java - JProgressBar setValue is not working, tried with SwingUtilities as well

Question

I have implemented a JProgressBar in a JTable. I used renderer for the ProgressBar NOT EDITOR.

Now I tried to implement a ProgressBar set value but due to EDT its not working so I used SwingUtilties but it did not work as well.

EXPECTED BEHAVIOUR - The JProgressBar must be setting value to 80 , currently it is showing only 0%

public class SkillSetTableProgressBarRenderer extends JProgressBar implements
        TableCellRenderer {

    public SkillSetTableProgressBarRenderer() {
        super(0, 100);
        super.setPreferredSize(new Dimension(100, 80));
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value,
            boolean isSelected, boolean hasFocus, int row, int column) {

        final JProgressBar bar = (JProgressBar) value;

        if (bar.getString().equals("JAVA") || bar.getString().equals("SWING"))
            super.setString("Mellow");
        else
            super.setString("GOOD");

        setOpaque(true);
        table.setOpaque(true);

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                System.err.println("MAIN ANDER");
                setValue(80);
                bar.setValue(80);
            }
        });

        super.setStringPainted(true);
        super.setIndeterminate(true);
        super.setPreferredSize(new Dimension(140, 16));
        if (isSelected) {
            super.setBackground(table.getSelectionBackground());
            super.setForeground(table.getSelectionForeground());
            // this.setBackground(table.getSelectionBackground());
        } else {
            super.setForeground(table.getForeground());
            super.setBackground(Color.WHITE);
        }

        return this;
    }

}

Answer 1

Looks like you're trying to use a ProgressBar as a CellRenderer. One thing you should know, is that CellRenders are only called when a cell is being drawn, and setting values at other moments has no effect: this is because Swing uses a flyweight pattern for renderers, and thus reuses the renderer.

To get the effect you want, you should

• notify the table that the cell is to be updated, for instance by updating its underlying model (that will fire the necessary events), and
• set all values you need before the getTableCellRendererComponent return, so, remove the invokeLater (the getter is called on the EDT, so you don't need to worry about threading there).