001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // 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
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.contrib.form.checkboxes;
016    
017    import org.apache.hivemind.ApplicationRuntimeException;
018    import org.apache.tapestry.BaseComponent;
019    import org.apache.tapestry.IRequestCycle;
020    
021    /**
022     * @author mb
023     * @since 4.0
024    */
025    public abstract class ControlCheckbox extends BaseComponent
026    {
027        public abstract CheckboxGroup getGroup();
028        
029        public CheckboxGroup getCheckboxGroup()
030        {
031            CheckboxGroup group = getGroup();
032            if (group == null) {
033                IRequestCycle cycle = getPage().getRequestCycle();
034                group = (CheckboxGroup) cycle.getAttribute(CheckboxGroup.CHECKBOX_GROUP_ATTRIBUTE);
035            }
036            if (group == null)
037                throw new ApplicationRuntimeException("The component " + getExtendedId() + " must be wrapped by a CheckboxGroup or the 'group' parameter must be set.");
038    
039            return group;
040        }
041    
042    }