java - 多个 JSlider 相互 react 始终等于 100%

Question

我正在尝试向 java swing 应用程序添加 3 个 JSlider，以便三个 slider 的总值(value)总和为 100。每个 slider 都是一个概率， slider A 是将值添加到队列的概率， slider B 是从队列中删除某个值的概率， slider C 是什么都不发生的概率。

示例: slider A 设置为 40， slider B 设置为 40， slider C 初始设置为 20。如果用户将 slider A 更改为 50，我希望 slider B 和 C 的值都减少 5。这样总数仍为 100。我知道当用户将值更改为 41 时可能会出现一些问题，因为我希望其他值保留为整数。

好的，在查看了有关 BoundedRangeModel 的一些信息后，我添加了一些代码。我已经设法让 slider 根据其他 slider 进行更改，但我仍然不确定如何实现初始值。此外， slider 似乎只能成对工作，而不是 3 个一组。

我会继续努力，如果我使用此方法想出一个令我满意的解决方案，我会将其发布在这里。

package stackoverflow;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.BoundedRangeModel;
import javax.swing.DefaultBoundedRangeModel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Controller {

public static void main(String[] args)
{
    //GUI up
    Frame f = new Frame();
    f.setSize(600, 600);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
}

@SuppressWarnings("serial")
public static class Frame extends JFrame implements PropertyChangeListener, ChangeListener
{
    //Sliders
    private JSlider s1;
    private JSlider s2;
    private JSlider s3;

    //Initial Values for fields (not sure how to implement)
    private int inis1 = 45;
    private int inis2 = 40;
    private int inis3 = 15;

    //Labels
    private JLabel s1Label;
    private JLabel s2Label;
    private JLabel s3Label;

    //Strings for labels
    private static String s1String = "Probability of adding one to queue";
    private static String s2String = "Probability of subtracting one from queue";
    private static String s3String = "Probability of doing nothing";

    public Frame()
    {
        //title of window
        super("Sliders");

        //Layout
        //Label Panel, GridBag Setup
        JPanel pane = new JPanel(new GridBagLayout());
        this.add(pane);
        GridBagConstraints c = new GridBagConstraints();

        class LimitedBoundedRangeModel extends DefaultBoundedRangeModel {
            BoundedRangeModel limit;

            public LimitedBoundedRangeModel(BoundedRangeModel limit) {
                this.limit = limit;
            }

            /** 
             * @inherited <p>
             */
            @Override
            public void setRangeProperties(int newValue, int newExtent, int newMin,
                    int newMax, boolean adjusting) {
                if (limit != null) {
                    int combined = newValue + limit.getValue();
                    if (combined > newMax) {
                        newValue = newMax - limit.getValue();
                    }
                }
                boolean invoke =
                        (adjusting != getValueIsAdjusting()) && !adjusting;
                 super.setRangeProperties(newValue, newExtent, newMin, newMax, adjusting);
                 if (invoke) {
                     SwingUtilities.invokeLater(new Runnable() {
                         public void run() {
                             fireStateChanged();   
                         }
                     });
                 }
                super.setRangeProperties(newValue, newExtent, newMin, newMax, adjusting);
            }
        }

        // use
        LimitedBoundedRangeModel firstModel = new LimitedBoundedRangeModel(null);
        LimitedBoundedRangeModel secondModel = new LimitedBoundedRangeModel(firstModel);
        LimitedBoundedRangeModel thirdModel = new LimitedBoundedRangeModel(secondModel);

        firstModel.limit = secondModel;
        secondModel.limit = thirdModel;
        thirdModel.limit = firstModel;

        s1 = new JSlider(firstModel);
        c.gridx = 0;
        c.gridy = 2;
        c.gridwidth = 5;
        pane.add(s1, c);

        s2 = new JSlider(secondModel);
        c.gridx = 0;
        c.gridy = 5;
        c.gridwidth = 5;
        pane.add(s2, c);

        s3 = new JSlider(thirdModel);
        c.gridx = 0;
        c.gridy = 7;
        c.gridwidth = 5;
        pane.add(s3, c);

        s1Label = new JLabel(s1String);
        c.gridx = 0;
        c.gridy = 2;
        c.gridwidth = 5;
        pane.add(s1Label, c);

        s2Label = new JLabel(s2String);
        c.gridx = 0;
        c.gridy = 4;
        c.gridwidth = 5;
        pane.add(s2Label, c);

        s3Label = new JLabel(s3String);
        c.gridx = 0;
        c.gridy = 6;
        c.gridwidth = 5;
        pane.add(s3Label, c);

        //enable 'tick' markers
        s1.setMajorTickSpacing(25);
        s1.setMinorTickSpacing(1);
        s1.setPaintTicks(true);
        s1.setPaintLabels(true);
        s1.setSnapToTicks(true);
        s2.setMajorTickSpacing(25);
        s2.setMinorTickSpacing(1);
        s2.setPaintTicks(true);
        s2.setPaintLabels(true);
        s2.setSnapToTicks(true);
        s3.setMajorTickSpacing(25);
        s3.setMinorTickSpacing(1);
        s3.setPaintTicks(true);
        s3.setPaintLabels(true);
        s3.setSnapToTicks(true);

        //Listening to sliders

        s1.addChangeListener(new ChangeListener()
        {
        public void stateChanged(ChangeEvent ce)
        {
            JSlider source = (JSlider)ce.getSource();
            if (!source.getValueIsAdjusting())
            {
                int P = (int)source.getValue();
                System.out.println("Probability of adding to queue is now: " + P);
                /*
                 * TODO
                 * Would setting the values of the other sliders here,
                 * instead of using the BoundedRangeModel work?
                 * Tricky math would have to be used.
                 */
               // s2Slider.setValue();

            }
           }
        });

        s2.addChangeListener(new ChangeListener()
        {
            public void stateChanged(ChangeEvent ce)
            {
                JSlider source = (JSlider)ce.getSource();
                if (!source.getValueIsAdjusting())
                {
                    int P = (int)source.getValue();
                    System.out.println("Probability of subtracting from queue is now: " + P);

                }
            }
        });
        s3.addChangeListener(new ChangeListener()
        {
            public void stateChanged(ChangeEvent ce)
            {
                JSlider source = (JSlider)ce.getSource();
                if (!source.getValueIsAdjusting())
                {
                    int P = (int)source.getValue();
                    System.out.println("Probability of doing nothing to the queue is now: " + P);
                }
            }
        });
    }   

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        // TODO Auto-generated method stub

    }

    @Override
    public void stateChanged(ChangeEvent e) {
        // TODO Auto-generated method stub
    }
}

}

Answer 1

一种方法，也许对某人有用:

package stackoverflow;

import java.awt.GridLayout;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class ConnectedSliders
{
    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                createAndShowGUI();
            }
        });
    }

    private static void createAndShowGUI()
    {
        JSlider s0 = new JSlider(0, 100, 30);
        JSlider s1 = new JSlider(0, 100, 40);
        JSlider s2 = new JSlider(0, 100, 30);

        SliderGroup sliderGroup = new SliderGroup();
        sliderGroup.add(s0);
        sliderGroup.add(s1);
        sliderGroup.add(s2);

        JPanel panel =new JPanel(new GridLayout(0,2));
        panel.add(s0);
        panel.add(createListeningLabel(s0));
        panel.add(s1);
        panel.add(createListeningLabel(s1));
        panel.add(s2);
        panel.add(createListeningLabel(s2));

        panel.add(createListeningLabel(s0, s1, s2));

        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(panel);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    private static JLabel createListeningLabel(final JSlider ... sliders)
    {
        final JLabel label = new JLabel("");
        for (JSlider slider : sliders)
        {
            slider.addChangeListener(new ChangeListener()
            {
                @Override
                public void stateChanged(ChangeEvent e)
                {
                    int sum = 0;
                    for (JSlider slider : sliders)
                    {
                        sum += slider.getValue();
                    }
                    label.setText("Sum: "+sum);
                }
            });
        }
        return label;
    }

    private static JLabel createListeningLabel(final JSlider slider)
    {
        final JLabel label = new JLabel("");
        slider.addChangeListener(new ChangeListener()
        {
            @Override
            public void stateChanged(ChangeEvent e)
            {
                label.setText(String.valueOf(slider.getValue()));
            }
        });
        return label;
    }


}


class SliderGroup
{
    private final Map<JSlider, Integer> values;
    private final LinkedList<JSlider> candidates;

    private final ChangeListener changeListener;
    private boolean updating = false;

    SliderGroup()
    {
        this.values = new HashMap<JSlider, Integer>();
        this.candidates = new LinkedList<JSlider>();

        changeListener = new ChangeListener()
        {
            @Override
            public void stateChanged(ChangeEvent e)
            {
                JSlider source = (JSlider)e.getSource();
                update(source);
            }
        };
    }

    private void update(JSlider source)
    {
        if (updating)
        {
            return;
        }
        updating = true;

        int delta = source.getValue() - values.get(source);
        if (delta > 0)
        {
            distributeRemove(delta, source);
        }
        else
        {
            distributeAdd(delta, source);
        }


        for (JSlider slider : candidates)
        {
            values.put(slider, slider.getValue());
        }

        updating = false;
    }


    private void distributeRemove(int delta, JSlider source)
    {
        int counter = 0;
        int remaining = delta;
        while (remaining > 0)
        {
            JSlider slider = candidates.removeFirst();
            counter++;

            if (slider == source)
            {
                candidates.addLast(slider);
            }
            else
            {
                if (slider.getValue() > 0)
                {
                    slider.setValue(slider.getValue()-1);
                    remaining--;
                    counter = 0;
                }
                candidates.addLast(slider);
                if (remaining == 0)
                {
                    break;
                }
            }
            if (counter > candidates.size())
            {
                String message = "Can not distribute "+delta+" among "+candidates;
                //System.out.println(message);
                //return;
                throw new IllegalArgumentException(message);
            }
        }
    }

    private void distributeAdd(int delta, JSlider source)
    {
        int counter = 0;
        int remaining = -delta;
        while (remaining > 0)
        {
            JSlider slider = candidates.removeLast();
            counter++;

            if (slider == source)
            {
                candidates.addFirst(slider);
            }
            else
            {
                if (slider.getValue() < slider.getMaximum())
                {
                    slider.setValue(slider.getValue()+1);
                    remaining--;
                    counter = 0;
                }
                candidates.addFirst(slider);
                if (remaining == 0)
                {
                    break;
                }
            }
            if (counter > candidates.size())
            {
                String message = "Can not distribute "+delta+" among "+candidates;
                //System.out.println(message);
                //return;
                throw new IllegalArgumentException(message);
            }
        }
    }


    void add(JSlider slider)
    {
        candidates.add(slider);
        values.put(slider, slider.getValue());
        slider.addChangeListener(changeListener);
    }

    void remove(JSlider slider)
    {
        candidates.remove(slider);
        values.remove(slider);
        slider.removeChangeListener(changeListener);
    }

}

核心是 SliderGroup 类(类似于 ButtonGroup):可以添加多个 JSlider。一个 slider 的更改将分布在其他 slider 中。正如评论中提到的，这种分布有点棘手:当一个人反复将 slider A 的值增加 1 时(例如，通过按右箭头光标键)，则其他 slider 的值必须反复减少 - 但是它不应该总是选择相同的 slider 来接收此更改，否则只有一个 slider 会移动。我使用接收更改的“候选” slider 的 LinkedList 解决了这个问题。当其他 slider 的值必须减小时，更改会从左到右分布在这些候选 slider 之间。收到更改的 slider 被放置在列表的末尾，以便当它们的值必须再次减少时，收到先前减少的 slider 将是候选列表中的最后一个。 (当它们的值必须增加时，也会做同样的事情，反之亦然)。似乎工作良好，但没有经过彻底测试: slider 将被强制具有“无效”值的情况下的行为(例如，当 A 和 B 具有其 MIN 值，但 C 没有其 MAX 值时，并且增加)可能取决于应用案例。目前，在这种情况下会引发异常，但简单地“忽略”这种情况也可能是合适的......