Multiline TreeTable View

Question

Hi,
i implemented a renderer from Jtree and one from JTextArea for the 2 columns of my JTable. My table model is a actually a tree structure with the nodes having a set of key and values. The JTree is use to display the keys in a tree structure and the JTextArea for the values for the coressoinding tree node. Here'e the codes...
public class TreeTableCellRenderer extends JTree implements TableCellRenderer {
     protected int visibleRow;
     public TreeTableCellRenderer(TreeModel model) {
     super(model);
     public void setBounds(int x, int y, int w, int h) {
     super.setBounds(x, 0, w, 16);
     public void paintComponent(Graphics g) {
     g.translate(0, -visibleRow * JTreeTable.this.getRowHeight());
     super.paintComponent(g);
     public Component getTableCellRendererComponent(JTable table,
                              Object value,
                              boolean isSelected,
                              boolean hasFocus,
                              int row, int column) {
     if(isSelected) {
               setBackground(table.getSelectionBackground());
     } else {
               setBackground(table.getBackground());
     visibleRow = row;
     return this;
public class TextAreaCellRenderer extends JTextArea implements TableCellRenderer {
     public TextAreaCellRenderer() {
          super();
          setWrapStyleWord(true);
          setLineWrap(true);
          setOpaque(true);
     public Component getTableCellRendererComponent(JTable table,
                                   Object value,
                                   boolean isSelected,
                                   boolean hasFocus,
                                   int row, int column) {
          if(isSelected) {
               setBackground(table.getSelectionBackground());
          } else {
               setBackground(table.getBackground());
          setText(value.toString());          
          int l = getLineCount();
          Dimension d = new Dimension(table.getWidth(), table.getRowHeight()*l);
          setPreferredSize(d);
          return this;
The problem is whent the values spans more than one line. The table row height does not adjust to show all the values.
Please help

Answer 1

You're retrieving the table's width; this is probably all right if
you only have one column. If you have more than one column, you'd
need to do something like
int columnWidth = table.getColumnModel().getColumn( columnNumber ).getWidth();to determine how much width you have available.
In adjusting the height, you'll need to determine how many lines are
needed for the width you have. This is not necessarily the same as
the line count, as that doesn't take into account any lines which have
wrapped. That is, a wrapped line only counts one towards the line count,
but it will count two or more towards the number of lines it takes to
display.
So for each line, you'll need to get the width of the line and
determine how many will fit in the width, something like
    String lineText = ... ;
    FontMetrics f = table.getFontMetrics( table.getFont() );
    int lineWidth = f.stringWidth( lineText );
    int lineRows = lineWidth / columnWidth + 1;
    totalRows += lineRows;There's a couple different ways to get the text for the line. Once you
have the total number of rows, then the height is simply
    int defaultHeight = getRowHeight();
    int currentHeight = getRowHeight( row );
    int neededHeight = 0;
    if ( totalRows <= 1 )
        neededHeight = defaultHeight;
    else
        neededHeight = numRows * defaultHeight;
    if ( currentHeight != neededHeight )
        setRowHeight( row, neededHeight );One caveat: you might not want to adjust the height directly in the
getTableCellRenderer method if you allow the columns to be resized
via their header.
Hope this helps.
: jay