/*******************************************************************************
 * Copyright (c) 2008, 2013 Oracle. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0, which accompanies this distribution
 * and is available at https://www.eclipse.org/legal/epl-2.0/.
 *
 * Contributors:
 *     Oracle - initial API and implementation
 ******************************************************************************/
package org.eclipse.jpt.common.ui.internal.widgets;

import java.util.ArrayList;
import java.util.Collection;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.fieldassist.FieldDecorationRegistry;
import org.eclipse.jface.resource.LocalResourceManager;
import org.eclipse.jface.resource.ResourceManager;
import org.eclipse.jface.viewers.ComboViewer;
import org.eclipse.jface.viewers.IBaseLabelProvider;
import org.eclipse.jpt.common.ui.WidgetFactory;
import org.eclipse.jpt.common.ui.internal.WorkbenchTools;
import org.eclipse.jpt.common.ui.internal.plugin.JptCommonUiPlugin;
import org.eclipse.jpt.common.ui.internal.swt.ComboModelAdapter;
import org.eclipse.jpt.common.ui.internal.swt.DateTimeModelAdapter;
import org.eclipse.jpt.common.ui.internal.swt.SpinnerModelAdapter;
import org.eclipse.jpt.common.ui.internal.swt.TriStateCheckBoxModelAdapter;
import org.eclipse.jpt.common.ui.internal.swt.bindings.SWTBindingTools;
import org.eclipse.jpt.common.ui.internal.swt.events.DisposeAdapter;
import org.eclipse.jpt.common.ui.internal.swt.listeners.SWTListenerTools;
import org.eclipse.jpt.common.utility.internal.model.value.CompositeBooleanPropertyValueModel;
import org.eclipse.jpt.common.utility.internal.model.value.NullCheckPropertyValueModelWrapper;
import org.eclipse.jpt.common.utility.internal.model.value.PredicatePropertyValueModel;
import org.eclipse.jpt.common.utility.internal.model.value.SimplePropertyValueModel;
import org.eclipse.jpt.common.utility.internal.model.value.StaticPropertyValueModel;
import org.eclipse.jpt.common.utility.internal.predicate.PredicateTools;
import org.eclipse.jpt.common.utility.internal.transformer.TransformerTools;
import org.eclipse.jpt.common.utility.model.Model;
import org.eclipse.jpt.common.utility.model.event.PropertyChangeEvent;
import org.eclipse.jpt.common.utility.model.listener.PropertyChangeAdapter;
import org.eclipse.jpt.common.utility.model.listener.PropertyChangeListener;
import org.eclipse.jpt.common.utility.model.value.ListValueModel;
import org.eclipse.jpt.common.utility.model.value.ModifiablePropertyValueModel;
import org.eclipse.jpt.common.utility.model.value.PropertyValueModel;
import org.eclipse.jpt.common.utility.transformer.Transformer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.DateTime;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Spinner;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.forms.widgets.ExpandableComposite;
import org.eclipse.ui.forms.widgets.Hyperlink;
import org.eclipse.ui.forms.widgets.Section;
import org.eclipse.ui.part.PageBook;

/**
 * The abstract definition of a pane which holds a {@link PropertyValueModel}
 * that contains the pane's subject.
 * <p>
 * This class contains convenience methods for building buttons, labels, check
 * boxes, radio buttons, etc.
 * <p>
 * It is possible to easily listen to any property changes coming from the
 * subject, {@link #addPropertyNames(Collection)} specifies which properties
 * are of interest and {@link #propertyChanged(String)} is used to notify the
 * pane when the property has changed.
 * 
 * @see DialogPane
 */
@SuppressWarnings("nls")
public abstract class Pane<T extends Model> {
	/**
	 * This will be <code>null</code> for <em>root</em> panes.
	 */
	private final Pane<?> parent;

	/**
	 * The listener registered with the subject in order to be notified when a
	 * property has changed, the property names are determined by
	 * {@link #getPropertyNames()}.
	 */
	private final PropertyChangeListener aspectChangeListener;

	/**
	 * The container of the pane's composite.
	 */
	private final Composite container;

	/**
	 * Flag used to stop the circular population of widgets.
	 */
	private boolean populating;

	/**
	 * This listener is registered with the {@link #subjectModel} in order to
	 * automatically repopulate this pane when the subject changes.
	 */
	private final PropertyChangeListener subjectChangeListener;

	/**
	 * The pane's subject.
	 */
	private final PropertyValueModel<? extends T> subjectModel;

	/**
	 * The widget factory used by the pane and all its descendant panes to
	 * create various common widgets.
	 * This will be <code>null</code> if the pane has a {@link #parent}.
	 */
	private final WidgetFactory widgetFactory;

	/**
	 * The resource manager used by the pane and all its descendant panes to
	 * allocate resources (images, colors, and fonts).
	 * This will be <code>null</code> if the pane has a {@link #parent}.
	 */
	private final ResourceManager resourceManager;

	/**
	 * The AND of the <em>enabled</em> model passed in via the constructor and
	 * the parent pane's <em>enabled</em> model.
	 */
	private final PropertyValueModel<Boolean> enabledModel;
	private final PropertyChangeListener enabledModelListener;

	/**
	 * A listener that allows us to stop listening to stuff when the control
	 * is disposed. (Critical for preventing memory leaks.)
	 */
	private final DisposeListener controlDisposeListener;


	/**
	 * Construct a pane that uses the specified parent pane's:<ul>
	 * <li>subject model
	 * <li><em>enabled</em> model
	 * </ul>
	 */
	protected Pane(
		Pane<? extends T> parent,
		Composite parentComposite
	) {
		this(parent, parent.getSubjectHolder(), parentComposite);
	}

	/**
	 * Construct a pane that uses the specified parent pane's:<ul>
	 * <li><em>enabled</em> model
	 * </ul>
	 */
	protected Pane(
		Pane<?> parent,
		PropertyValueModel<? extends T> subjectModel,
		Composite parentComposite
	) {
		this(parent, subjectModel, buildDefaultEnabledModel(), parentComposite);
	}

	/**
	 * Construct a pane that uses the specified parent pane's:<ul>
	 * <li>subject model
	 * </ul>
	 * The specified <em>enabled</em> model will be ANDed with the parent
	 * pane's <em>enabled</em> model (i.e. the pane can be <em>enabled</em>
	 * only if its parent pane is also <em>enabled</em>).
	 */
	protected Pane(
		Pane<? extends T> parent,
		Composite parentComposite,
		PropertyValueModel<Boolean> enabledModel
	) {
		this(parent, parent.getSubjectHolder(), enabledModel, parentComposite);
	}

	/**
	 * Construct a pane that uses the specified subject model and
	 * <em>enabled</em> model.
	 * <p>
	 * The specified <em>enabled</em> model will be ANDed with the parent
	 * pane's <em>enabled</em> model (i.e. the pane can be <em>enabled</em>
	 * only if its parent pane is also <em>enabled</em>).
	 */
	protected Pane(
		Pane<?> parent,
		PropertyValueModel<? extends T> subjectModel,
		PropertyValueModel<Boolean> enabledModel,
		Composite parentComposite
	) {
		this(parent, subjectModel, enabledModel, parentComposite, null, null);
	}

	/**
	 * Construct a <em>root</em> pane with the specified subject model, widget
	 * factory, and resource manager.
	 * The pane will be <em>disabled</em> whenever the subject is
	 * <code>null</code>.
	 */
	protected Pane(
		PropertyValueModel<? extends T> subjectModel,
		Composite parentComposite,
		WidgetFactory widgetFactory,
		ResourceManager resourceManager
	) {
		this(subjectModel, buildIsNotNullModel(subjectModel), parentComposite, widgetFactory, resourceManager);
	}

	/**
	 * Construct a <em>root</em> pane with the specified subject model,
	 * <em>enabled</em> model, widget factory, and resource manager.
	 * <p>
	 * The specified <em>enabled</em> model will be ANDed with the parent
	 * pane's <em>enabled</em> model (i.e. the pane can be <em>enabled</em>
	 * only if its parent pane is also <em>enabled</em>).
	 */
	protected Pane(
		PropertyValueModel<? extends T> subjectModel,
		PropertyValueModel<Boolean> enabledModel,
		Composite parentComposite,
		WidgetFactory widgetFactory,
		ResourceManager resourceManager
	) {
		this(null, subjectModel, enabledModel, parentComposite, widgetFactory, resourceManager);
	}

	/**
	 * This constructor is <code>private</code> so we can enable, but also
	 * require, <em>root</em> panes (i.e. panes without parents) to specify the
	 * following:<ul>
	 * <li>subject model
	 * <li>widget factory
	 * </ul>
	 */
	private Pane(
		Pane<?> parent,
		PropertyValueModel<? extends T> subjectModel,
		PropertyValueModel<Boolean> enabledModel,
		Composite parentComposite,
		WidgetFactory widgetFactory,
		ResourceManager resourceManager
	) {
		super();
		if ((subjectModel == null) || (enabledModel == null) || (parentComposite == null)) {
			throw new NullPointerException();
		}
		if (parent == null) {
			if ((widgetFactory == null) || (resourceManager == null)) {
				throw new NullPointerException();
			}
		}
		this.parent = parent;
		this.subjectModel = subjectModel;

		this.enabledModel = andEnabledModel(parent, enabledModel);
		this.enabledModelListener = this.buildEnabledModelListener();
		this.enabledModel.addPropertyChangeListener(PropertyValueModel.VALUE, this.enabledModelListener);

		this.widgetFactory = widgetFactory;
		this.resourceManager = (resourceManager == null) ? null : new LocalResourceManager(resourceManager);

		this.aspectChangeListener = this.buildAspectChangeListener();

		this.initialize();

		if (this.addsComposite()) {
			this.container = this.addComposite(parentComposite);
			this.initializeLayout(this.container);
		} else {
			this.container = null;
			this.initializeLayout(parentComposite);
		}
		this.controlDisposeListener = this.buildControlDisposeListener();
		this.getControl().addDisposeListener(this.controlDisposeListener);

		this.subjectChangeListener = this.buildSubjectChangeListener();
		this.subjectModel.addPropertyChangeListener(PropertyValueModel.VALUE, this.subjectChangeListener);

		this.engageListeners(getSubject());
		this.populate();
	}


	// ********** enabled model **********

	/**
	 * Return an <em>enabled</em> model that will result in the pane's
	 * <em>enabled</em> state always matching that of its parent pane.
	 */
	private static PropertyValueModel<Boolean> buildDefaultEnabledModel() {
		return new StaticPropertyValueModel<Boolean>(Boolean.TRUE);
	}

	/**
	 * Return a {@link Boolean} value model that will return
	 * {@link Boolean#TRUE} if the value of the specified value model is
	 * <em>not</em> <code>null</code>;
	 * {@link Boolean#FALSE} if the value <em>is</em> <code>null</code>.
	 */
	protected static PropertyValueModel<Boolean> buildIsNotNullModel(PropertyValueModel<?> valueModel) {
		return new PredicatePropertyValueModel<Object>(valueModel, PredicateTools.isNotNull());
	}

	/**
	 * Convenience method for sub-classes.
	 * Wrap the pane's {@link #subjectModel} in a {@link #buildIsNotNullModel(PropertyValueModel)};
	 * i.e. a model that returns whether the subject is <code>null</code>.
	 */
	protected PropertyValueModel<Boolean> buildSubjectIsNotNullModel() {
		return buildIsNotNullModel(this.subjectModel);
	}

	/**
	 * Return a {@link Boolean} value model that will return the AND of the
	 * value of the <em>enabled</em> model of the specified (typically parent) pane
	 * and the value of the specified <em>enabled</em> model.
	 * <p>
	 * This is useful for a pane that is <em>enabled</em> when both its parent
	 * pane is <em>enabled</em> <em>and</em> the pane's model indicates the
	 * pane should be <em>enabled</em>.
	 */
	@SuppressWarnings("unchecked")
	private static PropertyValueModel<Boolean> andEnabledModel(Pane<?> pane, PropertyValueModel<Boolean> enabledModel) {
		enabledModel = buildNonNullModel(enabledModel);
		// NB: we fetch private state from the pane
		return (pane == null) ? enabledModel : CompositeBooleanPropertyValueModel.and(pane.enabledModel, enabledModel);
	}

	/**
	 * Return a {@link Boolean} value model that will return the value of the
	 * specified {@link Boolean} value model if it is <em>not</em>
	 * <code>null</code>;
	 * {@link Boolean#FALSE} if the value is <code>null</code>.
	 * <p>
	 * This is useful for <em>enabled</em> models that might return <code>null</code>
	 * (which is typical with aspect adapters etc.).
	 */
	private static PropertyValueModel<Boolean> buildNonNullModel(PropertyValueModel<Boolean> booleanModel) {
		return new NullCheckPropertyValueModelWrapper<Boolean>(booleanModel, Boolean.FALSE);
	}


	// ********** initialization **********

	private PropertyChangeListener buildEnabledModelListener() {
		return new EnabledModelListener();
	}

	/* CU private */ class EnabledModelListener
		extends PropertyChangeAdapter
	{
		@Override
		public void propertyChanged(PropertyChangeEvent event) {
			Pane.this.enabledModelChanged(((Boolean) event.getOldValue()).booleanValue(), ((Boolean) event.getNewValue()).booleanValue());
		}
	}

	protected void enabledModelChanged(@SuppressWarnings("unused") boolean oldEnabled, @SuppressWarnings("unused") boolean newEnabled) {
		// NOP
	}

	private PropertyChangeListener buildSubjectChangeListener() {
		return SWTListenerTools.wrap(this.buildSubjectChangeListener_());
	}

	private PropertyChangeListener buildSubjectChangeListener_() {
		return new SubjectChangeListener();
	}

	/* CU private */ class SubjectChangeListener
		extends PropertyChangeAdapter
	{
		@Override
		@SuppressWarnings("unchecked")
		public void propertyChanged(PropertyChangeEvent e) {
			Pane.this.subjectChanged((T) e.getOldValue(), (T) e.getNewValue());
		}
	}

	/**
	 * Initialize the pane's models. This method is called before the pane's
	 * UI widget is built in {@link #initializeLayout(Composite)}.
	 */
	protected void initialize() {
		// do nothing by default
	}

	/**
	 * Build the pane's UI widget in the specified composite, using
	 * the models built in {@link #initialize()}.
	 */
	protected abstract void initializeLayout(Composite parentComposite);

	private DisposeListener buildControlDisposeListener() {
		return new ControlDisposeListener();
	}

	/* CU private */ class ControlDisposeListener
		extends DisposeAdapter
	{
		@Override
		public void widgetDisposed(DisposeEvent event) {
			Pane.this.controlDisposed();
		}
	}


	/**
	 * Adds any property names to the given collection in order to be notified
	 * when the actual property changes in the subject.
	 *
	 * @param propertyNames The collection of property names to register with the
	 * subject
	 */
	protected void addPropertyNames(Collection<String> propertyNames) {
	}

	private PropertyChangeListener buildAspectChangeListener() {
		return SWTListenerTools.wrap(buildAspectChangeListener_());
	}

	private PropertyChangeListener buildAspectChangeListener_() {
		return new PropertyChangeListener() {
			public void propertyChanged(PropertyChangeEvent e) {
				//subject() could have changed or is null because of the possibility of
				//"jumping" on the UI thread here and a selection change occuring
				if (e.getSource() == getSubject()) {
					updatePane(e.getPropertyName());
				}
			}
		};
	}

	/**
	 * Creates a new button using the given information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param buttonAction The action to be invoked when the button is pressed
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addButton(Composite container,
	                                   String text,
	                                   final Runnable buttonAction) {

		return this.addButton(container, text, null, buttonAction);
	}

	protected final Button addButton(Composite container,
        String text,
        final Runnable buttonAction,
        PropertyValueModel<Boolean> enabledModel) {

		return this.addButton(container, text, null, buttonAction, enabledModel);
	}

	/**
	 * Creates a new unmanaged <code>Button</code> widget.  Unmanaged means
	 * that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param buttonAction The action to be invoked when the button is pressed
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addUnmanagedButton(Composite container,
	                                   String text,
	                                   final Runnable buttonAction) {

		return this.addUnmanagedButton(container, text, null, buttonAction);
	}

	/**
	 * Creates a new button using the given information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param helpId The topic help ID to be registered for the new check box
	 * @param buttonAction The action to be invoked when the button is pressed
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addButton(Composite container,
	                                   String text,
	                                   String helpId,
	                                   final Runnable buttonAction) {

		Button button = addUnmanagedButton(container, text, helpId, buttonAction);
		this.bindEnabledState(button);

		return button;
	}

	protected final Button addButton(Composite container,
								        String text,
								        String helpId,
								        final Runnable buttonAction,
								        PropertyValueModel<Boolean> enabledModel) {

		Button button = addUnmanagedButton(container, text, helpId, buttonAction);
		this.bindEnabledState(enabledModel, button);

		return button;
	}

	/**
	 * Creates a new unmanaged <code>Button</code> widget.  Unmanaged means
	 * that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param helpId The topic help ID to be registered for the new check box
	 * @param buttonAction The action to be invoked when the button is pressed
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	private Button addUnmanagedButton(Composite container,
	                                   String text,
	                                   String helpId,
	                                   final Runnable buttonAction) {

		Button button = this.getWidgetFactory().createButton(container, text);
		button.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				buttonAction.run();
			}
		});

		if (helpId != null) {
			this.setHelp(button, helpId);
		}

		GridData gridData = new GridData();
		gridData.grabExcessHorizontalSpace = false;
		gridData.horizontalAlignment       = GridData.FILL;
		button.setLayoutData(gridData);

		return button;
	}

	/**
	 * This layout will leave space for decorations on widgets.
	 * Whether decorated or not, all of the widgets need the same indent
 	 * so that they align properly.
	 */
	protected GridData getFieldGridData() {
		int margin = FieldDecorationRegistry.getDefault()
				.getMaximumDecorationWidth();
		GridData data = new GridData();
		data.horizontalAlignment = SWT.FILL;
		data.widthHint = IDialogConstants.ENTRY_FIELD_WIDTH + margin;
		data.horizontalIndent = margin;
		data.grabExcessHorizontalSpace = true;
		return data;
	}

	/**
	 * Creates a new check box using the given information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param booleanHolder The holder of the selection state
	 * @param helpId The topic help ID to be registered for the new check box
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addCheckBox(
			Composite parent,
	        String buttonText,
	        ModifiablePropertyValueModel<Boolean> booleanHolder,
	        String helpId) {

		return this.addToggleButton(
			parent,
			buttonText,
			booleanHolder,
			helpId,
			SWT.CHECK);
	}

	protected final Button addCheckBox(
			Composite parent,
			String buttonText,
			ModifiablePropertyValueModel<Boolean> booleanHolder,
			String helpId,
			PropertyValueModel<Boolean> enabledModel) {

		Button button = this.addUnmanagedToggleButton(parent, buttonText, booleanHolder, helpId, SWT.CHECK);
		this.bindEnabledState(enabledModel, button);
		return button;
	}

	/**
	 * Creates a new non-editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Combo</code>
	 *
	 * @category Layout
	 */
	protected final Combo addCombo(Composite container) {
		Combo combo = this.addUnmanagedCombo(container);
		this.bindEnabledState(combo);
		return combo;
	}

	/**
	 * Creates a new non-editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Combo</code>
	 *
	 * @category Layout
	 */
	protected final Combo addCombo(Composite container, String helpId) {
		Combo combo = this.addUnmanagedCombo(container);

		if (helpId != null) {
			this.setHelp(combo, helpId);
		}

		this.bindEnabledState(combo);
		return combo;
	}

	/**
	 * Creates a new non-editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Combo</code>
	 *
	 * @category Layout
	 */
	private Combo addUnmanagedCombo(Composite container) {
		Combo combo = this.getWidgetFactory().createCombo(container);
		combo.setLayoutData(getFieldGridData());
		return combo;
	}

	/**
	 * Creates a new non-editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @param listHolder The <code>ListValueHolder</code>
	 * @param selectedItemHolder The holder of the selected item
	 * @param stringConverter The converter responsible to transform each item
	 * into a string representation
	 * @return The newly created <code>Combo</code>
	 *
	 * @category Layout
	 */
	protected final <V> Combo addCombo(Composite container,
	                                     ListValueModel<V> listHolder,
	                                     ModifiablePropertyValueModel<V> selectedItemHolder,
	                                     Transformer<V, String> stringConverter,
	                                     String helpId) {

		Combo combo = this.addCombo(container, helpId);

		ComboModelAdapter.adapt(
			listHolder,
			selectedItemHolder,
			combo,
			stringConverter
		);

		return combo;
	}

	/**
	 * Creates a new non-editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @param listHolder The <code>ListValueHolder</code>
	 * @param selectedItemHolder The holder of the selected item
	 * @param stringConverter The converter responsible to transform each item
	 * into a string representation
	 * @return The newly created <code>Combo</code>
	 *
	 * @category Layout
	 */
	private <V> Combo addUnmanagedCombo(Composite container,
	                                     ListValueModel<V> listHolder,
	                                     ModifiablePropertyValueModel<V> selectedItemHolder,
	                                     Transformer<V, String> stringConverter) {

		Combo combo = this.addUnmanagedCombo(container);

		ComboModelAdapter.adapt(
			listHolder,
			selectedItemHolder,
			combo,
			stringConverter
		);

		return combo;
	}

	protected final <V> Combo addCombo(
			Composite container,
			ListValueModel<V> listHolder,
			ModifiablePropertyValueModel<V> selectedItemHolder,
			Transformer<V, String> stringConverter,
			PropertyValueModel<Boolean> enabledModel) {

		Combo combo = this.addUnmanagedCombo(container, listHolder, selectedItemHolder, stringConverter);
		this.bindEnabledState(enabledModel, combo);
		return combo;
	}

	/**
	 * Creates a new <code>ComboViewer</code> using a <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @param labelProvider The provider responsible to convert the combo's items
	 * into human readable strings
	 * @return The newly created <code>ComboViewer</code>
	 *
	 * @category Layout
	 */
	protected final ComboViewer addComboViewer(Composite container,
	                                             IBaseLabelProvider labelProvider) {

		Combo combo = this.addCombo(container);
		ComboViewer viewer = new ComboViewer(combo);
		viewer.setLabelProvider(labelProvider);
		return viewer;
	}
	protected final ComboViewer addComboViewer(Composite container,
												IBaseLabelProvider labelProvider,
												String helpId) {
	
		Combo combo = this.addCombo(container, helpId);
		ComboViewer viewer = new ComboViewer(combo);
		viewer.setLabelProvider(labelProvider);
		return viewer;
	}

	/**
	 * Creates the main container of this pane. The layout and layout data are
	 * automatically set.
	 *
	 * @param parent The parent container
	 * @return The newly created <code>Composite</code> that will holds all the
	 * widgets created by this pane through {@link #initializeLayout(Composite)}
	 *
	 * @category Layout
	 */
	protected Composite addComposite(Composite parent) {
		return this.addSubPane(parent);
	}

	/**
	 * Return whether this Pane should add a Composite. Using this
	 * to reduce the number of SWT Controls (USER handles in windows) created.
	 * Typically you would return false if the Pane is for only 1 widget. In this case
	 * you need to override {@link #getControl()} to return the appropriate Control
	 */
	protected boolean addsComposite() {
		return true;
	}

	protected final <V> Combo addEditableCombo(
			Composite container,
			ListValueModel<V> listHolder,
			ModifiablePropertyValueModel<V> selectedItemHolder,
			Transformer<V, String> stringConverter,
			PropertyValueModel<Boolean> enabledModel) {

		return this.addEditableCombo(container, listHolder, selectedItemHolder, stringConverter, enabledModel, null);
	}

	protected final <V> Combo addEditableCombo(
			Composite container,
			ListValueModel<V> listHolder,
			ModifiablePropertyValueModel<V> selectedItemHolder,
			Transformer<V, String> stringConverter,
			PropertyValueModel<Boolean> enabledModel,
			String helpId) {

		Combo combo = this.addUnmanagedEditableCombo(container, listHolder, selectedItemHolder, stringConverter, helpId);
		this.bindEnabledState(enabledModel, combo);
		return combo;
	}

	protected final Combo addEditableCombo(Composite container) {
		return this.addEditableCombo(container, null);
	}

	protected final Combo addEditableCombo(Composite container, String helpId) {
		Combo combo = this.getWidgetFactory().createEditableCombo(container);

		if (helpId != null) {
			this.setHelp(combo, helpId);
		}

		combo.setLayoutData(getFieldGridData());
		this.bindEnabledState(combo);
		return combo;
	}

	protected final <V> Combo addEditableCombo(Composite container,
       											ListValueModel<V> listHolder,
       											ModifiablePropertyValueModel<V> selectedItemHolder) {
		
		return this.addEditableCombo(
			container, 
			listHolder, 
			selectedItemHolder, 
			TransformerTools.<V>objectToStringTransformer(),
			(String) null);
	}
	
	/**
	 * Creates a new editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @param listHolder The <code>ListValueHolder</code>
	 * @param selectedItemHolder The holder of the selected item
	 * @param stringConverter The converter responsible to transform each item
	 * into a string representation
	 * @return The newly created <code>Combo</code>
	 *
	 * @category Layout
	 */
	protected final <V> Combo addEditableCombo(Composite container,
	                                             ListValueModel<V> listHolder,
	                                             ModifiablePropertyValueModel<V> selectedItemHolder,
	                                             Transformer<V, String> stringConverter,
	                                             String helpId) {

		Combo combo = this.addEditableCombo(container, helpId);

		ComboModelAdapter.adapt(
			listHolder,
			selectedItemHolder,
			combo,
			stringConverter
		);

		return combo;
	}

	/**
	 * Creates a new editable <code>ComboViewer</code> using a <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @param labelProvider The provider responsible to convert the combo's items
	 * into human readable strings
	 * @return The newly created <code>ComboViewer</code>
	 *
	 * @category Layout
	 */
	protected final ComboViewer addEditableComboViewer(Composite container,
	                                                     IBaseLabelProvider labelProvider) {

		Combo combo = this.addEditableCombo(container);
		ComboViewer viewer = new ComboViewer(combo);
		viewer.setLabelProvider(labelProvider);
		return viewer;
	}

	/**
	 * Creates a new <code>Hyperlink</code> that will invoked the given
	 * <code>Runnable</code> when selected. The given action is always invoked
	 * from the UI thread.
	 *
	 * @param parent The parent container
	 * @param text The hyperlink's text
	 * @param hyperLinkAction The action to be invoked when the link was selected
	 * return The newly created <code>Hyperlink</code>
	 *
	 * @category Layout
	 */
	protected final Hyperlink addHyperlink(Composite parent,
	                                         String text,
	                                         final Runnable hyperLinkAction) {

		Hyperlink link = this.getWidgetFactory().createHyperlink(parent, text);
		this.bindEnabledState(link);

		link.addMouseListener(new MouseAdapter() {
			@Override
			public void mouseUp(MouseEvent e) {

				Hyperlink hyperLink = (Hyperlink) e.widget;

				if (hyperLink.isEnabled()) {
					hyperLinkAction.run();
				}
			}
		});

		return link;
	}

	protected final Hyperlink addHyperlink(Composite parent,
											String text) {

		Hyperlink link = this.getWidgetFactory().createHyperlink(parent, text);
		this.bindEnabledState(link);
		
		return link;
	}

	/**
	 * Creates a new label using the given information.
	 *
	 * @param parent The parent container
	 * @param labelText The label's text
	 *
	 * @category Layout
	 */
	protected final Label addLabel(Composite container,
	                                 String labelText) {

		Label label = this.addUnmanagedLabel(container, labelText);
		this.bindEnabledState(label);
		return label;
	}

	protected final Label addLabel(
			Composite container,
			String labelText,
			PropertyValueModel<Boolean> enabledModel
	) {
		Label label = this.addUnmanagedLabel(container, labelText);
		this.bindEnabledState(enabledModel, label);
		return label;
	}

	/**
	 * Creates a new unmanaged <code>Label</code> widget.  Unmanaged means
	 * that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param parent The parent container
	 * @param labelText The label's text
	 *
	 * @category Layout
	 */
	private Label addUnmanagedLabel(Composite container,
	                                 String labelText) {

		return this.getWidgetFactory().createLabel(container, labelText);
	}

	/**
	 * Creates a new managed spinner. Managed means that this Pane will
	 * handle enabling/disabling of this widget if a PaneEnabler is used.
	 *
	 * @param parent The parent container
	 * @param numberHolder The holder of the integer value
	 * @param defaultValue The value shown when the holder has <code>null</code>
	 * @param minimumValue The minimum value that the spinner will allow
	 * @param maximumValue The maximum value that the spinner will allow
	 * @param helpId The topic help ID to be registered for the new button
	 * @return The newly created <code>Spinner</code>
	 *
	 * @category Layout
	 */
	protected final Spinner addSpinner(Composite parent,
	                                     ModifiablePropertyValueModel<Integer> numberHolder,
	                                     int defaultValue,
	                                     int minimumValue,
	                                     int maximumValue,
	                                     String helpId) {

		Spinner spinner = addUnmanagedSpinner(parent, numberHolder, defaultValue, minimumValue, maximumValue, helpId);
		this.bindEnabledState(spinner);
		return spinner;
	}

	/**
	 * Creates a new unmanaged spinner.  Unmanaged means that this Pane will
	 * not handle the enabling/disabling of this widget.  The owning object will handle
	 * it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param parent The parent container
	 * @param numberHolder The holder of the integer value
	 * @param defaultValue The value shown when the holder has <code>null</code>
	 * @param minimumValue The minimum value that the spinner will allow
	 * @param maximumValue The maximum value that the spinner will allow
	 * @param helpId The topic help ID to be registered for the new button
	 * @return The newly created <code>Spinner</code>
	 *
	 * @category Layout
	 */
	private Spinner addUnmanagedSpinner(Composite parent,
	                                     ModifiablePropertyValueModel<Integer> numberHolder,
	                                     int defaultValue,
	                                     int minimumValue,
	                                     int maximumValue,
	                                     String helpId) {

		Spinner spinner = this.getWidgetFactory().createSpinner(parent);
		spinner.setMinimum(minimumValue);
		spinner.setMaximum(maximumValue);
		GridData gridData = getFieldGridData();
		gridData.grabExcessHorizontalSpace = false;
		spinner.setLayoutData(gridData);

		SpinnerModelAdapter.adapt(numberHolder, spinner, defaultValue);

		if (helpId != null) {
			this.setHelp(spinner, helpId);
		}

		return spinner;
	}

	/**
	 * Creates a new managed DateTime of type SWT.TIME.  Managed means that this Pane will
	 * handle enabling/disabling of this widget if a PaneEnabler is used.
	 *
	 * @param parent The parent container
	 * @param hoursHolder The holder of the hours integer value
	 * @param minutesHolder The holder of the minutes integer value
	 * @param secondsHolder The holder of the seconds integer value
	 * @param helpId The topic help ID to be registered for the new dateTime
	 * @return The newly created <code>DateTime</code>
	 *
	 * @category Layout
	 */
	protected final DateTime addDateTime(Composite parent,
											ModifiablePropertyValueModel<Integer> hoursHolder,
											ModifiablePropertyValueModel<Integer> minutesHolder,
											ModifiablePropertyValueModel<Integer> secondsHolder,
											String helpId) {

		DateTime dateTime = this.addUnmanagedDateTime(parent, hoursHolder, minutesHolder, secondsHolder, helpId);
		this.bindEnabledState(dateTime);

		return dateTime;
	}

	protected final DateTime addDateTime(
			Composite parent,
			ModifiablePropertyValueModel<Integer> hoursHolder,
			ModifiablePropertyValueModel<Integer> minutesHolder,
			ModifiablePropertyValueModel<Integer> secondsHolder,
			String helpId,
			PropertyValueModel<Boolean> enabledModel
	) {
		DateTime dateTime = this.addUnmanagedDateTime(parent, hoursHolder, minutesHolder, secondsHolder, helpId);
		this.bindEnabledState(enabledModel, dateTime);
		return dateTime;
	}

	/**
	 * Creates a new unmanaged DateTime of type SWT.TIME.  Unmanaged means that this Pane will
	 * not handle the enabling/disabling of this widget.  The owning object will handle
	 * it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param parent The parent container
	 * @param hoursHolder The holder of the hours integer value
	 * @param minutesHolder The holder of the minutes integer value
	 * @param secondsHolder The holder of the seconds integer value
	 * @param helpId The topic help ID to be registered for the new dateTime
	 * @return The newly created <code>DateTime</code>
	 *
	 * @category Layout
	 */
	private DateTime addUnmanagedDateTime(Composite parent,
											ModifiablePropertyValueModel<Integer> hoursHolder,
											ModifiablePropertyValueModel<Integer> minutesHolder,
											ModifiablePropertyValueModel<Integer> secondsHolder,
											String helpId) {

		DateTime dateTime = this.getWidgetFactory().createDateTime(parent, SWT.TIME);

		DateTimeModelAdapter.adapt(hoursHolder, minutesHolder, secondsHolder, dateTime);

		if (helpId != null) {
			this.setHelp(dateTime, helpId);
		}

		return dateTime;
	}
	/**
	 * Creates a new editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @param listHolder The <code>ListValueHolder</code>
	 * @param selectedItemHolder The holder of the selected item
	 * @param stringConverter The converter responsible to transform each item
	 * into a string representation
	 * @return The newly created <code>CCombo</code>
	 *
	 * @category Layout
	 */
	private <V> Combo addUnmanagedEditableCombo(Composite container,
	                                               ListValueModel<V> listHolder,
	                                               ModifiablePropertyValueModel<V> selectedItemHolder,
	                                               Transformer<V, String> stringConverter,
	                                               String helpId) {

		Combo combo = addUnmanagedEditableCombo(container, helpId);

		ComboModelAdapter.adapt(
			listHolder,
			selectedItemHolder,
			combo,
			stringConverter
		);

		return combo;
	}


	/**
	 * Creates a new editable <code>Combo</code>.
	 *
	 * @param container The parent container
	 * @return The newly created <code>CCombo</code>
	 *
	 * @category Layout
	 */
	private Combo addUnmanagedEditableCombo(Composite container,
												String helpId) {

		Combo combo = this.getWidgetFactory().createEditableCombo(container);
		combo.setLayoutData(getFieldGridData());
		

		if (helpId != null) {
			this.setHelp(container, helpId);
		}

		return combo;
	}

	/**
	 * Creates a new list and notify the given selection holder when the
	 * selection changes. If the selection count is different than one than the
	 * holder will receive <code>null</code>.
	 *
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new radio button
	 * @return The newly created <code>List</code>
	 *
	 * @category Layout
	 */
	protected final List addList(Composite container, String helpId) {

		return this.addList(
			container,
			new SimplePropertyValueModel<String>(),
			helpId
		);
	}

	/**
	 * Creates a new list and notify the given selection holder when the
	 * selection changes. If the selection count is different than one than the
	 * holder will receive <code>null</code>.
	 *
	 * @param container The parent container
	 * @param selectionHolder The holder of the unique selected item
	 * @param helpId The topic help ID to be registered for the new radio button
	 * @return The newly created <code>List</code>
	 *
	 * @category Layout
	 */
	protected final List addList(Composite container,
	                               ModifiablePropertyValueModel<String> selectionHolder,
	                               String helpId) {

		List list = this.addUnmanagedList(container, selectionHolder, helpId);
		this.bindEnabledState(list);

		return list;
	}

	/**
	 * Creates a new unmanaged list and notify the given selection holder when the
	 * selection changes. If the selection count is different than one than the
	 * holder will receive <code>null</code>.
	 * Unmanaged means that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param container The parent container
	 * @param selectionHolder The holder of the unique selected item
	 * @param helpId The topic help ID to be registered for the new radio button
	 * @return The newly created <code>List</code>
	 *
	 * @category Layout
	 */
	private List addUnmanagedList(Composite container,
	                               ModifiablePropertyValueModel<String> selectionHolder,
	                               String helpId) {

		List list = this.getWidgetFactory().createList(
			container,
			SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL | SWT.MULTI
		);

		list.addSelectionListener(buildSelectionListener(selectionHolder));
		list.setLayoutData(new GridData(GridData.FILL_BOTH));

		if (helpId != null) {
			this.setHelp(list, helpId);
		}

		return list;
	}

	/**
	 * Creates a new <code>Text</code> widget that has multiple lines.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Text</code> widget
	 *
	 */
	protected final Text addMultiLineText(Composite container) {

		Text text = this.getWidgetFactory().createMultiLineText(container);
		text.setLayoutData(getFieldGridData());
		this.bindEnabledState(text);

		return text;
	}

	/**
	 * Creates a new <code>Text</code> widget that has multiple lines.
	 *
	 * @param container The parent container
	 * @param lineCount The number of lines the text area should display
	 * @param helpId The topic help ID to be registered for the new text
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addMultiLineText(Composite container,
	                                      int lineCount,
	                                      String helpId) {

		Text text = this.addMultiLineText(container);
		adjustMultiLineTextLayout(lineCount, text, text.getLineHeight());

		if (helpId != null) {
			this.setHelp(text, helpId);
		}

		return text;
	}

	/**
	 * Creates a new <code>Text</code> widget that has multiple lines.
	 *
	 * @param container The parent container
	 * @param textHolder The holder of the text field's input
	 * @param lineCount The number of lines the text area should display
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addMultiLineText(Composite container,
	                                        ModifiablePropertyValueModel<String> textHolder,
	                                        int lineCount) {

		return this.addMultiLineText(container, textHolder, lineCount, null);
	}

	/**
	 * Creates a new <code>Text</code> widget that has multiple lines.
	 *
	 * @param container The parent container
	 * @param textModel The holder of the text field's input
	 * @param helpId The topic help ID to be registered for the new text
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addMultiLineText(Composite container,
	                                        ModifiablePropertyValueModel<String> textModel,
	                                        int lineCount,
	                                        String helpId) {

		Text text = this.addMultiLineText(container, lineCount, helpId);
		SWTBindingTools.bind(textModel, text);
		return text;
	}

	/**
	 * Adjusts the layout of the given container so that the text control has the correct amount of
	 * lines by default.
	 */
	protected final void adjustMultiLineTextLayout(int lineCount,
	                                               Control text,
	                                               int lineHeight) {

		// Specify the number of lines the text area should display
		GridData gridData = (GridData) text.getLayoutData();
		if (gridData == null) {
			gridData = this.getFieldGridData();
			text.setLayoutData(gridData);
		}
		gridData.heightHint = lineHeight * lineCount;
	}
	/**
	 * Creates a new <code>PageBook</code> and set the proper layout and layout
	 * data.
	 *
	 * @param container The parent container
	 * @return The newly created <code>PageBook</code>
	 *
	 * @category Layout
	 */
	protected final PageBook addPageBook(Composite container) {

		PageBook pageBook = new PageBook(container, SWT.NULL);
		pageBook.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		return pageBook;
	}

	/**
	 * Creates a new container without specifying any layout manager.
	 *
	 * @param container The parent of the new container
	 * @return The newly created <code>Composite</code>
	 *
	 * @category Layout
	 */
	protected final Composite addPane(Composite parent) {
		return this.getWidgetFactory().createComposite(parent);
	}

	/**
	 * Creates a new container using the given layout manager.
	 *
	 * @param parent The parent of the new container
	 * @param layout The layout manager of the new container
	 * @return The newly created container
	 *
	 * @category Layout
	 */
	protected final Composite addPane(Composite container, Layout layout) {

		container = this.addPane(container);
		container.setLayout(layout);
		container.setLayoutData(new GridData(GridData.FILL_BOTH));
		return container;
	}

	/**
	 * Creates a new <code>Text</code> widget.
	 *
	 * @param container The parent container
	 * @param textModel The holder of the text field's input
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addPasswordText(Composite container,
	                                       ModifiablePropertyValueModel<String> textModel) {

		Text text = this.addPasswordText(container);
		SWTBindingTools.bind(textModel, text);

		return text;
	}

	/**
	 * Creates a new <code>Text</code> widget.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addPasswordText(Composite container) {

		Text text = this.getWidgetFactory().createPasswordText(container);
		text.setLayoutData(getFieldGridData());

		this.bindEnabledState(text);
		return text;
	}

	/**
	 * Creates a new push button using the given information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param buttonAction The action to be invoked when the button is pressed
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addPushButton(Composite parent,
	                                       String buttonText,
	                                       final Runnable buttonAction) {

		return this.addPushButton(parent, buttonText, null, buttonAction);
	}

	/**
	 * Creates a new push button using the given information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param buttonAction The action to be invoked when the button is pressed
	 * @param helpId The topic help ID to be registered for the new radio button
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addPushButton(Composite parent,
	                                       String buttonText,
	                                       String helpId,
	                                       final Runnable buttonAction) {

		Button button = this.getWidgetFactory().createPushButton(parent, buttonText);
		bindEnabledState(button);
		button.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				buttonAction.run();
			}
		});

		button.setLayoutData(new GridData());

		if (helpId != null) {
			this.setHelp(button, helpId);
		}

		return button;
	}

	/**
	 * Creates a new check box using the given information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param booleanHolder The holder of the selection state
	 * @param helpId The topic help ID to be registered for the new radio button
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	protected final Button addRadioButton(Composite parent,
	                                        String buttonText,
	                                        ModifiablePropertyValueModel<Boolean> booleanHolder,
	                                        String helpId) {

		return this.addToggleButton(
			parent,
			buttonText,
			booleanHolder,
			helpId,
			SWT.RADIO
		);
	}

	/**
	 * Creates a new <code>Section</code>. A sub-pane is automatically added as
	 * its client and is the returned <code>Composite</code>.
	 *
	 * @param container The container of the new widget
	 * @param sectionText The text of the new section
	 * @param description The section's description
	 * @return The <code>Section</code>'s sub-pane
	 *
	 * @category Layout
	 */
	protected final Composite addSection(Composite container,
	                                       String sectionText,
	                                       String description) {

		return this.addSection(
			container,
			sectionText,
			description,
			ExpandableComposite.TITLE_BAR
		);
	}

	/**
	 * Creates a new <code>Section</code>. A sub-pane is automatically added as
	 * its client and is the returned <code>Composite</code>.
	 *
	 * @param container The container of the new widget
	 * @param sectionText The text of the new section
	 * @param description The section's description or <code>null</code> if none
	 * was provider
	 * @param type The type of section to create
	 * when to expand or collapse the section
	 * @return The <code>Section</code>'s sub-pane
	 *
	 * @category Layout
	 */
	private Composite addSection(Composite container,
	                               String sectionText,
	                               String description,
	                               int type) {

		Section section = this.getWidgetFactory().createSection(container, type | ((description != null) ? Section.DESCRIPTION : SWT.NULL));
		section.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		section.setText(sectionText);

		if (description != null) {
			section.setDescription(description);
		}

		Composite subPane = this.addSubPane(section);
		section.setClient(subPane);

		return subPane;
	}

	private SelectionListener buildSelectionListener(final ModifiablePropertyValueModel<String> selectionHolder) {
		return new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				List list = (List) e.widget;
				String[] selectedItems = list.getSelection();
				if ((selectedItems == null) || (selectedItems.length != 1)) {
					selectionHolder.setValue(null);
				}
				else {
					selectionHolder.setValue(selectedItems[0]);
				}
			}
		};
	}

	/**
	 * Creates a new <code>Composite</code> used as a sub-pane.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Composite</code> used as a sub-pane
	 *
	 * @category Layout
	 */
	protected final Composite addSubPane(Composite container) {
		return this.addSubPane(container, 0);
	}

	/**
	 * Creates a new <code>Composite</code> used as a sub-pane.
	 *
	 * @param container The parent container
	 * @param topMargin The extra spacing to add at the top of the pane
	 * @return The newly created <code>Composite</code> used as a sub-pane
	 *
	 * @category Layout
	 */
	protected final Composite addSubPane(Composite container, int topMargin) {
		return this.addSubPane(container, topMargin, 0);
	}

	/**
	 * Creates a new <code>Composite</code> used as a sub-pane.
	 *
	 * @param container The parent container
	 * @param topMargin The extra spacing to add at the top of the pane
	 * @param leftMargin The extra spacing to add to the left of the pane
	 * @return The newly created <code>Composite</code> used as a sub-pane
	 *
	 * @category Layout
	 */
	protected final Composite addSubPane(Composite container,
	                                       int topMargin,
	                                       int leftMargin) {

		return this.addSubPane(container, topMargin, leftMargin, 0, 0);
	}

	/**
	 * Creates a new <code>Composite</code> used as a sub-pane, the new widget
	 * will have its layout and layout data already initialized, the layout will
	 * be a <code>GridLayout</code> with 1 column.
	 *
	 * @param container The parent container
	 * @param topMargin The extra spacing to add at the top of the pane
	 * @param leftMargin The extra spacing to add to the left of the pane
	 * @param bottomMargin The extra spacing to add at the bottom of the pane
	 * @param rightMargin The extra spacing to add to the right of the pane
	 * @return The newly created <code>Composite</code> used as a sub-pane
	 *
	 * @category Layout
	 */
	protected final Composite addSubPane(Composite container,
	                                       int topMargin,
	                                       int leftMargin,
	                                       int bottomMargin,
	                                       int rightMargin) {

		return this.addSubPane(
			container,
			1,
			topMargin,
			leftMargin,
			bottomMargin,
			rightMargin);
	}

	/**
	 * Creates a new <code>Composite</code> used as a sub-pane, the new widget
	 * will have its layout and layout data already initialized, the layout will
	 * be a <code>GridLayout</code> with 1 column.
	 *
	 * @param container The parent container
	 * @param topMargin The extra spacing to add at the top of the pane
	 * @param leftMargin The extra spacing to add to the left of the pane
	 * @param bottomMargin The extra spacing to add at the bottom of the pane
	 * @param rightMargin The extra spacing to add to the right of the pane
	 * @return The newly created <code>Composite</code> used as a sub-pane
	 *
	 * @category Layout
	 */
	protected final Composite addSubPane(Composite container,
	                                       int columnCount,
	                                       int topMargin,
	                                       int leftMargin,
	                                       int bottomMargin,
	                                       int rightMargin) {

		GridLayout layout = new GridLayout(columnCount, false);
		layout.marginHeight = 0;
		layout.marginWidth  = 0;
		layout.marginTop    = topMargin;
		layout.marginLeft   = leftMargin;
		layout.marginBottom = bottomMargin;
		layout.marginRight  = rightMargin;

		container = this.addPane(container, layout);

		return container;
	}

	/**
	 * Creates a new table.
	 *
	 * @param container The parent container
	 * @param style The style to apply to the table
	 * @param helpId The topic help ID to be registered for the new table or
	 * <code>null</code> if no help ID is required
	 * @return The newly created <code>Table</code>
	 *
	 * @category Layout
	 */
	protected final Table addTable(Composite container,
	                                 int style,
	                                 String helpId) {

		Table table = addUnmanagedTable(container, style, helpId);
		this.bindEnabledState(table);

		return table;
	}
	/**
	 * Creates a new unmanaged table.  Unmanaged means that this Pane will
	 * not handle the enabling/disabling of this widget.  The owning object will handle
	 * it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param container The parent container
	 * @param style The style to apply to the table
	 * @param helpId The topic help ID to be registered for the new table or
	 * <code>null</code> if no help ID is required
	 * @return The newly created <code>Table</code>
	 *
	 * @category Layout
	 */
	protected final Table addUnmanagedTable(Composite container,
	                                 int style,
	                                 String helpId) {

		Table table = this.getWidgetFactory().createTable(container, style);
		table.setHeaderVisible(true);
		table.setLinesVisible(true);

		GridData gridData   = new GridData(GridData.FILL_BOTH);
		gridData.heightHint = table.getItemHeight() * 4;
		table.setLayoutData(gridData);

		if (helpId != null) {
			this.setHelp(table, helpId);
		}

		return table;
	}

	/**
	 * Creates a new table.
	 *
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new table or
	 * <code>null</code> if no help ID is required
	 * @return The newly created <code>Table</code>
	 *
	 * @category Layout
	 */
	protected final Table addTable(Composite container, String helpId) {

		return this.addTable(
			container,
			SWT.V_SCROLL | SWT.H_SCROLL | SWT.FULL_SELECTION | SWT.MULTI,
			helpId
		);
	}

	/**
	 * Creates a new unmanaged table.  Unmanaged means that this Pane will
	 * not handle the enabling/disabling of this widget.  The owning object will handle
	 * it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new table or
	 * <code>null</code> if no help ID is required
	 * @return The newly created <code>Table</code>
	 *
	 * @category Layout
	 */
	protected final Table addUnmanagedTable(Composite container, String helpId) {

		return this.addUnmanagedTable(
			container,
			SWT.V_SCROLL | SWT.H_SCROLL | SWT.FULL_SELECTION | SWT.MULTI,
			helpId
		);
	}

	/**
	 * Creates a new managed <code>Text</code> widget.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addText(Composite container) {
		Text text = this.addUnmanagedText(container);
		this.bindEnabledState(text);
		return text;
	}

	/**
	 * Creates a new unmanaged <code>Text</code> widget.  Unmanaged means
	 * that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param container The parent container
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	private Text addUnmanagedText(Composite container) {
		Text text = this.getWidgetFactory().createText(container);
		text.setLayoutData(getFieldGridData());
		return text;
	}

	/**
	 * Creates a new <code>Text</code> widget.
	 *
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new text
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addText(Composite container, String helpId) {

		Text text = this.addText(container);

		if (helpId != null) {
			this.setHelp(text, helpId);
		}

		return text;
	}

	/**
	 * Creates a new unmanaged <code>Text</code> widget.  Unmanaged means
	 * that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new text
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	private Text addUnmanagedText(Composite container, String helpId) {

		Text text = this.addUnmanagedText(container);

		if (helpId != null) {
			this.setHelp(text, helpId);
		}

		return text;
	}

	/**
	 * Creates a new <code>Text</code> widget.
	 *
	 * @param container The parent container
	 * @param textHolder The holder of the text field's input
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addText(Composite container,
	                               ModifiablePropertyValueModel<String> textHolder) {

		return this.addText(container, textHolder, null);
	}

	/**
	 * Creates a new <code>Text</code> widget.
	 *
	 * @param container The parent container
	 * @param textModel The holder of the text field's input
	 * @param helpId The topic help ID to be registered for the new text
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	protected final Text addText(Composite container,
	                               ModifiablePropertyValueModel<String> textModel,
	                               String helpId) {

		Text text = this.addText(container, helpId);
		SWTBindingTools.bind(textModel, text);

		return text;
	}

	protected final Text addText(
			Composite container,
			ModifiablePropertyValueModel<String> textHolder,
			String helpId,
			PropertyValueModel<Boolean> enabledModel
	) {
		Text text = this.addUnmanagedText(container, textHolder, helpId);
		this.bindEnabledState(enabledModel, text);
		return text;
	}

	/**
	 * Creates a new unmanaged <code>Text</code> widget.  Unmanaged means
	 * that this Pane will not handle the enabling/disabling of this widget.
	 * The owning object will handle it with its own PaneEnabler or ControlEnabler.
	 *
	 * @param container The parent container
	 * @param textModel The holder of the text field's input
	 * @param helpId The topic help ID to be registered for the new text
	 * @return The newly created <code>Text</code> widget
	 *
	 * @category Layout
	 */
	private Text addUnmanagedText(Composite container,
	                               ModifiablePropertyValueModel<String> textModel,
	                               String helpId) {

		Text text = this.addUnmanagedText(container, helpId);
		SWTBindingTools.bind(textModel, text);

		return text;
	}

	/**
	 * Creates a new container with a titled border.
	 *
	 * @param title The text of the titled border
	 * @param container The parent container
	 * @return The newly created <code>Composite</code> with a titled border
	 *
	 * @category Layout
	 */
	protected final Group addTitledGroup(Composite container, String title) {
		return this.addTitledGroup(container, title, null);
	}

	/**
	 * Creates a new container with a titled border.
	 *
	 * @param title The text of the titled border
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new group
	 * @return The newly created <code>Composite</code> with a titled border
	 *
	 * @category Layout
	 */
	protected final Group addTitledGroup(Composite container,
	                                      String title,
	                                      String helpId) {

		return addTitledGroup(container, title, 1, helpId);
	}

	/**
	 * Creates a new container with a titled border.
	 *
	 * @param title The text of the titled border
	 * @param container The parent container
	 * @param helpId The topic help ID to be registered for the new group
	 * @return The newly created <code>Composite</code> with a titled border
	 *
	 * @category Layout
	 */
	protected final Group addTitledGroup(Composite container,
	                                      String title,
	                                      int columnCount,
	                                      String helpId) {

		Group group = this.getWidgetFactory().createGroup(container, title);
		//manageWidget(group); TODO unsure if I want to manage groups,
		//also should probably rename this addUnmanagedTitledPane
		group.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

		GridLayout layout = new GridLayout(columnCount, false);
		layout.marginHeight = 0;
		layout.marginWidth  = 0;
		layout.marginTop    = 5;
		layout.marginLeft   = 5;
		layout.marginBottom = 5;
		layout.marginRight  = 5;
		group.setLayout(layout);

		if (helpId != null) {
			this.setHelp(group, helpId);
		}

		return group;
	}

	/**
	 * Creates a new unmanaged new toggle button (radio button or check box).
	 * Unmanaged means  that this Pane will not handle the enabling/disabling
	 * of this widget. The owning object will handle it with its own PaneEnabler
	 * or ControlEnabler.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param booleanModel The holder of the selection state
	 * @param helpId The topic help ID to be registered for the new button
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	private Button addUnmanagedToggleButton(
			Composite parent,
	        String buttonText,
	        ModifiablePropertyValueModel<Boolean> booleanModel,
	        String helpId,
	        int toggleButtonType) {

		Button button;

		if (toggleButtonType == SWT.PUSH) {
			button = this.getWidgetFactory().createPushButton(parent, buttonText);
		}
		else if (toggleButtonType == SWT.RADIO) {
			button = this.getWidgetFactory().createRadioButton(parent, buttonText);
		}
		else if (toggleButtonType == SWT.CHECK) {
			button = this.getWidgetFactory().createCheckBox(parent, buttonText);
		}
		else {
			button = this.getWidgetFactory().createButton(parent, buttonText);
		}

		button.setLayoutData(new GridData());
		SWTBindingTools.bind(booleanModel, button);

		if (helpId != null) {
			this.setHelp(button, helpId);
		}

		return button;
	}

	/**
	 * Creates a new toggle button (radio button or check box) using the given
	 * information.
	 *
	 * @param parent The parent container
	 * @param buttonText The button's text
	 * @param booleanHolder The holder of the selection state
	 * @param helpId The topic help ID to be registered for the new button
	 * @return The newly created <code>Button</code>
	 *
	 * @category Layout
	 */
	private Button addToggleButton(
			Composite parent,
	        String buttonText,
	        ModifiablePropertyValueModel<Boolean> booleanHolder,
	        String helpId,
	        int toggleButtonType) {

		Button button = addUnmanagedToggleButton(
				parent,
				buttonText,
				booleanHolder,
				helpId,
				toggleButtonType);
		this.bindEnabledState(button);
		return button;
	}

	/**
	 * Creates a new check box that can have 3 selection states (selected,
	 * unselected and partially selected.
	 *
	 * @param parent The parent container
	 * @param text The button's text
	 * @param booleanHolder The holder of the boolean value where <code>null</code>
	 * means partially selected
	 * @param helpId The topic help ID to be registered for the new check box
	 * @return The newly created <code>TriStateCheckBox</code>
	 *
	 * @category Layout
	 */
	protected final TriStateCheckBox addTriStateCheckBox(Composite parent,
	                                                       String text,
	                                                       ModifiablePropertyValueModel<Boolean> booleanHolder,
	                                                       String helpId) {

		TriStateCheckBox checkBox = this.addUnmanagedTriStateCheckBox(parent, text, booleanHolder, helpId);

		this.bindEnabledState(checkBox.getCheckBox());

		return checkBox;
	}

	protected final TriStateCheckBox addUnmanagedTriStateCheckBox(Composite parent,
	        String text,
	        ModifiablePropertyValueModel<Boolean> booleanHolder,
	        String helpId) {
	
		TriStateCheckBox checkBox = new TriStateCheckBox(
			parent,
			text,
			this.getWidgetFactory()
		);
		
		TriStateCheckBoxModelAdapter.adapt(
			booleanHolder,
			checkBox
		);
		
		if (helpId != null) {
			this.setHelp(checkBox.getCheckBox(), helpId);
		}
		
		return checkBox;
	}

	/**
	 * Creates a new check box that can have 3 selection states (selected,
	 * unselected and partially selected.
	 *
	 * @param parent The parent container
	 * @param text The button's text
	 * @param booleanHolder The holder of the boolean value where <code>null</code>
	 * means partially selected
	 * @param textModel The holder of the string to put in parenthesis after
	 * the check box's text when it is partially selected
	 * @param helpId The topic help ID to be registered for the new check box
	 * @return The newly created <code>TriStateCheckBox</code>
	 *
	 * @category Layout
	 */
	protected final TriStateCheckBox addTriStateCheckBoxWithDefault(Composite parent,
	                                                                  String text,
	                                                                  ModifiablePropertyValueModel<Boolean> booleanHolder,
	                                                                  PropertyValueModel<String> textModel,
	                                                                  String helpId) {

		TriStateCheckBox checkBox = this.addTriStateCheckBox(
			parent,
			text,
			booleanHolder,
			helpId
		);

		SWTBindingTools.bindTextLabel(textModel, checkBox.getCheckBox());

		return checkBox;
	}

	protected final TriStateCheckBox addTriStateCheckBoxWithDefault(Composite parent,
			        String text,
			        ModifiablePropertyValueModel<Boolean> booleanHolder,
			        PropertyValueModel<String> textModel,
			        PropertyValueModel<Boolean> enabledModel,
			        String helpId) {
			
		TriStateCheckBox checkBox = this.addUnmanagedTriStateCheckBox(parent, text, booleanHolder, helpId);
		
		this.bindEnabledState(enabledModel, checkBox.getCheckBox());
		
		SWTBindingTools.bindTextLabel(textModel, checkBox.getCheckBox());
		
		return checkBox;
	}

	/**
	 * Requests this pane to populate its widgets with the subject's values.
	 *
	 * @category Populate
	 */
	protected void doPopulate() {
		JptCommonUiPlugin.instance().trace(TRACE_OPTION, "doPopulate");
	}


	// ********** enabled models **********

	protected boolean isEnabled() {
		return this.enabledModel.getValue().booleanValue();
	}

	/**
	 * Control the <em>enabled</em> state of the specified controls with the
	 * pane's {@link #enabledModel}.
	 * <p>
	 * Use {@link #bindEnabledState(PropertyValueModel, Control...)} if the
	 * controls might be disabled when the pane is enabled.
	 */
	protected void bindEnabledState(Control... controls) {
		SWTBindingTools.bindEnabledState(this.enabledModel, controls);
	}

	/**
	 * Use the specified boolean model to determine the <em>enabled</em>
	 * state of the specified controls (i.e. when the <em>pane</em> is enabled).
	 * If the specified boolean model returns <code>null</code> (which is
	 * typical of aspect adapters), the controls will be disabled.
	 * <p>
	 * Use {@link #bindEnabledState(Control...)} if the
	 * controls are only enabled when the pane is enabled.
	 */
	protected void bindEnabledState(PropertyValueModel<Boolean> controlsEnabledModel, Control... controls) {
		SWTBindingTools.bindEnabledState(this.andEnabledModel(controlsEnabledModel), controls);
	}

	/**
	 * AND the specified boolean model with the pane's {@link #enabledModel},
	 * resulting in an <em>enabled</em> model that can only be <code>true</code>
	 * when the pane as a whole is enabled.
	 */
	private PropertyValueModel<Boolean> andEnabledModel(PropertyValueModel<Boolean> booleanModel) {
		return andEnabledModel(this, booleanModel);
	}


	// ********** subject listeners **********

	/**
	 * Engage the specified subject
	 */
	private void engageListeners(T subject) {
		if (subject != null) {
			this.engageListeners_(subject);
		}
	}

	/**
	 * Pre-condition: the specified subject is not <code>null</code>
	 */
	protected void engageListeners_(T subject) {
		JptCommonUiPlugin.instance().trace(TRACE_OPTION, "engageListeners_({0})", subject);

		for (String propertyName : this.getPropertyNames()) {
			subject.addPropertyChangeListener(propertyName, this.aspectChangeListener);
		}
	}

	/**
	 * Disengage the specified subject
	 */
	private void disengageListeners(T subject) {
		if (subject != null) {
			this.disengageListeners_(subject);
		}
	}

	/**
	 * Pre-condition: the specified subject is not <code>null</code>
	 */
	protected void disengageListeners_(T subject) {
		JptCommonUiPlugin.instance().trace(TRACE_OPTION, "disengageListeners_({0})", subject);

		for (String propertyName : this.getPropertyNames()) {
			subject.removePropertyChangeListener(propertyName, this.aspectChangeListener);
		}
	}

	/**
	 * Returns the main <code>Composite</code> of this pane.
	 *
	 * @return The main container
	 *
	 * @category Layout
	 */
	public Control getControl() {
		if (!addsComposite()) {
			throw new IllegalStateException("Must override getControl() if addsComposite() returns false");
		}
		return this.container;
	}

	/**
	 * Returns the subject holder used by this pane.
	 *
	 * @return The holder of the subject
	 *
	 * @category Populate
	 */
	protected final PropertyValueModel<? extends T> getSubjectHolder() {
		return this.subjectModel;
	}

	/**
	 * If the pane is a <em>root</em> pane, return its widget factory;
	 * otherwise return the pane's parent's widget factory.
	 */
	protected final WidgetFactory getWidgetFactory() {
		return (this.parent == null) ? this.widgetFactory : this.parent.getWidgetFactory();
	}

	/**
	 * If the pane is a <em>root</em> pane, return its resource manager;
	 * otherwise return the pane's parent's resource manager.
	 */
	public final ResourceManager getResourceManager() {
		return (this.parent == null) ? this.resourceManager : this.parent.getResourceManager();
	}

	protected final void setHelp(Control control, String contextID) {
		WorkbenchTools.setHelp(control, contextID);
	}

	protected final boolean isPopulating() {
		return this.populating;
	}

	/**
	 * Notifies this pane to populate itself using the subject's information.
	 *
	 * @category Populate
	 */
	private void populate() {
		if (!this.getControl().isDisposed()) {
			JptCommonUiPlugin.instance().trace(TRACE_OPTION, "populate");
			this.repopulate();
		}
	}

	/**
	 * The subject's specified property has changed.
	 */
	protected void propertyChanged(@SuppressWarnings("unused") String propertyName) {
		// NOP
	}

	/**
	 * Return the names of the subject's properties we listen to here and notify
	 * via calls to {@link #propertyChanged(String)}.
	 */
	private Collection<String> getPropertyNames() {
		ArrayList<String> propertyNames = new ArrayList<String>();
		this.addPropertyNames(propertyNames);
		return propertyNames;
	}

	/**
	 * This method is called (perhaps internally) when this needs to repopulate
	 * but the object of interest has not changed.
	 */
	protected final void repopulate() {
		JptCommonUiPlugin.instance().trace(TRACE_OPTION, "repopulate");

		try {
			this.setPopulating(true);
			this.doPopulate();
		} finally {
			this.setPopulating(false);
		}
	}

	/**
	 * Sets the internal flag that is used to determine whether the pane is being
	 * populated or not. During population, it is required to not update the
	 * widgets when the model is updated nor to update the model when the widgets
	 * are being synchronized with the model's values.
	 */
	protected final void setPopulating(boolean populating) {
		this.populating = populating;
	}

	/**
	 * Either show or hides this pane.
	 */
	public void setVisible(boolean visible) {
		if (this.container != null && !this.container.isDisposed()) {
			this.container.setVisible(visible);
		}
	}

	/**
	 * @see Control#getShell()
	 */
	public final Shell getShell() {
		return this.getControl().getShell();
	}

	/**
	 * Return the pane's subject.
	 */
	public T getSubject() {
		return this.subjectModel.getValue();
	}

	/**
	 * The pane's subject has changed. Disconnect any listeners from the old
	 * subject and connect those listeners to the new subject.
	 */
	/* CU private */ final void subjectChanged(T oldSubject, T newSubject) {
		if ( ! this.getControl().isDisposed()) {
			JptCommonUiPlugin.instance().trace(TRACE_OPTION, "subjectChanged({0}, {1})", oldSubject, newSubject);
			this.disengageListeners(oldSubject);
			this.repopulate();
			this.engageListeners(newSubject);
		}
	}

	private void updatePane(String propertyName) {
		if (!isPopulating() && !this.getControl().isDisposed()) {
			this.populating = true;

			try {
				propertyChanged(propertyName);
			}
			finally {
				this.populating = false;
			}
		}
	}

	protected void controlDisposed() {
		// the control is not yet "disposed" when we receive this event
		// so we can still remove our listeners
		JptCommonUiPlugin.instance().trace(TRACE_OPTION, "control disposed");

		this.disengageListeners(getSubject());

		this.subjectModel.removePropertyChangeListener(PropertyValueModel.VALUE, this.subjectChangeListener);

		this.enabledModel.removePropertyChangeListener(PropertyValueModel.VALUE, this.enabledModelListener);
		this.getControl().removeDisposeListener(this.controlDisposeListener);
		if (this.parent == null) {
			this.resourceManager.dispose();
		}
	}

	private static final String TRACE_OPTION = Pane.class.getSimpleName();
}