/*
* Copyright (c) 2007 BUSINESS OBJECTS SOFTWARE LIMITED
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Business Objects nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* CompositeScopedEntityFilter.java
* Creation date: Oct 14, 2005.
* By: Joseph Wong
*/
package org.openquark.cal.filter;
import java.util.List;
import org.openquark.cal.compiler.Scope;
import org.openquark.cal.compiler.ScopedEntity;
/**
* A composite scoped entity filter which accepts a scoped entity if and only if
* all its constituent filters accept the entity.
*
* @author Joseph Wong
*/
public abstract class CompositeScopedEntityFilter implements ScopedEntityFilter {
/**
* A specialized subclass for composing two filters.
*
* @author Joseph Wong
*/
private static final class DoubleFilter extends CompositeScopedEntityFilter {
/** The first filter. */
private final ScopedEntityFilter f1;
/** The second filter. */
private final ScopedEntityFilter f2;
/**
* Constructs a composite filter.
* @param f1 the first filter.
* @param f2 the second filter.
*/
private DoubleFilter(final ScopedEntityFilter f1, final ScopedEntityFilter f2) {
if (f1 == null || f2 == null) {
throw new NullPointerException();
}
this.f1 = f1;
this.f2 = f2;
}
/**
* {@inheritDoc}
*/
public boolean acceptScopedEntity(final ScopedEntity entity) {
return f1.acceptScopedEntity(entity) && f2.acceptScopedEntity(entity);
}
/**
* {@inheritDoc}
*/
public boolean acceptBasedOnScopeOnly(final Scope scope) {
return f1.acceptBasedOnScopeOnly(scope) && f2.acceptBasedOnScopeOnly(scope);
}
}
/**
* A specialized subclass for composing three filters.
*
* @author Joseph Wong
*/
private static final class TripleFilter extends CompositeScopedEntityFilter {
/** The first filter. */
private final ScopedEntityFilter f1;
/** The second filter. */
private final ScopedEntityFilter f2;
/** The third filter. */
private final ScopedEntityFilter f3;
/**
* Constructs a composite filter.
* @param f1 the first filter.
* @param f2 the second filter.
* @param f3 the third filter.
*/
private TripleFilter(final ScopedEntityFilter f1, final ScopedEntityFilter f2, final ScopedEntityFilter f3) {
if (f1 == null || f2 == null || f3 == null) {
throw new NullPointerException();
}
this.f1 = f1;
this.f2 = f2;
this.f3 = f3;
}
/**
* {@inheritDoc}
*/
public boolean acceptScopedEntity(final ScopedEntity entity) {
return f1.acceptScopedEntity(entity) && f2.acceptScopedEntity(entity) && f3.acceptScopedEntity(entity);
}
/**
* {@inheritDoc}
*/
public boolean acceptBasedOnScopeOnly(final Scope scope) {
return f1.acceptBasedOnScopeOnly(scope) && f2.acceptBasedOnScopeOnly(scope) && f3.acceptBasedOnScopeOnly(scope);
}
}
/**
* A general composite filter composed of 0 or more constituent filters.
*
* @author Joseph Wong
*/
private static final class GeneralCompositeFilter extends CompositeScopedEntityFilter {
/** The array of filters. */
private final ScopedEntityFilter[] filterArray;
/**
* Constructs a composite filter.
* @param filterList a List of ScopedEntityFilters specifying the constituent filters.
*/
private GeneralCompositeFilter(final List<ScopedEntityFilter> filterList) {
if (filterList == null) {
throw new NullPointerException();
}
filterArray = filterList.toArray(new ScopedEntityFilter[0]);
}
/**
* {@inheritDoc}
*/
public boolean acceptScopedEntity(final ScopedEntity entity) {
for (int i = 0; i < filterArray.length; i++) {
if (!filterArray[i].acceptScopedEntity(entity)) {
return false;
}
}
return true;
}
/**
* {@inheritDoc}
*/
public boolean acceptBasedOnScopeOnly(final Scope scope) {
for (int i = 0; i < filterArray.length; i++) {
if (!filterArray[i].acceptBasedOnScopeOnly(scope)) {
return false;
}
}
return true;
}
}
/**
* Private constructor.
* Factory methods should be used instead for constructing instances.
*/
private CompositeScopedEntityFilter() {}
/**
* Factory method for constructing a composite scoped entity filter composed of two filters.
* @param f1 the first filter.
* @param f2 the second filter.
* @return the composite of f1 and f2.
*/
public static ScopedEntityFilter make(final ScopedEntityFilter f1, final ScopedEntityFilter f2) {
return new DoubleFilter(f1, f2);
}
/**
* Factory method for constructing a composite scoped entity filter composed of three filters.
* @param f1 the first filter.
* @param f2 the second filter.
* @param f3 the third filter.
* @return the composite of f1, f2, and f3.
*/
public static ScopedEntityFilter make(final ScopedEntityFilter f1, final ScopedEntityFilter f2, final ScopedEntityFilter f3) {
return new TripleFilter(f1, f2, f3);
}
/**
* Factory method for constructing a composite scoped entity filter from a list of filters.
* @param filterList a List of ScopedEntityFilters specifying the constituents of the composite filter. Cannot be null, but can be empty.
* @return the appropriate composite filter.
*/
public static ScopedEntityFilter make(final List<ScopedEntityFilter> filterList) {
switch (filterList.size()) {
case 0:
return new AcceptAllScopedEntitiesFilter();
case 1:
return filterList.get(0);
case 2:
return make(filterList.get(0), filterList.get(1));
case 3:
return make(filterList.get(0), filterList.get(1), filterList.get(2));
default:
return new GeneralCompositeFilter(filterList);
}
}
}