001/*
002 * BridJ - Dynamic and blazing-fast native interop for Java.
003 * http://bridj.googlecode.com/
004 *
005 * Copyright (c) 2010-2013, Olivier Chafik (http://ochafik.com/)
006 * All rights reserved.
007 *
008 * Redistribution and use in source and binary forms, with or without
009 * modification, are permitted provided that the following conditions are met:
010 * 
011 *     * Redistributions of source code must retain the above copyright
012 *       notice, this list of conditions and the following disclaimer.
013 *     * Redistributions in binary form must reproduce the above copyright
014 *       notice, this list of conditions and the following disclaimer in the
015 *       documentation and/or other materials provided with the distribution.
016 *     * Neither the name of Olivier Chafik nor the
017 *       names of its contributors may be used to endorse or promote products
018 *       derived from this software without specific prior written permission.
019 * 
020 * THIS SOFTWARE IS PROVIDED BY OLIVIER CHAFIK AND CONTRIBUTORS ``AS IS'' AND ANY
021 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
022 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
023 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
024 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
025 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
026 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
027 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
028 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
029 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
030 */
031package org.bridj;
032
033import org.bridj.ann.Constructor;
034
035/**
036 * Base class for C structs.
037 *
038 * @author Olivier
039 */
040@org.bridj.ann.Runtime(CRuntime.class)
041public abstract class StructObject extends NativeObject {
042
043    protected StructIO io;
044
045    protected StructObject() {
046        super();
047    }
048
049    /**
050     * Identified constructor with an arbirary number of arguments
051     *
052     * @param voidArg always null, here to disambiguate some sub-constructors
053     * @param constructorId identifier of the constructor, has to match a
054     * {@link Constructor} annotation or be -1.
055     * @param args
056     */
057    protected StructObject(Void voidArg, int constructorId, Object... args) {
058        super(constructorId, args);
059    }
060
061    protected StructObject(Pointer<? extends StructObject> peer, Object... targs) {
062        super(peer, targs);
063    }
064
065    /**
066     * Creates a String out of this struct using BridJ.describe(this) (see {@link BridJ#describe(NativeObject)
067     * }).
068     */
069    @Override
070    public String toString() {
071        return BridJ.describe(this);
072    }
073    
074    /**
075     * Get the offset of a field in a struct.
076     */
077    public static long offsetOfField(StructObject o, String name) {
078        for (StructFieldDescription desc : o.io.desc.fields) {
079            if (desc.name.equals(name)) {
080                return desc.byteOffset;
081            }
082        }
083        throw new NoSuchFieldError(name);
084    }
085}