JavaFX: Custom traversing with key combinations - javafx-2

Question

I have a table with one editing combobox and three editable text fields,
editable fields create like this:
public class EditingCell extends TableCell<Person, String> {
private TextField textField;
public EditingCell() {
}
#Override
public void startEdit() {
super.startEdit();
if (textField == null) {
createTextField();
}
setGraphic(textField);
setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
Platform.runLater(new Runnable() {
#Override
public void run() {
textField.requestFocus();
textField.selectAll();
}
});
}
#Override
public void cancelEdit() {
super.cancelEdit();
setText((String) getItem());
setContentDisplay(ContentDisplay.TEXT_ONLY);
}
#Override
public void updateItem(String item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
if (isEditing()) {
if (textField != null) {
textField.setText(getString());
}
setGraphic(textField);
setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
} else {
setText(getString());
setContentDisplay(ContentDisplay.TEXT_ONLY);
}
}
}
private void createTextField() {
textField = new TextField(getString());
textField.setMinWidth(this.getWidth() - this.getGraphicTextGap() * 2);
textField.setOnKeyPressed(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent t) {
if (t.getCode() == KeyCode.ENTER) {
commitEdit(textField.getText());
} else if (t.getCode() == KeyCode.ESCAPE) {
cancelEdit();
} else if (t.getCode() == KeyCode.TAB) {
commitEdit(textField.getText());
TableColumn nextColumn = getNextColumn(!t.isShiftDown());
if (nextColumn != null) {
getTableView().edit(getTableRow().getIndex(), nextColumn);
}
}
}
});
textField.focusedProperty().addListener(new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
if (!newValue && textField != null) {
commitEdit(textField.getText());
}
}
});
}
private String getString() {
return getItem() == null ? "" : getItem().toString();
}
/**
*
* #param forward true gets the column to the right, false the column to the left of the current column
* #return
*/
private TableColumn<Person, ?> getNextColumn(boolean forward) {
List<TableColumn<Person, ?>> columns = new ArrayList<>();
for (TableColumn<Person, ?> column : getTableView().getColumns()) {
columns.addAll(getLeaves(column));
}
//There is no other column that supports editing.
if (columns.size() < 2) {
return null;
}
int currentIndex = columns.indexOf(getTableColumn());
int nextIndex = currentIndex;
if (forward) {
nextIndex++;
if (nextIndex > columns.size() - 1) {
nextIndex = 0;
}
} else {
nextIndex--;
if (nextIndex < 0) {
nextIndex = columns.size() - 1;
}
}
return columns.get(nextIndex);
}
private List<TableColumn<Person, ?>> getLeaves(TableColumn<Person, ?> root) {
List<TableColumn<Person, ?>> columns = new ArrayList<>();
if (root.getColumns().isEmpty()) {
//We only want the leaves that are editable.
if (root.isEditable()) {
columns.add(root);
}
return columns;
} else {
for (TableColumn<Person, ?> column : root.getColumns()) {
columns.addAll(getLeaves(column));
}
return columns;
}
}
}
And editable combo column create like this:
public static void createEditingComboColumn(final TableColumn<DUMMY_PurchaseOrderLine, String> Column, final ObservableList<String>comboData, final ObservableList<DUMMY_PurchaseOrderLine> Pdata) {
Column.setCellFactory(new Callback<TableColumn<DUMMY_PurchaseOrderLine,String>,TableCell<DUMMY_PurchaseOrderLine,String>>(){
#Override
public TableCell<DUMMY_PurchaseOrderLine, String> call(TableColumn<DUMMY_PurchaseOrderLine, String> p) {
final TableCell<DUMMY_PurchaseOrderLine, String> cell = new TableCell<DUMMY_PurchaseOrderLine, String>(){
#Override
public void updateItem(String item, boolean empty) {
if(item!=null){
final ComboBox editableComboBox = new ComboBox(comboData);
editableComboBox.setEditable(true);
editableComboBox.setMaxWidth(Double.MAX_VALUE);
Platform.runLater(new Runnable() {
#Override
public void run() {
editableComboBox.requestFocus();
}
});
setGraphic(editableComboBox);
}
}
};
cell.addEventFilter(KeyEvent.KEY_PRESSED,new EventHandler<KeyEvent>(){
#Override
public void handle(KeyEvent t) {
activeRow = cell.getIndex();
if(t.getCode() == KeyCode.TAB||t.getCode() ==KeyCode.RIGHT){
cell.getTableView().edit(cell.getTableRow().getIndex(),cell.getTableView().getColumns().get(1) );
}
}
});
return cell;
}
});
}
Problem: when I press TAB/Right arrow key from any column work properly ,but when I press SHIFT+Tab /left arrow from second column focus goes out. How I focus first column (editing combo) from second column using keyboard?
Thanks....

Answer 1

The condition below in key event handler
if (t.getCode() == KeyCode.TAB)
will handle "TAB" + Any modifier, which means it will handle "Ctrl+TAB", "Alt+TAB", "Shift+Alt+TAB" etc. The same is true for "Right" key. So to handle the "TAB" alone only, the preferred way is to define KeyCodeCombination.
Your posted code is partial, not executable ie. not SSCCE. As I understand your problem lays in key event handling. Because of this I wrote a completely different code but demonstrates the explanation mentioned above. See example, and try to traverse forward with key combination different from "TAB" or "RIGHT". Try with "Ctrl+TAB" or "Alt+RIGHT". It will not work for them, as expected.
public class TraverseDemo extends Application {
#Override
public void start(Stage primaryStage) {
final TextField textField1 = new TextField();
final TextField textField2 = new TextField();
final TextField textField3 = new TextField();
// Diasble all traversals since we will manage them manually, for only textField2.
textField1.setFocusTraversable(false);
textField2.setFocusTraversable(false);
textField3.setFocusTraversable(false);
// Define key combinations for traversals.
final KeyCombination kcTab = KeyCodeCombination.valueOf("TAB");
final KeyCombination kcShiftTab = KeyCodeCombination.valueOf("Shift+TAB");
final KeyCombination kcRight = KeyCodeCombination.valueOf("RIGHT");
final KeyCombination kcLeft = KeyCodeCombination.valueOf("LEFT");
// Default initial focused textfield
requestFocus(textField2);
textField2.addEventFilter(KeyEvent.KEY_PRESSED, new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent t) {
if (kcTab.match(t) || kcRight.match(t)) {
System.out.println("traverse forward");
requestFocus(textField3);
} else if (kcShiftTab.match(t) || kcLeft.match(t)) {
System.out.println("traverse backward");
requestFocus(textField1);
}
}
});
StackPane root = new StackPane();
root.getChildren().add(HBoxBuilder.create().spacing(10).children(textField1, textField2, textField3).build());
Scene scene = new Scene(root, 300, 150);
primaryStage.setScene(scene);
primaryStage.show();
}
private void requestFocus(final Node node) {
Platform.runLater(new Runnable() {
#Override
public void run() {
node.requestFocus();
}
});
}
public static void main(String[] args) {
launch(args);
}
}