Java tutorial
/** * This file is part of mycollab-web-community. * * mycollab-web-community is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * mycollab-web-community 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with mycollab-web-community. If not, see <http://www.gnu.org/licenses/>. */ package com.esofthead.mycollab.community.ui.chart; import com.vaadin.server.*; import com.vaadin.server.StreamResource.StreamSource; import com.vaadin.ui.Embedded; import org.apache.batik.svggen.SVGGraphics2D; import org.jfree.chart.ChartUtilities; import org.jfree.chart.JFreeChart; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import java.awt.*; import java.io.*; import java.util.zip.GZIPOutputStream; /** * A simple JFreeChart wrapper that renders charts in SVG to browser. * <p/> * To use this component, you'll need all the common JFreeChart and Batik * libraries. * <p/> * For MSIE it will fall back to PNG rendering (not that nice when printing). * <p/> * Supported sizes are currently just pixels, inches, centimeters (converted to * pixels by 96dpi). Set them to wrapper. * <p/> * TODO make it support relative sizes (should be possible to do cleanly with * SVG) * <p/> * TODO when browsers develop SVG could be painted to target instead of * registering application resource. This would shorten rendering time and * lessen memory consumption on server. This already works ok for webkit * browsers. Firefox and Opera fail with gradients. * * @author mattitahvonen */ @SuppressWarnings("serial") public class JFreeChartWrapper extends Embedded { public enum RenderingMode { SVG, PNG, AUTO } private static final Logger log = LoggerFactory.getLogger(JFreeChartWrapper.class); // 809x 500 ~g olden ratio private static final int DEFAULT_WIDTH = 809; private static final int DEFAULT_HEIGHT = 500; private final JFreeChart chart; private Resource res; private RenderingMode mode = RenderingMode.AUTO; private boolean gzipEnabled = false; private int graphWidthInPixels = -1; private int graphHeightInPixels = -1; private String aspectRatio = "none"; // stretch to fill whole space public JFreeChartWrapper(JFreeChart chartToBeWrapped) { chart = chartToBeWrapped; setWidth(DEFAULT_WIDTH, Unit.PIXELS); setHeight(DEFAULT_HEIGHT, Unit.PIXELS); } public JFreeChartWrapper(JFreeChart chartToBeWrapped, RenderingMode renderingMode) { this(chartToBeWrapped); setRenderingMode(renderingMode); } /** * Compress SVG charts in wrapper. It makes sense to put this on if the * server does not automatically compress responses. * * @param compress true to enable component level compression, default false */ public void setGzipCompression(boolean compress) { this.gzipEnabled = compress; } private void setRenderingMode(RenderingMode newMode) { if (newMode == RenderingMode.PNG) { setType(TYPE_IMAGE); } else { setType(TYPE_OBJECT); setMimeType("image/svg+xml"); } mode = newMode; } @Override public void attach() { super.attach(); if (mode == RenderingMode.AUTO) { WebBrowser browser = Page.getCurrent().getWebBrowser(); if (browser.isIE() && browser.getBrowserMajorVersion() < 9) { setRenderingMode(RenderingMode.PNG); } else { // all decent browsers support SVG setRenderingMode(RenderingMode.SVG); } } setResource("src", getSource()); } @Override public void detach() { super.detach(); } /** * This method may be used to tune rendering of the chart when using * relative sizes. Most commonly you should use just use common methods * inherited from {@link Sizeable} interface. * <p/> * Sets the pixel size of the area where the graph is rendered. Most commonly developer may need to fine tune the value when the {@link JFreeChartWrapper} has a relative size. * * @param width * @see JFreeChartWrapper#getGraphWidth() * @see #setSvgAspectRatio(String) */ public void setGraphWidth(int width) { graphWidthInPixels = width; } /** * This method may be used to tune rendering of the chart when using * relative sizes. Most commonly you should use just use common methods * inherited from {@link Sizeable} interface. * <p/> * Sets the pixel size of the area where the graph is rendered. Most commonly developer may need to fine tune the value when the {@link JFreeChartWrapper} has a relative size. * * @param height * @see JFreeChartWrapper#getGraphHeigt() * @see #setSvgAspectRatio(String) */ public void setGraphHeight(int height) { graphHeightInPixels = height; } /** * Gets the pixel width into which the graph is rendered. Unless explicitly * set, the value is derived from the components size, except when the * component has relative size. */ public int getGraphWidth() { if (graphWidthInPixels > 0) { return graphWidthInPixels; } int width; float w = getWidth(); if (w < 0) { return DEFAULT_WIDTH; } switch (getWidthUnits()) { case CM: width = (int) (w * 96 / 2.54); break; case INCH: width = (int) (w * 96); break; case PERCENTAGE: width = DEFAULT_WIDTH; break; default: width = (int) w; break; } return width; } /** * Gets the pixel height into which the graph is rendered. Unless explicitly * set, the value is derived from the components size, except when the * component has relative size. */ public int getGraphHeight() { if (graphHeightInPixels > 0) { return graphHeightInPixels; } int height; float w = getHeight(); if (w < 0) { return DEFAULT_HEIGHT; } switch (getWidthUnits()) { case CM: height = (int) (w * 96 / 2.54); break; case INCH: height = (int) (w * 96); break; case PERCENTAGE: height = DEFAULT_HEIGHT; break; default: height = (int) w; break; } return height; } public String getSvgAspectRatio() { return aspectRatio; } /** * See SVG spec from W3 for more information. * Default is "none" (stretch), another common value is "xMidYMid" (stretch * proportionally, align middle of the area). * * @param svgAspectRatioSetting */ public void setSvgAspectRatio(String svgAspectRatioSetting) { aspectRatio = svgAspectRatioSetting; } @Override public Resource getSource() { if (res == null) { StreamSource streamSource = new StreamResource.StreamSource() { private ByteArrayInputStream bytestream = null; ByteArrayInputStream getByteStream() { if (chart != null && bytestream == null) { int width = getGraphWidth(); int height = getGraphHeight(); if (mode == RenderingMode.SVG) { DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder docBuilder = null; try { docBuilder = docBuilderFactory.newDocumentBuilder(); } catch (ParserConfigurationException e1) { throw new RuntimeException(e1); } Document document = docBuilder.newDocument(); Element svgelem = document.createElement("svg"); document.appendChild(svgelem); // Create an instance of the SVG Generator SVGGraphics2D svgGenerator = new SVGGraphics2D(document); // draw the chart in the SVG generator chart.draw(svgGenerator, new Rectangle(width, height)); Element el = svgGenerator.getRoot(); el.setAttributeNS(null, "viewBox", "0 0 " + width + " " + height + ""); el.setAttributeNS(null, "style", "width:100%;height:100%;"); el.setAttributeNS(null, "preserveAspectRatio", getSvgAspectRatio()); // Write svg to buffer ByteArrayOutputStream baoutputStream = new ByteArrayOutputStream(); Writer out; try { OutputStream outputStream = gzipEnabled ? new GZIPOutputStream(baoutputStream) : baoutputStream; out = new OutputStreamWriter(outputStream, "UTF-8"); /* * don't use css, FF3 can'd deal with the result * perfectly: wrong font sizes */ boolean useCSS = false; svgGenerator.stream(el, out, useCSS, false); outputStream.flush(); outputStream.close(); bytestream = new ByteArrayInputStream(baoutputStream.toByteArray()); } catch (Exception e) { log.error("Error while generating SVG chart", e); } } else { // Draw png to bytestream try { byte[] bytes = ChartUtilities.encodeAsPNG(chart.createBufferedImage(width, height)); bytestream = new ByteArrayInputStream(bytes); } catch (Exception e) { log.error("Error while generating PNG chart", e); } } } else { bytestream.reset(); } return bytestream; } @Override public InputStream getStream() { return getByteStream(); } }; res = new StreamResource(streamSource, String.format("graph%d", System.currentTimeMillis())) { @Override public int getBufferSize() { if (getStreamSource().getStream() != null) { try { return getStreamSource().getStream().available(); } catch (IOException e) { log.warn("Error while get stream info", e); return 0; } } else { return 0; } } @Override public long getCacheTime() { return 0; } @Override public String getFilename() { if (mode == RenderingMode.PNG) { return super.getFilename() + ".png"; } else { return super.getFilename() + (gzipEnabled ? ".svgz" : ".svg"); } } @Override public DownloadStream getStream() { DownloadStream downloadStream = new DownloadStream(getStreamSource().getStream(), getMIMEType(), getFilename()); if (gzipEnabled && mode == RenderingMode.SVG) { downloadStream.setParameter("Content-Encoding", "gzip"); } return downloadStream; } @Override public String getMIMEType() { if (mode == RenderingMode.PNG) { return "image/png"; } else { return "image/svg+xml"; } } }; } return res; } /** * {@inheritDoc} */ @Override public void markAsDirty() { super.markAsDirty(); res = null; } }