How can we get the selected rows in a ProblemView in Eclipse?

Question

In our eclipse plugin we are using a problem view extending ProblemView. One of the action attached to the rows in the view is properties. When user clicking on this action she/he should see the information about the problem. The problem is that the objects showed in ProblemView are of a type which has considered to be use in eclipse internally: org.eclipse.ui.views.markers.internal.ProblemMarker and using it will cause a warning:

Discouraged access: The type ProblemMarker is not accessible due to restriction on required library org.eclipse.ui.ide_3.7.0.v20110809-1737.jar

Anybody knows how we can take the rows in ProblemView as IMarker or something like that without getting this warning?

The code I want to replace is here:

    Object obj = getStructuredSelection().getFirstElement();
    if (!(obj instanceof ProblemMarker)) {
        return;
    }
    ProblemMarker marker = (ProblemMarker) obj;
    TrayDialog dialog = new TrayDialog(this.part.getSite().getShell(), 
            Messages.propertiesTitle);
    dialog.setMarker(marker.getMarker());
    dialog.open();