Re: setCellRenderer for s

From:

"Bart Cremers" <bart.cremers@THRWHITE.remove-dii-this>

Newsgroups:

comp.lang.java.gui

Date:

Wed, 27 Apr 2011 15:26:39 GMT

Message-ID:

<1164973743.688072.246160@l12g2000cwl.googlegroups.com>

To: comp.lang.java.gui

terpatwork@hotmail.com wrote:

Hi,
I'm working on JTable ->HTML Table representations and I'm trying to
figure out how to set a CellRenderer for a specific cell, rather than
for the entire column.
For example, JTable.setDefaultRenderer(ImageIcon.class, new
MyImageIconRenderer()) will work if I want the entire column to be
rendered using that renderer, but is there a way that I can specify a
cell renderer for a specific cell as opposed to the entire column?

The idea is when some body creates an HTML table, the data isn't always
of the same type in a certain column, so I'd like to be able to grab
the class of a specific cell, then render it using the renderer I've
created for that class.

If anything else is needed to make my question more clear, feel free to
ask!

Thanks in advance

This is easily solved by creating a renderer which delegate work to
other renderers based on the class of the passed value.

Here's some code doing exactyle this:

/*
* Author: Bart Cremers
* Date: 1-dec-2006
* Time: 12:26:24
*/
package quick;

import javax.swing.table.TableCellRenderer;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.*;
import java.awt.*;
import java.util.Map;
import java.util.HashMap;
import java.util.Date;

public class MultiRenderer implements TableCellRenderer {
    private TableCellRenderer defaultRenderer = new
DefaultTableCellRenderer();

    private Map<Class, TableCellRenderer> registeredRenderers = new
HashMap<Class, TableCellRenderer>();

    public Component getTableCellRendererComponent(JTable table, Object
value, boolean isSelected, boolean hasFocus,
                                                   int row, int column)
{
        TableCellRenderer delegate = null;
        if (value != null) {
            delegate = getDelegate(value.getClass());
        }

        if (delegate == null) {
            delegate = defaultRenderer;
        }

        return delegate.getTableCellRendererComponent(table, value,
isSelected, hasFocus, row, column);
    }

    public void registerRenderer(Class type, TableCellRenderer
renderer) {
        registeredRenderers.put(type, renderer);
    }

    private TableCellRenderer getDelegate(Class type) {
        TableCellRenderer delegate = null;
        while (type != null && delegate == null) {
            delegate = registeredRenderers.get(type);
            type = type.getSuperclass();
        }
        return delegate;
    }

    /* Sample code */
    private static final Object[] colNames = new Object[] {
        "A", "B", "C"
    };
    private static final Object[][] rowData = new Object[][] {
        new Object[] { 1, "Test", null },
        new Object[] { 2, 20, "Foo" },
        new Object[] { 3, 10, 10 },
        new Object[] { 4, true, false },
        new Object[] { 5, false, "Bar" },
        new Object[] { 6, new Date(), true },
        new Object[] { 7, 10, new Date() },
    };

    public static void main(String[] args) {
        JFrame f = new JFrame();

        JTable table = new JTable(rowData, colNames);

        MultiRenderer multiRenderer = new MultiRenderer();
        multiRenderer.registerRenderer(Boolean.class,
table.getDefaultRenderer(Boolean.class));
        multiRenderer.registerRenderer(Date.class,
table.getDefaultRenderer(Date.class));
        multiRenderer.registerRenderer(Number.class,
table.getDefaultRenderer(Number.class));

table.getColumnModel().getColumn(1).setCellRenderer(multiRenderer);

table.getColumnModel().getColumn(2).setCellRenderer(multiRenderer);

        f.add(new JScrollPane(table), BorderLayout.CENTER);

        f.pack();
        f.setLocationRelativeTo(null);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
    /* End sample code */
}

Regards,

Bart

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