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Archive for August, 2008

Auto Resize JTable Column Width

without comments

This code should resize your JTable column width based on the contents of the header and data.

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    public JTable autoResizeColWidth(JTable table, DefaultTableModel model) {
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        table.setModel(model);
 
        int margin = 5;
 
        for (int i = 0; i < table.getColumnCount(); i++) {
            int                     vColIndex = i;
            DefaultTableColumnModel colModel  = (DefaultTableColumnModel) table.getColumnModel();
            TableColumn             col       = colModel.getColumn(vColIndex);
            int                     width     = 0;
 
            // Get width of column header
            TableCellRenderer renderer = col.getHeaderRenderer();
 
            if (renderer == null) {
                renderer = table.getTableHeader().getDefaultRenderer();
            }
 
            Component comp = renderer.getTableCellRendererComponent(table, col.getHeaderValue(), false, false, 0, 0);
 
            width = comp.getPreferredSize().width;
 
            // Get maximum width of column data
            for (int r = 0; r < table.getRowCount(); r++) {
                renderer = table.getCellRenderer(r, vColIndex);
                comp     = renderer.getTableCellRendererComponent(table, table.getValueAt(r, vColIndex), false, false,
                        r, vColIndex);
                width = Math.max(width, comp.getPreferredSize().width);
            }
 
            // Add margin
            width += 2 * margin;
 
            // Set the width
            col.setPreferredWidth(width);
        }
 
        ((DefaultTableCellRenderer) table.getTableHeader().getDefaultRenderer()).setHorizontalAlignment(
            SwingConstants.LEFT);
 
        // table.setAutoCreateRowSorter(true);
        table.getTableHeader().setReorderingAllowed(false);
 
        for (int i = 0; i < table.getColumnCount(); i++) {
            TableColumn column = table.getColumnModel().getColumn(i);
 
            column.setCellRenderer(new DefaultTableColour());
        }
 
        return table;
    }

Example:

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// Must pass the model
DefaultTableModel model = new DefaultTableModel();
jTable = autoResizeColWidth(jTable, model);

Tested on JRE v5 and JRE v6

Written by mree

August 13th, 2008 at 2:49 pm

Posted in programming