# DrawObject.java

    /*
     * Licensed to the Apache Software Foundation (ASF) under one or more
     * contributor license agreements.  See the NOTICE file distributed with
     * this work for additional information regarding copyright ownership.
     * The ASF licenses this file to You under the Apache License, Version 2.0
     * (the "License"); you may not use this file except in compliance with
     * the License.  You may obtain a copy of the License at
     *
     *      http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    package org.apache.pdfbox.contentstream.operator.graphics;

    import java.io.IOException;
    import java.util.List;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.pdfbox.contentstream.operator.MissingOperandException;
    import org.apache.pdfbox.cos.COSBase;
    import org.apache.pdfbox.cos.COSName;
    import org.apache.pdfbox.pdmodel.MissingResourceException;
    import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
    import org.apache.pdfbox.pdmodel.graphics.form.PDTransparencyGroup;
    import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
    import org.apache.pdfbox.pdmodel.graphics.PDXObject;
    import org.apache.pdfbox.contentstream.operator.Operator;
    import org.apache.pdfbox.contentstream.operator.OperatorName;

    /**
     * Do: Draws an XObject.
     *
     * @author Ben Litchfield
     * @author John Hewson
     */
    public final class DrawObject extends GraphicsOperatorProcessor
    {
        private static final Log LOG = LogFactory.getLog(DrawObject.class);

        @Override
        public void process(Operator operator, List<COSBase> operands) throws IOException
        {
            if (operands.isEmpty())
            {
                throw new MissingOperandException(operator, operands);
            }
            COSBase base0 = operands.get(0);
            if (!(base0 instanceof COSName))
            {
                return;
            }
            COSName objectName = (COSName) base0;
            PDXObject xobject = context.getResources().getXObject(objectName);

            if (xobject == null)
            {
                throw new MissingResourceException("Missing XObject: " + objectName.getName());
            }
            else if (xobject instanceof PDImageXObject)
            {
                PDImageXObject image = (PDImageXObject)xobject;
                context.drawImage(image);
            }
            else if (xobject instanceof PDFormXObject)
            {
                try
                {
                    context.increaseLevel();
                    if (context.getLevel() > 50)
                    {
                        LOG.error("recursion is too deep, skipping form XObject");
                        return;
                    }
                    if (xobject instanceof PDTransparencyGroup)
                    {
                        context.showTransparencyGroup((PDTransparencyGroup) xobject);
                    }
                    else
                    {
                        context.showForm((PDFormXObject) xobject);
                    }
                }
                finally
                {
                    context.decreaseLevel();
                }
            }
        }

        @Override
        public String getName()
        {
            return OperatorName.DRAW_OBJECT;
        }
    }