Perform built-in row drop in trees.




In order to simplify drag & drop programming in the same list, the ui.DragDrop class provides the dropInternal() utility method, to be called in the ON DROP block. This method will perform all the row changes in the array and move row selection as well as cell attributes.

When implementing drag & drop on a tree-view, dropping an element on the tree requires complex code in order to handle parent-child relationships. Nodes can be inserted under a parent between two children, appended at the end of the children list, and at different levels in the tree hierarchy. However, the dropInternal() method can also be used on simple lists displayed in a regular TABLE.

A call to dropInternal() will silently be ignored, if the drag source is not the drop target, or if the method is called in a different context as ON DROP.

For more details about dropping elements in tree-views, see Drag & drop.