Java tutorial
/* * Copyright (C) 2009 Camptocamp * * This file is part of MapFish Server * * MapFish Server is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * MapFish Server 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with MapFish Server. If not, see <http://www.gnu.org/licenses/>. */ package org.mapfish.print; import com.lowagie.text.*; import com.lowagie.text.pdf.*; import org.apache.log4j.Logger; import org.mapfish.print.config.layout.HeaderFooter; import org.mapfish.print.utils.PJsonObject; import java.io.IOException; import java.util.*; import java.util.List; /** * Listen to events from the PDF document in order to render the * custom {@link org.mapfish.print.ChunkDrawer}s, the header/footer and the background. */ public class PDFCustomBlocks extends PdfPageEventHelper { public static final Logger LOGGER = Logger.getLogger(PDFCustomBlocks.class); private ChunkDrawer last = null; private final PdfWriter writer; private final RenderingContext context; private HeaderFooter header; private PJsonObject headerParams; private HeaderFooter footer; private PJsonObject footerParams; private String backgroundPdf; private final List<Exception> errors = Collections.synchronizedList(new ArrayList<Exception>()); /** * cache of background PDF pages */ private final Map<String, PdfImportedPage> backgroundPdfs = new HashMap<String, PdfImportedPage>(); /** * block for rendering the totalpage number. */ private TotalPageNum totalPageNum = null; public PDFCustomBlocks(PdfWriter writer, RenderingContext context) { this.writer = writer; this.context = context; writer.setPageEvent(this); } public void onStartPage(PdfWriter writer, Document document) { super.onStartPage(writer, document); final PdfContentByte dc = writer.getDirectContent(); addBackground(writer, document, dc); } public void onEndPage(PdfWriter writer, Document document) { final PdfContentByte dc = writer.getDirectContent(); addHeader(document, dc); addFooter(document, dc); addErrors(writer); super.onEndPage(writer, document); } public void onCloseDocument(PdfWriter writer, Document document) { if (totalPageNum != null) { totalPageNum.render(writer); } super.onCloseDocument(writer, document); } private void addBackground(PdfWriter writer, Document document, PdfContentByte dc) { if (backgroundPdf != null) { try { PdfImportedPage page = backgroundPdfs.get(backgroundPdf); if (page == null) { PdfReader reader = new PdfReader(backgroundPdf); page = writer.getImportedPage(reader, 1); backgroundPdfs.put(backgroundPdf, page); } final Rectangle pageSize = document.getPageSize(); final boolean rotate = (page.getWidth() < page.getHeight()) ^ (pageSize.getWidth() < pageSize.getHeight()); if (rotate) { dc.addTemplate(page, 0, -1, 1, 0, 0, pageSize.getHeight()); } else { dc.addTemplate(page, 0, 0); } } catch (IOException e) { addError(e); } } } private void addHeader(Document document, PdfContentByte dc) { if (header != null) { Rectangle rectangle = new Rectangle(document.left(), document.top(), document.right(), document.top() + header.getHeight()); header.render(rectangle, dc, headerParams, context); } } private void addFooter(Document document, PdfContentByte dc) { if (footer != null) { Rectangle rectangle = new Rectangle(document.left(), document.bottom() - footer.getHeight(), document.right(), document.bottom()); footer.render(rectangle, dc, footerParams, context); } } private void addErrors(PdfWriter writer) { if (errors.size() > 0) { StringBuilder errorTxt = new StringBuilder(); for (int i = 0; i < errors.size(); i++) { Exception exception = errors.get(i); errorTxt.append(exception).append("\n"); } errors.clear(); final Rectangle rect = new Rectangle(20f, 40f, 40f, 60f); final PdfAnnotation annotation = PdfAnnotation.createText(writer, rect, "Error", errorTxt.toString(), false, "Note"); writer.addAnnotation(annotation); if (LOGGER.isDebugEnabled()) { LOGGER.debug("Added an annotation for errors"); } } } /** * Register a custom drawer. */ public void addChunkDrawer(ChunkDrawer chunkDrawer) { last = chunkDrawer; } /** * Called when a custom drawer has been rendered. */ public void blockRendered(ChunkDrawer chunkDrawer) { if (last == chunkDrawer) { last = null; } } /** * Schedule a absolute block (like a !columns or a !map). */ public void addAbsoluteDrawer(AbsoluteDrawer chunkDrawer) throws DocumentException { if (last != null) { //a chunk drawer is scheduled, need to draw oneself after it. last.addAbsoluteDrawer(chunkDrawer); } else { //no chunk drawer is scheduled. We can draw it right away. chunkDrawer.render(writer.getDirectContent()); } } public void setHeader(HeaderFooter header, PJsonObject params) { this.header = header; this.headerParams = params; } public void setFooter(HeaderFooter footer, PJsonObject params) { this.footer = footer; this.footerParams = params; } public void setBackgroundPdf(String backgroundPdf) { this.backgroundPdf = backgroundPdf; } public void addError(Exception e) { errors.add(e); if (LOGGER.isDebugEnabled()) { LOGGER.warn("Error while adding a PDF element", e); } else { LOGGER.warn("Error while adding a PDF element" + e.toString()); } } public Chunk getOrCreateTotalPagesBlock(Font font) throws BadElementException { if (totalPageNum == null) { totalPageNum = new TotalPageNum(writer, font); } return totalPageNum.createPlaceHolder(); } /** * Base class for the absolute drawers */ public static abstract class AbsoluteDrawer { public abstract void render(PdfContentByte dc) throws DocumentException; } }