Just in case anyone has the same problem I figured this out by extending the class sap.ui.commons.treeNode like this:
sap.ui.commons.TreeNode.extend("HoverTreeNode", {
metadata: {
events: {
"hover" : {}
}
},
onmouseover : function(evt) {
this.fireHover();
},
});
And then:
new HoverTreeNode({
selectionMode: sap.ui.commons.TreeSelectionMode.Single,
hover: function(oEvent){
alert("hoveeer");
}
});