EDIT

import org.eclipse.swt.widgets.Text;

import eu.etaxonomy.taxeditor.ui.combo.taxon.TaxonNodeCombo;

    private Text txtTextFilter;

    private TaxonNodeCombo comboTaxon;

        GridLayout gl_composite = new GridLayout();

        composite.setLayout(gl_composite);

        Composite composite_1 = new Composite(composite, SWT.NONE);

        composite_1.setLayoutData(new GridData(SWT.FILL, SWT.TOP, true, false, 1, 1));

        composite_1.setLayout(new GridLayout(3, false));

        txtTextFilter = new Text(composite_1, SWT.BORDER);

        txtTextFilter.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 1, 1));

        comboTaxon = new TaxonNodeCombo(composite_1, SWT.NONE);

        comboTaxon.setInput(matrix.getWorkingSet().getTaxonSubtreeFilter());

        Button btnRefreshButton = new Button(composite_1, SWT.NONE);

        btnRefreshButton.setToolTipText(Messages.SpecimenSelectionDialog_REFRESH);

 eu.etaxonomy.taxeditor.ui.combo.taxon,

/**

* Copyright (C) 2017 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.taxeditor.ui.combo.taxon;

import org.eclipse.jface.viewers.ComboViewer;

import org.eclipse.jface.viewers.ISelectionChangedListener;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.swt.SWT;

import org.eclipse.swt.custom.CCombo;

import org.eclipse.swt.layout.FillLayout;

import org.eclipse.swt.widgets.Composite;

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

/**

 *

 * @author pplitzner

 * @since Apr 10, 2018

 *

 */

public class TaxonNodeCombo extends Composite{

    private ComboViewer viewer;

    public TaxonNodeCombo(Composite parent, int style){

        super(parent, style);

        setLayout(new FillLayout());

        viewer = new ComboViewer(new CCombo(this, SWT.READ_ONLY | SWT.SINGLE));

        viewer.setContentProvider(new TaxonNodeComboContentProvider());

        viewer.setLabelProvider(new TaxonNodeComboLabelProvider());

    }

    public void setInput(Object input){

        viewer.setInput(input);

    }

    public TaxonNode getSelection(){

        IStructuredSelection structuredSelection = viewer.getStructuredSelection();

        if(structuredSelection!=null && !structuredSelection.isEmpty()){

            return (TaxonNode) structuredSelection.getFirstElement();

        }

        return null;

    }

    public void setElement(TaxonNode element){

        int index = viewer.getCCombo().indexOf(element.getTaxon().getTitleCache());

        viewer.getCCombo().select(index);

    }

    public void addSelectionChangedListener(ISelectionChangedListener listener){

        viewer.addSelectionChangedListener(listener);

    }

}

/**

* Copyright (C) 2017 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.taxeditor.ui.combo.taxon;

import java.util.ArrayList;

import java.util.Collection;

import java.util.List;

import org.eclipse.jface.viewers.IStructuredContentProvider;

import eu.etaxonomy.cdm.api.service.ITaxonNodeService;

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

import eu.etaxonomy.taxeditor.store.CdmStore;

/**

 * @author pplitzner

 * @since Nov 24, 2017

 *

 */

public class TaxonNodeComboContentProvider implements IStructuredContentProvider {

    @Override

    public Object[] getElements(Object inputElement) {

        Collection<TaxonNode> nodes = (Collection<TaxonNode>)inputElement;

        List<TaxonNode> allNodes = new ArrayList<>();

        nodes.forEach(node->{

            allNodes.add(node);

            allNodes.addAll(CdmStore.getService(ITaxonNodeService.class).loadChildNodesOfTaxonNode(node, null, true, null));

        });

        return allNodes.toArray();

    }

}

/**

* Copyright (C) 2017 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.taxeditor.ui.combo.taxon;

import org.eclipse.jface.viewers.LabelProvider;

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

/**

 * @author pplitzner

 * @since Nov 24, 2017

 *

 */

public class TaxonNodeComboLabelProvider extends LabelProvider {

    /**

     * {@inheritDoc}

     */

    @Override

    public String getText(Object element) {

        if(element instanceof TaxonNode){

            return ((TaxonNode) element).getTaxon().getTitleCache();

        }

        return super.getText(element);

    }

}