Java JTable Column Size Calculate calcColumnWidth(JTable table, int col)

Description

Calculates the optimal width for the column of the given table.

License

Open Source License

Parameter

Parameter	Description
table	the table to calculate the column width
col	the column to calculate the widths

Return

the width, -1 if error

Declaration

public static int calcColumnWidth(JTable table, int col) 

Method Source Code

//package com.java2s;
/*/*from w w  w .  j  a  v  a  2  s  .co  m*/
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

import java.awt.Component;

import javax.swing.JTable;

import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
import javax.swing.table.TableModel;

public class Main {
    private JTable jtable;

    /**
     * calcs the optimal column width of the given column
     */
    public int calcColumnWidth(int col) {
        return calcColumnWidth(getJTable(), col);
    }

    /**
     *  Calculates the optimal width for the column of the given table. The
     *  calculation is based on the preferred width of the header and cell
     *  renderer.
     *  <br>
     *  Taken from the newsgoup de.comp.lang.java with some modifications.<br>
     *  Taken from FOPPS/EnhancedTable - http://fopps.sourceforge.net/<br>
     *
     *  @param table    the table to calculate the column width
     *  @param col      the column to calculate the widths
     *  @return         the width, -1 if error
     */
    public static int calcColumnWidth(JTable table, int col) {
        int width = calcHeaderWidth(table, col);
        if (width == -1)
            return width;

        TableColumnModel columns = table.getColumnModel();
        TableModel data = table.getModel();
        int rowCount = data.getRowCount();
        TableColumn column = columns.getColumn(col);
        try {
            for (int row = rowCount - 1; row >= 0; --row) {
                Component c = table.prepareRenderer(
                        table.getCellRenderer(row, col), row, col);
                width = Math.max(width, c.getPreferredSize().width + 10);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return width;
    }

    /**
     * returns the JTable
     */
    public JTable getJTable() {
        return jtable;
    }

    /**
     * calcs the optimal header width of the given column
     */
    public int calcHeaderWidth(int col) {
        return calcHeaderWidth(getJTable(), col);
    }

    /**
     *  Calculates the optimal width for the header of the given table. The
     *  calculation is based on the preferred width of the header renderer.
     *
     *  @param table    the table to calculate the column width
     *  @param col      the column to calculate the widths
     *  @return         the width, -1 if error
     */
    public static int calcHeaderWidth(JTable table, int col) {
        if (table == null)
            return -1;

        if (col < 0 || col > table.getColumnCount()) {
            System.out.println("invalid col " + col);
            return -1;
        }

        JTableHeader header = table.getTableHeader();
        TableCellRenderer defaultHeaderRenderer = null;
        if (header != null)
            defaultHeaderRenderer = header.getDefaultRenderer();
        TableColumnModel columns = table.getColumnModel();
        TableModel data = table.getModel();
        TableColumn column = columns.getColumn(col);
        int width = -1;
        TableCellRenderer h = column.getHeaderRenderer();
        if (h == null)
            h = defaultHeaderRenderer;
        if (h != null) {
            // Not explicitly impossible
            Component c = h.getTableCellRendererComponent(table,
                    column.getHeaderValue(), false, false, -1, col);
            width = c.getPreferredSize().width + 5;
        }

        return width;
    }
}

Related

1. adjustColumnSizes(JTable table, int column, int margin)
2. autoSizeCols(JTable table)
3. autoSizeTableColumns(JTable table)
4. calcColumnWidths(final JTable table)
5. calcColumnWidths(final JTable table)
6. calcColumnWidths(JTable table)
7. calcColumnWidths(JTable table)