/*******************************************************************************
* Copyright (c) 2007 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
*******************************************************************************/
package org.eclipse.ui.internal;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.eclipse.core.expressions.ICountable;
import org.eclipse.core.expressions.IIterable;
import org.eclipse.core.runtime.IAdapterFactory;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
/**
* Adapts ISelection instances to either IIterable or ICountable. For use with
* core expressions.
*
* @since 3.3
*/
public class SelectionAdapterFactory implements IAdapterFactory {
private static final ICountable ICOUNT_0 = new ICountable() {
/*
* (non-Javadoc)
*
* @see org.eclipse.core.expressions.ICountable#count()
*/
public int count() {
return 0;
}
};
private static final ICountable ICOUNT_1 = new ICountable() {
/*
* (non-Javadoc)
*
* @see org.eclipse.core.expressions.ICountable#count()
*/
public int count() {
return 1;
}
};
private static final IIterable ITERATE_EMPTY = new IIterable() {
/*
* (non-Javadoc)
*
* @see org.eclipse.core.expressions.IIterable#iterator()
*/
public Iterator iterator() {
return Collections.EMPTY_LIST.iterator();
}
};
/**
* The classes we can adapt to.
*/
private static final Class[] CLASSES = new Class[] { IIterable.class,
ICountable.class };
public Object getAdapter(Object adaptableObject, Class adapterType) {
if (adaptableObject instanceof ISelection) {
if (adapterType == IIterable.class) {
return iterable((ISelection) adaptableObject);
} else if (adapterType == ICountable.class) {
return countable((ISelection) adaptableObject);
}
}
return null;
}
private Object iterable(final ISelection sel) {
if (sel.isEmpty()) {
return ITERATE_EMPTY;
}
if (sel instanceof IStructuredSelection) {
return new IIterable() {
public Iterator iterator() {
return ((IStructuredSelection) sel).iterator();
}
};
}
final List list = Arrays.asList(new Object[] { sel });
return new IIterable() {
public Iterator iterator() {
return list.iterator();
}
};
}
private Object countable(final ISelection sel) {
if (sel.isEmpty()) {
return ICOUNT_0;
}
if (sel instanceof IStructuredSelection) {
final IStructuredSelection ss = (IStructuredSelection) sel;
return new ICountable() {
public int count() {
return ss.size();
}
};
}
return ICOUNT_1;
}
public Class[] getAdapterList() {
return CLASSES;
}
}