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 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.tools.internal.xjc.reader.xmlschema;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import java.util.Collections;

import com.sun.xml.internal.xsom.XSAnnotation;

import com.sun.xml.internal.xsom.XSAttGroupDecl;

import com.sun.xml.internal.xsom.XSAttributeDecl;

import com.sun.xml.internal.xsom.XSAttributeUse;

import com.sun.xml.internal.xsom.XSComplexType;

import com.sun.xml.internal.xsom.XSComponent;

import com.sun.xml.internal.xsom.XSContentType;

import com.sun.xml.internal.xsom.XSElementDecl;

import com.sun.xml.internal.xsom.XSFacet;

import com.sun.xml.internal.xsom.XSIdentityConstraint;

import com.sun.xml.internal.xsom.XSModelGroup;

import com.sun.xml.internal.xsom.XSModelGroupDecl;

import com.sun.xml.internal.xsom.XSNotation;

import com.sun.xml.internal.xsom.XSParticle;

import com.sun.xml.internal.xsom.XSSchema;

import com.sun.xml.internal.xsom.XSSchemaSet;

import com.sun.xml.internal.xsom.XSSimpleType;

import com.sun.xml.internal.xsom.XSType;

import com.sun.xml.internal.xsom.XSWildcard;

import com.sun.xml.internal.xsom.XSXPath;

import com.sun.xml.internal.xsom.visitor.XSVisitor;

/**

 * Finds which {@link XSComponent}s refer to which {@link XSComplexType}s.

 *

 * @author Kohsuke Kawaguchi

 */

final class RefererFinder implements XSVisitor {

    private final Set<Object> visited = new HashSet<Object>();

    private final Map<XSComponent,Set<XSComponent>> referers = new HashMap<XSComponent,Set<XSComponent>>();

    public Set<XSComponent> getReferer(XSComponent src) {

        Set<XSComponent> r = referers.get(src);

        if(r==null) return Collections.emptySet();

        return r;

    }

    public void schemaSet(XSSchemaSet xss) {

        if(!visited.add(xss))       return;

        for (XSSchema xs : xss.getSchemas()) {

            schema(xs);

        }

    }

    public void schema(XSSchema xs) {

        if(!visited.add(xs))       return;

        for (XSComplexType ct : xs.getComplexTypes().values()) {

            complexType(ct);

        }

        for (XSElementDecl e : xs.getElementDecls().values()) {

            elementDecl(e);

        }

    }

    public void elementDecl(XSElementDecl e) {

        if(!visited.add(e))       return;

        refer(e,e.getType());

        e.getType().visit(this);

    }

    public void complexType(XSComplexType ct) {

        if(!visited.add(ct))       return;

        refer(ct,ct.getBaseType());

        ct.getBaseType().visit(this);

        ct.getContentType().visit(this);

    }

    public void modelGroupDecl(XSModelGroupDecl decl) {

        if(!visited.add(decl))  return;

        modelGroup(decl.getModelGroup());

    }

    public void modelGroup(XSModelGroup group) {

        if(!visited.add(group))  return;

        for (XSParticle p : group.getChildren()) {

            particle(p);

        }

    }

    public void particle(XSParticle particle) {

        // since the particle method is side-effect free, no need to check for double-visit.

        particle.getTerm().visit(this);

    }

    // things we don't care

    public void simpleType(XSSimpleType simpleType) {}

    public void annotation(XSAnnotation ann) {}

    public void attGroupDecl(XSAttGroupDecl decl) {}

    public void attributeDecl(XSAttributeDecl decl) {}

    public void attributeUse(XSAttributeUse use) {}

    public void facet(XSFacet facet) {}

    public void notation(XSNotation notation) {}

    public void identityConstraint(XSIdentityConstraint decl) {}

    public void xpath(XSXPath xp) {}

    public void wildcard(XSWildcard wc) {}

    public void empty(XSContentType empty) {}

    /**

     * Called for each reference to record the fact.

     *

     * So far we only care about references to types.

     */

    private void refer(XSComponent source, XSType target) {

        Set<XSComponent> r = referers.get(target);

        if(r==null) {

            r = new HashSet<XSComponent>();

            referers.put(target,r);

        }

        r.add(source);

    }

}