如果从cellrenderer更改数据，如何计算列调整后的jTable宽度和高度

Question

null

     package com.swing.data;

import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.TableModel;

public class SimpleTableDemo extends JPanel implements ActionListener {
    private boolean DEBUG = false;
    private JTable table = null;
    private TableColumnAdjuster app = null;
    String[] columnNames = {"First Name",
            "Last Name",
            "Sport",
            "# of Years",
            "Vegetarian"};
    Object[][] data = {
            {"Kathy", "Smith",
             "Snowboarding", new Integer(5), new Boolean(false)},
            {"John", "Doe",
             "Rowing", new Integer(3), new Boolean(true)},
            {"Sue", "Black",
             "Knitting", new Integer(2), new Boolean(false)},
            {"Jane", "White",
             "Speed reading", new Integer(20), new Boolean(true)},
            {"Joe", "Brown",
             "Pool", new Integer(10), new Boolean(false)}
            };
    CutomTableCellRenderer renderer = null;
    public SimpleTableDemo() {
        super(new GridLayout(1,0));
        table = new JTable(data, columnNames);
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);

        if (DEBUG) {
            table.addMouseListener(new MouseAdapter() {
                public void mouseClicked(MouseEvent e) {
                    printDebugData(table);
                }
            });
        }
        renderer = new CutomTableCellRenderer(table.getDefaultRenderer(Object.class));
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        table.setDefaultRenderer(Object.class, renderer);
        //table.setSelectionMode(JTable.AUTO_RESIZE_SUBSEQUENT_COLUMNS);
        JScrollPane scrollPane = new JScrollPane(table);
        app = new TableColumnAdjuster(table);
        app.adjustColumns();
       // scrollPane.setRowHeaderView(jRowTable);
        //scrollPane.setCorner(JScrollPane.UPPER_LEFT_CORNER,jRowTable.getTableHeader());
        //scrollPane.setSize(300,300);
        //Create the scroll pane and add the table to it.

        //Add the scroll pane to this panel.
        add(scrollPane);
        JButton button = new JButton("Change");
        add(button);
        button.addActionListener(this);

    }

    private void printDebugData(JTable table) {
        int numRows = table.getRowCount();
        int numCols = table.getColumnCount();
        javax.swing.table.TableModel model = table.getModel();

        System.out.println("Value of data: ");
        for (int i=0; i < numRows; i++) {
            System.out.print("    row " + i + ":");
            for (int j=0; j < numCols; j++) {
                System.out.print("  " + model.getValueAt(i, j));
            }
            System.out.println();
        }
        System.out.println("--------------------------");
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("SimpleTableDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        SimpleTableDemo newContentPane = new SimpleTableDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        renderer.setText("Modified.............................");  
        app.adjustColumns();
        System.out.println("tableWidth:" + table.getWidth() + "tableHeight:" + table.getHeight());
    }
}

null

**

package com.swing.data;

import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;

/*
 *  Class to manage the widths of colunmns in a table.
 *
 *  Various properties control how the width of the column is calculated.
 *  Another property controls whether column width calculation should be dynamic.
 *  Finally, various Actions will be added to the table to allow the user
 *  to customize the functionality.
 *
 *  This class was designed to be used with tables that use an auto resize mode
 *  of AUTO_RESIZE_OFF. With all other modes you are constrained as the width
 *  of the columns must fit inside the table. So if you increase one column, one
 *  or more of the other columns must decrease. Because of this the resize mode
 *  of RESIZE_ALL_COLUMNS will work the best.
 */
public class TableColumnAdjuster implements PropertyChangeListener, TableModelListener
{
    private JTable table;
    private int spacing;
    private boolean isColumnHeaderIncluded;
    private boolean isColumnDataIncluded;
    private boolean isOnlyAdjustLarger;
    private boolean isDynamicAdjustment;
    private Map<TableColumn, Integer> columnSizes = new HashMap<TableColumn, Integer>();

    /*
     *  Specify the table and use default spacing
     */
    public TableColumnAdjuster(JTable table)
    {
        this(table, 6);
    }

    /*
     *  Specify the table and spacing
     */
    public TableColumnAdjuster(JTable table, int spacing)
    {
        this.table = table;
        this.spacing = spacing;
        setColumnHeaderIncluded( true );
        setColumnDataIncluded( true );
        setOnlyAdjustLarger( true );
        setDynamicAdjustment( false );
        installActions();
    }

    /*
     *  Adjust the widths of all the columns in the table
     */
    public void adjustColumns()
    {
        TableColumnModel tcm = table.getColumnModel();

        for (int i = 0; i < tcm.getColumnCount(); i++)
        {
            adjustColumn(i);
        }
    }

    /*
     *  Adjust the width of the specified column in the table
     */
    public void adjustColumn(final int column)
    {
        TableColumn tableColumn = table.getColumnModel().getColumn(column);

        if (! tableColumn.getResizable()) return;

        int columnHeaderWidth = getColumnHeaderWidth( column );
        int columnDataWidth   = getColumnDataWidth( column );
        int preferredWidth    = Math.max(columnHeaderWidth, columnDataWidth);

        updateTableColumn(column, preferredWidth);
    }

    /*
     *  Calculated the width based on the column name
     */
    private int getColumnHeaderWidth(int column)
    {
        if (! isColumnHeaderIncluded) return 0;

        TableColumn tableColumn = table.getColumnModel().getColumn(column);
        Object value = tableColumn.getHeaderValue();
        TableCellRenderer renderer = tableColumn.getHeaderRenderer();

        if (renderer == null)
        {
            renderer = table.getTableHeader().getDefaultRenderer();
        }

        Component c = renderer.getTableCellRendererComponent(table, value, false, false, -1, column);
        return c.getPreferredSize().width;
    }

    /*
     *  Calculate the width based on the widest cell renderer for the
     *  given column.
     */
    private int getColumnDataWidth(int column)
    {
        if (! isColumnDataIncluded) return 0;

        int preferredWidth = 0;
        int maxWidth = table.getColumnModel().getColumn(column).getMaxWidth();

        for (int row = 0; row < table.getRowCount(); row++)
        {
            preferredWidth = Math.max(preferredWidth, getCellDataWidth(row, column));

            //  We've exceeded the maximum width, no need to check other rows

            if (preferredWidth >= maxWidth)
                break;
        }

        return preferredWidth;
    }

    /*
     *  Get the preferred width for the specified cell
     */
    private int getCellDataWidth(int row, int column)
    {
        //  Inovke the renderer for the cell to calculate the preferred width

        TableCellRenderer cellRenderer = table.getCellRenderer(row, column);
        Component c = table.prepareRenderer(cellRenderer, row, column);
        int width = c.getPreferredSize().width + table.getIntercellSpacing().width;

        return width;
    }

    /*
     *  Update the TableColumn with the newly calculated width
     */
    private void updateTableColumn(int column, int width)
    {
        final TableColumn tableColumn = table.getColumnModel().getColumn(column);

        if (! tableColumn.getResizable()) return;

        width += spacing;

        //  Don't shrink the column width

        if (isOnlyAdjustLarger)
        {
            width = Math.max(width, tableColumn.getPreferredWidth());
        }

        columnSizes.put(tableColumn, new Integer(tableColumn.getWidth()));
        table.getTableHeader().setResizingColumn(tableColumn);
        tableColumn.setWidth(width);
    }

    /*
     *  Restore the widths of the columns in the table to its previous width
     */
    public void restoreColumns()
    {
        TableColumnModel tcm = table.getColumnModel();

        for (int i = 0; i < tcm.getColumnCount(); i++)
        {
            restoreColumn(i);
        }
    }

    /*
     *  Restore the width of the specified column to its previous width
     */
    private void restoreColumn(int column)
    {
        TableColumn tableColumn = table.getColumnModel().getColumn(column);
        Integer width = columnSizes.get(tableColumn);

        if (width != null)
        {
            table.getTableHeader().setResizingColumn(tableColumn);
            tableColumn.setWidth( width.intValue() );
        }
    }

    /*
     *  Indicates whether to include the header in the width calculation
     */
    public void setColumnHeaderIncluded(boolean isColumnHeaderIncluded)
    {
        this.isColumnHeaderIncluded = isColumnHeaderIncluded;
    }

    /*
     *  Indicates whether to include the model data in the width calculation
     */
    public void setColumnDataIncluded(boolean isColumnDataIncluded)
    {
        this.isColumnDataIncluded = isColumnDataIncluded;
    }

    /*
     *  Indicates whether columns can only be increased in size
     */
    public void setOnlyAdjustLarger(boolean isOnlyAdjustLarger)
    {
        this.isOnlyAdjustLarger = isOnlyAdjustLarger;
    }

    /*
     *  Indicate whether changes to the model should cause the width to be
     *  dynamically recalculated.
     */
    public void setDynamicAdjustment(boolean isDynamicAdjustment)
    {
        //  May need to add or remove the TableModelListener when changed

        if (this.isDynamicAdjustment != isDynamicAdjustment)
        {
            if (isDynamicAdjustment)
            {
                table.addPropertyChangeListener( this );
                table.getModel().addTableModelListener( this );
            }
            else
            {
                table.removePropertyChangeListener( this );
                table.getModel().removeTableModelListener( this );
            }
        }

        this.isDynamicAdjustment = isDynamicAdjustment;
    }
//
//  Implement the PropertyChangeListener
//
    public void propertyChange(PropertyChangeEvent e)
    {
        //  When the TableModel changes we need to update the listeners
        //  and column widths

        if ("model".equals(e.getPropertyName()))
        {
            TableModel model = (TableModel)e.getOldValue();
            model.removeTableModelListener( this );

            model = (TableModel)e.getNewValue();
            model.addTableModelListener( this );
            adjustColumns();
        }
    }
//
//  Implement the TableModelListener
//
    public void tableChanged(TableModelEvent e)
    {
        if (! isColumnDataIncluded) return;

        //  A cell has been updated

        if (e.getType() == TableModelEvent.UPDATE)
        {
            int column = table.convertColumnIndexToView(e.getColumn());

            //  Only need to worry about an increase in width for this cell

            if (isOnlyAdjustLarger)
            {
                int row = e.getFirstRow();
                TableColumn tableColumn = table.getColumnModel().getColumn(column);

                if (tableColumn.getResizable())
                {
                    int width = getCellDataWidth(row, column);
                    updateTableColumn(column, width);
                }
            }

            //  Could be an increase of decrease so check all rows

            else
            {
                adjustColumn( column );
            }
        }

        //  The update affected more than one column so adjust all columns

        else
        {
            adjustColumns();
        }
    }

    /*
     *  Install Actions to give user control of certain functionality.
     */
    private void installActions()
    {
        installColumnAction(true,  true,  "adjustColumn",   "control ADD");
        installColumnAction(false, true,  "adjustColumns",  "control shift ADD");
        installColumnAction(true,  false, "restoreColumn",  "control SUBTRACT");
        installColumnAction(false, false, "restoreColumns", "control shift SUBTRACT");

        installToggleAction(true,  false, "toggleDynamic",  "control MULTIPLY");
        installToggleAction(false, true,  "toggleLarger",   "control DIVIDE");
    }

    /*
     *  Update the input and action maps with a new ColumnAction
     */
    private void installColumnAction(
        boolean isSelectedColumn, boolean isAdjust, String key, String keyStroke)
    {
        Action action = new ColumnAction(isSelectedColumn, isAdjust);
        KeyStroke ks = KeyStroke.getKeyStroke( keyStroke );
        table.getInputMap().put(ks, key);
        table.getActionMap().put(key, action);
    }

    /*
     *  Update the input and action maps with new ToggleAction
     */
    private void installToggleAction(
        boolean isToggleDynamic, boolean isToggleLarger, String key, String keyStroke)
    {
        Action action = new ToggleAction(isToggleDynamic, isToggleLarger);
        KeyStroke ks = KeyStroke.getKeyStroke( keyStroke );
        table.getInputMap().put(ks, key);
        table.getActionMap().put(key, action);
    }

    /*
     *  Action to adjust or restore the width of a single column or all columns
     */
    class ColumnAction extends AbstractAction
    {
        private boolean isSelectedColumn;
        private boolean isAdjust;

        public ColumnAction(boolean isSelectedColumn, boolean isAdjust)
        {
            this.isSelectedColumn = isSelectedColumn;
            this.isAdjust = isAdjust;
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            //  Handle selected column(s) width change actions

            if (isSelectedColumn)
            {
                int[] columns = table.getSelectedColumns();

                for (int i = 0; i < columns.length; i++)
                {
                    if (isAdjust)
                        adjustColumn(columns[i]);
                    else
                        restoreColumn(columns[i]);
                }
            }
            else
            {
                if (isAdjust)
                    adjustColumns();
                else
                    restoreColumns();
            }
        }
    }

    /*
     *  Toggle properties of the TableColumnAdjuster so the user can
     *  customize the functionality to their preferences
     */
    class ToggleAction extends AbstractAction
    {
        private boolean isToggleDynamic;
        private boolean isToggleLarger;

        public ToggleAction(boolean isToggleDynamic, boolean isToggleLarger)
        {
            this.isToggleDynamic = isToggleDynamic;
            this.isToggleLarger = isToggleLarger;
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            if (isToggleDynamic)
            {
                setDynamicAdjustment(! isDynamicAdjustment);
                return;
            }

            if (isToggleLarger)
            {
                setOnlyAdjustLarger(! isOnlyAdjustLarger);
                return;
            }
        }
    }
}

**

• CutomTableCellRenderer.java

package com.swing.data;

import java.awt.Color;
import java.awt.Component;

import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellRenderer;
public class CutomTableCellRenderer extends DefaultTableCellRenderer 
{   
    private TableCellRenderer mWrappedRenderer; 
    private String text = "Original";
    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }

    public CutomTableCellRenderer(TableCellRenderer pWrappedRenderer) { 
        mWrappedRenderer = pWrappedRenderer; 
        } 

    public Component getTableCellRendererComponent
       (JTable table, Object value, boolean isSelected,
       boolean hasFocus, int row, int column) 
    {
        Component cell = mWrappedRenderer.getTableCellRendererComponent(table, value, isSelected,
                   hasFocus, row, column); 


            if( row == 1 )
            {

                JLabel label = (JLabel)cell;
                label.setText(text);
            }
            else
            {
                cell.setBackground( Color.white );
            }

        return cell;
    }
}

Answer 1

在ActionListener的代码中

renderer.setText("Modified.............................");
app.adjustColumns();
System.out.println("tableWidth:" + table.getWidth() + "tableHeight:" + table.getHeight());

对app.adjustColumns()的调用只触发新的布局，调整后的列只有在事件完成后才可见，即在方法完成并写入输出后才可见。

您可以通过将输出封装到另一个事件中来轻松地验证它：

System.out.println("PRE  tableWidth:" + table.getWidth() + "tableHeight:" + table.getHeight());
SwingUtilities.invokeLater(new Runnable() {
    @Override
    public void run() {
        System.out.println("POST tableWidth:" + table.getWidth() + "tableHeight:" + table.getHeight());
    }
});

PRE  tableWidth:390tableHeight:80
POST tableWidth:710tableHeight:80