1/* 2 * ProGuard -- shrinking, optimization, obfuscation, and preverification 3 * of Java bytecode. 4 * 5 * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu) 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the Free 9 * Software Foundation; either version 2 of the License, or (at your option) 10 * any later version. 11 * 12 * This program is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with this program; if not, write to the Free Software Foundation, Inc., 19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21package proguard.shrink; 22 23import proguard.classfile.*; 24import proguard.classfile.visitor.ClassVisitor; 25 26/** 27 * This ClassVisitor delegates all its method calls to another ClassVisitor, 28 * but only for Clazz objects that are marked as used. 29 * 30 * @see UsageMarker 31 * 32 * @author Eric Lafortune 33 */ 34public class UsedClassFilter 35implements ClassVisitor 36{ 37 private final UsageMarker usageMarker; 38 private final ClassVisitor classVisitor; 39 40 41 /** 42 * Creates a new UsedClassFilter. 43 * @param usageMarker the usage marker that is used to mark the classes 44 * and class members. 45 * @param classVisitor the class visitor to which the visiting will be 46 * delegated. 47 */ 48 public UsedClassFilter(UsageMarker usageMarker, 49 ClassVisitor classVisitor) 50 { 51 this.usageMarker = usageMarker; 52 this.classVisitor = classVisitor; 53 } 54 55 56 // Implementations for ClassVisitor. 57 58 public void visitProgramClass(ProgramClass programClass) 59 { 60 if (usageMarker.isUsed(programClass)) 61 { 62 classVisitor.visitProgramClass(programClass); 63 } 64 } 65 66 67 public void visitLibraryClass(LibraryClass libraryClass) 68 { 69 if (usageMarker.isUsed(libraryClass)) 70 { 71 classVisitor.visitLibraryClass(libraryClass); 72 } 73 } 74} 75