JFace TableViewer: Make cell background-color blink

Question

I am currently working on a Eclipse RCP application that displays multiple TableViewers containing editable cells. Those cells are connected via EMF databinding to my model.

Now I want the cell after editing it to blink green, meaning to set the background-color to green and then fade out. To make it easier getting started, I want to set the cell-background-color to green and then back to white after 1 second.

What of cause works is to set the background-color to green, but I can't get it to set back to white after one second since the ViewerCell that I am editing is automatically set to null by then, and I don't know why.

Here's a code extract (that does not work) from my CellLabelProvider:

@Override
public void update(final ViewerCell cell) {
     //this works:
     cell.setBackground(new Color(Display.getCurrent(), 0, 255, 0));        
     Display.getCurrent().timerExec(1000, new Runnable() {
          public void run() {
                //for this I get a NullPointerException:
                cell.setBackground(new Color(Display.getCurrent(), 255, 255, 255));
          }
     });
}

Any help would be much appreciated!

Answer 1

There was a bug associated with the fix that sets ViewerRow to null in ViewerCell https://bugs.eclipse.org/bugs/show_bug.cgi?id=201280

To fix the issue that you have, you should not use ViewerCell.

Try this code

col.setLabelProvider(new ColumnLabelProvider() {
          @Override
          public void update(final ViewerCell cell) {
               cell.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_DARK_GREEN)); 
               final int index = cell.getColumnIndex();
               final TableItem item = (TableItem) cell.getItem();
               Display.getCurrent().timerExec(1000, new Runnable() {
                    public void run() {
                      //make sure table is not disposed
                      item.setBackground(index, Display.getDefault().getSystemColor(SWT.COLOR_WHITE));
                    }
               });
          }
        });