java - 设置 swing JSlider 和 JTextField 的勾选行为

Question

这是我的图形用户界面:

下面是一个 SSCCE，它将准确地生成此内容。 JSlider 连接到 JTextField，显示 0 到 100 之间的值。

我设置了以下设置，使其以 10 为间隔停止。它可以工作，但拖动时文本字段仍会显示 10 秒之间的值(例如 73)，然后在松开 slider 时调整它。有没有办法只显示十，即使在拖动时也是如此？

js.setMinorTickSpacing(10);
js.setSnapToTicks(true);

SSCCE:

import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.text.NumberFormat;
import javax.swing.*;
import javax.swing.event.*;
import net.miginfocom.swing.MigLayout;

public class SSCCE {
    public static void main(String[] args) {
        JFrame frame = new JFrame("SSCCE JSlider + JTextField");
        JPanel panel = new JPanel(new MigLayout("", "[200!][100!]", ""));

        final JSlider js = new JSlider();
        final JFormattedTextField tf = new JFormattedTextField(NumberFormat.getNumberInstance());

        js.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent e) {
                tf.setText(String.valueOf(js.getValue()));
            }
        });
        tf.addKeyListener(new KeyAdapter() {
            @Override
            public void keyReleased(KeyEvent ke) {
                String typed = tf.getText();
                js.setValue(0);
                if (!typed.matches("\\d+")) {
                    return;
                }
                int value = Integer.parseInt(typed);
                js.setValue(value);
            }
        });
        js.setMinorTickSpacing(10);
        js.setSnapToTicks(true);

        panel.add(js);
        panel.add(tf, "grow");
        frame.add(panel);
        frame.pack();
        frame.setVisible(true);
    }
}

Answer 1

It works, but the textfield will still show values between the 10s (Like 73) when dragging, and then adjust it when i let go of the slider. Is there a way to ONLY show tens, even when dragging?

只需将当前 JSlider 值四舍五入到最接近的 10，然后将 JTextField 设置为该数字:

 js.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent e) {

                if(js.getValueIsAdjusting()) {//slider value is still being adjusted
                    int num=(int)(Math.rint((double) js.getValue() / 10) * 10);//round to nearest 10
                    tf.setText(String.valueOf(num));//set textfield with value of nearest 10                  
                } else {//slider value has been set/no adjustments happenening
                    tf.setText(String.valueOf(js.getValue()));
                }

            }
        });

另请阅读 Concurrency in Swing ，特别是 Event Dispatch thread (EDT) ，这要求我们通过 SwingUtilities.invokeXXX 创建和操作 EDT 上的所有 Swing 组件 block :

SwingUtilities.invokeLater(new Runnable() {
    @Override
    public void run() {
        //create/manipulate UI, components etc here
    }
});