000,
+        scroll: false,
+        containment: "parent",
+        revert: "invalid"
+    },
+    preventRecursiveMoves: true, // Prevent dropping nodes on own descendants
+    preventVoidMoves: true, // Prevent dropping nodes 'before self', etc.
+
+    dragStart: function (node, data) {
+        // This function MUST be defined to enable dragging for the tree.
+        // Return false to cancel dragging of node.
+        return true;
+    },
+    dragEnter: function (node, data) {
+        /* data.otherNode may be null for non-fancytree droppables.
+        * Return false to disallow dropping on node. In this case
+        * dragOver and dragLeave are not called.
+        * Return 'over', 'before, or 'after' to force a hitMode.
+        * Return ['before', 'after'] to restrict available hitModes.
+        * Any other return value will calc the hitMode from the cursor position.
+        */
+        // Prevent dropping a parent below another parent (only sort
+        // nodes under the same parent):
+        //    if(node.parent !== data.otherNode.parent){
+        //      return false;
+        //    }
+        // Don't allow dropping *over* a node (would create a child). Just
+        // allow changing the order:
+        //    return ["before", "after"];
+        // Accept everything:
+        return true;
+    },
+    dragExpand: function (node, data) {
+        // return false to prevent auto-expanding data.node on hover
+    },
+    dragOver: function (node, data) {
+    },
+    dragLeave: function (node, data) {
+    },
+    dragStop: function (node, data) {
+    },
+    dragDrop: function (node, data) {
+        // This function MUST be defined to enable dropping of items on the tree.
+        // data.hitMode is 'before', 'after', or 'over'.
+
+        if (data.hitMode === "before") {
+            moveBeforeNode(data.otherNode, node);
+        }
+        else if (data.hitMode === "after") {
+            moveAfterNode(data.otherNode, node);
+        }
+        else if (data.hitMode === "over") {
+            moveToNode(data.otherNode, node);
+        }
+        else {
+            throw new Exception("Unknown hitMode=" + data.hitMode);
+        }
+    }
+};