Bug in treeview display when editing cell

Question

I have two bugs when I use a treeview, here's what happen :

BUG 1 : Not validate changes

How to create the bug : Let's suppose I want to edit the cell "Id" in my treview.

I enter something else :

But I change my mind, I don't want to edit this item, so instead of clicking on enter and validate,I click left on something else, everything seems ok, I'm back to picture one, but if I click to edit the "Id" cell again, i'm directly back at picture 2, and "Id-Edit" is show to me, it means the cancel of the edit didn't work well ...

BUG 2 : The change of value

It happens rarely but happens, when I click on a celle to edit it, this cell take the text of another cell, here's an example :

The "Id" take the text of another cell when I edit it, but if I cancel the edit, eveything is back to normal again, like in picture one.

Here's the code that I use for my treeview :

    public class DatabaseStructureView extends TreeView<Object> {

    TreeItem<Object> root;

    public DatabaseStructureView() {
        FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("DatabaseStructureView.fxml"));

        fxmlLoader.setRoot(this);
        fxmlLoader.setController(this);
        try {
            fxmlLoader.load();
        } catch (IOException exception) {
            throw new RuntimeException(exception);
        }

        this.setEditable(true);
        this.setCellFactory((TreeView<Object> param) -> new TextFieldTreeCellImpl());
        root = new TreeItem<>();
        this.setRoot(root);
        setShowRoot(false);
        root.setExpanded(true);
    }

    private final class TextFieldTreeCellImpl extends TreeCell<Object> {

        private TextField textField;

        @Override
        public void startEdit() {
            super.startEdit();

            if (textField == null) {
                createTextField();
            }
            setText(null);
            setGraphic(textField);
            textField.selectAll();
        }

        @Override
        public void cancelEdit() {
            super.cancelEdit();
            setText(getString());
            setGraphic(getTreeItem().getGraphic());
        }

        @Override
        public void updateItem(Object item, boolean empty) {
            super.updateItem(item, empty);

            if (empty) {
                setText(null);
                setGraphic(null);
            } else {
                if (isEditing()) {
                    if (textField != null) {
                        textField.setText(getString());
                    }
                    setText(null);
                    setGraphic(textField);
                } else {
                    setText(getString());
                    setGraphic(getTreeItem().getGraphic());
                }
            }
        }

        private void createTextField() {
            textField = new TextField(getString());
            textField.setOnKeyReleased(new EventHandler<KeyEvent>() {

                @Override
                public void handle(KeyEvent t) {
                    if (t.getCode() == KeyCode.ENTER) {
                        commitEdit(getDatabase(textField.getText()));
                    } else if (t.getCode() == KeyCode.ESCAPE) {
                        cancelEdit();
                    }
                }
            });
        }

        private Database getDatabase(String text) {
            return new Database(text);
        }

        private String getString() {
            return getItem() == null ? "" : getItem().toString();
        }
    }

    /**
     *
     * @param db
     */
    public void setDatabase(Database db) {
        TreeItem<Object> dbRoot = new TreeItem<>(db);
        dbRoot.setExpanded(true);

        db.getVariables().stream().forEach((var) -> {
            dbRoot.getChildren().add(new TreeItem<>(var));
        });

        if (!root.getChildren().contains(dbRoot)) {
            root.getChildren().add(dbRoot);
        }
    }

    /**
     *
     * @param dbs
     */
    public void setDatabases(List<Database> dbs) {
        dbs.stream().forEach((db) -> {
            setDatabase(db);
        });
    }
}

As you may see, my tree view is not fill with String but with an object that I create, and is Database , that's why I use Object type. I think my problem comes from the update function, but don't know why.

Thanks for reading :)

Answer 1

In the startEdit() method, you need to set the text of the text field to the correct value:

    @Override
    public void startEdit() {
        super.startEdit();

        if (textField == null) {
            createTextField();
        }

        textField.setText(getString());

        setText(null);
        setGraphic(textField);
        textField.selectAll();
    }