JTable - multiple lines in a cell AND cells not editable?

[Olya Smith]

Hi all,

I have a bit of a problem.

I'm using JTable for displaying a calendar.

It is important that more than 1 line is displayed in a cell. To do this, I wrote class MultiLineCellRenderer that extends JTextArea and implements TableCellRenderer (solution I found on the Internet).

Then I realised that the cells should not be editable. For this, I wrote class MyTableModel that extends AbstractTableModel (again, solution from the Internet).

So I apllied both to the table, like this:

table.setModel(new MyTableModel(data, columnNames));
table.setDefaultRenderer(String.class, new MultiLineCellRenderer());

The problem: It looks like I can use either one or the other. If I use the renderer for my table, multiple lines are shown in cells, but the cells are editable. If I use the table model, or both, then the cells are not editable, but only 1 line is displayed in each cell :-/

Any suggestions? Can the renderer and the table model be used together?

Thanks in advance!

[Paul Clapham]

You didn't say whether your TableModel overrides the isCellEditable() method.

[Olya Smith]

Paul Clapham wrote:You didn't say whether your TableModel overrides the isCellEditable() method.

Sorry - yes, it does, and it returns false for all cells.

[Paul Clapham]

Okay. Then I would have the cell renderer call setEditable(false) on the JTextArea which it wraps.

[Rob Camick]

Can the renderer and the table model be used together?

Yes.

For this, I wrote class MyTableModel that extends AbstractTableModel (again, solution from the Internet).

There is no need to create a new TableModel for this. You can extend the DefaultTableModel and override the isCellEditable(...) method. Or you can extend JTable and do the same.

table.setModel(new MyTableModel(data, columnNames)); 
table.setDefaultRenderer(String.class, new MultiLineCellRenderer()); 

Did you also override the getColumnClass() method of the TableModel? The default is to return Object, so your renderer would never be used.

If you need more help then post your SSCCE that demonstrates the problem because we can't keep guessing what you custom code may or may not look like.

[Olya Smith]

Paul Clapham wrote:Okay. Then I would have the cell renderer call setEditable(false) on the JTextArea which it wraps.

I called setEditable(false) in the renderer. Not sure if I've put it in the right place. Will post my code in the next comment.

[Olya Smith]

Ok, here is my code (sorry I thought the answer to my question might be trivial, so didn't post the code in the first place):

class MyTableModel extends AbstractTableModel{
private String[][] data;
private String[] columnNames;
	public MyTableModel(String[][] d, String[] cn) {
		data = d;
		columnNames = cn;
	}
	public boolean isCellEditable(int row, int col) {
		return false;
	}

    public Object getValueAt(int row, int col) {
        return data[row][col];
    }

    public int getColumnCount() {
        return columnNames.length;
    }

    public int getRowCount() {
        return data.length;
    }

    public String getColumnName(int col) {
        return columnNames[col];
    }
}

class MultiLineCellRenderer extends JTextArea implements TableCellRenderer {

	public MultiLineCellRenderer() {
    	setLineWrap(true);
    	setWrapStyleWord(true);
    	setOpaque(true);
    	setEditable(false); //this line doesn't seem to be doing anything
  	}

	public Component getTableCellRendererComponent(JTable table, Object value,
		boolean isSelected, boolean hasFocus, int row, int column) {
		if (isSelected) {
		 	setForeground(table.getSelectionForeground());
			setBackground(table.getSelectionBackground());
		}
		else {
		  	setForeground(table.getForeground());
		  	setBackground(table.getBackground());
		}
		setFont(table.getFont());
		if (hasFocus) {
		  	setBorder(UIManager.getBorder("Table.focusCellHighlightBorder"));
		  	if (table.isCellEditable(row, column)) {
		    	setForeground(UIManager.getColor("Table.focusCellForeground"));
		    	setBackground(UIManager.getColor("Table.focusCellBackground"));
		  	}
		}
		else {
		  	setBorder(new EmptyBorder(1, 2, 1, 2));
		}
		setText((value == null) ? "" : value.toString());
		setEditable(false); //this line doesn't seem to be doing anything
		return this;
	}
}

[Rob Spoor]

Please UseCodeTags next time; I've added them for you this time.

Rob C was right. You specified the renderer for String.class, but your table model says the column's class is Object.class.

[Olya Smith]

Rob Prime wrote:Please UseCodeTags next time; I've added them for you this time.

Rob C was right. You specified the renderer for String.class, but your table model says the column's class is Object.class.

Wow! It works!

I changed

table.setDefaultRenderer(String.class, new MultiLineCellRenderer());

to

table.setDefaultRenderer(Object.class, new MultiLineCellRenderer());

and it works now!

Thank you guys very much!

P.S.
will use tags next time, thanks.

[Olya Smith]

Rob Camick wrote:

Did you also override the getColumnClass() method of the TableModel? The default is to return Object, so your renderer would never be used.

You were right - that was the problem! Thank you for your help.

[Anika Islam]

Thank you so much...I am so much grateful to you.

[Campbell Ritchie]

AI: welcome to the Ranch

This shows how useful old threads can sometimes be.