JavaFx TableView get changed rows - javafx

Question

I have a problem with JavaFx.
I have a table view, which shows the Data I want.
Now I change the Data in the TableView.
My changeListener works, so far so good.
Now I want the rows of the table with changes in it to appear in a different color.
But I just can't find a way to get the specific row.
I tried to google the solution but all I can find is how to get a selected row.
But there won't be any user input. The data just refreshes.
Can you help me?
Probably I was just to stupid to find the right keywords.
I think of something like:
tableview.getRow(indexOfChangedRow).setStyle

Answer 1

The TableRow maintains a property called Item, which holds the data for the row. You need a RowFactory that binds the background to some value in your Table data. Generally, your Table data is going to have fields composed of ObservableValues, like Properties. So you end up with a Property (the Table data Model), which is composed of Properties. This means that you'll need a ChangeListener to manually reset the Binding on the Background property of the TableRow whenever the Item property is changed.
Here's an example:
public class TableBackground extends Application {
private ObservableList<TableModel> tableData = FXCollections.observableArrayList();
#Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setScene(new Scene(createContent()));
primaryStage.show();
}
private Parent createContent() {
BorderPane borderPane = new BorderPane();
borderPane.setCenter(createTable());
borderPane.setBottom(createAddBox());
return borderPane;
}
private Node createTable() {
TableView<TableModel> tableView = new TableView<>();
TableColumn<TableModel, String> firstColumn = new TableColumn<>("Field 1");
firstColumn.setCellValueFactory(p -> p.getValue().field1Property());
tableView.getColumns().add(firstColumn);
TableColumn<TableModel, String> secondColumn = new TableColumn<>("Field 2");
secondColumn.setCellValueFactory(p -> p.getValue().field2Property());
tableView.getColumns().add(secondColumn);
tableView.setItems(tableData);
Background redBackground = new Background(new BackgroundFill(Color.RED, null, null));
Background blueBackground = new Background(new BackgroundFill(Color.CORNFLOWERBLUE, null, null));
tableView.setRowFactory(t -> {
TableRow<TableModel> row = new TableRow<TableModel>();
row.itemProperty().addListener((ob, oldValue, newValue) -> {
row.backgroundProperty().bind(Bindings.createObjectBinding(() -> newValue.isNewRow() ? redBackground : blueBackground,
newValue.newRowProperty()));
});
return row;
});
return tableView;
}
private Node createAddBox() {
TextField textField1 = new TextField();
TextField textField2 = new TextField();
Button button = new Button("Add Row");
button.setOnAction(evt -> {
tableData.forEach(dataItem -> dataItem.setNewRow(false));
tableData.add(new TableModel(textField1.getText(), textField2.getText()));
});
return new HBox(10, textField1, textField2, button);
}
}
And the TableModel would look like this:
public class TableModel {
private StringProperty field1 = new SimpleStringProperty("");
private StringProperty field2 = new SimpleStringProperty("");
private BooleanProperty newRow = new SimpleBooleanProperty(true);
public TableModel(String field1Data, String field2Data) {
field1.set(field1Data);
field2.set(field2Data);
setNewRow(true);
}
public String getField1() {
return field1.get();
}
public StringProperty field1Property() {
return field1;
}
public void setField1(String field1) {
this.field1.set(field1);
}
public String getField2() {
return field2.get();
}
public StringProperty field2Property() {
return field2;
}
public void setField2(String field2) {
this.field2.set(field2);
}
public boolean isNewRow() {
return newRow.get();
}
public BooleanProperty newRowProperty() {
return newRow;
}
public void setNewRow(boolean newRow) {
this.newRow.set(newRow);
}
}
The important part is the RowFactory:
Background redBackground = new Background(new BackgroundFill(Color.RED, null, null));
Background blueBackground = new Background(new BackgroundFill(Color.CORNFLOWERBLUE, null, null));
tableView.setRowFactory(t -> {
TableRow<TableModel> row = new TableRow<TableModel>();
row.itemProperty().addListener((ob, oldValue, newValue) -> {
row.backgroundProperty().bind(Bindings.createObjectBinding(() -> newValue.isNewRow() ? redBackground : blueBackground,
newValue.newRowProperty()));
});
return row;
});
It's a plain vanilla row except that it has a ChangeListener on row.itemProperty() which puts a Binding on row.backgroundProperty() based on value of new items TableModel.newRowProperty(). If it's new, then the background is red, otherwise it's blue.
The Button OnAction event, sets all of the existing rows newRowProperty() to false, and then adds a new row with newRowProperty() set to true. This means that all of the existing rows will turn blue, and the new row will be red.