JavaFX TreeTableView set custom node in row cell - javafx

Question

I want to create a treetableview which can show for every tree item a sub tree with a row which contains custom nodes (in this case a button).
In the end i want to make it look like that.
In order to achieve that i probably need a custom row factory.
//set custom row factory
treeTableView.setRowFactory(new Callback<TreeTableView<Struct>, TreeTableRow<Struct>>() {
#Override
public TreeTableRow<Struct> call(TreeTableView<Struct> param) {
return new TreeTableRow<Struct>(){
#Override
protected void updateItem(Struct item, boolean empty) {
super.updateItem(item, empty);
//check if row has values
if (!empty) {
//override the row cell graphics if boolean is set
if (item.isCustomRow()) {
setGraphic(new StackPane(new Button("Button")));
}
} else {
setGraphic(null);
}
}
};
}
});
My idea was to override the updateItem() method and use the setGraphic() method to display the button. To indicate whether the tree item shows my own graphic node or the default, i added a boolean to my tableview structure class (Struct).
//Struct contains treetable data
class Struct {
...
//the boolean defines if the row graphics should be overridden
Boolean customRow;
...
public Boolean isCustomRow() {
return customRow;
}}
The result which i got can you see here. I looks like the empty column cells inside the row blocks my own node.
I suspect that i also need a custom TreeTableRowSkin but i didnt find any examples how to implement this. Is there anyone who can help me to solve this?
The full code example can be found here.