JavaFX Custom Table Cell - Strange behavior - javafx-8

Question

I have this code:
import javafx.application.Application;
import javafx.beans.property.SimpleObjectProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Callback;
public class Example extends Application
{
#Override
public void start(Stage stage) throws Exception
{
TableView<Color> table = new TableView<>();
ObservableList<Color> colors = FXCollections.observableArrayList();
table.setItems(colors);
table.setEditable(true);
TableColumn<Color, Color> column = new TableColumn<>();
column.setCellValueFactory(param -> new SimpleObjectProperty<>(param.getValue()));
column.setCellFactory(param ->
{
ObservableList<Color> menuColors = FXCollections.observableArrayList();
menuColors.addAll(Color.RED, Color.GREEN, Color.BLUE);
return new ComboBoxTableCell(menuColors);
});
Button button = new Button("Add row");
button.setOnAction(event -> colors.add(Color.BLACK));
VBox box = new VBox(table, button);
table.getColumns().add(column);
table.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
stage.setScene(new Scene(box));
stage.show();
}
public class ComboBoxTableCell extends TableCell<Color, Color>
{
private ComboBox<Color> comboBox;
public ComboBoxTableCell(ObservableList<Color> colors)
{
comboBox = createFancyComboBox(colors);
setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
}
#Override
public void updateItem(Color item, boolean empty)
{
if (item == null || empty)
setGraphic(null);
else
setGraphic(comboBox);
}
}
private ComboBox<Color> createFancyComboBox(ObservableList<Color> colors)
{
ComboBox<Color> comboBox = new ComboBox<>(colors);
Callback<ListView<Color>, ListCell<Color>> factory = list -> new ColorSquare();
comboBox.setCellFactory(factory);
comboBox.setButtonCell(factory.call(null));
comboBox.setValue(colors.get(0));
return comboBox;
}
public static class ColorSquare extends ListCell<Color>
{
#Override
public void updateItem(Color item, boolean empty)
{
super.updateItem(item, empty);
Rectangle rect = new Rectangle(18, 18);
if (item != null)
{
rect.setFill(item);
setGraphic(rect);
}
}
}
public static void main(String[] args)
{
launch(args);
}
}
If I try to run it, click on the button, change the color to for Green and click 8 times on the button, the green square will disapper.
How do I fix this and why is it happening? The real code isn't much different from this, this is the only problem I have. Thank you.

Answer 1

I have noticed that at times the rerendering of a table cell doesn't work right after a certain number of attempts. I had one where I was updating a remaining amount when the user entered a value in another cell.
To solve this I would toggle visibility of the column.
column.setVisible(false);
column.setVisible(true);
I would do this immediately after the action that changed the value in the cell.
It's a hack but seems to work.