/*******************************************************************************
 *  Copyright (c) 2008 Oracle. All rights reserved.
 *  This program and the accompanying materials are made available under the
 *  terms of the Eclipse Public License v1.0 which accompanies this
 *  distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 *  Contributors: Oracle. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jpt.ui.internal.widgets;

import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jpt.ui.internal.listeners.SWTPropertyChangeListenerWrapper;
import org.eclipse.jpt.ui.internal.swt.ListBoxModelAdapter;
import org.eclipse.jpt.ui.internal.swt.ListBoxModelAdapter.SelectionChangeEvent;
import org.eclipse.jpt.ui.internal.swt.ListBoxModelAdapter.SelectionChangeListener;
import org.eclipse.jpt.utility.internal.CollectionTools;
import org.eclipse.jpt.utility.internal.StringConverter;
import org.eclipse.jpt.utility.internal.model.Model;
import org.eclipse.jpt.utility.internal.model.event.PropertyChangeEvent;
import org.eclipse.jpt.utility.internal.model.listener.PropertyChangeListener;
import org.eclipse.jpt.utility.internal.model.value.ListValueModel;
import org.eclipse.jpt.utility.internal.model.value.PropertyValueModel;
import org.eclipse.jpt.utility.internal.model.value.SimplePropertyValueModel;
import org.eclipse.jpt.utility.internal.model.value.WritablePropertyValueModel;
import org.eclipse.jpt.utility.internal.model.value.swing.ObjectListSelectionModel;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.List;

/**
 * This implementation of the <code>AddRemovePane</code> uses a <code>List</code>
 * as its main widget.
 * <p>
 * Here the layot of this pane:
 * <pre>
 * -----------------------------------------------------------------------------
 * | ------------------------------------------------------------- ----------- |
 * | | Item 1                                                    | | Add...  | |
 * | | ...                                                       | ----------- |
 * | | Item n                                                    | ----------- |
 * | |                                                           | | Edit... | |
 * | |                                                           | ----------- |
 * | |                                                           | ----------- |
 * | |                                                           | | Remove  | |
 * | |                                                           | ----------- |
 * | -------------------------------------------------------------             |
 * -----------------------------------------------------------------------------</pre>
 *
 * @version 2.0
 * @since 1.0
 */
public class AddRemoveListPane<T extends Model> extends AddRemovePane<T>
{
	/**
	 * The main widget of this add/remove pane.
	 */
	private List list;

	/**
	 * Flag used to prevent circular
	 */
	private boolean locked;

	/**
	 * Creates a new <code>AddRemoveListPane</code>.
	 *
	 * @param parentPane The parent container of this one
	 * @param parent The parent container
	 * @param adapter
	 * @param listHolder The <code>ListValueModel</code> containing the items
	 * @param selectedItemHolder The holder of the selected item, if more than
	 * one item or no items are selected, then <code>null</code> will be passed
	 * @param labelProvider The renderer used to format the list holder's items
	 */
	public AddRemoveListPane(AbstractPane<? extends T> parentPane,
	                         Composite parent,
	                         Adapter adapter,
	                         ListValueModel<?> listHolder,
	                         WritablePropertyValueModel<?> selectedItemHolder,
	                         ILabelProvider labelProvider) {

		super(parentPane,
		      parent,
		      adapter,
		      listHolder,
		      selectedItemHolder,
		      labelProvider);
	}

	/**
	 * Creates a new <code>AddRemoveListPane</code>.
	 *
	 * @param parentPane The parent container of this one
	 * @param parent The parent container
	 * @param adapter
	 * @param listHolder The <code>ListValueModel</code> containing the items
	 * @param selectedItemHolder The holder of the selected item, if more than
	 * one item or no items are selected, then <code>null</code> will be passed
	 * @param labelProvider The renderer used to format the list holder's items
	 * @param helpId The topic help ID to be registered with this pane
	 */
	public AddRemoveListPane(AbstractPane<? extends T> parentPane,
	                         Composite parent,
	                         Adapter adapter,
	                         ListValueModel<?> listHolder,
	                         WritablePropertyValueModel<?> selectedItemHolder,
	                         ILabelProvider labelProvider,
	                         String helpId) {

		super(parentPane,
		      parent,
		      adapter,
		      listHolder,
		      selectedItemHolder,
		      labelProvider,
		      helpId);
	}

	/**
	 * Creates a new <code>AddRemoveListPane</code>.
	 *
	 * @param parentPane The parent container of this one
	 * @param subjectHolder The holder of the subject
	 * @param adapter
	 * @param parent The parent container
	 * @param listHolder The <code>ListValueModel</code> containing the items
	 * @param selectedItemHolder The holder of the selected item, if more than
	 * one item or no items are selected, then <code>null</code> will be passed
	 * @param labelProvider The renderer used to format the list holder's items
	 */
	public AddRemoveListPane(AbstractPane<?> parentPane,
	                         PropertyValueModel<? extends T> subjectHolder,
	                         Composite parent,
	                         Adapter adapter,
	                         ListValueModel<?> listHolder,
	                         WritablePropertyValueModel<?> selectedItemHolder,
	                         ILabelProvider labelProvider) {

		super(parentPane,
		      subjectHolder,
		      parent,
		      adapter,
		      listHolder,
		      selectedItemHolder,
		      labelProvider);
	}

	/**
	 * Creates a new <code>AddRemoveListPane</code>.
	 *
	 * @param parentPane The parent container of this one
	 * @param subjectHolder The holder of the subject
	 * @param adapter
	 * @param parent The parent container
	 * @param listHolder The <code>ListValueModel</code> containing the items
	 * @param selectedItemHolder The holder of the selected item, if more than
	 * one item or no items are selected, then <code>null</code> will be passed
	 * @param labelProvider The renderer used to format the list holder's items
	 * @param helpId The topic help ID to be registered with this pane
	 */
	public AddRemoveListPane(AbstractPane<?> parentPane,
	                         PropertyValueModel<? extends T> subjectHolder,
	                         Composite parent,
	                         Adapter adapter,
	                         ListValueModel<?> listHolder,
	                         WritablePropertyValueModel<?> selectedItemHolder,
	                         ILabelProvider labelProvider,
	                         String helpId) {

		super(parentPane,
		      subjectHolder,
		      parent,
		      adapter,
		      listHolder,
		      selectedItemHolder,
		      labelProvider,
		      helpId);
	}

	private WritablePropertyValueModel<String> buildSelectedItemHolder() {
		return new SimplePropertyValueModel<String>();
	}

	private PropertyChangeListener buildSelectedItemPropertyChangeListener() {
		return new SWTPropertyChangeListenerWrapper(
			buildSelectedItemPropertyChangeListener_()
		);
	}

	private PropertyChangeListener buildSelectedItemPropertyChangeListener_() {
		return new PropertyChangeListener() {
			public void propertyChanged(PropertyChangeEvent e) {
				if (list.isDisposed()) {
					return;
				}
				if (!locked) {
					locked = true;

					try {
						Object value = e.newValue();
						getSelectionModel().setSelectedValue(e.newValue());
						int index = -1;

						if (value != null) {
							index = CollectionTools.indexOf(getListHolder().iterator(), value);
						}

						list.select(index);
						updateButtons();
					}
					finally {
						locked = false;
					}
				}
			}
		};
	}

	private SelectionChangeListener<Object> buildSelectionListener() {
		return new SelectionChangeListener<Object>() {
			public void selectionChanged(SelectionChangeEvent<Object> e) {
				AddRemoveListPane.this.selectionChanged();
			}
		};
	}

	private StringConverter<Object> buildStringConverter(final ILabelProvider labelProvider) {
		return new StringConverter<Object>() {
			public String convertToString(Object item) {
				return labelProvider.getText(item);
			}
		};
	}

	/*
	 * (non-Javadoc)
	 */
	@Override
	@SuppressWarnings("unchecked")
	protected void initializeMainComposite(Composite container,
	                                       Adapter adapter,
	                                       ListValueModel<?> listHolder,
	                                       WritablePropertyValueModel<?> selectedItemHolder,
	                                       ILabelProvider labelProvider,
	                                       String helpId) {

		list = buildList(container, buildSelectedItemHolder(), helpId);

		ListBoxModelAdapter<Object> listModel = ListBoxModelAdapter.adapt(
			(ListValueModel<Object>) listHolder,
			new SimplePropertyValueModel<Object>(),
			list,
			buildStringConverter(labelProvider)
		);

		listModel.addSelectionChangeListener(buildSelectionListener());

		selectedItemHolder.addPropertyChangeListener(
			PropertyValueModel.VALUE,
			buildSelectedItemPropertyChangeListener()
		);
	}

	/**
	 * The selection has changed, update (1) the selected item holder, (2) the
	 * selection model and (3) the buttons.
	 */
	private void selectionChanged() {

		if (locked) {
			return;
		}

		locked = true;

		try {
			WritablePropertyValueModel<Object> selectedItemHolder = getSelectedItemHolder();
			ObjectListSelectionModel selectionModel = getSelectionModel();
			int selectionCount = list.getSelectionCount();

			if (selectionCount == 0) {
				selectedItemHolder.setValue(null);
				selectionModel.clearSelection();
			}
			else if (selectionCount != 1) {
				selectedItemHolder.setValue(null);
				selectionModel.clearSelection();

				for (int index : list.getSelectionIndices()) {
					selectionModel.addSelectionInterval(index, index);
				}
			}
			else {
				int selectedIndex = list.getSelectionIndex();
				Object selectedItem = getListHolder().get(selectedIndex);

				selectedItemHolder.setValue(selectedItem);
				selectionModel.setSelectedValue(selectedItem);
			}

			updateButtons();
		}
		finally {
			locked = false;
		}
	}

	/**
	 * Selects the given value, which can be <code>null</code>.
	 *
	 * @param value The new selected value
	 */
	public void setSelectedItem(Object value) {
		getSelectedItemHolder().setValue(value);
	}
}