A JavaFX 14 Treview with TreeItem<Label> in this structure;
- Root
- Group
- Child
- Group
- Child
- Child
- Group
I have attached a ContextMenu to the Label at the Root to add and remove Groups. And I am able to disable the Remove Groups when there are no groups using;
removeGroupMenuItem.disableProperty().bind(Bindings.isEmpty(treeView.getRoot().getChildren()));
However, I have now attached ContextMenu to the Label of each Group that allows adding a child or removing all children. My question is, how can I disable the Remove All Children MenuItem if one or more Groups are selected.
I have tried which does not work;
removeAllChildrenMenuItem.disableProperty().bind(Bindings.createBooleanBinding(() -> treeView.getSelectionModel().getSelectedItems().stream().flatMap(f -> f.getChildren().stream()).collect(Collectors.toList()).size() == 0, treeView.selectionModelProperty()));
Any thought welcome!
Your Binding will not be invalidated because your code waits for the SelectionModel property to be changed, not the selected items:
Bindings.createBooleanBinding(() -> treeView.getSelectionModel().getSelectedItems().stream().flatMap(f -> f.getChildren().stream()).collect(Collectors.toList()).size() == 0, treeView.selectionModelProperty());
You can fix that by changing the dependencies of the binding:
Bindings.createBooleanBinding(() -> treeView.getSelectionModel().getSelectedItems().stream().flatMap(f -> f.getChildren().stream()).collect(Collectors.toList()).size() == 0, treeView.getSelectionModel().getSelectedItems());
Note: If you change the tree's selection model by using treeView.setSelectionModel(...) anywhere else in your code, you have to rebind disable property again. If this is a common thing in your code, you can add a dependency to the selection model so the code become like this:
Bindings.createBooleanBinding(() -> {...}, treeView.selectionModelProperty(), treeView.getSelectionModel().getSelectedItems());
That means, recalculate the value whenever the selection model or the selected items change.