CyclicXYItemRenderer


1   /* ======================================
2    * JFreeChart : a free Java chart library
3    * ======================================
4    *
5    * Project Info:  http://www.jfree.org/jfreechart/index.html
6    * Project Lead:  David Gilbert (david.gilbert@object-refinery.com);
7    *
8    * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
9    *
10   * This library is free software; you can redistribute it and/or modify it under the terms
11   * of the GNU Lesser General Public License as published by the Free Software Foundation;
12   * either version 2.1 of the License, or (at your option) any later version.
13   *
14   * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
15   * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16   * See the GNU Lesser General Public License for more details.
17   *
18   * You should have received a copy of the GNU Lesser General Public License along with this
19   * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
20   * Boston, MA 02111-1307, USA.
21   *
22   * ---------------------------
23   * CyclicXYItemRenderer.java
24   * ---------------------------
25   * (C) Copyright 2003, by Nicolas Brodu and Contributors.
26   *
27   * Original Author:  Nicolas Brodu;
28   * Contributor(s): -
29   *
30   * $Id: CyclicXYItemRenderer.java,v 1.1 2003/11/20 08:54:13 brodu Exp $
31   *
32   * Changes
33   * -------
34   * 19-Nov-2003 : Initial import to JFreeChart from the JSynoptic project (NB);
35   * 
36   */
37  
38  package org.jfree.chart.renderer;
39  
40  import java.awt.Graphics2D  ;
41  import java.awt.geom.Rectangle2D  ;
42  
43  import org.jfree.chart.CrosshairInfo;
44  import org.jfree.chart.axis.CyclicNumberAxis;
45  import org.jfree.chart.axis.ValueAxis;
46  import org.jfree.chart.labels.XYToolTipGenerator;
47  import org.jfree.chart.plot.PlotRenderingInfo;
48  import org.jfree.chart.plot.XYPlot;
49  import org.jfree.chart.urls.XYURLGenerator;
50  import org.jfree.data.DatasetChangeListener;
51  import org.jfree.data.DatasetGroup;
52  import org.jfree.data.XYDataset;
53  
54  /**
55   * The Cyclic XY item renderer is specially designed to handle cyclic axis. 
56   * While the standard renderer would draw a line across the plot when a cycling occurs, the cyclic
57   * renderer splits the line at each cycle end instead. This is done by interpolating new points at 
58   * cycle boundary. Thus, correct appearance is restored. 
59   * 
60   * The Cyclic XY item renderer works exactly like a standard XY item renderer with non-cyclic axis. 
61   *
62   * @author Nicolas Brodu
63   */
64  public class CyclicXYItemRenderer extends StandardXYItemRenderer {
65  
66      /** Overloaded contructor. See StandardXYItemRenderer */
67      public CyclicXYItemRenderer() {
68          super();
69      }
70  
71      /** Overloaded contructor. See StandardXYItemRenderer */
72      public CyclicXYItemRenderer(int type) {
73          super(type);
74      }
75  
76      /** Overloaded contructor. See StandardXYItemRenderer */
77      public CyclicXYItemRenderer(int type, XYToolTipGenerator toolTipGenerator) {
78          super(type, toolTipGenerator);
79      }
80  
81      /** Overloaded contructor. See StandardXYItemRenderer */
82      public CyclicXYItemRenderer(int type, XYToolTipGenerator toolTipGenerator,
83              XYURLGenerator urlGenerator) {
84          super(type, toolTipGenerator, urlGenerator);
85      }
86  
87      
88      /** Draws the visual representation of a single data item.
89       * When using cyclic axis, do not draw a line from right to left when cycling as would a 
90       * standard XY item renderer, but instead draw a line from the previous point to the cycle bound 
91       * in the last cycle, and a line from the cycle bound to current point in the current cycle.  
92       * @see org.jfree.chart.renderer.XYItemRenderer#drawItem(java.awt.Graphics2D, org.jfree.chart.renderer.XYItemRendererState, java.awt.geom.Rectangle2D, org.jfree.chart.plot.PlotRenderingInfo, org.jfree.chart.plot.XYPlot, org.jfree.chart.axis.ValueAxis, org.jfree.chart.axis.ValueAxis, org.jfree.data.XYDataset, int, int, org.jfree.chart.CrosshairInfo, int)
93       */
94      public void drawItem(Graphics2D   g2, XYItemRendererState state,
95              Rectangle2D   dataArea, PlotRenderingInfo info, XYPlot plot,
96              ValueAxis domainAxis, ValueAxis rangeAxis, XYDataset dataset,
97              int series, int item, CrosshairInfo crosshairInfo, int pass) {
98  
99          if ((!getPlotLines()) || ((!(domainAxis instanceof CyclicNumberAxis)) && (!(rangeAxis instanceof CyclicNumberAxis))) || (item<=0)) {
100             super.drawItem(g2, state, dataArea, info, plot, domainAxis, rangeAxis, dataset, series, item, crosshairInfo, pass);
101             return;
102         }
103 
104         // get the previous data point...
105         Number   xn = dataset.getXValue(series, item - 1);
106         Number   yn = dataset.getYValue(series, item - 1);
107         // If null, don't draw line => then delegate to parent
108         if (yn == null || xn == null) {
109             super.drawItem(g2, state, dataArea, info, plot, domainAxis, rangeAxis, dataset, series, item, crosshairInfo, pass);
110             return;
111         }
112         double[] x = new double[2];
113         double[] y = new double[2];
114         x[0] = xn.doubleValue();
115         y[0] = yn.doubleValue();
116         
117         // get the data point...
118         xn = dataset.getXValue(series, item);
119         yn = dataset.getYValue(series, item);
120         // If null, don't draw line at all
121         if (yn == null || xn == null) {
122             return;
123         }
124         x[1] = xn.doubleValue();
125         y[1] = yn.doubleValue();
126 
127         // Now split the segment as needed
128         double xcycleBound = Double.NaN;
129         double ycycleBound = Double.NaN;
130         boolean xBoundMapping = false, yBoundMapping = false;
131         CyclicNumberAxis cnax = null, cnay = null;
132 
133         if (domainAxis instanceof CyclicNumberAxis) {
134             cnax = (CyclicNumberAxis)domainAxis;
135             xcycleBound = cnax.getCycleBound();
136             xBoundMapping = cnax.isBoundMappedToLastCycle();
137             // If the segment must be splitted, insert a new point
138             // Strict test forces to have real segments (not 2 equal points) and avoids division by 0 
139             if ((x[0]!=x[1]) && ((xcycleBound>=x[0]) && (xcycleBound<=x[1]) ||  (xcycleBound>=x[1]) && (xcycleBound<=x[0]))) {
140                 double[] nx = new double[3];
141                 double[] ny = new double[3];
142                 nx[0] = x[0]; nx[2] = x[1]; ny[0] = y[0]; ny[2] = y[1];
143                 nx[1] = xcycleBound;
144                 ny[1] = (y[1] - y[0]) * (xcycleBound - x[0]) / (x[1] - x[0]) + y[0];
145                 x = nx; y = ny;
146             }
147         }
148 
149         if (rangeAxis instanceof CyclicNumberAxis) {
150             cnay = (CyclicNumberAxis)rangeAxis;
151             ycycleBound = cnay.getCycleBound();
152             yBoundMapping = cnay.isBoundMappedToLastCycle();
153             // The split may occur in either x splitted segments, if any, but not in both
154             if ((y[0]!=y[1]) && ((ycycleBound>=y[0]) && (ycycleBound<=y[1]) ||  (ycycleBound>=y[1]) && (ycycleBound<=y[0]))) {
155                 double[] nx = new double[x.length+1];
156                 double[] ny = new double[y.length+1];
157                 nx[0] = x[0]; nx[2] = x[1]; ny[0] = y[0]; ny[2] = y[1];
158                 ny[1] = ycycleBound;
159                 nx[1] = (x[1] - x[0]) * (ycycleBound - y[0]) / (y[1] - y[0]) + x[0];
160                 if (x.length==3) { 
161                     nx[3] = x[2]; ny[3] = y[2]; 
162                 }
163                 x = nx; y = ny;
164             }
165             else if ((x.length==3) && (y[1]!=y[2]) && ((ycycleBound>=y[1]) && (ycycleBound<=y[2]) ||  (ycycleBound>=y[2]) && (ycycleBound<=y[1]))) {
166                 double[] nx = new double[4];
167                 double[] ny = new double[4];
168                 nx[0] = x[0]; nx[1] = x[1]; nx[3] = x[2]; 
169                 ny[0] = y[0]; ny[1] = y[1]; ny[3] = y[2];
170                 ny[2] = ycycleBound;
171                 nx[2] = (x[2] - x[1]) * (ycycleBound - y[1]) / (y[2] - y[1]) + x[1];
172                 x = nx; y = ny;
173             }
174         }
175         
176         // If the line is not wrapping, then parent is OK
177         if (x.length==2) {
178             super.drawItem(g2, state, dataArea, info, plot, domainAxis, rangeAxis, dataset, series, item, crosshairInfo, pass);
179             return;
180         }
181 
182         OverwriteDataSet newset = new OverwriteDataSet(x,y,dataset);
183 
184         if (cnax!=null) {
185             if (xcycleBound==x[0]) cnax.setBoundMappedToLastCycle(x[1] <= xcycleBound);
186             if (xcycleBound==x[1]) cnax.setBoundMappedToLastCycle(x[0] <= xcycleBound);
187         }
188         if (cnay!=null) {
189             if (ycycleBound==y[0]) cnay.setBoundMappedToLastCycle(y[1] <= ycycleBound);
190             if (ycycleBound==y[1]) cnay.setBoundMappedToLastCycle(y[0] <= ycycleBound);
191         }
192         super.drawItem(g2, state, dataArea, info, plot, domainAxis, rangeAxis, newset, series, 1, crosshairInfo, pass);
193 
194         if (cnax!=null) {
195             if (xcycleBound==x[1]) cnax.setBoundMappedToLastCycle(x[2] <= xcycleBound);
196             if (xcycleBound==x[2]) cnax.setBoundMappedToLastCycle(x[1] <= xcycleBound);
197         }
198         if (cnay!=null) {
199             if (ycycleBound==y[1]) cnay.setBoundMappedToLastCycle(y[2] <= ycycleBound);
200             if (ycycleBound==y[2]) cnay.setBoundMappedToLastCycle(y[1] <= ycycleBound);
201         }
202         super.drawItem(g2, state, dataArea, info, plot, domainAxis, rangeAxis, newset, series, 2, crosshairInfo, pass);
203 
204         if (x.length==4) {
205             if (cnax!=null) {
206                 if (xcycleBound==x[2]) cnax.setBoundMappedToLastCycle(x[3] <= xcycleBound);
207                 if (xcycleBound==x[3]) cnax.setBoundMappedToLastCycle(x[2] <= xcycleBound);
208             }
209             if (cnay!=null) {
210                 if (ycycleBound==y[2]) cnay.setBoundMappedToLastCycle(y[3] <= ycycleBound);
211                 if (ycycleBound==y[3]) cnay.setBoundMappedToLastCycle(y[2] <= ycycleBound);
212             }
213             super.drawItem(g2, state, dataArea, info, plot, domainAxis, rangeAxis, newset, series, 3, crosshairInfo, pass);
214         }
215         
216         if (cnax!=null) cnax.setBoundMappedToLastCycle(xBoundMapping);
217         if (cnay!=null) cnay.setBoundMappedToLastCycle(yBoundMapping);
218     }
219 
220     /** A dataset to hold the interpolated points when drawing new lines */
221     protected static class OverwriteDataSet implements XYDataset {
222         
223         protected XYDataset delegateSet;
224         Double   [] x, y;
225         
226         public OverwriteDataSet(double [] x, double[] y, XYDataset delegateSet) {
227             this.delegateSet = delegateSet;
228             this.x = new Double  [x.length]; this.y = new Double  [y.length];
229             for (int i=0; i<x.length; ++i) { 
230                 this.x[i] = new Double  (x[i]);
231                 this.y[i] = new Double  (y[i]);
232             }
233         }
234 
235         public int getItemCount(int series) {
236             return x.length;
237         }
238 
239         public Number   getXValue(int series, int item) {
240             return x[item];
241         }
242 
243         public Number   getYValue(int series, int item) {
244             return y[item];
245         }
246 
247         public int getSeriesCount() {
248             return delegateSet.getSeriesCount();
249         }
250 
251         public String   getSeriesName(int series) {
252             return delegateSet.getSeriesName(series);
253         }
254 
255         public void addChangeListener(DatasetChangeListener listener) {
256             // unused in parent
257         }
258 
259         public void removeChangeListener(DatasetChangeListener listener) {
260             // unused in parent
261         }
262 
263         public DatasetGroup getGroup() {
264             // unused but must return something, so while we are at it...
265             return delegateSet.getGroup();
266         }
267 
268         public void setGroup(DatasetGroup group) {
269             // unused in parent
270         }
271         
272     }
273     
274 }
275 
276 
277
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