org.goko.common.elements.list.GkList.java Source code

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Here is the source code for org.goko.common.elements.list.GkList.java

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/*******************************************************************************
 *    This file is part of Goko.
 *
 *   Goko is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Goko is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Goko.  If not, see <http://www.gnu.org/licenses/>.
 *******************************************************************************/
package org.goko.common.elements.list;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.jface.databinding.viewers.ObservableListContentProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.ListViewer;
import org.eclipse.swt.widgets.Composite;
import org.goko.core.log.GkLog;

public class GkList<T> extends ListViewer {
    public static final GkLog LOG = GkLog.getLogger(GkList.class);

    public GkList(Composite parent, IObservableList list, Class<T> clazz, String labelField) {
        super(parent);
        buildListViewer(list, clazz, labelField);
    }

    protected void buildListViewer(IObservableList list, Class<T> clazz, String labelField) {
        setContentProvider(new ObservableListContentProvider());
        setInput(list);
        setLabelProvider(new BeanLabelProvider(labelField, clazz));
    }

    public GkList(Composite parent, int style) {
        super(parent, style);
    }

    public List<T> getSelectedElements() {
        List<T> selection = new ArrayList<T>();
        IStructuredSelection structuredSelection = (IStructuredSelection) getSelection();
        for (Iterator iterator = structuredSelection.iterator(); iterator.hasNext();) {
            T element = (T) iterator.next();
            selection.add(element);
        }
        return selection;
    }

    class BeanLabelProvider<T> extends LabelProvider {
        String fieldName;
        Class<T> clazz;
        Method getMethod;

        BeanLabelProvider(String fieldName, Class<T> clazz) {
            this.fieldName = fieldName;
            this.clazz = clazz;
        }

        /** (inheritDoc)
         * @see org.eclipse.jface.viewers.LabelProvider#getText(java.lang.Object)
         */
        @Override
        public String getText(Object element) {
            if (element == null) {
                return "";
            }
            if (element.getClass() != clazz) {
                throw new IllegalArgumentException("Class does not match. Got '" + element.getClass()
                        + "', expected '" + clazz.toString() + "'");
            }
            if (getMethod == null) {
                try {
                    findGetMethod();
                } catch (NoSuchFieldException e) {
                    LOG.error(e);
                    return null;
                } catch (SecurityException e) {
                    LOG.error(e);
                    return null;
                } catch (NoSuchMethodException e) {
                    LOG.error(e);
                    return null;
                }
            }
            String label = StringUtils.EMPTY;
            try {
                Object obj = getMethod.invoke(element);
                label = String.valueOf(obj);
            } catch (IllegalAccessException e) {
                LOG.error(e);
                return null;
            } catch (IllegalArgumentException e) {
                LOG.error(e);
                return null;
            } catch (InvocationTargetException e) {
                LOG.error(e);
                return null;
            }
            return label;
        }

        private void findGetMethod() throws NoSuchFieldException, SecurityException, NoSuchMethodException {
            String expectedName = "get" + StringUtils.upperCase(StringUtils.substring(fieldName, 0, 1))
                    + StringUtils.substring(fieldName, 1);
            getMethod = clazz.getDeclaredMethod(expectedName);
        }

    }

}