CircleLayout


1   package prefuse.action.layout;
2   
3   import java.awt.geom.Rectangle2D  ;
4   import java.util.Iterator  ;
5   
6   import prefuse.data.tuple.TupleSet;
7   import prefuse.visual.VisualItem;
8   
9   /**
10   * Layout action that positions visual items along a circle. By default,
11   * items are sorted in the order in which they iterated over.
12   * 
13   * @author <a HREF="http://jheer.org">jeffrey heer</a>
14   */
15  public class CircleLayout extends Layout {
16      
17      private double m_radius; // radius of the circle layout
18      
19      /**
20       * Create a CircleLayout; the radius of the circle layout will be computed
21       * automatically based on the display size.
22       * @param group the data group to layout
23       */
24      public CircleLayout(String   group) {
25          super(group);
26      }
27      
28      /**
29       * Create a CircleLayout; use the specified radius for the the circle layout,
30       * regardless of the display size.
31       * @param group the data group to layout
32       * @param radius the radius of the circle layout.
33       */
34      public CircleLayout(String   group, double radius) {
35          super(group);
36          m_radius = radius;
37      }
38      
39      /**
40       * Return the radius of the layout circle.
41       * @return the circle radius
42       */
43      public double getRadius() {
44          return m_radius;
45      }
46  
47      /**
48       * Set the radius of the layout circle.
49       * @param radius the circle radius to use
50       */
51      public void setRadius(double radius) {
52          m_radius = radius;
53      }
54      
55      /**
56       * @see prefuse.action.Action#run(double)
57       */
58      public void run(double frac) {
59          TupleSet ts = m_vis.getGroup(m_group); 
60          
61          int nn = ts.getTupleCount();
62          
63          Rectangle2D   r = getLayoutBounds();  
64          double height = r.getHeight();
65          double width = r.getWidth();
66          double cx = r.getCenterX();
67          double cy = r.getCenterY();
68  
69          double radius = m_radius;
70          if (radius <= 0) {
71              radius = 0.45 * (height < width ? height : width);
72          }
73  
74          Iterator   items = ts.tuples();
75          for (int i=0; items.hasNext(); i++) {
76              VisualItem n = (VisualItem)items.next();
77              double angle = (2*Math.PI*i) / nn;
78              double x = Math.cos(angle)*radius + cx;
79              double y = Math.sin(angle)*radius + cy;
80              setX(n, null, x);
81              setY(n, null, y);
82          }
83      }
84  
85  } // end of class CircleLayout
86
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags