// Get the set of model ids selected

			Set selectedModels;

			selectedModels = getSelectedModelIds(true);

	 * Return a set of currently selected model ids

	 * @param nullIfAll Affects what will be returned if all are selected,

	 *            i.e. if true and all are selected then this will return <code>null</code>.

	 * @return A set of identifiers for the currently selected models, or <code>null</code>

	 *            if all are selected and <code>nullIfAll</code> is <code>true</code>. 

	 */

	private Set getSelectedModelIds(boolean nullIfAll) {

		Object[] itemsCheckedInList = fPluginListViewer.getCheckedElements();

		IPluginModelBase[] allModels = getCurrentModels();

		boolean allSelected = (itemsCheckedInList.length == allModels.length);

		if (nullIfAll && allSelected) {

			// All items are selected - no need to do any magic, just return null

			return null;

		}

		Set selectedModels;

		// Build a set containing the ids of the selected plugin/bundle/fragments

		selectedModels = new HashSet();

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

			Object item = itemsCheckedInList[i];

			if (item instanceof IPluginModel) {

				IPluginModel pluginModel = (IPluginModel) item;

				String id = pluginModel.getPluginBase().getId();

				selectedModels.add(id);

			} else if (item instanceof IFragmentModel) {

				IFragmentModel fragmentModel = (IFragmentModel) item;

				String id = fragmentModel.getPluginBase().getId();

				selectedModels.add(id);

			}

		}

		return selectedModels;

	}

	/**

	 * Restore the selection to the specified set of models.

	 * @param selectedModels Set of plugin/bundle identifiers

	 * @return true if the selection occurred, false if it didn't

	 */

	private boolean handleRestoreSelection(Set selectedModels) {

		boolean restoredSelection = false;

		if (selectedModels != null) {

			int numSelected = 0;

			IPluginModelBase[] allModels = getCurrentModels();

			// There are two ways of dealing with the checking of the UI widgets:

			//  (1) un-check them all and selectively check individual ones

			//  (1) check them all and selectively un-check individual ones

			// The method chosen depends on the ratio of selectedModels to allModels.

			// This method cannot be guaranteed to be accurate since the set of plugins

			// between two targets may be completely different, but it's going to give a

			// reasonable guess.

			boolean checkingMethod = true;

			if (selectedModels.size() > (allModels.length / 2)) {

				// more than half the number of models to be selected than

				// models we have in total, so selectively un-check

				checkingMethod = false;

			}

			fPluginListViewer.setAllChecked(!checkingMethod);

			fPluginTreeViewer.setAllChecked(!checkingMethod);

			restoredSelection = true;

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

				IPluginModelBase model = allModels[i];

				String id = model.getPluginBase().getId();

				boolean selected = selectedModels.contains(id);

				if (selected) {

					numSelected++;

					if (checkingMethod) {

						fPluginListViewer.setChecked(model, true);

						fPluginTreeViewer.setChecked(model, true);

					}

				} else if (!checkingMethod) {

					fPluginListViewer.setChecked(model, false);

					fPluginTreeViewer.setChecked(model, false);

				}

				if (model.isEnabled() != selected) {

					fChangedModels.add(model);

				} else if (fChangedModels.contains(model) && model.isEnabled() == selected) {

					fChangedModels.remove(model);

				}

			}

			// Handle grey-ness in table

			Set parents = fTreeViewerContents.keySet();

			Iterator parentIter = parents.iterator();

			while (parentIter.hasNext()) {

				File parent = (File) parentIter.next();

				handleGrayChecked(parent, true);

			}

			setCounter(numSelected);

		}

		return restoredSelection;

	}

	/**