java - Gridbag 布局中的 JSpinner

Question

我有一个简单的网格包布局，当我仅使用文本字段时，它可以正常工作。当我放入 JSpinner 时，整个布局变得完全困惑。我的意思是我的三列中的两列完全消失，第二列，唯一出现的列，无论窗口大小如何，都会占用窗口的整个宽度。完整代码如下。

这个问题似乎与旋转器有关，如果我使用其他类型的 JComponent(例如 JLabel)，问题不会显现出来。我做错了什么导致 JSpinner 完全破坏了布局？

package product_data.ui;

import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JSpinner;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SpinnerNumberModel;

import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;

public class StrippedProductEditor extends JFrame {

    /**
     * 
     */
    private static final long serialVersionUID = 5429511033322948114L;
    private JLabel lblManufacturer;
    private JLabel lblSku;
    private JTextField mfrText;
    private JTextField skuText;
    private JTextArea extraText;
    private JLabel lblListPrice;
    private JSpinner spinner;


    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    new StrippedProductEditor();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public StrippedProductEditor() {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        GridBagLayout gridBagLayout = new GridBagLayout();
        gridBagLayout.columnWidths = new int[] { 0, 0, 0 };
        gridBagLayout.rowHeights = new int[] { 0, 0, 0, };
        gridBagLayout.columnWeights = new double[] { 0.0, 1.0, 1.0 };
        gridBagLayout.rowWeights = new double[] { 0.0, 0.0, 0.0};
        getContentPane().setLayout(gridBagLayout);

        lblManufacturer = new JLabel("Manufacturer");
        GridBagConstraints gbc_lblManufacturer = new GridBagConstraints();
        gbc_lblManufacturer.insets = new Insets(0, 0, 5, 5);
        gbc_lblManufacturer.gridx = 0;
        gbc_lblManufacturer.gridy = 0;
        getContentPane().add(lblManufacturer, gbc_lblManufacturer);

        mfrText = new JTextField();
        GridBagConstraints gbc_lblMfrText = new GridBagConstraints();
        gbc_lblMfrText.insets = new Insets(0, 0, 5, 5);
        gbc_lblMfrText.fill = GridBagConstraints.HORIZONTAL;
        gbc_lblMfrText.gridx = 1;
        gbc_lblMfrText.gridy = 0;
        getContentPane().add(mfrText, gbc_lblMfrText);

        lblSku = new JLabel("SKU");
        GridBagConstraints gbc_lblSku = new GridBagConstraints();
        gbc_lblSku.insets = new Insets(0, 0, 5, 5);
        gbc_lblSku.gridx = 0;
        gbc_lblSku.gridy = 1;
        getContentPane().add(lblSku, gbc_lblSku);

        skuText = new JTextField();
        GridBagConstraints gbc_textField_1 = new GridBagConstraints();
        gbc_textField_1.insets = new Insets(0, 0, 5, 5);
        gbc_textField_1.fill = GridBagConstraints.HORIZONTAL;
        gbc_textField_1.gridx = 1;
        gbc_textField_1.gridy = 1;
        getContentPane().add(skuText, gbc_textField_1);
        skuText.setColumns(10);

        extraText = new JTextArea();
        JScrollPane dictScrollPane = new JScrollPane(extraText);
        GridBagConstraints gbc_dict = new GridBagConstraints();
        gbc_dict.insets = new Insets(0, 0, 5, 5);
        gbc_dict.gridx = 2;
        gbc_dict.gridy = 0;
        gbc_dict.gridheight = 2;
        gbc_dict.fill = GridBagConstraints.BOTH;

        getContentPane().add(dictScrollPane, gbc_dict);
        lblListPrice = new JLabel("List Price");
        GridBagConstraints gbc_lblListPrice = new GridBagConstraints();
        gbc_lblListPrice.insets = new Insets(0, 0, 5, 5);
        gbc_lblListPrice.gridx = 0;
        gbc_lblListPrice.gridy = 2;
        getContentPane().add(lblListPrice, gbc_lblListPrice);

        double lp = 99.9;
        SpinnerNumberModel m = new SpinnerNumberModel(lp, 0.0d,
                Double.MAX_VALUE, 0.01d);
        spinner = new JSpinner(m);
        GridBagConstraints gbc_spinner = new GridBagConstraints();
        gbc_spinner.fill = GridBagConstraints.HORIZONTAL;
        gbc_spinner.insets = new Insets(0, 0, 5, 5);
        gbc_spinner.gridx = 1;
        gbc_spinner.gridy = 2;
        //commenting out this line will make the layout look 
        //correct, but then the spinner is missing.
        getContentPane().add(spinner, gbc_spinner);

        this.pack();
        this.setVisible(true);
    }

}

Answer 1

因此，在深入研究代码之后，我发现 JSpinner.NumberEditor(用于支持 SpinnerNumberModel 的编辑器)正在使用以下方法计算字段 columns 属性:

try {
    String maxString = formatter.valueToString(model.getMinimum());
    String minString = formatter.valueToString(model.getMaximum());
    ftf.setColumns(Math.max(maxString.length(),
                            minString.length()));
}
catch (ParseException e) {
    // TBD should throw a chained error here
}

现在，事实证明，maxString 等于 0(是的，我知道)，minString 等于...

179,769,313,486,231,570,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000

等于 411 个字符...opps...

现在，您可以将模型的最大值减少到更现实的值(例如一百万)，或者您可以使用类似的东西手动调整微调器的大小...

((JSpinner.NumberEditor) spinner.getEditor()).getTextField().setColumns(10);

就我个人而言，我更喜欢选项一;)