2 * Copyright 2006 the original author or authors.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package org.wamblee.gpx;
19 import java.awt.Graphics2D;
20 import java.awt.Image;
21 import java.awt.geom.Rectangle2D;
23 import org.jfree.chart.axis.ValueAxis;
24 import org.jfree.chart.plot.XYPlot;
25 import org.jfree.chart.renderer.xy.XYItemRenderer;
26 import org.jfree.data.xy.XYDataset;
29 * Extension of XY plot that provides automatic zooming of the background
32 * @author Erik Brakkee
34 public class ZoomableBackgroundXYPlot extends XYPlot {
37 * Initial domain axis.
39 private double _x1 = 1.0;
40 private double _x2 = -1.0; // _x2 < _x1 initially to make signify uninitialized values.
45 private double _y1 = 1.0;
46 private double _y2 = -1.0; // _y2 < _y1 initially to make signify uninitialized values.
48 public ZoomableBackgroundXYPlot(XYDataset aDataset,
49 ValueAxis aDomainAxis, ValueAxis aRangeAxis, XYItemRenderer aRenderer) {
50 super(aDataset, aDomainAxis, aRangeAxis, aRenderer);
54 * @see org.jfree.chart.plot.Plot#drawBackgroundImage(java.awt.Graphics2D, java.awt.geom.Rectangle2D)
57 protected void drawBackgroundImage(Graphics2D g2, Rectangle2D area) {
58 //System.out.println("--------");
59 //System.out.println("Area: " + area);
60 //System.out.println("Graphics clip: " + g2.getClipBounds());
61 //System.out.println("Domain axis: " + getDomainAxis().getLowerBound() + " " +
62 // getDomainAxis().getUpperBound());
64 // Get the current domain axis bounds
65 double y1 = getDomainAxis().getLowerBound();
66 double y2 = getDomainAxis().getUpperBound();
67 double x1 = getRangeAxis().getLowerBound();
68 double x2 = getRangeAxis().getUpperBound();
71 // initial domain axis bounds
78 Image background = getBackgroundImage();
79 int width = background.getWidth(null);
80 int height = background.getHeight(null);
82 // Determine the part of the image to be drawn on the screen based on the scaling
83 // of the domain axes.
84 int imageX1 = (int)Math.round(1 + (x1 - _x1)*(width-1)/(_x2 - _x1));
85 int imageX2 = (int)Math.round(1 + (x2 - _x1)*(width-1)/(_x2 - _x1));
86 // Note: y-axis of image goes from bottom to top.
87 int imageY2 = (int)Math.round(height + (y1 - _y1)*(1-height)/(_y2 - _y1));
88 int imageY1 = (int)Math.round(height + (y2 - _y1)*(1-height)/(_y2 - _y1));
90 // Draw the correct part of the image on the screen.
91 g2.drawImage(background, (int)area.getMinX(), (int)area.getMinY(), (int)area.getMaxX(), (int)area.getMaxY(),
92 imageX1, imageY1, imageX2, imageY2, null);
94 // System.out.println("========");