Primefaces dragdrop abort?

[An Ar]

Hello, everyone.  I am trying to figure out how to add conditions to a drag/drop event and cancel it if conditions are not right.  So far I've not been able to find anything in PrimeFaces documentation.

My markup:

	<h:form id="treeForm">
		<p:growl id="msgs" showDetail="true" skipDetailIfEqualsSummary="true" />
		
		<p:tree value="#{treeView.root}" var="node" selectionMode="single" selection="#{treeService.selectedNode}"
				draggable="true" droppable="true">
		
			<p:ajax event="dragdrop" listener="#{treeService.onDragDrop}" update=":treeForm:msgs" /> <!-- is this a good place to add my conditions? -->
			
			<p:treeNode expandedIcon="fa fa-fw fa-folder-open" collapsedIcon="fa fa-fw fa-folder">
				<h:outputText value="#{node.name}" />
			</p:treeNode>
			
			<p:treeNode type="module" icon="fa fa-fw fa-folder" >
				<h:outputText value="#{node.name}" />
			</p:treeNode>
			
			<p:treeNode type="lesson" icon="fa fa-fw fa-book">
				<h:outputText value="#{node.name}" />
			</p:treeNode>

			<p:treeNode type="page" icon="fa fa-fw fa-file-text">
				<h:outputText value="#{node.name}" />
			</p:treeNode>
			
		</p:tree>
	</h:form>

inside my TreeService.java I have the following method, triggered on ajax dragdrop event:

    public void onDragDrop(TreeDragDropEvent event) {
        TreeNode dragNode = event.getDragNode();
        TreeNode dropNode = event.getDropNode();           
        // can drag/drop process be aborted from here based on some logic?
    }

Thank you!

[Tim Holloway]

Drag and drop is done by the user. The drag-drop JavaScript is just what gets called when they do it. So to abort a drag-drop operation, the user just releases the mouse button while not positioned over any drop area.

I think there is supposed to be an event that firest to let you know that the drop terminated, but I can't recall what that is.

[An Ar]

As always, thanks for pointing the way, Tim!