Automatically adjust Jtable Column to fit content

Question

I am trying to match the JTable column width depending on the data inside. My Code:

    for(int column = 0; column < gui.testsuiteInfoTable.getColumnCount(); column ++){
        int  width =0;
    for (int row = 0; row < gui.testsuiteInfoTable.getRowCount(); row++) {
         TableCellRenderer renderer = gui.testsuiteInfoTable.getCellRenderer(row, column);
         Component comp = gui.testsuiteInfoTable.prepareRenderer(renderer, row, column);
         width = Math.max (comp.getPreferredSize().width, width);
         System.out.println(width);
     }
    TableColumn col = new TableColumn();
    col = gui.testsuiteInfoTable.getColumnModel().getColumn(column);
    System.out.println(width);
    col.setWidth(width);
    gui.testsuiteInfoTable.revalidate();

    }
}

The sizes are correct I guess but the table columns still all have the same width! The table is embedded in a ScrollPane in a GridBagLayout is that the problem? Thanks for any suggestions.

Answer 1

This is all you need:

JTable table = new JTable(){
    @Override
       public Component prepareRenderer(TableCellRenderer renderer, int row, int column) {
           Component component = super.prepareRenderer(renderer, row, column);
           int rendererWidth = component.getPreferredSize().width;
           TableColumn tableColumn = getColumnModel().getColumn(column);
           tableColumn.setPreferredWidth(Math.max(rendererWidth + getIntercellSpacing().width, tableColumn.getPreferredWidth()));
           return component;
        }
    };
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

The table will adjust each column width automatically to fit the content. There's no need to control when to trigger the resizing.

Answer 2

col.setWidth(width);

Read the JTable API and follow the link on How to Use Tables. In that tutorial they use the setPreferredWidth(...) to suggest a width for a column.

You may also want to check out the Table Column Adjuster which does this for you. This solution can also take into account the width of the column header.

Answer 3

If you can use an extra library, try Swingx (https://java.net/projects/swingx) There you have a JXTable, with a method "packAll()", that does exactly what you are asking for