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package org.netbeans.html.context.impl;

import net.java.html.BrwsrCtx;

import org.netbeans.html.context.spi.Contexts.Builder;

/** Internal communication between API (e.g. {@link BrwsrCtx}), SPI

 * (e.g. {@link Builder}) and the implementation package.

 *

 * @author Jaroslav Tulach

 */

public abstract class CtxAccssr {

    private static CtxAccssr DEFAULT;

    static {

        // run initializers

        try {

            BrwsrCtx.EMPTY.getClass();

        } catch (NullPointerException ex) {

            // ignore

        }

    }

    protected CtxAccssr() {

        if (DEFAULT != null) throw new IllegalStateException();

        DEFAULT = this;

    }

    protected abstract BrwsrCtx newContext(CtxImpl impl);

    protected abstract CtxImpl find(BrwsrCtx context);

    static CtxAccssr getDefault() {

        return DEFAULT;

    }

}