added gps project

[utils] / gps / src / main / java / org / wamblee / gpx / ZoomableBackgroundXYPlot.java

diff --git a/gps/src/main/java/org/wamblee/gpx/ZoomableBackgroundXYPlot.java b/gps/src/main/java/org/wamblee/gpx/ZoomableBackgroundXYPlot.java
new file mode 100644 (file)
index 0000000..8de0711
--- /dev/null
+++ b/gps/src/main/java/org/wamblee/gpx/ZoomableBackgroundXYPlot.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2006 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */ 
+
+package org.wamblee.gpx;
+
+import java.awt.Graphics2D;
+import java.awt.Image;
+import java.awt.geom.Rectangle2D;
+
+import org.jfree.chart.axis.ValueAxis;
+import org.jfree.chart.plot.XYPlot;
+import org.jfree.chart.renderer.xy.XYItemRenderer;
+import org.jfree.data.xy.XYDataset;
+
+/**
+ * Extension of XY plot that provides automatic zooming of the background 
+ * image. 
+ */
+public class ZoomableBackgroundXYPlot extends XYPlot {
+    
+    /*
+     * Initial domain axis. 
+     */
+    private double _x1 = 1.0;
+    private double _x2 = -1.0; // _x2 < _x1 initially to make signify uninitialized values.
+    
+    /*
+     * Initial range axis.
+     */
+    private double _y1 = 1.0;
+    private double _y2 = -1.0; // _y2 < _y1 initially to make signify uninitialized values.
+    
+    public ZoomableBackgroundXYPlot(XYDataset aDataset, 
+            ValueAxis aDomainAxis, ValueAxis aRangeAxis, XYItemRenderer aRenderer) { 
+        super(aDataset, aDomainAxis, aRangeAxis, aRenderer);
+    }
+    
+    /* (non-Javadoc)
+     * @see org.jfree.chart.plot.Plot#drawBackgroundImage(java.awt.Graphics2D, java.awt.geom.Rectangle2D)
+     */
+    @Override
+    protected void drawBackgroundImage(Graphics2D g2, Rectangle2D area) {
+        //System.out.println("--------");
+        //System.out.println("Area: " + area);
+        //System.out.println("Graphics clip: " + g2.getClipBounds());
+        //System.out.println("Domain axis: " + getDomainAxis().getLowerBound() + " " + 
+        //        getDomainAxis().getUpperBound());
+        
+        // Get the current domain axis bounds
+        double y1 = getDomainAxis().getLowerBound();
+        double y2 = getDomainAxis().getUpperBound();
+        double x1 = getRangeAxis().getLowerBound();
+        double x2 = getRangeAxis().getUpperBound();
+        
+        if ( _x2 < _x1 ) { 
+            // initial domain axis bounds
+            _y1 = y1;
+            _y2 = y2;
+            _x1 = x1;
+            _x2 = x2;
+        }
+        
+        Image background = getBackgroundImage();
+        int width = background.getWidth(null);
+        int height = background.getHeight(null);
+        
+        // Determine the part of the image to be drawn on the screen based on the scaling
+        // of the domain axes. 
+        int imageX1 = (int)Math.round(1 + (x1 - _x1)*(width-1)/(_x2 - _x1));
+        int imageX2 = (int)Math.round(1 + (x2 - _x1)*(width-1)/(_x2 - _x1));
+        // Note: y-axis of image goes from bottom to top. 
+        int imageY2 = (int)Math.round(height + (y1 - _y1)*(1-height)/(_y2 - _y1));
+        int imageY1 = (int)Math.round(height + (y2 - _y1)*(1-height)/(_y2 - _y1));
+        
+        // Draw the correct part of the image on the screen. 
+        g2.drawImage(background, (int)area.getMinX(), (int)area.getMinY(), (int)area.getMaxX(), (int)area.getMaxY(), 
+                       imageX1, imageY1, imageX2, imageY2, null);
+     
+       // System.out.println("========");
+    }
+
+}