EDIT

/**

 * 

 */

package eu.etaxonomy.taxeditor.forms.term;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

import org.apache.log4j.Logger;

import org.eclipse.jface.util.PropertyChangeEvent;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.DisposeEvent;

import org.eclipse.swt.events.DisposeListener;

import org.eclipse.swt.events.SelectionEvent;

import org.eclipse.swt.events.SelectionListener;

import org.eclipse.swt.graphics.Color;

import org.eclipse.swt.widgets.Combo;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Label;

import org.eclipse.swt.widgets.Listener;

import eu.etaxonomy.cdm.model.common.DefinedTermBase;

import eu.etaxonomy.taxeditor.editor.EditorUtil;

import eu.etaxonomy.taxeditor.forms.AbstractCdmFormElement;

import eu.etaxonomy.taxeditor.forms.CdmFormFactory;

import eu.etaxonomy.taxeditor.forms.CdmPropertyChangeEvent;

import eu.etaxonomy.taxeditor.forms.ICdmFormElement;

import eu.etaxonomy.taxeditor.forms.IEnableableFormElement;

import eu.etaxonomy.taxeditor.preference.PreferencesUtil;

import eu.etaxonomy.taxeditor.preference.Resources;

import eu.etaxonomy.taxeditor.store.CdmStore;

/**

 * <p>Abstract AbstractTermComboElement class.</p>

 *

 * @author n.hoffmann

 * @created Nov 5, 2009

 * @version 1.0

 * @param <T>

 */

public abstract class AbstractTermComboElement<T extends DefinedTermBase> extends AbstractCdmFormElement implements SelectionListener, DisposeListener, IEnableableFormElement{

	private static final Logger logger = Logger.getLogger(AbstractTermComboElement.class);

	T selection;

	private static String EMPTY_ELEMENT_LABEL = "";

	T emptyElement;

	protected Label label;

	private Combo combo;

	private ArrayList<T> terms;

	private Comparator<T> termComparator;

	private Composite msgComposite;

	/**

	 * <p>Constructor for AbstractTermComboElement.</p>

	 *

	 * @param parentElement a {@link eu.etaxonomy.taxeditor.forms.ICdmFormElement} object.

	 * @param style a int.

	 * @param formFactory a {@link eu.etaxonomy.taxeditor.forms.CdmFormFactory} object.

	 * @param labelString a {@link java.lang.String} object.

	 * @param selection a T object.

	 * @param visibleItems a int.

	 * @param <T> a T object.

	 */

	public AbstractTermComboElement(CdmFormFactory formFactory, ICdmFormElement parentElement, String labelString, T selection, int visibleItems, int style) {

		super(formFactory, parentElement);

		if(labelString != null){

			label = formFactory.createLabel(getLayoutComposite(), labelString);

			addControl(label);

		}

        // create combo

        combo = new Combo(getLayoutComposite(), SWT.BORDER | SWT.READ_ONLY);

		addControl(combo);

        combo.setLayoutData(CdmFormFactory.FILL_HORIZONTALLY());

        combo.setVisibleItemCount(visibleItems);

        populateTerms();

        combo.addSelectionListener(this);

        combo.addDisposeListener(this);

        PreferencesUtil.getPreferenceStore().addPropertyChangeListener(this);

        if(selection != null){

        	setSelection(selection);

        }

	}

	/**

	 * <p>Getter for the field <code>selection</code>.</p>

	 *

	 * @return a T object.

	 */

	public T getSelection(){

		return selection;

	}

	/**

	 * <p>Setter for the field <code>selection</code>.</p>

	 *

	 * @param selection a T object.

	 */

	public void setSelection(T selection){

		Listener[] listeners = combo.getListeners(SWT.Selection);

		for (Listener listener : listeners){

			combo.removeListener(SWT.Selection, listener);

		}

		int index = terms.indexOf(selection);

		if(index == -1){

			createTermNotInPreferredTerms(selection);

		}else{

			combo.select(index);

		}

		for (Listener listener : listeners){

			combo.addListener(SWT.Selection, listener);

		}

	}

	private void populateTerms(){

		List<T> preferredTerms = preferredTerms();

		combo.removeAll();

		terms = new ArrayList<T>();

		int i = 1;

		int index = 0;

		// Add an empty element for when nothing was selected already

		combo.add(EMPTY_ELEMENT_LABEL);

		terms.add(emptyElement);

		if(termComparator != null)

			Collections.sort(preferredTerms, termComparator);

		for (T term : preferredTerms) {

			String label = getLabel(term); 

			if (label == null) {

				if(term.getTitleCache() != null){

					label = term.getTitleCache();

					logger.error("Term does not have a representation: " + term + ", " + term.getUuid());

				}else{

					label = "Unknown";

					logger.error("Representation Label and TitleCache empty for term: " + term + ", " + term.getUuid());

				}

			}

			combo.add(label);

			terms.add(term);

			i++;

			if (selection != null) {

				if (selection.equals(term)) {

			 		index = i;

				}

			} else {

				// TODO isn't it better to put the last language at the top of the menu, not automatically select?

//					if (lastLanguage != null && lastLanguage.equals(language)) {

//						index = i;  

//					}

			}

		}

		// Check whether language is in menu

		if (msgComposite != null) {

			msgComposite.dispose();

			msgComposite = null;

		}

		if (selection != null && index == 0) {

			createTermNotInPreferredTerms(selection);

		}

		combo.select(index);	

	}

	/*

	 * (non-Javadoc)

	 * @see eu.etaxonomy.taxeditor.forms.IEnableableFormElement#setEnabled(boolean)

	 */

	/** {@inheritDoc} */

	public void setEnabled(boolean enabled) {

		combo.setEnabled(enabled);

	}

	/**

	 * <p>preferredTerms</p>

	 *

	 * @return a {@link java.util.List} object.

	 */

	protected abstract List<T> preferredTerms();

	/**

	 * May be overridden by derived classes if the desired label string does not

	 * reside in term.getLabel();

	 *

	 * @param term a T object.

	 * @return a {@link java.lang.String} object.

	 */

	protected String getLabel(T term){

		return term.getLabel(CdmStore.getDefaultLanguage());

	}

	private void createTermNotInPreferredTerms(T term) {

//		PreferencesUtil.addTermToPreferredTerms(term);

//	

//		msgComposite = formFactory.createComposite(getLayoutComposite());

//		msgComposite.setLayout(LAYOUT());

//		msgComposite.setLayoutData(FILL_GRID_HORIZONTALLY(2, 1));

//		

//		String langText = term.getDescription() == null ? term.getLabel() : term.getDescription();

//		langText += " is used here, but was not in your list of preferred terms.";

//		Label label = formFactory.createLabel(msgComposite, langText, SWT.WRAP);

//

//		

//		msgComposite.moveBelow(combo);

//		

//		getLayoutComposite().layout();

//		setSelection(term);

	}

	/**

	 * <p>addSelectionListener</p>

	 *

	 * @param listener a {@link org.eclipse.swt.events.SelectionListener} object.

	 */

	public void addSelectionListener(SelectionListener listener){

		combo.addSelectionListener(listener);

	}

	/**

	 * <p>removeSelectionListener</p>

	 *

	 * @param listener a {@link org.eclipse.swt.events.SelectionListener} object.

	 */

	public void removeSelectionListener(SelectionListener listener){

		combo.removeSelectionListener(listener);

	}

	/* (non-Javadoc)

	 * @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)

	 */

	/** {@inheritDoc} */

	public void widgetSelected(SelectionEvent e) {

		selection = terms.get(combo.getSelectionIndex());

		firePropertyChangeEvent(new CdmPropertyChangeEvent(this, e));

	}

	/* (non-Javadoc)

	 * @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent)

	 */

	/** {@inheritDoc} */

	public void propertyChange(PropertyChangeEvent event) {

		super.propertyChange(event);

		if (event != null && PreferencesUtil.PREFERRED_TERMS_CHANGE.equals(event.getProperty())) {

			populateTerms();

		}

	}

	/** {@inheritDoc} */

	public void setSelected(boolean selected) {

		label.setBackground(getColor(selected));

	}

	/** {@inheritDoc} */

	public void widgetDisposed(DisposeEvent e) {

		PreferencesUtil.getPreferenceStore().removePropertyChangeListener(this);

	}

	// not used

	/** {@inheritDoc} */

	public void widgetDefaultSelected(SelectionEvent e) {}

	/** {@inheritDoc} */

	public void setIrrelevant(boolean irrelevant) {

		String colorId = irrelevant ? Resources.COLOR_COMPOSITE_IRRELEVANT : Resources.COLOR_COMPOSITE_BACKGROUND;

		Color color = EditorUtil.getColor(colorId);

		combo.setBackground(color);

	}

	/** {@inheritDoc} */

	@Override

	public void setBackground(Color color) {

		if(label != null)

			label.setBackground(color);

	}

}