/*******************************************************************************
* Copyright (c) 2007 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.ipa.callgraph;
/**
* A context that first checks with A, then defaults to B.
*/
public class DelegatingContext implements Context {
private final Context A;
private final Context B;
public DelegatingContext(Context A, Context B) {
this.A = A;
this.B = B;
if (A == null) {
throw new IllegalArgumentException("null A");
}
if (B == null) {
throw new IllegalArgumentException("null B");
}
}
@Override
public ContextItem get(ContextKey name) {
ContextItem result = A.get(name);
if (result == null) {
result = B.get(name);
}
return result;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + A.hashCode();
result = prime * result + B.hashCode();
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
DelegatingContext other = (DelegatingContext) obj;
if (!A.equals(other.A))
return false;
if (!B.equals(other.B))
return false;
return true;
}
@Override
public String toString() {
return "DelegatingContext [A=" + A + ", B=" + B + "]";
}
}