Java tutorial
/** * Copyright (C) 2001-2019 by RapidMiner and the contributors * * Complete list of developers available at our web site: * * http://rapidminer.com * * This program is free software: you can redistribute it and/or modify it under the terms of the * GNU Affero General Public License as published by the Free Software Foundation, either version 3 * of the License, or (at your option) any later version. * * This program 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 * Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License along with this program. * If not, see http://www.gnu.org/licenses/. */ package com.rapidminer.gui.actions.export; import java.awt.Color; import java.awt.Component; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import javax.imageio.ImageIO; import org.freehep.graphics2d.VectorGraphics; import org.freehep.graphicsio.ps.PSGraphics2D; import org.freehep.graphicsio.svg.SVGGraphics2D; import com.lowagie.text.Document; import com.lowagie.text.Rectangle; import com.lowagie.text.pdf.DefaultFontMapper; import com.lowagie.text.pdf.PdfContentByte; import com.lowagie.text.pdf.PdfTemplate; import com.lowagie.text.pdf.PdfWriter; import com.rapidminer.gui.tools.PrintingTools; import com.rapidminer.tools.I18N; /** * A class for exporting {@link PrintableComponent}s as image. The currently supported formats are * PNG, JPG, PDF, SVG, and EPS. * * @author Nils Woehler * */ public class ImageExporter { private static final String EPS = "eps"; private static final String SVG = "svg"; private static final String JPG = "jpg"; private static final String PNG = "png"; private static final String PDF = "pdf"; public enum ExportStatus { EXPORTED, ABORTED } private static final String[] FILE_EXTENSIONS = new String[] { PNG, JPG, SVG, EPS, PDF }; private static final String[] EXTENSION_DESCRIPTIONS = new String[] { "Portable Network Graphics", "JPEG", "Scalable Vector Graphics", "Encapsulated PostScript", "Portable Document Format" }; private PrintableComponent printableComponent; public ImageExporter(PrintableComponent printableComponent) { this.printableComponent = printableComponent; } /** * Opens a dialog that prompts for a file location. Depending on the file extensions the * provided component is exported as a bitmap or vector graphics image. * * @return the export status, which is EXPORTED or ABORTED. * * @throws IOException * in case something goes wrong */ public ExportStatus exportImage() throws ImageExportException { File chosenFile; try { chosenFile = PrintingTools.promptForFileLocation("export_image", FILE_EXTENSIONS, EXTENSION_DESCRIPTIONS); } catch (IOException e) { throw new ImageExportException("", e); } // no file chosen, do nothing if (chosenFile == null) { return ExportStatus.ABORTED; } String extension = chosenFile.getName().substring(chosenFile.getName().lastIndexOf('.') + 1); switch (extension) { case JPG: exportBitmap(JPG, chosenFile); break; case PNG: exportBitmap(PNG, chosenFile); break; case SVG: exportVectorGraphics(SVG, chosenFile); break; case EPS: exportVectorGraphics(EPS, chosenFile); break; case PDF: exportVectorGraphics(PDF, chosenFile); break; default: throw new ImageExportException(I18N.getMessage(I18N.getUserErrorMessagesBundle(), "error.image_export.unknown_format", extension)); } return ExportStatus.EXPORTED; } private void exportBitmap(String formatName, File outputFile) throws ImageExportException { int width = printableComponent.getExportComponent().getWidth(); int height = printableComponent.getExportComponent().getHeight(); BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics graphics = image.getGraphics(); graphics.setColor(Color.white); graphics.fillRect(0, 0, width, height); printableComponent.getExportComponent().print(graphics); try { ImageIO.write(image, formatName, outputFile); } catch (IOException e) { throw new ImageExportException( I18N.getMessage(I18N.getUserErrorMessagesBundle(), "error.image_export.export_failed"), e); } } private void exportVectorGraphics(String formatName, File outputFile) throws ImageExportException { Component component = printableComponent.getExportComponent(); int width = component.getWidth(); int height = component.getHeight(); try (FileOutputStream fs = new FileOutputStream(outputFile)) { switch (formatName) { case PDF: // create pdf document with slightly increased width and height // (otherwise the image gets cut off) Document document = new Document(new Rectangle(width + 5, height + 5)); PdfWriter writer = PdfWriter.getInstance(document, fs); document.open(); PdfContentByte cb = writer.getDirectContent(); PdfTemplate tp = cb.createTemplate(width, height); Graphics2D g2 = tp.createGraphics(width, height, new DefaultFontMapper()); component.print(g2); g2.dispose(); cb.addTemplate(tp, 0, 0); document.close(); break; case SVG: exportFreeHep(component, fs, new SVGGraphics2D(fs, new Dimension(width, height))); break; case EPS: exportFreeHep(component, fs, new PSGraphics2D(fs, new Dimension(width, height))); break; default: // cannot happen break; } } catch (Exception e) { throw new ImageExportException( I18N.getMessage(I18N.getUserErrorMessagesBundle(), "error.image_export.export_failed"), e); } } private void exportFreeHep(Component component, FileOutputStream fs, VectorGraphics vg) { vg.startExport(); component.print(vg); vg.endExport(); vg.dispose(); } }