import org.eclipse.jface.dialogs.*;

	private static final String DIALOG_SETTINGS = "org.eclipse.pde.internal.ui.search.PluginSearchPage"; //$NON-NLS-1$

	private static final String PREVIOUS_QUERIES_SETTINGS_KEY = "previousQueries"; //$NON-NLS-1$

		protected static final String SEPARATOR = "\n"; //$NON-NLS-1$

		/**

		 * Returns the ordered fields of the object separated by newlines.

		 * Newlines were chosen because the query text can not contain newlines

		 * which means it is a safe character to split by.

		 * 

		 * The names of selected working sets are added after the normal properties.

		 */

		public String toString() {

			StringBuilder out = new StringBuilder();

			out.append(text);

			out.append(SEPARATOR);

			out.append(isCaseSensitive);

			out.append(SEPARATOR);

			out.append(searchElement);

			out.append(SEPARATOR);

			out.append(limit);

			out.append(SEPARATOR);

			out.append(externalScope);

			out.append(SEPARATOR);

			out.append(workspaceScope);

			// add working sets to the end if there is any

			if (workingSets != null) {

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

					out.append(SEPARATOR);

					out.append(workingSets[i].getName());

				}

			}

			return out.toString();

		}

		/**

		 * Reads the string representation of the fields created

		 * by the toString method.

		 * @param data

		 * @returns the success status of the read. false if the data was invalid.

		 */

		public boolean readString(String data) {

			String[] parts = data.split(SEPARATOR);

			if (parts.length < 6) {

				return false;

			}

			text = parts[0];

			isCaseSensitive = Boolean.parseBoolean(parts[1]);

			searchElement = Integer.parseInt(parts[2]);

			limit = Integer.parseInt(parts[3]);

			externalScope = Integer.parseInt(parts[4]);

			workspaceScope = Integer.parseInt(parts[5]);

			// if there are more than 6 they are selected working sets

			// look them up by name and add them to the array

			if (parts.length > 6) {

				IWorkingSetManager manager = PlatformUI.getWorkbench().getWorkingSetManager();

				workingSets = new IWorkingSet[parts.length - 6];

				// offset i by six to start after normal properties

				for (int i = 6; i < parts.length; i++) {

					IWorkingSet set = manager.getWorkingSet(parts[i]);

					if (set != null) {

						workingSets[i - 6] = set;

					}

				}

			}

			return true;

		}

		restorePreviousQueries(); // load from dialog settings

		// Save the queries array to persistent storage

		savePreviousQueries();

	/**

	 * Saves the previousQueries array to IDialogSettings.

	 * Serializes the QueryData objects into an array of strings.

	 */

	private void savePreviousQueries() {

		IDialogSettings settings = getDialogSettings();

		String[] items = new String[previousQueries.size()];

		// build up the items array by serializing each query

		for (int i = 0; i < previousQueries.size(); i++) {

			QueryData item = (QueryData) previousQueries.get(i);

			items[i] = item.toString();

		}

		settings.put(PREVIOUS_QUERIES_SETTINGS_KEY, items);

	}

	/**

	 * Restores the dialog from IDialogSettings.

	 * Destroys the previousQueries array and rebuilds it from persistent storage.

	 */

	private void restorePreviousQueries() {

		IDialogSettings settings = getDialogSettings();

		String[] items = settings.getArray(PREVIOUS_QUERIES_SETTINGS_KEY);

		if (items == null) {

			return; // no previous data to load

		}

		previousQueries.clear();

		// build up the previousQueries array by serializing each query

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

			String itemdata = items[i];

			QueryData newData = new QueryData();

			boolean success = newData.readString(itemdata);

			if (success)

				previousQueries.add(newData);

		}

	}

	protected IDialogSettings getDialogSettings() {

		IDialogSettings settings = PDEPlugin.getDefault().getDialogSettings().getSection(DIALOG_SETTINGS);

		if (settings == null) {

			settings = PDEPlugin.getDefault().getDialogSettings().addNewSection(DIALOG_SETTINGS);

		}

		return settings;

	}