001    /*
002     * Created on Apr 12, 2008
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005     * in compliance with the License. You may obtain a copy of the License at
006     *
007     * http://www.apache.org/licenses/LICENSE-2.0
008     *
009     * Unless required by applicable law or agreed to in writing, software distributed under the License
010     * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011     * or implied. See the License for the specific language governing permissions and limitations under
012     * the License.
013     *
014     * Copyright @2008-2010 the original author or authors.
015     */
016    package org.fest.swing.driver;
017    
018    import static org.fest.swing.driver.ModelValueToString.asText;
019    
020    import java.awt.Component;
021    
022    import javax.swing.JList;
023    
024    import org.fest.swing.annotation.RunsInCurrentThread;
025    import org.fest.swing.cell.JListCellReader;
026    
027    /**
028     * Understands the default implementation of <code>{@link JListCellReader}</code>.
029     *
030     * @author Alex Ruiz
031     * @author Yvonne Wang
032     */
033    public class BasicJListCellReader implements JListCellReader {
034    
035      private final CellRendererReader rendererReader;
036    
037      /**
038       * Creates a new </code>{@link BasicJListCellReader}</code> that uses a
039       * <code>{@link BasicCellRendererReader}</code> to read the value from the cell renderer component in a
040       * <code>JList</code>.
041       */
042      public BasicJListCellReader() {
043        this(new BasicCellRendererReader());
044      }
045    
046      /**
047       * Creates a new </code>{@link BasicJListCellReader}</code>.
048       * @param rendererReader knows how to read values from the cell renderer component in a
049       * <code>JList</code>.
050       * @throws NullPointerException if <code>rendererReader</code> is <code>null</code>.
051       */
052      public BasicJListCellReader(CellRendererReader rendererReader) {
053        if (rendererReader == null)
054          throw new NullPointerException("CellRendererReader should not be null");
055        this.rendererReader = rendererReader;
056      }
057    
058      /**
059       * Returns the internal value of a cell in a <code>{@link JList}</code> as expected in a test.
060       * <p>
061       * <b>Note:</b> This method is <b>not</b> guaranteed to be executed in the event dispatch thread (EDT.) Clients are
062       * responsible for calling this method from the EDT.
063       * </p>
064       * @param list the given <code>JList</code>.
065       * @param index the index of the cell.
066       * @return the internal value of a cell in a <code>JList</code> as expected in a test.
067       * @see CellRendererReader#valueFrom(Component)
068       */
069      @RunsInCurrentThread
070      public String valueAt(JList list, int index) {
071        Object element = list.getModel().getElementAt(index);
072        Component c = list.getCellRenderer().getListCellRendererComponent(list, element, index, true, true);
073        String value = (c != null) ? rendererReader.valueFrom(c) : null;
074        if (value != null) return value;
075        return asText(element);
076      }
077    }