import org.eclipse.swt.SWT;

import org.eclipse.ui.*;

	 * Return the modal shell that is currently open. If there isn't one then

	 * return null.

	 * 

	 * @param shell

	 *            A shell to exclude from the search. May be <code>null</code>.

	 * 

	 * @return Shell or <code>null</code>.

	 */

	private static Shell getModalShellExcluding(Shell shell) {

		IWorkbench workbench = PlatformUI.getWorkbench();

		Shell[] shells = workbench.getDisplay().getShells();

		int modal = SWT.APPLICATION_MODAL | SWT.SYSTEM_MODAL

				| SWT.PRIMARY_MODAL;

		for (int i = 0; i < shells.length; i++) {

			if (shells[i].equals(shell)) {

				break;

			}

			// Do not worry about shells that will not block the user.

			if (shells[i].isVisible()) {

				int style = shells[i].getStyle();

				if ((style & modal) != 0) {

					return shells[i];

				}

			}

		}

		return null;

	}

	/**

	 * Utility method to get the best parenting possible for a dialog. If there

	 * is a modal shell create it so as to avoid two modal dialogs. If not then

	 * return the shell of the active workbench window. If neither can be found

	 * return null.

	 * 

	 * @return Shell or <code>null</code>

	 */

	private static Shell getDefaultParent() {

		Shell modal = getModalShellExcluding(null);

		if (modal != null) {

			return modal;

		}

		return getNonModalShell();

	}

	/**

	 * Get the active non modal shell. If there isn't one return null.

	 * 

	 * @return Shell

	 */

	private static Shell getNonModalShell() {

		IWorkbenchWindow window = PlatformUI.getWorkbench()

				.getActiveWorkbenchWindow();

		if (window == null) {

			IWorkbenchWindow[] windows = PlatformUI.getWorkbench()

					.getWorkbenchWindows();

			if (windows.length > 0)

				return windows[0].getShell();

		} else

			return window.getShell();

		return null;

	}

	/**