Use ChoiceBox to show specific data in TableView JavaFX - javafx

Question

I am trying to use a choicebox to show specific data in a tableview.
Lets say that i have 4 columns, "name" "Price" "Category" "in Stock", in my tableview. My tableview is getting its data from an .txt document, and it is possible to add data through textfields in my GUI.
My choicebox is holding value "Category 1" "Category 2" "Category 3", and my tableview is holding data in 6 rows, where 3 rows has category 1, and 3 rows has category 2.
What i want to do is, if i choose category 1 in my choicebox my tableview should only show data which is of category 1, and so on.
I am totally lost.
My Code.
private TableView<DTOArt> table = new TableView<DTOArt>();
private ObservableList<DTOArt> data = FXCollections.observableArrayList();
private ObservableList filCat = FXCollections.observableArrayList("Category 1","Category 2","Category 3");
public VBox getTableView(){
VBox tabelView = new VBox();
tabelView.setSpacing(5);
tabelView.setPadding(new Insets(10,10,10,10));
table.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
table.setEditable(true);
TableColumn nameCol = new TableColumn("Name");
nameCol.setCellValueFactory(new PropertyValueFactory<DTOArt, String>("name"));
TableColumn priceCol = new TableColumn("Price");
priceCol.setCellValueFactory(new PropertyValueFactory<DTOArt, String>("price"));
TableColumn categoryCol = new TableColumn("Category");
categoryCol.setCellValueFactory(new PropertyValueFactory<DTOArt, String>("category"));
TableColumn inStockCol = new TableColumn("in Stock");
inStockCol.setCellValueFactory(new PropertyValueFactory<DTOArt, String>("inStock"));
table.setItems(data);
table.getColumns().addAll(nameCol,priceCol,categoryCol,inStockCol);
tabelView.getChildren().add(table);
return tabelView;
}
My choiceBox.
ChoiceBox categoryCB = new ChoiceBox();
categoryCB.setItems(filCat);
categoryCB.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<String>(){
#Override
public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue){
}
});

Answer 1

Wrap the list of all items in a FilteredList. This allows you to specify a Predicate to filter the items by.
private final ObservableList<DTOArt> data = FXCollections.observableArrayList();
private final FilteredList<DTOArt> filteredData = new FilteredList<>(data);
ChoiceBox<String> categoryCB = new ChoiceBox<>();
categoryCB.setItems(filCat);
categoryCB.valueProperty().addListener(new ChangeListener<String>(){
#Override
public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue){
filteredData.setPredicate(newValue == null ? null : (DTOArt e) -> newValue.equals(e.getCategory()));
}
});
table.setItems(filteredData);
Furthermore if you want to allow dynamically changing the category, you should use an extractor for the ObservableList
private final ObservableList<DTOArt> data = FXCollections.observableArrayList((DTOArt e) -> new Observable[] { e.categoryProperty() });