JSpinner采用双格式

Question

我想创建支持非整数值的JSpinner，例如2.01和-3.456，所以getValue（）返回一个Double。

不仅仅是这个，但我希望步长应该是动态的，使用类似下面的公式（10％的大小）：

stepSize = 0.1 * pow(10, round( log(currentValue) ));

有可能吗？或者我应该问，麻烦值得吗？

更新

通过调整Vishal的答案，我制作了以下课程来制作漂亮的双旋转器。到目前为止，他们已经证明在我的程序中工作得很好，尽管我会将自适应步长抽象到另一个父类中，以便我可以在以后制作AdaptiveDoubleSpinners和AdaptiveIntegerSpinners。

import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class DoubleSpinner extends JSpinner {

    private static final long serialVersionUID = 1L;
    private static final double STEP_RATIO = 0.1;

    private SpinnerNumberModel model;

    public DoubleSpinner() {
        super();
        // Model setup
        model = new SpinnerNumberModel(0.0, -1000.0, 1000.0, 0.1);
        this.setModel(model);

        // Step recalculation
        this.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent e) {
                Double value = getDouble();
                // Steps are sensitive to the current magnitude of the value
                long magnitude = Math.round(Math.log10(value));
                double stepSize = STEP_RATIO * Math.pow(10, magnitude);
                model.setStepSize(stepSize);
            }
        });
    }

    /**
     * Returns the current value as a Double
     */
    public Double getDouble() {
        return (Double)getValue();
    }

}

Answer 1

是的，这是可能的。请参阅下面给出的示例：

import java.awt.Container;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.BorderLayout;
import java.util.Calendar;
import java.util.Date;

import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;


public class SpinnerDemo extends JFrame 
{
    JSpinner s;
    SpinnerNumberModel model ;
    JSpinner.NumberEditor editor;
    JTextField stepText;
    JButton bStepSet;
    public void prepareAndShowGUI()
    {
        model = new SpinnerNumberModel(0.0,-1000.0 ,1000.0,0.1);
        s = new JSpinner(model);
        editor = new JSpinner.NumberEditor(s) ;
        s.setEditor(editor);
        stepText = new JTextField(10);
        bStepSet = new JButton("Set Step");
        bStepSet.addActionListener( new ActionListener()
        {
            @Override
            public void actionPerformed(ActionEvent evt)
            {
                try
                {
                    /* You can apply your stepSize deduction logic here*/
                    Double val = Double.parseDouble(stepText.getText().trim()); 
                    /*Setting the stepSize*/
                    model.setStepSize(val);
                }
                catch (Exception ex){}
            }
        });
        Container c = getContentPane();
        c.add(s);
        JPanel southPanel = new JPanel();
        southPanel.add(stepText);southPanel.add(bStepSet);
        c.add(southPanel,BorderLayout.SOUTH);
        pack();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    public static void main(String args[]) 
    {
        SwingUtilities.invokeLater( new Runnable()
        {
            @Override
            public void run()
            {
                SpinnerDemo sd = new SpinnerDemo();
                sd.prepareAndShowGUI();
            }
        });
    }
}