EDIT

package eu.etaxonomy.cdm.vaadin.view.dbstatus;

import java.sql.SQLException;

import java.util.List;

import com.vaadin.data.Container;

import com.vaadin.data.Property.ValueChangeEvent;

import com.vaadin.data.Property.ValueChangeListener;

import com.vaadin.data.util.IndexedContainer;

import com.vaadin.event.ShortcutAction.KeyCode;

import com.vaadin.navigator.View;

import com.vaadin.navigator.ViewChangeListener.ViewChangeEvent;

import com.vaadin.ui.Alignment;

import com.vaadin.ui.Button;

import com.vaadin.ui.Button.ClickEvent;

import com.vaadin.ui.Button.ClickListener;

import com.vaadin.ui.ComboBox;

import com.vaadin.ui.CustomComponent;

import com.vaadin.ui.Label;

import com.vaadin.ui.Panel;

import com.vaadin.ui.Tree;

import com.vaadin.ui.VerticalLayout;

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

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

import eu.etaxonomy.cdm.model.taxon.TaxonNode;

import eu.etaxonomy.cdm.vaadin.container.TaxonNodeContainer;

public class DistributionSelectionView extends CustomComponent implements IDistributionSelectionComponent, View, ClickListener{

    private VerticalLayout mainLayout;

    private Panel panel_1;

    private VerticalLayout verticalLayout_2;

    private Button button_proceed;

    private ComboBox distributionAreaBox;

    private ComboBox classificationBox;

    private Tree taxonTree;

    private Label label_1;

    private static final long serialVersionUID = 1L;

	private DistributionSelectionComponentListener distListener;

	/**

	 * The constructor should first build the main layout, set the

	 * composition root and then do any custom initialization.

	 *

	 * The constructor will not be automatically regenerated by the

	 * visual editor.

	 */

	public DistributionSelectionView(){

		buildMainLayout();

		setCompositionRoot(mainLayout);

		setStyleName("login");

		button_proceed.addClickListener(this);

		button_proceed.setClickShortcut(KeyCode.ENTER, null);

	}

	@Override

	public void addListener(DistributionSelectionComponentListener listener) {

		distListener = listener;

	}

	@Override

	public void buttonClick(ClickEvent event) {

		TaxonNode taxonNode = (TaxonNode) taxonTree.getValue();

		if(taxonNode==null){

			taxonNode = (TaxonNode) classificationBox.getValue();

		}

		TermVocabulary<DefinedTermBase> term = (TermVocabulary<DefinedTermBase>)distributionAreaBox.getValue();

		try {

			distListener.buttonClick(taxonNode, term);

		} catch (SQLException e) {

			e.printStackTrace();

		}

	}

	public void dataBinding(){

		classificationBox.setItemCaptionPropertyId(TaxonNodeContainer.LABEL);

		classificationBox.setContainerDataSource(new TaxonNodeContainer(null));

		classificationBox.setImmediate(true);

		classificationBox.addValueChangeListener(new ValueChangeListener() {

			@Override

			public void valueChange(ValueChangeEvent event) {

				TaxonNode parentNode = (TaxonNode) event.getProperty().getValue();

				taxonTree.setContainerDataSource(new TaxonNodeContainer(parentNode));

			}

		});

        taxonTree.setItemCaptionPropertyId(TaxonNodeContainer.LABEL);

		List<TermVocabulary<DefinedTermBase>> namedAreaList = distListener.getNamedAreaList();

		Container d = new IndexedContainer(namedAreaList);

		distributionAreaBox.setContainerDataSource(d);

	}

	@Override

	public void enter(ViewChangeEvent event) {

	}

    private VerticalLayout buildMainLayout() {

        // common part: create layout

        mainLayout = new VerticalLayout();

        mainLayout.setImmediate(false);

        mainLayout.setWidth("100%");

        mainLayout.setHeight("100%");

        mainLayout.setMargin(false);

        // top-level component properties

        setWidth("100.0%");

        setHeight("100.0%");

        // panel_1

        panel_1 = buildPanel_1();

        mainLayout.addComponent(panel_1);

        mainLayout.setComponentAlignment(panel_1, new Alignment(48));

        return mainLayout;

    }

    private Panel buildPanel_1() {

        // common part: create layout

        panel_1 = new Panel();

        panel_1.setImmediate(false);

        panel_1.setWidth("-1px");

        panel_1.setHeight("-1px");

        // verticalLayout_2

        verticalLayout_2 = buildVerticalLayout_2();

        panel_1.setContent(verticalLayout_2);

        return panel_1;

    }

    private VerticalLayout buildVerticalLayout_2() {

        // common part: create layout

        verticalLayout_2 = new VerticalLayout();

        verticalLayout_2.setImmediate(false);

        verticalLayout_2.setWidth("-1px");

        verticalLayout_2.setHeight("-1px");

        verticalLayout_2.setMargin(true);

        verticalLayout_2.setSpacing(true);

        // label_1

        label_1 = new Label();

        label_1.setImmediate(false);

        label_1.setWidth("213px");

        label_1.setHeight("-1px");

        label_1.setValue("Please choose a Classification and/or taxon and a distribution area to proceed.");

        verticalLayout_2.addComponent(label_1);

        // classificationBox

        classificationBox = new ComboBox();

        classificationBox.setCaption("Classification: ");

        classificationBox.setImmediate(false);

        classificationBox.setWidth("200px");

        classificationBox.setHeight("-1px");

        verticalLayout_2.addComponent(classificationBox);

        // distributionAreaBox

        distributionAreaBox = new ComboBox();

        distributionAreaBox.setCaption("Distribution Area");

        distributionAreaBox.setImmediate(false);

        distributionAreaBox.setWidth("200px");

        distributionAreaBox.setHeight("-1px");

        verticalLayout_2.addComponent(distributionAreaBox);

        // taxon tree

        taxonTree = new Tree("Taxonomy");

        taxonTree.setWidth("200px");

        verticalLayout_2.addComponent(taxonTree);

        // button_proceed

        button_proceed = new Button();

        button_proceed.setCaption("Proceed");

        button_proceed.setImmediate(true);

        button_proceed.setWidth("-1px");

        button_proceed.setHeight("-1px");

        verticalLayout_2.addComponent(button_proceed);

        verticalLayout_2.setComponentAlignment(button_proceed, new Alignment(10));

        return verticalLayout_2;

    }

}