org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/tasks/ui/wizards/AbstractTaskRepositoryPage.java - mylyn/org.eclipse.mylyn.tasks - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2013 David Green and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
  * https://www.eclipse.org/legal/epl-2.0
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     David Green - initial API and implementation
  *     Tasktop Technologies - improvements
  *     Helen Bershadskaya - improvements for bug 242445
  *******************************************************************************/

 package org.eclipse.mylyn.tasks.ui.wizards;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.MultiStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.dialogs.IMessageProvider;
 import org.eclipse.jface.layout.GridDataFactory;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.util.SafeRunnable;
 import org.eclipse.jface.wizard.WizardPage;
 import org.eclipse.mylyn.commons.core.StatusHandler;
 import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
 import org.eclipse.mylyn.internal.tasks.ui.wizards.Messages;
 import org.eclipse.mylyn.tasks.core.TaskRepository;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.ui.forms.events.ExpansionAdapter;
 import org.eclipse.ui.forms.events.ExpansionEvent;
 import org.eclipse.ui.forms.widgets.ExpandableComposite;
 import org.eclipse.ui.forms.widgets.FormToolkit;

 /**
  * An abstract base class for repository settings page that supports the <code>taskRepositoryPageContribution</code>
  * extension point. {@link ITaskRepositoryPage} implementations are encouraged to extend
  * {@link AbstractRepositorySettingsPage} if possible as it provides a standard UI for managing server settings.
  *
  * @see AbstractRepositorySettingsPage
  * @author David Green
  * @author Steffen Pingel
  * @since 3.1
  */
 public abstract class AbstractTaskRepositoryPage extends WizardPage implements ITaskRepositoryPage {

 	private static final String CLASS = "class"; //$NON-NLS-1$

 	private static final String ID = "id"; //$NON-NLS-1$

 	private static final String KIND = "connectorKind"; //$NON-NLS-1$

 	private static final String TASK_REPOSITORY_PAGE_CONTRIBUTION = "taskRepositoryPageContribution"; //$NON-NLS-1$

 	private static final String TASK_REPOSITORY_PAGE_CONTRIBUTION_EXTENSION = "org.eclipse.mylyn.tasks.ui.taskRepositoryPageContribution"; //$NON-NLS-1$

 	private static final Comparator<AbstractTaskRepositoryPageContribution> CONTRIBUTION_COMPARATOR = new ContributionComparator();

 	private final TaskRepository repository;

 	private final List<AbstractTaskRepositoryPageContribution> contributions;

 	FormToolkit toolkit;

 	private final AbstractTaskRepositoryPageContribution.Listener contributionListener = new AbstractTaskRepositoryPageContribution.Listener() {
 		public void validationRequired(AbstractTaskRepositoryPageContribution contribution) {
 			validatePageSettings();
 		}
 	};

 	/**
 	 * @since 3.1
 	 */
 	public AbstractTaskRepositoryPage(String title, String description, TaskRepository repository) {
 		super(title);
 		this.repository = repository;
 		this.contributions = new ArrayList<AbstractTaskRepositoryPageContribution>();
 		setTitle(title);
 		setDescription(description);
 	}

 	/**
 	 * Get the kind of connector supported by this page.
 	 *
 	 * @return the kind of connector, never null
 	 * @since 3.1
 	 */
 	public abstract String getConnectorKind();

 	@Override
 	public void dispose() {
 		if (toolkit != null) {
 			toolkit.dispose();
 			toolkit = null;
 		}
 		super.dispose();
 	}

 	/**
 	 * Creates the contents of the page. Subclasses may override this method to change where the contributions are
 	 * added.
 	 *
 	 * @since 2.0
 	 */
 	public void createControl(Composite parent) {
 		initializeDialogUnits(parent);
 		toolkit = new FormToolkit(TasksUiPlugin.getDefault().getFormColors(parent.getDisplay()));

 		Composite compositeContainer = new Composite(parent, SWT.NONE);
 		GridLayout layout = new GridLayout(3, false);
 		compositeContainer.setLayout(layout);

 //		Composite compositeContainer = new Composite(parent, SWT.NULL);
 //		Layout layout = new FillLayout();
 //		compositeContainer.setLayout(layout);

 		createSettingControls(compositeContainer);
 		createContributionControls(compositeContainer);

 		Dialog.applyDialogFont(compositeContainer);
 		setControl(compositeContainer);
 		//getControl().getShell().pack();
 	}

 	/**
 	 * Creates the controls of this page.
 	 *
 	 * @since 3.1
 	 */
 	protected abstract void createSettingControls(Composite parent);

 	@Override
 	public boolean isPageComplete() {
 		return super.isPageComplete() && conributionsIsPageComplete();
 	}

 	@Override
 	public boolean canFlipToNextPage() {
 		return super.canFlipToNextPage() && contributionsCanFlipToNextPage();
 	}

 	private boolean contributionsCanFlipToNextPage() {
 		for (AbstractTaskRepositoryPageContribution contribution : contributions) {
 			if (!contribution.canFlipToNextPage()) {
 				return false;
 			}
 		}
 		return true;
 	}

 	private boolean conributionsIsPageComplete() {
 		for (AbstractTaskRepositoryPageContribution contribution : contributions) {
 			if (!contribution.isPageComplete()) {
 				return false;
 			}
 		}
 		return true;
 	}

 	/**
 	 * Subclasses should only call this method if they override {@link #createContents(Composite)}.
 	 *
 	 * @param parentControl
 	 *            the container into which the contributions will create their UI
 	 * @since 3.1
 	 */
 	protected void createContributionControls(final Composite parentControl) {
 		contributions.clear();
 		contributions.addAll(findApplicableContributors());

 		if (!contributions.isEmpty()) {
 			final List<AbstractTaskRepositoryPageContribution> badContributions = new ArrayList<AbstractTaskRepositoryPageContribution>();
 			for (final AbstractTaskRepositoryPageContribution contribution : contributions) {
 				SafeRunnable.run(new SafeRunnable() {
 					public void run() throws Exception {
 						contribution.init(getConnectorKind(), repository);
 						contribution.addListener(contributionListener);
 					}

 					@Override
 					public void handleException(Throwable e) {
 						badContributions.add(contribution);
 						StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, NLS.bind(
 								"Problems occured when initializing contribution \"{0}\"", contribution.getId()), e)); //$NON-NLS-1$
 					}
 				});
 			}
 			contributions.removeAll(badContributions);

 			Collections.sort(contributions, CONTRIBUTION_COMPARATOR);

 			for (final AbstractTaskRepositoryPageContribution contribution : contributions) {
 				final ExpandableComposite section = createSection(parentControl, contribution.getTitle());
 				section.setToolTipText(contribution.getDescription());

 				SafeRunnable.run(new SafeRunnable() {
 					public void run() throws Exception {
 						Control control = contribution.createControl(section);
 						section.setClient(control);
 					}

 					@Override
 					public void handleException(Throwable e) {
 						section.dispose();
 						StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, NLS.bind(
 								"Problems occured when creating control for contribution \"{0}\"", //$NON-NLS-1$
 								contribution.getId()), e));
 					}
 				});
 			}
 		}
 	}

 	/**
 	 * @since 3.1
 	 */
 	protected ExpandableComposite createSection(final Composite parentControl, String title) {
 		final ExpandableComposite section = toolkit.createExpandableComposite(parentControl,
 				ExpandableComposite.TWISTIE | ExpandableComposite.CLIENT_INDENT | ExpandableComposite.COMPACT);
 		section.clientVerticalSpacing = 0;
 		section.setBackground(parentControl.getBackground());
 		section.setFont(JFaceResources.getFontRegistry().getBold(JFaceResources.DIALOG_FONT));
 		section.addExpansionListener(new ExpansionAdapter() {
 			@Override
 			public void expansionStateChanged(ExpansionEvent e) {
 				parentControl.layout(true);
 				getControl().getShell().pack();
 			}
 		});
 		section.setText(title);
 		GridDataFactory.fillDefaults().indent(0, 5).grab(true, false).span(3, SWT.DEFAULT).applyTo(section);
 		return section;
 	}

 	/**
 	 * Validate the settings of this page, not including contributions. This method should not be called directly by
 	 * page implementations. Always run on a UI thread.
 	 *
 	 * @return the status, or null if there are no messages.
 	 * @see #validatePageSettings()
 	 * @since 3.1
 	 */
 	protected abstract IStatus validate();

 	/**
 	 * Overriding methods should call <code>super.applyTo(repository)</code>
 	 *
 	 * @since 3.1
 	 */
 	public void applyTo(TaskRepository repository) {
 		applyContributionSettingsTo(repository);
 	}

 	private void applyContributionSettingsTo(TaskRepository repository) {
 		for (AbstractTaskRepositoryPageContribution contribution : contributions) {
 			contribution.applyTo(repository);
 		}
 	}

 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * Invokes {@link #applyTo(TaskRepository)} by default. Client may override.
 	 *
 	 * @since 3.6
 	 */
 	public void performFinish(TaskRepository repository) {
 		applyTo(repository);
 	}

 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * Invokes {@link #applyTo(TaskRepository)} by default. Client may override.
 	 *
 	 * @since 3.7
 	 * @return true to indicate the finish request was accepted, and false to indicate that the finish request was
 	 *         refused
 	 */
 	public boolean preFinish(TaskRepository repository) {
 		return true;
 	}

 	/**
 	 * Returns a status if there is a message to display, otherwise null.
 	 */
 	private IStatus computeValidation() {
 		final MultiStatus cumulativeResult = new MultiStatus(TasksUiPlugin.ID_PLUGIN, IStatus.OK,
 				Messages.AbstractTaskRepositoryPage_Validation_failed, null);

 		// validate the page
 		IStatus result = validate();
 		if (result != null) {
 			cumulativeResult.add(result);
 		}

 		// validate contributions
 		for (final AbstractTaskRepositoryPageContribution contribution : contributions) {
 			SafeRunnable.run(new SafeRunnable() {
 				public void run() throws Exception {
 					IStatus result = contribution.validate();
 					if (result != null) {
 						cumulativeResult.add(result);
 					}
 				}

 				@Override
 				public void handleException(Throwable e) {
 					StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, NLS.bind(
 							"Problems occured when validating contribution \"{0}\"", contribution.getId()), e)); //$NON-NLS-1$
 				}
 			});
 		}

 		return cumulativeResult;
 	}

 	/**
 	 * Validate all settings in the page including contributions. This method should be called whenever a setting is
 	 * changed on the page. The results of validation are applied and the buttons of the page are updated.
 	 *
 	 * @see #validate(IProgressMonitor)
 	 * @see #applyValidationResult(IStatus[])
 	 */
 	private void validatePageSettings() {
 		IStatus validationStatus = computeValidation();
 		applyValidationResult(validationStatus);
 		getWizard().getContainer().updateButtons();
 	}

 	/**
 	 * Apply the results of validation to the page. The implementation finds the most {@link IStatus#getSeverity()
 	 * severe} status and {@link #setMessage(String, int) applies the message} to the page.
 	 *
 	 * @param status
 	 *            the status of the validation, or null
 	 */
 	private void applyValidationResult(IStatus status) {
 		if (status == null || status.isOK()) {
 			setMessage(null, IMessageProvider.INFORMATION);
 			setErrorMessage(null);
 		} else {
 			// find the most severe status
 			int messageType;
 			switch (status.getSeverity()) {
 			case IStatus.OK:
 			case IStatus.INFO:
 				messageType = IMessageProvider.INFORMATION;
 				break;
 			case IStatus.WARNING:
 				messageType = IMessageProvider.WARNING;
 				break;
 			case IStatus.ERROR:
 			default:
 				messageType = IMessageProvider.ERROR;
 				break;
 			}
 			setErrorMessage(null);
 			setMessage(status.getMessage(), messageType);
 		}
 	}

 	private List<AbstractTaskRepositoryPageContribution> findApplicableContributors() {
 		List<AbstractTaskRepositoryPageContribution> contributors = new ArrayList<AbstractTaskRepositoryPageContribution>();

 		IExtensionRegistry registry = Platform.getExtensionRegistry();

 		IExtensionPoint editorExtensionPoint = registry.getExtensionPoint(TASK_REPOSITORY_PAGE_CONTRIBUTION_EXTENSION);
 		IExtension[] editorExtensions = editorExtensionPoint.getExtensions();
 		for (IExtension extension : editorExtensions) {
 			IConfigurationElement[] elements = extension.getConfigurationElements();
 			for (IConfigurationElement element : elements) {
 				if (element.getName().equals(TASK_REPOSITORY_PAGE_CONTRIBUTION)) {
 					String kind = element.getAttribute(KIND);
 					if (kind == null || kind.length() == 0 || kind.equals(getConnectorKind())) {
 						String id = element.getAttribute(ID);
 						try {
 							if (id == null || id.length() == 0) {
 								throw new IllegalStateException(TASK_REPOSITORY_PAGE_CONTRIBUTION + "/@" + ID //$NON-NLS-1$
 										+ " is required"); //$NON-NLS-1$
 							}
 							Object contributor = element.createExecutableExtension(CLASS);
 							AbstractTaskRepositoryPageContribution pageContributor = (AbstractTaskRepositoryPageContribution) contributor;
 							pageContributor.setId(id);
 							if (pageContributor.isEnabled()) {
 								contributors.add(pageContributor);
 							}
 						} catch (Throwable e) {
 							StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Could not load " //$NON-NLS-1$
 									+ TASK_REPOSITORY_PAGE_CONTRIBUTION + " '" + id + "' from plug-in " //$NON-NLS-1$//$NON-NLS-2$
 									+ element.getContributor().getName(), e));
 						}
 					}
 				}
 			}
 		}

 		return contributors;
 	}

 	private static class ContributionComparator implements Comparator<AbstractTaskRepositoryPageContribution> {

 		public int compare(AbstractTaskRepositoryPageContribution o1, AbstractTaskRepositoryPageContribution o2) {
 			if (o1 == o2) {
 				return 0;
 			}
 			String s1 = o1.getTitle();
 			String s2 = o2.getTitle();
 			int i = s1.compareTo(s2);
 			if (i == 0) {
 				i = o1.getId().compareTo(o2.getId());
 			}
 			return i;
 		}

 	}
 }
	/*******************************************************************************
	* Copyright (c) 2004, 2013 David Green and others.
	*
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License v. 2.0 which is available at
	* https://www.eclipse.org/legal/epl-2.0
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* David Green - initial API and implementation
	* Tasktop Technologies - improvements
	* Helen Bershadskaya - improvements for bug 242445
	*******************************************************************************/

	package org.eclipse.mylyn.tasks.ui.wizards;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.List;

	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.IExtensionPoint;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.MultiStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.dialogs.IMessageProvider;
	import org.eclipse.jface.layout.GridDataFactory;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.util.SafeRunnable;
	import org.eclipse.jface.wizard.WizardPage;
	import org.eclipse.mylyn.commons.core.StatusHandler;
	import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
	import org.eclipse.mylyn.internal.tasks.ui.wizards.Messages;
	import org.eclipse.mylyn.tasks.core.TaskRepository;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.ui.forms.events.ExpansionAdapter;
	import org.eclipse.ui.forms.events.ExpansionEvent;
	import org.eclipse.ui.forms.widgets.ExpandableComposite;
	import org.eclipse.ui.forms.widgets.FormToolkit;

	/**
	* An abstract base class for repository settings page that supports the <code>taskRepositoryPageContribution</code>
	* extension point. {@link ITaskRepositoryPage} implementations are encouraged to extend
	* {@link AbstractRepositorySettingsPage} if possible as it provides a standard UI for managing server settings.
	*
	* @see AbstractRepositorySettingsPage
	* @author David Green
	* @author Steffen Pingel
	* @since 3.1
	*/
	public abstract class AbstractTaskRepositoryPage extends WizardPage implements ITaskRepositoryPage {

	private static final String CLASS = "class"; //$NON-NLS-1$

	private static final String ID = "id"; //$NON-NLS-1$

	private static final String KIND = "connectorKind"; //$NON-NLS-1$

	private static final String TASK_REPOSITORY_PAGE_CONTRIBUTION = "taskRepositoryPageContribution"; //$NON-NLS-1$

	private static final String TASK_REPOSITORY_PAGE_CONTRIBUTION_EXTENSION = "org.eclipse.mylyn.tasks.ui.taskRepositoryPageContribution"; //$NON-NLS-1$

	private static final Comparator<AbstractTaskRepositoryPageContribution> CONTRIBUTION_COMPARATOR = new ContributionComparator();

	private final TaskRepository repository;

	private final List<AbstractTaskRepositoryPageContribution> contributions;

	FormToolkit toolkit;

	private final AbstractTaskRepositoryPageContribution.Listener contributionListener = new AbstractTaskRepositoryPageContribution.Listener() {
	public void validationRequired(AbstractTaskRepositoryPageContribution contribution) {
	validatePageSettings();
	}
	};

	/**
	* @since 3.1
	*/
	public AbstractTaskRepositoryPage(String title, String description, TaskRepository repository) {
	super(title);
	this.repository = repository;
	this.contributions = new ArrayList<AbstractTaskRepositoryPageContribution>();
	setTitle(title);
	setDescription(description);
	}

	/**
	* Get the kind of connector supported by this page.
	*
	* @return the kind of connector, never null
	* @since 3.1
	*/
	public abstract String getConnectorKind();

	@Override
	public void dispose() {
	if (toolkit != null) {
	toolkit.dispose();
	toolkit = null;
	}
	super.dispose();
	}

	/**
	* Creates the contents of the page. Subclasses may override this method to change where the contributions are
	* added.
	*
	* @since 2.0
	*/
	public void createControl(Composite parent) {
	initializeDialogUnits(parent);
	toolkit = new FormToolkit(TasksUiPlugin.getDefault().getFormColors(parent.getDisplay()));

	Composite compositeContainer = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout(3, false);
	compositeContainer.setLayout(layout);

	// Composite compositeContainer = new Composite(parent, SWT.NULL);
	// Layout layout = new FillLayout();
	// compositeContainer.setLayout(layout);

	createSettingControls(compositeContainer);
	createContributionControls(compositeContainer);

	Dialog.applyDialogFont(compositeContainer);
	setControl(compositeContainer);
	//getControl().getShell().pack();
	}

	/**
	* Creates the controls of this page.
	*
	* @since 3.1
	*/
	protected abstract void createSettingControls(Composite parent);

	@Override
	public boolean isPageComplete() {
	return super.isPageComplete() && conributionsIsPageComplete();
	}

	@Override
	public boolean canFlipToNextPage() {
	return super.canFlipToNextPage() && contributionsCanFlipToNextPage();
	}

	private boolean contributionsCanFlipToNextPage() {
	for (AbstractTaskRepositoryPageContribution contribution : contributions) {
	if (!contribution.canFlipToNextPage()) {
	return false;
	}
	}
	return true;
	}

	private boolean conributionsIsPageComplete() {
	for (AbstractTaskRepositoryPageContribution contribution : contributions) {
	if (!contribution.isPageComplete()) {
	return false;
	}
	}
	return true;
	}

	/**
	* Subclasses should only call this method if they override {@link #createContents(Composite)}.
	*
	* @param parentControl
	* the container into which the contributions will create their UI
	* @since 3.1
	*/
	protected void createContributionControls(final Composite parentControl) {
	contributions.clear();
	contributions.addAll(findApplicableContributors());

	if (!contributions.isEmpty()) {
	final List<AbstractTaskRepositoryPageContribution> badContributions = new ArrayList<AbstractTaskRepositoryPageContribution>();
	for (final AbstractTaskRepositoryPageContribution contribution : contributions) {
	SafeRunnable.run(new SafeRunnable() {
	public void run() throws Exception {
	contribution.init(getConnectorKind(), repository);
	contribution.addListener(contributionListener);
	}

	@Override
	public void handleException(Throwable e) {
	badContributions.add(contribution);
	StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, NLS.bind(
	"Problems occured when initializing contribution \"{0}\"", contribution.getId()), e)); //$NON-NLS-1$
	}
	});
	}
	contributions.removeAll(badContributions);

	Collections.sort(contributions, CONTRIBUTION_COMPARATOR);

	for (final AbstractTaskRepositoryPageContribution contribution : contributions) {
	final ExpandableComposite section = createSection(parentControl, contribution.getTitle());
	section.setToolTipText(contribution.getDescription());

	SafeRunnable.run(new SafeRunnable() {
	public void run() throws Exception {
	Control control = contribution.createControl(section);
	section.setClient(control);
	}

	@Override
	public void handleException(Throwable e) {
	section.dispose();
	StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, NLS.bind(
	"Problems occured when creating control for contribution \"{0}\"", //$NON-NLS-1$
	contribution.getId()), e));
	}
	});
	}
	}
	}

	/**
	* @since 3.1
	*/
	protected ExpandableComposite createSection(final Composite parentControl, String title) {
	final ExpandableComposite section = toolkit.createExpandableComposite(parentControl,
	ExpandableComposite.TWISTIE \| ExpandableComposite.CLIENT_INDENT \| ExpandableComposite.COMPACT);
	section.clientVerticalSpacing = 0;
	section.setBackground(parentControl.getBackground());
	section.setFont(JFaceResources.getFontRegistry().getBold(JFaceResources.DIALOG_FONT));
	section.addExpansionListener(new ExpansionAdapter() {
	@Override
	public void expansionStateChanged(ExpansionEvent e) {
	parentControl.layout(true);
	getControl().getShell().pack();
	}
	});
	section.setText(title);
	GridDataFactory.fillDefaults().indent(0, 5).grab(true, false).span(3, SWT.DEFAULT).applyTo(section);
	return section;
	}

	/**
	* Validate the settings of this page, not including contributions. This method should not be called directly by
	* page implementations. Always run on a UI thread.
	*
	* @return the status, or null if there are no messages.
	* @see #validatePageSettings()
	* @since 3.1
	*/
	protected abstract IStatus validate();

	/**
	* Overriding methods should call <code>super.applyTo(repository)</code>
	*
	* @since 3.1
	*/
	public void applyTo(TaskRepository repository) {
	applyContributionSettingsTo(repository);
	}

	private void applyContributionSettingsTo(TaskRepository repository) {
	for (AbstractTaskRepositoryPageContribution contribution : contributions) {
	contribution.applyTo(repository);
	}
	}

	/**
	* {@inheritDoc}
	* <p>
	* Invokes {@link #applyTo(TaskRepository)} by default. Client may override.
	*
	* @since 3.6
	*/
	public void performFinish(TaskRepository repository) {
	applyTo(repository);
	}

	/**
	* {@inheritDoc}
	* <p>
	* Invokes {@link #applyTo(TaskRepository)} by default. Client may override.
	*
	* @since 3.7
	* @return true to indicate the finish request was accepted, and false to indicate that the finish request was
	* refused
	*/
	public boolean preFinish(TaskRepository repository) {
	return true;
	}

	/**
	* Returns a status if there is a message to display, otherwise null.
	*/
	private IStatus computeValidation() {
	final MultiStatus cumulativeResult = new MultiStatus(TasksUiPlugin.ID_PLUGIN, IStatus.OK,
	Messages.AbstractTaskRepositoryPage_Validation_failed, null);

	// validate the page
	IStatus result = validate();
	if (result != null) {
	cumulativeResult.add(result);
	}

	// validate contributions
	for (final AbstractTaskRepositoryPageContribution contribution : contributions) {
	SafeRunnable.run(new SafeRunnable() {
	public void run() throws Exception {
	IStatus result = contribution.validate();
	if (result != null) {
	cumulativeResult.add(result);
	}
	}

	@Override
	public void handleException(Throwable e) {
	StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, NLS.bind(
	"Problems occured when validating contribution \"{0}\"", contribution.getId()), e)); //$NON-NLS-1$
	}
	});
	}

	return cumulativeResult;
	}

	/**
	* Validate all settings in the page including contributions. This method should be called whenever a setting is
	* changed on the page. The results of validation are applied and the buttons of the page are updated.
	*
	* @see #validate(IProgressMonitor)
	* @see #applyValidationResult(IStatus[])
	*/
	private void validatePageSettings() {
	IStatus validationStatus = computeValidation();
	applyValidationResult(validationStatus);
	getWizard().getContainer().updateButtons();
	}

	/**
	* Apply the results of validation to the page. The implementation finds the most {@link IStatus#getSeverity()
	* severe} status and {@link #setMessage(String, int) applies the message} to the page.
	*
	* @param status
	* the status of the validation, or null
	*/
	private void applyValidationResult(IStatus status) {
	if (status == null \|\| status.isOK()) {
	setMessage(null, IMessageProvider.INFORMATION);
	setErrorMessage(null);
	} else {
	// find the most severe status
	int messageType;
	switch (status.getSeverity()) {
	case IStatus.OK:
	case IStatus.INFO:
	messageType = IMessageProvider.INFORMATION;
	break;
	case IStatus.WARNING:
	messageType = IMessageProvider.WARNING;
	break;
	case IStatus.ERROR:
	default:
	messageType = IMessageProvider.ERROR;
	break;
	}
	setErrorMessage(null);
	setMessage(status.getMessage(), messageType);
	}
	}

	private List<AbstractTaskRepositoryPageContribution> findApplicableContributors() {
	List<AbstractTaskRepositoryPageContribution> contributors = new ArrayList<AbstractTaskRepositoryPageContribution>();

	IExtensionRegistry registry = Platform.getExtensionRegistry();

	IExtensionPoint editorExtensionPoint = registry.getExtensionPoint(TASK_REPOSITORY_PAGE_CONTRIBUTION_EXTENSION);
	IExtension[] editorExtensions = editorExtensionPoint.getExtensions();
	for (IExtension extension : editorExtensions) {
	IConfigurationElement[] elements = extension.getConfigurationElements();
	for (IConfigurationElement element : elements) {
	if (element.getName().equals(TASK_REPOSITORY_PAGE_CONTRIBUTION)) {
	String kind = element.getAttribute(KIND);
	if (kind == null \|\| kind.length() == 0 \|\| kind.equals(getConnectorKind())) {
	String id = element.getAttribute(ID);
	try {
	if (id == null \|\| id.length() == 0) {
	throw new IllegalStateException(TASK_REPOSITORY_PAGE_CONTRIBUTION + "/@" + ID //$NON-NLS-1$
	+ " is required"); //$NON-NLS-1$
	}
	Object contributor = element.createExecutableExtension(CLASS);
	AbstractTaskRepositoryPageContribution pageContributor = (AbstractTaskRepositoryPageContribution) contributor;
	pageContributor.setId(id);
	if (pageContributor.isEnabled()) {
	contributors.add(pageContributor);
	}
	} catch (Throwable e) {
	StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Could not load " //$NON-NLS-1$
	+ TASK_REPOSITORY_PAGE_CONTRIBUTION + " '" + id + "' from plug-in " //$NON-NLS-1$//$NON-NLS-2$
	+ element.getContributor().getName(), e));
	}
	}
	}
	}
	}

	return contributors;
	}

	private static class ContributionComparator implements Comparator<AbstractTaskRepositoryPageContribution> {

	public int compare(AbstractTaskRepositoryPageContribution o1, AbstractTaskRepositoryPageContribution o2) {
	if (o1 == o2) {
	return 0;
	}
	String s1 = o1.getTitle();
	String s2 = o2.getTitle();
	int i = s1.compareTo(s2);
	if (i == 0) {
	i = o1.getId().compareTo(o2.getId());
	}
	return i;
	}

	}
	}