如何使JTable列不包含JTextField，而包含JTextAreas？

Question

请告诉我，如何使一个JTable列包含JTextAreas，所以当用户键入很多文本时，单元格的高度将增加，并且我们可以看到多于一行（单元格被扩展；结果，行也将扩展）

Answer 1

You need to write your own cell renderer and editor based on JTextArea:

    public class Start
{
    public static class JTextPaneCellEditor extends AbstractCellEditor implements TableCellEditor, KeyListener
    {
        private JViewport viewport;
        private JTable table;
        private int row;
        private JTextPane pane;

        public JTextPaneCellEditor(){
            viewport = new JViewport();
            pane = new JTextPane();
            viewport.add(pane);
            pane.addKeyListener(this);
        }

        @Override public Object getCellEditorValue(){
            return pane.getText();
        }

        @Override public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column){
            this.table = table;
            this.row = row;
            pane.setText(value.toString());
            int newHeight = (int)pane.getPreferredSize().getHeight();
            if(table.getRowHeight(row) < newHeight){
                table.setRowHeight(row, newHeight);
            }
            return pane;
        }

        @Override public boolean isCellEditable(EventObject e){
            if (e instanceof MouseEvent) {
                return ((MouseEvent)e).getClickCount() >= 2;
            }
            return true;
        }

        @Override public void keyTyped(KeyEvent e){
            table.setRowHeight(row, (int)pane.getPreferredSize().getHeight());
        }

        @Override public void keyPressed(KeyEvent e){
            if(e.getKeyCode() == KeyEvent.VK_ENTER){
                stopCellEditing();
            }
        }

        @Override public void keyReleased(KeyEvent e){
        }
    }

    private static class JTextPaneCellRenderer extends JViewport implements TableCellRenderer
    {
        JTextPane pane;
        JTextPaneCellRenderer(){
            pane = new JTextPane();
            add(pane);
        }

        @Override public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column){
            pane.setText(value.toString());
            table.setRowHeight(row, (int)pane.getPreferredSize().getHeight());
            return this;
        }
    }

    public static void main(String[] args){
        JTable table = new JTable(new String[][]{{"String String String String StringString String String String StringString String String String StringString String String String StringString String String String String"}, {"String 2"}}, new String[]{"Column"});
        table.setDefaultRenderer(Object.class, new JTextPaneCellRenderer());
        table.setDefaultEditor(Object.class, new JTextPaneCellEditor());

        JFrame test = new JFrame();
        test.add(new JScrollPane(table));
        test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        test.setSize(300, 300);
        test.setLocationRelativeTo(null);
        test.setVisible(true);
    }
}

EDIT: add viewports for better sizing. But the row is still not expanded on first edit. Does anyone have any ideas?

EDIT2: I agree with the comments. The thing you want is possible, but you need untested, hackish custom implementation. You will be better off if you redesigned your layout to exclude such JTable sorcery.

Answer 2

@Jakub Zaverka

I'll delete this answer later

import java.awt.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.text.*;

public class AutoWrapTest {

    public JComponent makeUI() {
        String[] columnNames = {"TextAreaCellRenderer"};
        Object[][] data = {
            {"123456789012345678901234567890"},
            {"dddddddddddddddddddddddddddddddddddddddddddddddddddddddddx"},
            {"----------------------------------------------0"},
            {">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>|"},};
        TableModel model = new DefaultTableModel(data, columnNames) {

            private static final long serialVersionUID = 1L;

            @Override
            public boolean isCellEditable(int row, int column) {
                return false;
            }
        };
        JTable table = new JTable(model) {

            private static final long serialVersionUID = 1L;

            @Override
            public void doLayout() {
                TableColumn col = getColumnModel().getColumn(0);
                for (int row = 0; row < getRowCount(); row++) {
                    Component c = prepareRenderer(col.getCellRenderer(), row, 0);
                    if (c instanceof JTextArea) {
                        JTextArea a = (JTextArea) c;
                        int h = getPreferredHeight(a) + getIntercellSpacing().height;
                        if (getRowHeight(row) != h) {
                            setRowHeight(row, h);
                        }
                    }
                }
                super.doLayout();
            }            //http://tips4java.wordpress.com/2008/10/26/text-utilities/

            private int getPreferredHeight(JTextComponent c) {
                Insets insets = c.getInsets();
                View view = c.getUI().getRootView(c).getView(0);
                int preferredHeight = (int) view.getPreferredSpan(View.Y_AXIS);
                return preferredHeight + insets.top + insets.bottom;
            }
        };
        table.setEnabled(false);
        table.setShowGrid(false);
        table.setTableHeader(null);
        table.getColumnModel().getColumn(0).setCellRenderer(new TextAreaCellRenderer());
        JScrollPane sp = new JScrollPane(table);
        sp.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        JPanel p = new JPanel(new BorderLayout());
        p.add(sp);
        return p;
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                createAndShowGUI();
            }
        });
    }

    public static void createAndShowGUI() {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        f.getContentPane().add(new AutoWrapTest().makeUI());
        f.setSize(200, 200);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

class TextAreaCellRenderer extends JTextArea implements TableCellRenderer {

    private static final long serialVersionUID = 1L;
    private final Color evenColor = new Color(230, 240, 255);

    public TextAreaCellRenderer() {
        super();
        setLineWrap(true);
        setWrapStyleWord(true);
        setBorder(BorderFactory.createEmptyBorder(2, 2, 2, 2));
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        if (isSelected) {
            setForeground(table.getSelectionForeground());
            setBackground(table.getSelectionBackground());
        } else {
            setForeground(table.getForeground());
            setBackground(table.getBackground());
            setBackground((row % 2 == 0) ? evenColor : getBackground());
        }
        setFont(table.getFont());
        setText((value == null) ? "" : value.toString());
        return this;
    }
}