JTable -> Custom Cell Renderer -> JTextArea

[Ravi Sathish]

Hi Ranchers,

I have a JTable; Need a JTextArea renderer in one of the columns; But TextArea is not completely visible. How to get the scrollbars with in the table cell?

Here's what I'm doing right now:

While constructing table:

 
//check if column is 3
if(c==3)
            {
            column.setCellRenderer(new TextAreaTableCellRenderer());
            column.setPreferredWidth(300) ;
            }
setRowHeight(24); 
 
// In my TextAreaTableCellRenderer()
setText(value.toString());
setTextLineWrap(true);
setAutoscrolls(true);

I would appreciate any suggestions, work-arounds , code-samples to resolve this issue?

TIA
Ravi

[qunfeng wang]

Hi,Ravi.
I'm intrested in your cellrender.Do you use it due to multiline table?Once I implement a cellrender like you.But it looks not very nice in JDK1.4.Can you share your cellrender with me?If anyone can add a scrollbar,that's better.I guess your render just render the TextArea.Maybe you need a render can render scrollbar too.

[Craig Wood]

import java.awt.*;
import java.util.EventObject;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
 
public class RendererTest
{
    public RendererTest()
    {
        JTable table = getTable();
        TableColumnModel colModel = table.getColumnModel();
        TableColumn col = colModel.getColumn(1);
        col.setCellRenderer(new CustomRenderer());
        col.setCellEditor(new CustomEditor());
        table.setRowHeight(50);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new JScrollPane(table));
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
 
    private JTable getTable()
    {
        String[] tournies = {
            "tournament 1\ntournament 2\n", "tournament 1\n",
            "tournament 1\ntounrament 2\ntournament 3\ntournament 4\n",
            "tournament 1\ntounrament 2\ntournament 3\ntournament 4\n" +
            "tournament 5\ntounrament 6\ntournament 7\ntournament 8\n" +
            "tournament 9\ntounrament 10\ntournament 11\ntournament 12\n"
        };
        String[] colNames = { "city", "tournaments", "sea" };
        Object[][] data = {
            { "San Diego", tournies[0], "Pacific" },
            { "Cape Cod",  tournies[1], "Atlantic" },
            { "Sarasota",  tournies[2], "Gulf" },
            { "Seattle",   tournies[3], "Pacific" }
        };
        DefaultTableModel model = new DefaultTableModel(data, colNames);
        return new JTable(model);
    }
 
    public static void main(String[] args)
    {
        new RendererTest();
    }
}
 
class CustomRenderer implements TableCellRenderer
{
    JScrollPane scrollPane;
    JTextArea textArea;
 
    public CustomRenderer()
    {
        textArea = new JTextArea();
        scrollPane = new JScrollPane(textArea);
    }
 
    public Component getTableCellRendererComponent(JTable table,
                                                   Object value,
                                                   boolean isSelected,
                                                   boolean hasFocus,
                                                   int row, int column)
    {
        textArea.setText((String)value);
        return scrollPane;
    }
}
 
class CustomEditor implements TableCellEditor
{
    JTextArea textArea;
    JScrollPane scrollPane;
 
    public CustomEditor()
    {
        textArea = new JTextArea();
        scrollPane = new JScrollPane(textArea);
    }
 
    public Component getTableCellEditorComponent(JTable table,
                                                 Object value,
                                                 boolean isSelected,
                                                 int row, int column)
    {
        textArea.setText((String)value);
        return scrollPane;
    }
 
    public void addCellEditorListener(CellEditorListener l) { }
    public void cancelCellEditing() { }
    public Object getCellEditorValue()
    {
        return textArea.getText();
    }
    public boolean isCellEditable(EventObject anEvent)
    {
        return true;
    }
    public void removeCellEditorListener(CellEditorListener l) { }
    public boolean shouldSelectCell(EventObject anEvent)
    {
        return true;
    }
    public boolean stopCellEditing()
    {
        return true;
    }
}

[Ravi Sathish]

Thanks Craig,

Now scrollPane is visible but I can't do scrollable operations on it. Do I need a mouseListener here? I'm guessing I missing something here... Please let me know if you ever experienced a problem like this.

Ravi

[Scott Delap]

Putting a scroll pane type component in a JTable is difficult at best. The reason for this is that JTable doesn't contain components. It creates an image using the renderer for each cell and paints that. There is no component behind each cell. As a result you can't add a mouse listener to your renderer. The JTable uses the renderer to derive the image to use for the cell and then throws it away.

When a cell is clicked and goes into editing mode, the table then creates an actual component based on the corresponding editor that is mapped to it. This component has its bounds/location defined as the area the cell renderer derived image previously occupied.

Relating this to your problem, you could have a cell renderer that uses a JTextArea and editor that uses a JTextArea. However, the first click the user makes won't scroll. It will trigger editing mode. You can hack around this but it isn't pretty.

I would suggest using a JTextfield renderer that displays text as "Text..." or something. When going into editing mode you can have a popup show up that contains your JTextArea.

[Ravi Sathish]

Thanks Scott,

Neat Idea; TextField with a pop-up JTextArea... I'll work on it and let you know the results

Regards
Ravi