JavaFX TextField：文本溢出时如何“自动滚动”到右侧

Question

我使用TextField 来显示用户在我的应用程序中打开的目录的路径。

目前，如果路径无法容纳在 TextField 内，则在远离此控件/单击远离此控件时，看起来好像路径已被截断：

我希望设置TextField 的行为，这样当我将注意力从它移开时，里面显示的路径会自动滚动到右侧，并且用户能够看到他们打开的目录。 IE。像这样：

我怎样才能做到这一点？我已经尝试调整here 给出的答案

如下在我的 FXML Controller 类中的 initialize() 方法中：

// Controller class fields
@FXML TextField txtMoisParentDirectory;
private String moisParentDirectory;

// ...

txtMoisParentDirectory.textProperty().addListener(new ChangeListener<String>() {

                @Override
                public void changed(ObservableValue<? extends String> observable, String oldStr, String newStr) {
                    moisParentDirectory = newStr;
                    txtMoisParentDirectory.selectPositionCaret(moisParentDirectory.length());
                    txtMoisParentDirectory.deselect();

                }
            });

但它不起作用。

Answer 1

您的问题是基于两个事件，输入文本的长度和失去焦点，所以为了解决它，我使用了属性textProperty() 和focusedProperty()，结果如下：

import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class Launcher extends Application{

private Pane root = new Pane();
private Scene scene;
private TextField tf = new TextField();
private TextField tft = new TextField();

private int location = 0;

@Override
public void start(Stage stage) throws Exception {


    scrollChange(); 
    tft.setLayoutX(300);
    root.getChildren().addAll(tft,tf);
    scene = new Scene(root,400,400);
    stage.setScene(scene);
    stage.show();

}

private void scrollChange(){


    tf.textProperty().addListener(new ChangeListener<String>() {

        @Override
        public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {

            location = tf.getText().length();

        }
    });


    tf.focusedProperty().addListener(new ChangeListener<Boolean>() {

        @Override
        public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {

            if(!newValue){

                Platform.runLater( new Runnable() {
                    @Override
                    public void run() {

                        tf.positionCaret(location);

                    }
                });


            }


        }
    });



}


public static void main(String[] args) {

    launch(args); 

}


}

关于Platform.runLater，我在这个答案Here之后添加了它，我不知道为什么没有它它就无法工作，祝你好运！

Answer 2

tf.textProperty().addListener(new ChangeListener<String>() {
        @Override
        public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
            int location = tf.getText().length();
            Platform.runLater(() -> {
                tf.positionCaret(location);
            });
        }
    });

这也是可行的

Answer 3

由于其他答案对我不起作用，这里有一个解决方案应该可以解决问题：

private TextField txtField;

// Both ChangeListeners just call moveCaretToEnd(), we need them both because of differing data types we are listening to
private final ChangeListener<Number> caretChangeListener = (observable, oldValue, newValue) -> moveCaretToEnd();
private final ChangeListener<String> textChangeListener = (observable, oldValue, newValue) -> moveCaretToEnd();

// This method moves the caret to the end of the text
private void moveCaretToEnd() {
     Platform.runLater(() -> {
         txtField.deselect();
         txtField.end();
     });
}

public void initialize() {
    // Immediatly add the listeners on initialization (or once you created the TextField if you are not using FXML)
    txtField.caretPositionProperty().addListener(caretChangeListener);
    txtField.textProperty().addListener(textChangeListener);

    txtField.focusedProperty().addListener((observable, oldValue, isFocused) -> {
        if (isFocused) {
            // once the TextField has been focused remove the listeners to enable normal editing of the text
            txtField.caretPositionProperty().removeListener(caretChangeListener);
            txtField.textProperty().removeListener(textChangeListener);
        } else {
            // when the focus is lost apply the listeners again
            moveCaretToEnd();
            txtField.caretPositionProperty().addListener(caretChangeListener);
            txtField.textProperty().addListener(textChangeListener);
        }
    });
}