/*******************************************************************************
* Copyright (c) 2007, 2009 Wind River Systems 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:
* Wind River Systems - initial API and implementation
*******************************************************************************/
package org.eclipse.cdt.dsf.datamodel;
import java.util.Arrays;
/**
* Generic DM context used to combine several DM Contexts. This object allows
* clients and other services to combine several contexts into one in order to
* pass them as an argument to a method which takes a generic context as an
* argument.
*
* @since 1.0
*/
public class CompositeDMContext implements IDMContext {
public static String INVALID_SESSION_ID = ""; //$NON-NLS-1$
/**
* The list of parent contexts that this composite context is made up of.
*/
private final IDMContext[] fParents;
/**
* Main constructor provides all data needed to implement the <code>IDMContext</code>
* interface.
* @param parents Array of parent contexts that this composite context is
* made up of. It can be an empty array, but it cannot be null.
*/
public CompositeDMContext(IDMContext[] parents) {
fParents = parents;
}
/**
* Returns the session ID of the first element in the array of parents of this
* context. May return an empty string if the parents array has no elements.
* <p>
* Note: The session ID is primarily used by UI components to get access to the
* correct session and executor for the given context. The composite context is
* intended to be created by clients which already know the session ID so
* the fact that this method may not return a reliable result is acceptable.
* </p>
*/
public String getSessionId() {
IDMContext[] parents = getParents();
if (parents.length > 0) {
return parents[0].getSessionId();
} else {
return INVALID_SESSION_ID;
}
}
/**
* Returns the list of parents that this composite context is based on. Subclasses
* may override this method to calculate their own set of parents.
*/
public IDMContext[] getParents() {
return fParents;
}
/**
* Returns the given adapter of the last DMVMContext element found in the tree
* path of this composite context. Will return null if no DMVMContext is found
* in path.
* @see #getSessionId()
*/
@SuppressWarnings("unchecked")
public Object getAdapter(Class adapterType) {
IDMContext[] parents = getParents();
if (parents.length > 0) {
return parents[0].getAdapter(adapterType);
} else {
return null;
}
}
@Override
public boolean equals(Object obj) {
return obj instanceof CompositeDMContext && Arrays.equals(((CompositeDMContext)obj).getParents(), getParents());
}
@Override
public int hashCode() {
return Arrays.hashCode(getParents());
}
}