单击时选择 JavaFX 可编辑组合框文本

Question

点击可编辑组合框时，我有一个关于文本选择的问题。

目前发生的情况是，鼠标光标只是转到输入的那个位置，并没有选择整个文本字段。我想在点击时突出显示/选择整个文本字段，但它没有这样做。

我希望单击文本字段会做什么：

这是我的自动完成课程：

public class AutoCompleteComboBoxListener<T> implements EventHandler<KeyEvent> {

private ComboBox comboBox;
private StringBuilder sb;
private ObservableList<T> data;
private boolean moveCaretToPos = false;
private int caretPos;
private Button button;

public AutoCompleteComboBoxListener(final ComboBox comboBox, final Button button) {
    this.comboBox = comboBox;
    sb = new StringBuilder();
    data = comboBox.getItems();

    this.comboBox.setEditable(true);

    this.button = button;

    this.comboBox.setOnKeyPressed(new EventHandler<KeyEvent>() {

        @Override
        public void handle(KeyEvent t) {
            System.out.println("misaja");
            System.out.println(t);

            comboBox.hide();
        }
    });
    this.comboBox.setOnKeyReleased(AutoCompleteComboBoxListener.this);
}

@Override
public void handle(KeyEvent event) {

    System.out.println("nonoh");
    System.out.println(event.getCode());
    UI.bitLogger.logging(String.valueOf(event.getCode()));

    if (event.getCode() == (KeyCode.ENTER)) {
        System.out.println("erki");
        button.fire();
    }

    if (event.getCode() == KeyCode.UP) {
        caretPos = -1;
        moveCaret(comboBox.getEditor().getText().length());
        return;
    } else if (event.getCode() == KeyCode.DOWN) {
        if (!comboBox.isShowing()) {
            comboBox.show();
        }
        caretPos = -1;
        moveCaret(comboBox.getEditor().getText().length());
        return;
    } else if (event.getCode() == KeyCode.BACK_SPACE) {
        moveCaretToPos = true;
        caretPos = comboBox.getEditor().getCaretPosition();
    } else if (event.getCode() == KeyCode.DELETE) {
        moveCaretToPos = true;
        caretPos = comboBox.getEditor().getCaretPosition();
    }

    if (event.getCode() == KeyCode.RIGHT || event.getCode() == KeyCode.LEFT
            || event.isControlDown() || event.getCode() == KeyCode.HOME
            || event.getCode() == KeyCode.END || event.getCode() == KeyCode.TAB) {
        return;
    }

    ObservableList list = FXCollections.observableArrayList();
    for (int i = 0; i < data.size(); i++) {
        if (data.get(i).toString().toLowerCase().startsWith(
                AutoCompleteComboBoxListener.this.comboBox
                        .getEditor().getText().toLowerCase())) {
            list.add(data.get(i));
        }
    }
    String t = comboBox.getEditor().getText();

    comboBox.setItems(list);
    comboBox.getEditor().setText(t);
    if (!moveCaretToPos) {
        caretPos = -1;
    }
    moveCaret(t.length());
    if (!list.isEmpty()) {
        comboBox.show();
    }
}

private void moveCaret(int textLength) {
    if (caretPos == -1) {
        comboBox.getEditor().positionCaret(textLength);
    } else {
        comboBox.getEditor().positionCaret(caretPos);
    }
    moveCaretToPos = false;
}

我在这里创建组合框：

    final ComboBox comboBox = new ComboBox(options);
    comboBox.setPrefWidth(320);

    comboBox.setValue("");

    //ComboBox comboBox = new ComboBox();

    new AutoCompleteComboBoxListener<>(comboBox, goButton);

    comboBox.addEventFilter(KeyEvent.KEY_RELEASED, new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {
            if (ke.getCode() == KeyCode.ENTER) {
                //System.out.println("ENTER was released");
                goButton.fire();
            }
        }
    });

    comboBox.addEventFilter(MouseEvent.MOUSE_PRESSED, new EventHandler<MouseEvent>() {
        @Override
        public void handle(MouseEvent mouseEvent) {
            System.out.println("mouse click detected2! " + mouseEvent.getSource());
            //comboBox.getEditor().requestFocus();
            //comboBox.getEditor().requestFocus();
            //comboBox.requestFocus();
            //comboBox.getEditor().selectAll();
            //comboBox.requestFocus();
            //None of these seem to work.
        }
    });

我现在添加的是这样的：

 comboBox.getEditor().focusedProperty().addListener(new ChangeListener<Boolean>()
    {
        @Override
        public void changed(ObservableValue<? extends Boolean> arg0, Boolean oldPropertyValue, Boolean newPropertyValue)
        {
            if (newPropertyValue)
            {
                System.out.println("Textfield on focus");
                comboBox.requestFocus();
                comboBox.getEditor().selectAll();
            }
            else
            {
                System.out.println("Textfield out focus");
            }
        }
    });

但它所做的只是选择/突出显示文本片刻，然后再次删除突出显示。

Answer 1

您应该尝试通过在文本字段上添加焦点侦听器来做到这一点，如下所示：

comboBox.getEditor().focusedProperty().addListener(
    (observable, oldValue, newValue) -> {
        if (newValue) {
            // Select the content of the field when the field gets the focus.
            Platform.runLater(comboBox.getEditor()::selectAll);
        }
    }
);

此代码适用于Java 8，之前版本对应的代码为：

comboBox.getEditor().focusedProperty().addListener(
    new ChangeListener<Boolean>() {
        @Override
        public void changed(final ObservableValue<? extends Boolean> observable, 
                            final Boolean oldValue, final Boolean newValue) {
            if (newValue) {
                Platform.runLater(
                    new Runnable() {
                        @Override
                        public void run() {
                            comboBox.getEditor().selectAll();
                        }
                    }
                );
            }
        }
    }
);