# PDPolygonAppearanceHandler.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.pdmodel.interactive.annotation.handlers;

    import java.io.IOException;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    import org.apache.pdfbox.cos.COSArray;
    import org.apache.pdfbox.cos.COSBase;
    import org.apache.pdfbox.cos.COSNumber;
    import org.apache.pdfbox.pdmodel.common.PDRectangle;
    import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
    import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationPolygon;
    import org.apache.pdfbox.pdmodel.PDAppearanceContentStream;
    import org.apache.pdfbox.pdmodel.PDDocument;
    import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationMarkup;
    import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceStream;
    import org.apache.pdfbox.pdmodel.interactive.annotation.PDBorderEffectDictionary;
    import org.apache.pdfbox.pdmodel.interactive.annotation.PDBorderStyleDictionary;

    /**
     * Handler to generate the polygon annotations appearance.
     *
     */
    public class PDPolygonAppearanceHandler extends PDAbstractAppearanceHandler
    {
        private static final Log LOG = LogFactory.getLog(PDPolygonAppearanceHandler.class);

        public PDPolygonAppearanceHandler(PDAnnotation annotation)
        {
            super(annotation);
        }

        public PDPolygonAppearanceHandler(PDAnnotation annotation, PDDocument document)
        {
            super(annotation, document);
        }

        @Override
        public void generateNormalAppearance()
        {
            PDAnnotationPolygon annotation = (PDAnnotationPolygon) getAnnotation();
            float lineWidth = getLineWidth();
            PDRectangle rect = annotation.getRectangle();
            if (rect == null)
            {
                return;
            }

            // Adjust rectangle even if not empty
            // CTAN-example-Annotations.pdf p2
            float minX = Float.MAX_VALUE;
            float minY = Float.MAX_VALUE;
            float maxX = Float.MIN_VALUE;
            float maxY = Float.MIN_VALUE;

            float[][] pathArray = getPathArray(annotation);
            if (pathArray == null)
            {
                return;
            }
            for (int i = 0; i < pathArray.length; ++i)
            {
                for (int j = 0; j < pathArray[i].length / 2; ++j)
                {
                    float x = pathArray[i][j * 2];
                    float y = pathArray[i][j * 2 + 1];
                    minX = Math.min(minX, x);
                    minY = Math.min(minY, y);
                    maxX = Math.max(maxX, x);
                    maxY = Math.max(maxY, y);
                }
            }

            rect.setLowerLeftX(Math.min(minX - lineWidth, rect.getLowerLeftX()));
            rect.setLowerLeftY(Math.min(minY - lineWidth, rect.getLowerLeftY()));
            rect.setUpperRightX(Math.max(maxX + lineWidth, rect.getUpperRightX()));
            rect.setUpperRightY(Math.max(maxY + lineWidth, rect.getUpperRightY()));
            annotation.setRectangle(rect);

            try (PDAppearanceContentStream contentStream = getNormalAppearanceAsContentStream())
            {
                boolean hasStroke = contentStream.setStrokingColorOnDemand(getColor());

                boolean hasBackground = contentStream
                        .setNonStrokingColorOnDemand(annotation.getInteriorColor());

                setOpacity(contentStream, annotation.getConstantOpacity());

                contentStream.setBorderLine(lineWidth, annotation.getBorderStyle(), annotation.getBorder());

                PDBorderEffectDictionary borderEffect = annotation.getBorderEffect();
                if (borderEffect != null && borderEffect.getStyle().equals(PDBorderEffectDictionary.STYLE_CLOUDY))
                {
                    CloudyBorder cloudyBorder = new CloudyBorder(contentStream,
                        borderEffect.getIntensity(), lineWidth, getRectangle());
                    cloudyBorder.createCloudyPolygon(pathArray);
                    annotation.setRectangle(cloudyBorder.getRectangle());
                    PDAppearanceStream appearanceStream = annotation.getNormalAppearanceStream();
                    appearanceStream.setBBox(cloudyBorder.getBBox());
                    appearanceStream.setMatrix(cloudyBorder.getMatrix());
                }
                else
                {
                    // Acrobat applies a padding to each side of the bbox so the line is
                    // completely within the bbox.

                    for (int i = 0; i < pathArray.length; i++)
                    {
                        float[] pointsArray = pathArray[i];
                        // first array shall be of size 2 and specify the moveto operator
                        if (i == 0 && pointsArray.length == 2)
                        {
                            contentStream.moveTo(pointsArray[0], pointsArray[1]);
                        }
                        else
                        {
                            // entries of length 2 shall be treated as lineto operator
                            if (pointsArray.length == 2)
                            {
                                contentStream.lineTo(pointsArray[0], pointsArray[1]);
                            }
                            else if (pointsArray.length == 6)
                            {
                                contentStream.curveTo(pointsArray[0], pointsArray[1],
                                        pointsArray[2], pointsArray[3],
                                        pointsArray[4], pointsArray[5]);
                            }
                        }
                    }
                    contentStream.closePath();
                }
                contentStream.drawShape(lineWidth, hasStroke, hasBackground);
            }
            catch (IOException e)
            {
                LOG.error(e);
            }
        }

        private float[][] getPathArray(PDAnnotationPolygon annotation)
        {
            // PDF 2.0: Path takes priority over Vertices
            float[][] pathArray = annotation.getPath();
            if (pathArray == null)
            {
                // convert PDF 1.* array to PDF 2.0 array
                float[] verticesArray = annotation.getVertices();
                if (verticesArray == null)
                {
                    return null;
                }
                int points = verticesArray.length / 2;
                pathArray = new float[points][2];
                for (int i = 0; i < points; ++i)
                {
                    pathArray[i][0] = verticesArray[i * 2];
                    pathArray[i][1] = verticesArray[i * 2 + 1];
                }
            }
            return pathArray;
        }

        @Override
        public void generateRolloverAppearance()
        {
            // No rollover appearance generated for a polygon annotation
        }

        @Override
        public void generateDownAppearance()
        {
            // No down appearance generated for a polygon annotation
        }

        /**
         * Get the line with of the border.
         *
         * Get the width of the line used to draw a border around the annotation.
         * This may either be specified by the annotation dictionaries Border
         * setting or by the W entry in the BS border style dictionary. If both are
         * missing the default width is 1.
         *
         * @return the line width
         */
        // TODO: according to the PDF spec the use of the BS entry is annotation
        // specific
        // so we will leave that to be implemented by individual handlers.
        // If at the end all annotations support the BS entry this can be handled
        // here and removed from the individual handlers.
        float getLineWidth()
        {
            PDAnnotationMarkup annotation = (PDAnnotationMarkup) getAnnotation();

            PDBorderStyleDictionary bs = annotation.getBorderStyle();

            if (bs != null)
            {
                return bs.getWidth();
            }

            COSArray borderCharacteristics = annotation.getBorder();
            if (borderCharacteristics.size() >= 3)
            {
                COSBase base = borderCharacteristics.getObject(2);
                if (base instanceof COSNumber)
                {
                    return ((COSNumber) base).floatValue();
                }
            }

            return 1;
        }
    }