001    package org.gwtbootstrap3.client.ui;
002    
003    /*
004     * #%L
005     * GwtBootstrap3
006     * %%
007     * Copyright (C) 2013 GwtBootstrap3
008     * %%
009     * Licensed under the Apache License, Version 2.0 (the "License");
010     * you may not use this file except in compliance with the License.
011     * You may obtain a copy of the License at
012     * 
013     *      http://www.apache.org/licenses/LICENSE-2.0
014     * 
015     * Unless required by applicable law or agreed to in writing, software
016     * distributed under the License is distributed on an "AS IS" BASIS,
017     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018     * See the License for the specific language governing permissions and
019     * limitations under the License.
020     * #L%
021     */
022    
023    import org.gwtbootstrap3.client.ui.base.AbstractListItem;
024    import org.gwtbootstrap3.client.ui.base.button.AbstractToggleButton;
025    import org.gwtbootstrap3.client.ui.constants.Styles;
026    
027    import com.google.gwt.dom.client.Element;
028    import com.google.gwt.user.client.ui.Widget;
029    
030    /**
031     * Drop down item within a list, e.g. {@link NavTabs}, {@link NavPills} or
032     * {@link Navbar}.
033     * <p/>
034     * <h3>UiBinder example</h3>
035     * <p/>
036     * <pre>
037     * {@code
038     *     <b:NavTabs>
039     *         <b:AnchorListItem active="true">Item 1</b:AnchorListItem>
040     *         <b:AnchorListItem>Item 2</b:AnchorListItem>
041     *         <b:ListDropDown>
042     *             <b:AnchorButton toggle="DROPDOWN">Dropdown</b:AnchorButton>
043     *             <b:DropDownMenu>
044     *                 <b:AnchorListItem>Dropdown 1</b:AnchorListItem>
045     *                 <b:AnchorListItem>Dropdown 2</b:AnchorListItem>
046     *                 <b:AnchorListItem>Dropdown 3</b:AnchorListItem>
047     *             </b:DropDownMenu>
048     *         </b:ListDropDown>
049     *         <b:AnchorListItem>Item 3</b:AnchorListItem>
050     *     </b:NavTabs>
051     * }
052     * </pre>
053     *
054     * @author Sven Jacobs
055     * @see NavTabs
056     * @see NavPills
057     * @see Navbar
058     */
059    public class ListDropDown extends AbstractListItem {
060    
061        public ListDropDown() {
062            setStyleName(Styles.DROPDOWN);
063        }
064    
065        @Override
066        public void add(final Widget child) {
067            if (child instanceof AbstractToggleButton) {
068                if (!(child instanceof AnchorButton)) {
069                    throw new IllegalArgumentException("Only buttons of type AnchorButton can be added to ListDropDown");
070                }
071    
072                child.setStyleName(Styles.DROPDOWN_TOGGLE);
073            }
074    
075            add(child, (Element) getElement());
076        }
077    }