MigLayout对JScrollBar对象中包含的JTable对象感到困惑

Question

看来MigLayout被JScrollPane对象中包含的JTable对象搞糊涂了.由于在JScrollPane中使用JTable似乎很常见,我认为找出原因很重要.

在附加的示例程序中,创建了一个简化的表单,由12行和4列组成.所有宽度和高度均设置为百分比.表单中添加了许多组件,所有组件都按单元格位置添加.一些跨越行或列.最后一列显示单元格行索引和大小百分比.

如果程序以参数"JLabel"启动,则JSCrollPane中包含的JLabel将添加到第0列,所有对齐看起来都很好.如果程序以参数"JTable"启动,则所有列的行大小都会中断.

这是一个错误还是一个功能？

Make:  javac -classpath <path to miglayout> migtest.java
Usage:  java -classpath <path to miglayout> migtest <JTable|JLabel>

注意:如果下面的代码看起来是混淆的(没有标签),我尝试了各种粘贴方法 - 我无法让预览看起来正确.让我知道我能做些什么来解决它.

import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.util.*;
import java.io.*;
import java.text.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.filechooser.*;
import javax.swing.table.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;
import javax.swing.table.TableColumn;
import net.miginfocom.swing.MigLayout;

public class Migtest extends JFrame {
    public final static int appWidth = 1200; // default

    public final static int appHeight = 800; // default

    String[] clientColNames = { "Name", "Address", "Alternate Address" };

    JComponent createClientsPane(int numCols, String arg) {
        if (arg.equals("jtable")) {
            JTable clientsTable = new JTable(1, numCols);
            clientsTable.getTableHeader().setReorderingAllowed(false);
            clientsTable.getSelectionModel().setSelectionMode(
                    ListSelectionModel.SINGLE_SELECTION);
            clientsTable.getSelectionModel().setSelectionInterval(0, 0);
            JScrollPane scrollPane = new JScrollPane(clientsTable);
            return scrollPane;
        } else
            return new JScrollPane(new JLabel("bear tenders"));
    }

    void init(String[] args) {
        JPanel topPanel = null, subpanel = null;
        String arg;
        if (args.length != 1) {
            System.out.println("missing arg - s/b 'JLabel' or 'jTable'");
            System.exit(0);
        }
        arg = args[0].trim().toLowerCase();
        if (!arg.equals("jlabel") && !arg.equals("jtable")) {
            System.out.println("missing arg - s/b 'JLabel' or 'jTable'");
            System.exit(0);
        }
        setSize(appWidth, appHeight);
        topPanel = new JPanel(new MigLayout("fill,debug",
                "[30%][15%][50%][5%]",
                "[5%][7%][5%][10%][7%][7%][7%][7%][6%][7%][2%][30%]"));
        JCheckBox dynamicInstrumentCheckbox = new JCheckBox(
                "Wood Activities Enabled", false);
        topPanel.add(dynamicInstrumentCheckbox, "cell 0 2");
        topPanel.add(new JLabel("BEAR TENDERS"), "cell 0 4, alignx center");
        topPanel.add(createClientsPane(clientColNames.length, arg),
                "cell 0 5, spany 4, grow");
        topPanel.add(new JLabel("BEAR FACTS"), "cell 1 4, alignx center");
        JRadioButton noneButton = new JRadioButton("None");
        topPanel.add(noneButton, "cell 1 5, gapleft 2%");
        JRadioButton rangeButton = new JRadioButton("Fact 1");
        topPanel.add(rangeButton, "cell 1 6, gapleft 2%");
        JRadioButton playbackButton = new JRadioButton("Fact 2");
        topPanel.add(playbackButton, "cell 1 7, gapleft 2%");
        JButton controlsButton = new JButton("Controls =>");
        topPanel.add(controlsButton, "cell 1 8, alignx center");
        topPanel.add(new JLabel("GUMMY BEARS"), "cell 2 1, alignx center");
        topPanel.add(new JLabel("(gummy bears)"), "cell 2 2, spany 4, grow");
        topPanel.add(new JLabel("CHICAGO BEARS"), "cell 2 6, alignx center");
        topPanel.add(new JLabel("(chicago bears)"), "cell 2 7, spany 3, grow");
        topPanel.add(new JLabel("LOG"), "cell 0 10, alignx left");
        JButton clearLogButton = new JButton("Clear Log");
        topPanel.add(clearLogButton, "cell 2 10, alignx right");
        topPanel.add(new JLabel("(log pane)"), "cell 0 11, spanx 3, grow");
        topPanel.add(new JLabel("0-5%"), "cell 3 0, grow");
        topPanel.add(new JLabel("1-7%"), "cell 3 1, grow");
        topPanel.add(new JLabel("2-5%"), "cell 3 2, grow");
        topPanel.add(new JLabel("3-10%"), "cell 3 3, grow");
        topPanel.add(new JLabel("4-7%"), "cell 3 4, grow");
        topPanel.add(new JLabel("5-7%"), "cell 3 5, grow");
        topPanel.add(new JLabel("6-7%"), "cell 3 6, grow");
        topPanel.add(new JLabel("7-7%"), "cell 3 7, grow");
        topPanel.add(new JLabel("8-6%"), "cell 3 8, grow");
        topPanel.add(new JLabel("9-7%"), "cell 3 9, grow");
        topPanel.add(new JLabel("10-2%"), "cell 3 10, grow");
        topPanel.add(new JLabel("11-30%"), "cell 3 11, grow");
        setContentPane(topPanel);
    }

    public static void main(String[] args) {
        try {
            Migtest thisTest = new Migtest();
            thisText.init(args);
//            thisTest.init(new String[] {"jLabel"});
//            thisTest.init(new String[] {"jTable"});

            // center app window
            GraphicsConfiguration gc = thisTest.getGraphicsConfiguration();
            Rectangle bounds = gc.getBounds();
            thisTest.setLocation(
                    (int) ((bounds.width - thisTest.appWidth) / 2),
                    (int) ((bounds.height - thisTest.appHeight) / 2));
            thisTest.setVisible(true);
        } catch (Exception e) {
            System.out.println("runTest caught exception:  " + e.getMessage());
            e.printStackTrace();
        }
    }
} // class test

Answer 1

这是很多组件限制(对我来说真的很难挖掘它们;-)所以只是一个粗略的答案类型:

标签与表之间的区别在于后者实现可滚动,特别是它

Dimension getPreferredScrollableViewportSize();

这被实现为返回固定维度,遗憾的是在表的init代码中进行了硬编码:

setPreferredScrollableViewportSize(new Dimension(450, 400));

这很少是你想要的.

对MigLayout的影响是,相当大的区域(并且在实际行上的内容)溢出其单元格以至于其他单元格必须缩小.

在您的上下文中的出路是简单地将prefViewport设置为null:

clientsTable.setPreferredScrollableViewportSize(null);

(编辑说明重点在于您的上下文 - 不同的LayoutManagers会混淆,请参阅最近的问题)

一个更通用的解决方案可能是将getter实现为更合理的东西,用#of行计算偏好(粗略地,但不完全是,JXTable的作用)

@Override 
public Dimension getPreferredScrollableViewportSize() {
    if (preferredViewportSize == null) { // hasn't been hard-coded
        if (visibleRowCount < 0) { // a property similar as in JList
             return getPreferredSize(); // use the actual size
        } else {
             Dimension pref = getPreferredSize();
           // calculate height based on # rows that should be visible 
             pref.height = ....
             return pref;
        } 
    } 
    return super.getPr...
}