I created a ButtonClick-Action, to create a new Child-Node for a selected TreeItem, expand the selected TreeItem and enter editing-mode for the newly created Child. Unfortunatly a wrong cell is entering editing-mode, even though the editingCellProperty is set correctly. When the editing-mode is finished, the correct TreeItem gets changed.

My intended workflow was the following: User initiates an action which results in a new TreeItem in a TreeTableView below the currently selected TreeItem. The selected Parent should get expanded and the newly created Item should enter editing-mode, so the user can directly enter the desired name.

In the latest official JDK Version (8u5), I did not succed entering editing-mode most of the time, which is why I created a Stackoverflow post (http://stackoverflow.com/questions/24290072/why-javafx-treetableview-edit-mode-gets-undesirably-canceled), but there I have been told, that with Version 8u20-ea my posted example would work.

After changing to the newest JDK (1.8.0_20-ea-b19) version it indeed entered editmode and everything seemed ok, until I changed the size of the window, then suddenly the TreeTableView mixed up indeces and the described behaviour occured.

The bug occurs in most stage-sizes, for example 400x800, but when I set it to 400x400 it suddenly works as expected. So I am wondering if there is any relationship between the cell-index and the stage-size? Is there anything I am doing wrong? I was not able to find any explanation for this sort of behaviour.

Here the Example, where the described behaviour occurs.

/**
 * Small Example to evaluate, why the wrong cell gets targeted when initializing edit mode by index.
 *
 * Intended Workflow: User clicks a Button to create a new Child-Node for a selected TreeItem, expand the
 * selected TreeItem and enter editing-mode for the newly created Child. Unfortunatly a wrong cell is entering
 * editing-mode, even though the editingCellProperty is set correctly. When the editing-mode is finished, the
 * correct TreeItem gets changed.
 *
 * @author ymene
 */
import javafx.application.Application;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeTableColumn;
import javafx.scene.control.TreeTablePosition;
import javafx.scene.control.TreeTableView;
import javafx.scene.control.cell.TextFieldTreeTableCell;
import javafx.scene.control.cell.TreeItemPropertyValueFactory;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class TreeTableViewCreateExpandAndEditMain extends Application {
    private int id = 0;

    @Override
    public void start(final Stage primaryStage) {
        //Generating Testdata:
        TreeItem<Item> root = new TreeItem<>(new Item(++id, "Root"));

        TreeItem<Item> item1 = new TreeItem<>(new Item(++id, "Item1"));
        TreeItem<Item> item11 = new TreeItem<>(new Item(++id, "Item11"));
        TreeItem<Item> item2 = new TreeItem<>(new Item(++id, "Item2"));
        TreeItem<Item> item3 = new TreeItem<>(new Item(++id, "Item3"));
        TreeItem<Item> item31 = new TreeItem<>(new Item(++id, "Item31"));

        root.getChildren().add(item1);
        item1.getChildren().add(item11);
        root.getChildren().add(item2);
        root.getChildren().add(item3);
        item3.getChildren().add(item31);

        TreeTableColumn<Item, Integer> columnId = new TreeTableColumn<>("ColumnId");
        TreeTableColumn<Item, String> columnName = new TreeTableColumn<>("ColumnName");

        columnId.setCellValueFactory(new TreeItemPropertyValueFactory<Item, Integer>("id"));
        columnName.setCellValueFactory(new TreeItemPropertyValueFactory<Item, String>("name"));

        //Using Default-CellFactory:
        columnName.setCellFactory(TextFieldTreeTableCell.forTreeTableColumn());

        //Commiting Cellcontent-Changes:
        columnName.setOnEditCommit(new EventHandler<TreeTableColumn.CellEditEvent<Item, String>>() {
            @Override
            public void handle(final TreeTableColumn.CellEditEvent<Item, String> event) {
                final Item item = event.getRowValue().getValue();
                System.out.println("Change Item " + item + " from " + event.getOldValue() + " to new value "
                        + event.getNewValue());
                item.setName(event.getNewValue());
            }
        });

        //Creating TreeTableView:
        final TreeTableView<Item> treeTableView = new TreeTableView<>(root);

        //Listener at editingCellProperty, to keep track, what is happening here:
        treeTableView.editingCellProperty().addListener(new ChangeListener<TreeTablePosition<Item, ?>>() {
            @Override
            public void changed(final ObservableValue<? extends TreeTablePosition<Item, ?>> observable,
                                final TreeTablePosition<Item, ?> oldValue,
                                final TreeTablePosition<Item, ?> newValue) {
                System.out.println("EditingCellProperty changed to: "
                        + (newValue != null ? newValue.getTreeItem() : newValue)
                        + (newValue != null ? " at row " + newValue.getRow() : ""));
            }
        });

        treeTableView.getColumns().add(columnName);
        treeTableView.getColumns().add(columnId);
        treeTableView.setShowRoot(false);
        treeTableView.setColumnResizePolicy(TreeTableView.CONSTRAINED_RESIZE_POLICY);

        treeTableView.setEditable(true);
        columnId.setEditable(false);

        BorderPane layout = new BorderPane();

        Button button = new Button("DoAction!");
        button.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(final ActionEvent event) {
                createNodeAtSelectedAsChild();
            }

            private void createNodeAtSelectedAsChild() {
        /*
         * This Method should create a new node at the currently selected node, expand the selected node and start editing the new created node, after selecting it.
         */
                final TreeItem<Item> selectedItem = treeTableView.getSelectionModel().getSelectedItem();

                final TreeItem<Item> newItem =
                        new TreeItem<>(new Item(++id, "newItemFor" + selectedItem.getValue().getName()));
                selectedItem.getChildren().add(newItem);

                selectedItem.expandedProperty().set(true);
                final int rowIndex = treeTableView.getRow(newItem);

                // treeTableView.getSelectionModel().select( rowIndex );//The desired row gets selected
                //
                // System.out.println( "Edit Row: " + rowIndex + " edit Value: " + newItem.getValue().getName() );
                // System.out.println( "SelectedIndex: " + treeTableView.getSelectionModel().getSelectedIndex() );

                treeTableView.edit(rowIndex, columnName);//Wrong Cell edited, why? Especially this seems to depend on Stage-Size. At 400x400 it works.
            }
        });

        layout.setCenter(treeTableView);
        layout.setBottom(button);

        Scene scene = new Scene(layout, 400, 800);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(final String[] args) {
        launch(args);
    }


    public static class Item {
        private final IntegerProperty id = new SimpleIntegerProperty();
        private final StringProperty name = new SimpleStringProperty();

        public Item(final int id, final String name) {
            this.id.set(id);
            this.name.set(name);
        }

        public int getId() {
            return id.get();
        }

        public String getName() {
            return name.get();
        }

        public void setId(final int id) {
            this.id.set(id);
        }

        public void setName(final String name) {
            this.name.set(name);
        }

        public IntegerProperty idProperty() {
            return id;
        }

        public StringProperty nameProperty() {
            return name;
        }

        @Override
        public String toString() {
            return "[Item: " + "name=" + getName() + ", id=" + getId() + "]";
        }
    }
}