Source for org.jfree.chart.plot.dial.DialLayer

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jfreechart/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * --------------
  28:  * DialLayer.java
  29:  * --------------
  30:  * (C) Copyright 2006-2007, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * Changes
  36:  * -------
  37:  * 03-Nov-2006 : Version 1 (DG);
  38:  * 
  39:  */
  40: 
  41: package org.jfree.chart.plot.dial;
  42: 
  43: import java.awt.Graphics2D;
  44: import java.awt.geom.Rectangle2D;
  45: import java.io.Serializable;
  46: import java.util.EventListener;
  47: 
  48: /**
  49:  * A dial layer draws itself within a reference frame.  The view frame is a
  50:  * subset of the reference frame, and defines the area that is actually 
  51:  * visible. 
  52:  * <br><br>
  53:  * Classes that implement this interface should be {@link Serializable}, 
  54:  * otherwise chart serialization may fail.
  55:  */
  56: public interface DialLayer {
  57:    
  58:     /** 
  59:      * Returns a flag that indicates whether or not the layer is visible. 
  60:      * 
  61:      * @return A boolean.
  62:      */
  63:     public boolean isVisible();
  64:     
  65:     /**
  66:      * Registers a listener with this layer, so that it receives notification
  67:      * of changes to this layer.
  68:      * 
  69:      * @param listener  the listener.
  70:      */
  71:     public void addChangeListener(DialLayerChangeListener listener);
  72:     
  73:     /**
  74:      * Deregisters a listener, so that it no longer receives notification of
  75:      * changes to this layer.
  76:      * 
  77:      * @param listener  the listener.
  78:      */
  79:     public void removeChangeListener(DialLayerChangeListener listener);
  80:     
  81:     /**
  82:      * Returns <code>true</code> if the specified listener is currently 
  83:      * registered with the this layer.
  84:      * 
  85:      * @param listener  the listener.
  86:      * 
  87:      * @return A boolean.
  88:      */    
  89:     public boolean hasListener(EventListener listener);
  90:     
  91:     /**
  92:      * Returns <code>true</code> if the drawing should be clipped to the
  93:      * dial window (which is defined by the {@link DialFrame}), and 
  94:      * <code>false</code> otherwise.
  95:      *
  96:      * @return A boolean.
  97:      */
  98:     public boolean isClippedToWindow();
  99:     
 100:     /**
 101:      * Draws the content of this layer.
 102:      *
 103:      * @param g2  the graphics target (<code>null</code> not permitted).
 104:      * @param plot  the plot (typically this should not be <code>null</code>, 
 105:      *     but for a layer that doesn't need to reference the plot, it may
 106:      *     be permitted).
 107:      * @param frame  the reference frame for the dial's geometry 
 108:      *     (<code>null</code> not permitted).  This is typically larger than
 109:      *     the visible area of the dial (see the next parameter).
 110:      * @param view  the visible area for the dial (<code>null</code> not 
 111:      *     permitted).
 112:      */
 113:     public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame, 
 114:             Rectangle2D view);
 115:     
 116: }