Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library 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 2.1 of the License, or * (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ------------------- * VectorRenderer.java * ------------------- * (C) Copyright 2007, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * $Id: VectorRenderer.java,v 1.1.2.2 2007/02/02 14:09:05 mungady Exp $ * * Changes * ------- * 30-Jan-2007 : Version 1 (DG); * */ package org.jfree.experimental.chart.renderer.xy; import java.awt.Graphics2D; import java.awt.geom.GeneralPath; import java.awt.geom.Line2D; import java.awt.geom.Rectangle2D; import java.io.Serializable; import org.jfree.chart.axis.ValueAxis; import org.jfree.chart.plot.CrosshairState; import org.jfree.chart.plot.PlotOrientation; import org.jfree.chart.plot.PlotRenderingInfo; import org.jfree.chart.plot.XYPlot; import org.jfree.chart.renderer.xy.AbstractXYItemRenderer; import org.jfree.chart.renderer.xy.XYItemRenderer; import org.jfree.chart.renderer.xy.XYItemRendererState; import org.jfree.data.Range; import org.jfree.data.xy.XYDataset; import org.jfree.experimental.data.xy.VectorXYDataset; /** * A renderer that represents data from an {@link VectorXYDataset} by drawing a * line with an arrow at each (x, y) point. * * WARNING: THIS CLASS IS NOT PART OF THE STANDARD JFREECHART API AND IS * SUBJECT TO ALTERATION OR REMOVAL. DO NOT RELY ON THIS CLASS FOR * PRODUCTION USE. Please experiment with this code and provide feedback. */ public class VectorRenderer extends AbstractXYItemRenderer implements XYItemRenderer, Cloneable, Serializable { private double baseLength = 0.10; private double headLength = 0.14; /** * Creates a new <code>XYBlockRenderer</code> instance with default * attributes. */ public VectorRenderer() { } /** * Returns the lower and upper bounds (range) of the x-values in the * specified dataset. * * @param dataset the dataset (<code>null</code> permitted). * * @return The range (<code>null</code> if the dataset is <code>null</code> * or empty). */ public Range findDomainBounds(XYDataset dataset) { if (dataset == null) { throw new IllegalArgumentException("Null 'dataset' argument."); } double minimum = Double.POSITIVE_INFINITY; double maximum = Double.NEGATIVE_INFINITY; int seriesCount = dataset.getSeriesCount(); double lvalue; double uvalue; if (dataset instanceof VectorXYDataset) { VectorXYDataset vdataset = (VectorXYDataset) dataset; for (int series = 0; series < seriesCount; series++) { int itemCount = dataset.getItemCount(series); for (int item = 0; item < itemCount; item++) { double delta = vdataset.getDeltaXValue(series, item); if (delta < 0.0) { uvalue = vdataset.getXValue(series, item); lvalue = uvalue + delta; } else { lvalue = vdataset.getXValue(series, item); uvalue = lvalue + delta; } minimum = Math.min(minimum, lvalue); maximum = Math.max(maximum, uvalue); } } } else { for (int series = 0; series < seriesCount; series++) { int itemCount = dataset.getItemCount(series); for (int item = 0; item < itemCount; item++) { lvalue = dataset.getXValue(series, item); uvalue = lvalue; minimum = Math.min(minimum, lvalue); maximum = Math.max(maximum, uvalue); } } } if (minimum > maximum) { return null; } else { return new Range(minimum, maximum); } } /** * Returns the range of values the renderer requires to display all the * items from the specified dataset. * * @param dataset the dataset (<code>null</code> permitted). * * @return The range (<code>null</code> if the dataset is <code>null</code> * or empty). */ public Range findRangeBounds(XYDataset dataset) { if (dataset == null) { throw new IllegalArgumentException("Null 'dataset' argument."); } double minimum = Double.POSITIVE_INFINITY; double maximum = Double.NEGATIVE_INFINITY; int seriesCount = dataset.getSeriesCount(); double lvalue; double uvalue; if (dataset instanceof VectorXYDataset) { VectorXYDataset vdataset = (VectorXYDataset) dataset; for (int series = 0; series < seriesCount; series++) { int itemCount = dataset.getItemCount(series); for (int item = 0; item < itemCount; item++) { double delta = vdataset.getDeltaYValue(series, item); if (delta < 0.0) { uvalue = vdataset.getYValue(series, item); lvalue = uvalue + delta; } else { lvalue = vdataset.getYValue(series, item); uvalue = lvalue + delta; } minimum = Math.min(minimum, lvalue); maximum = Math.max(maximum, uvalue); } } } else { for (int series = 0; series < seriesCount; series++) { int itemCount = dataset.getItemCount(series); for (int item = 0; item < itemCount; item++) { lvalue = dataset.getYValue(series, item); uvalue = lvalue; minimum = Math.min(minimum, lvalue); maximum = Math.max(maximum, uvalue); } } } if (minimum > maximum) { return null; } else { return new Range(minimum, maximum); } } /** * Draws the block representing the specified item. * * @param g2 the graphics device. * @param state the state. * @param dataArea the data area. * @param info the plot rendering info. * @param plot the plot. * @param domainAxis the x-axis. * @param rangeAxis the y-axis. * @param dataset the dataset. * @param series the series index. * @param item the item index. * @param crosshairState the crosshair state. * @param pass the pass index. */ public void drawItem(Graphics2D g2, XYItemRendererState state, Rectangle2D dataArea, PlotRenderingInfo info, XYPlot plot, ValueAxis domainAxis, ValueAxis rangeAxis, XYDataset dataset, int series, int item, CrosshairState crosshairState, int pass) { double x = dataset.getXValue(series, item); double y = dataset.getYValue(series, item); double dx = 0.0; double dy = 0.0; if (dataset instanceof VectorXYDataset) { dx = ((VectorXYDataset) dataset).getDeltaXValue(series, item); dy = ((VectorXYDataset) dataset).getDeltaYValue(series, item); } double xx0 = domainAxis.valueToJava2D(x, dataArea, plot.getDomainAxisEdge()); double yy0 = rangeAxis.valueToJava2D(y, dataArea, plot.getRangeAxisEdge()); double xx1 = domainAxis.valueToJava2D(x + dx, dataArea, plot.getDomainAxisEdge()); double yy1 = rangeAxis.valueToJava2D(y + dy, dataArea, plot.getRangeAxisEdge()); Line2D line; PlotOrientation orientation = plot.getOrientation(); if (orientation.equals(PlotOrientation.HORIZONTAL)) { line = new Line2D.Double(yy0, xx0, yy1, xx1); } else { line = new Line2D.Double(xx0, yy0, xx1, yy1); } g2.setPaint(getItemPaint(series, item)); g2.setStroke(getItemStroke(series, item)); g2.draw(line); // calculate the arrow head and draw it... double dxx = (xx1 - xx0); double dyy = (yy1 - yy0); double bx = xx0 + (1.0 - this.baseLength) * dxx; double by = yy0 + (1.0 - this.baseLength) * dyy; double cx = xx0 + (1.0 - this.headLength) * dxx; double cy = yy0 + (1.0 - this.headLength) * dyy; double angle = 0.0; if (dxx != 0.0) { angle = Math.PI / 2.0 - Math.atan(dyy / dxx); } double deltaX = 2.0 * Math.cos(angle); double deltaY = 2.0 * Math.sin(angle); double leftx = cx + deltaX; double lefty = cy - deltaY; double rightx = cx - deltaX; double righty = cy + deltaY; GeneralPath p = new GeneralPath(); p.moveTo((float) xx1, (float) yy1); p.lineTo((float) rightx, (float) righty); p.lineTo((float) bx, (float) by); p.lineTo((float) leftx, (float) lefty); p.closePath(); g2.draw(p); } /** * Tests this <code>VectorRenderer</code> for equality with an arbitrary * object. This method returns <code>true</code> if and only if: * <ul> * <li><code>obj</code> is an instance of <code>VectorRenderer</code> (not * <code>null</code>);</li> * <li><code>obj</code> has the same field values as this * <code>VectorRenderer</code>;</li> * </ul> * * @param obj the object (<code>null</code> permitted). * * @return A boolean. */ public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof VectorRenderer)) { return false; } VectorRenderer that = (VectorRenderer) obj; if (this.baseLength != that.baseLength) { return false; } if (this.headLength != that.headLength) { return false; } return super.equals(obj); } /** * Returns a clone of this renderer. * * @return A clone of this renderer. * * @throws CloneNotSupportedException if there is a problem creating the * clone. */ public Object clone() throws CloneNotSupportedException { return super.clone(); } }