Merge branch 'GabiAxel-master'

Author: fritz-c

README.md

@@ -59,7 +59,7 @@ getNodeKey                | func           | defaultGetNodeKey   |          | De
 onMoveNode                | func           |                     |          | Called after node move operation. <div>`({ treeData: object[], node: object, treeIndex: number, path: number[] or string[] }): void`</div>
 onVisibilityToggle        | func           |                     |          | Called after children nodes collapsed or expanded. <div>`({ treeData: object[], node: object, expanded: bool }): void`</div>
 canDrag                   | func or bool   | `true`              |          | Return false from callback to prevent node from dragging, by hiding the drag handle. Set prop to `false` to disable dragging on all nodes. <div>`({ node: object, path: number[] or string[], treeIndex: number, lowerSiblingCounts: number[], isSearchMatch: bool, isSearchFocus: bool }): bool`</div>
-canDrop                   | func           |                     |          | Return false to prevent node from dropping in the given location. <div>`({ node: object, prevPath: number[] or string[], prevParent: object, nextPath: number[] or string[], nextParent: object}): bool`</div>
+canDrop                   | func           |                     |          | Return false to prevent node from dropping in the given location. <div>`({ node: object, prevPath: number[] or string[], prevParent: object, prevTreeIndex: number, nextPath: number[] or string[], nextParent: object, nextTreeIndex: number}): bool`</div>
 reactVirtualizedListProps | object         |                     |          | Custom properties to hand to the [react-virtualized list](https://github.com/bvaughn/react-virtualized/blob/master/docs/List.md#prop-types)
 rowHeight                 | number or func | `62`                |          | Used by react-virtualized. Either a fixed row height (number) or a function that returns the height of a row given its index: `({ index: number }): number`
 slideRegionSize           | number         | `100`               |          | Size in px of the region near the edges that initiates scrolling on dragover.

src/utils/drag-and-drop-utils.js

@@ -19,6 +19,7 @@ const nodeDragSource = {
             node:       props.node,
             parentNode: props.parentNode,
             path:       props.path,
+            treeIndex:  props.treeIndex,
         };
     },
 
@@ -90,10 +91,12 @@ function canDrop(dropTargetProps, monitor) {
 
         return dropTargetProps.customCanDrop({
             node,
-            prevPath:   monitor.getItem().path,
-            prevParent: monitor.getItem().parentNode,
-            nextPath:   addedResult.path,
-            nextParent: addedResult.parentNode,
+            prevPath:      monitor.getItem().path,
+            prevParent:    monitor.getItem().parentNode,
+            prevTreeIndex: monitor.getItem().treeIndex,
+            nextPath:      addedResult.path,
+            nextParent:    addedResult.parentNode,
+            nextTreeIndex: addedResult.treeIndex,
         });
     }