public class ViewContentProvider implements IStructuredContentProvider {

    private List<Project> projects = new ArrayList<Project>();

    private void addProject(Project project) {
        if (!projects.contains(project)) {
            projects.add(project);
        }
    }

    public void addProjects(List<Project> projects) {
        for (Project project : projects) {
            addProject(project);
        }
    }

    @Override
    public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {

    }

    @Override
    public void dispose() {

    }

    @Override
    public Object[] getElements(Object parent) {
        return projects.toArray();
    }
}