/*******************************************************************************
* Copyright (c) 2006, 2015 IBM Corporation and others.
* 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
* Matthew Hall - bug 194734
* Stefan Xenos <sxenos@gmail.com> - Bug 335792
*******************************************************************************/
package org.eclipse.core.databinding.observable.value;
import org.eclipse.core.databinding.observable.Diffs;
import org.eclipse.core.databinding.observable.IDiff;
/**
* @param <T>
* the type of value being observed
* @since 1.0
*
*/
public abstract class ValueDiff<T> implements IDiff {
/**
* Creates a value diff.
*/
public ValueDiff() {
}
/**
* @return the old value
*/
public abstract T getOldValue();
/**
* @return the new value
*/
public abstract T getNewValue();
@Override
public boolean equals(Object obj) {
if (obj instanceof ValueDiff) {
ValueDiff<?> val = (ValueDiff<?>) obj;
return Diffs.equals(val.getNewValue(), getNewValue())
&& Diffs.equals(val.getOldValue(), getOldValue());
}
return false;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
Object nv = getNewValue();
Object ov = getOldValue();
result = prime * result + ((nv == null) ? 0 : nv.hashCode());
result = prime * result + ((ov == null) ? 0 : ov.hashCode());
return result;
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer
.append(getClass().getName())
.append("{oldValue [") //$NON-NLS-1$
.append(getOldValue() != null ? getOldValue().toString() : "null") //$NON-NLS-1$
.append("], newValue [") //$NON-NLS-1$
.append(getNewValue() != null ? getNewValue().toString() : "null") //$NON-NLS-1$
.append("]}"); //$NON-NLS-1$
return buffer.toString();
}
}