001 /* 002 * Created on Dec 23, 2007 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 @2007-2010 the original author or authors. 015 */ 016 package org.fest.swing.format; 017 018 import static org.fest.util.Strings.concat; 019 020 import java.awt.Component; 021 022 /** 023 * Understands a template for implementations of <code>{@link ComponentFormatter}</code>. 024 * 025 * @author Yvonne Wang 026 */ 027 public abstract class ComponentFormatterTemplate implements ComponentFormatter { 028 029 /** 030 * Returns the <code>String</code> representation of the given <code>{@link Component}</code>. 031 * @param c the given <code>Component</code>. 032 * @return the <code>String</code> representation of the given <code>Component</code>. 033 * @throws NullPointerException if the given <code>Component</code> is <code>null</code>. 034 * @throws IllegalArgumentException if the type of the given <code>Component</code> is not supported by this 035 * formatter. 036 */ 037 public final String format(Component c) { 038 validateTypeOf(c); 039 return doFormat(c); 040 } 041 042 /** 043 * Returns the <code>String</code> representation of the given <code>{@link Component}</code>. 044 * @param c the given <code>Component</code>. 045 * @return the <code>String</code> representation of the given <code>Component</code>. 046 */ 047 protected abstract String doFormat(Component c); 048 049 private void validateTypeOf(Component c) { 050 if (c == null) throw new NullPointerException("The component should not be null"); 051 if (!targetType().isAssignableFrom(c.getClass())) 052 throw new IllegalArgumentException(concat("This formatter only supports components of type ", targetType().getName())); 053 } 054 055 056 }