graph2d.java

java 作图的程序

package graph;

import java.awt.*;
import java.applet.*;
import java.util.*;
import java.lang.*;
import java.io.StreamTokenizer;
import java.io.InputStream;
import java.io.IOException;
import java.net.URL;

/*
**************************************************************************
**
**                      Class  graph.Graph2D
**
**************************************************************************
**    Copyright (C) 1995, 1996 Leigh Brookshaw
**
**    This program is free software; you can redistribute it and/or modify
**    it under the terms of the GNU General Public License as published by
**    the Free Software Foundation; either version 2 of the License, or
**    (at your option) any later version.
**
**    This program is distributed in the hope that it will be useful,
**    but WITHOUT ANY WARRANTY; without even the implied warranty of
**    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**    GNU General Public License for more details.
**
**    You should have received a copy of the GNU General Public License
**    along with this program; if not, write to the Free Software
**    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**************************************************************************
**
** class Graph2D extends Canvas 
**
** The main entry point and interface for the 2D graphing package.
** This class keeps track of the DataSets and the Axes.
** It has the main drawing engine that positions axis etc.
**
*************************************************************************/


/**
 * This is the main plotting class. It partitions the canvas to contain the
 * specified axes with the remaining space taken with the plotting region.
 * Axes are packed against the walls of the canvas. The <B>paint</B> and
 * <B>update</B> methods of this class handle all the drawing operations of the
 * graph. This means that independent components like Axis and DataSets must be
 * registered with this class to be incorporated into the plot.
 *
 * @version  $Revision: 1.12 $, $Date: 1996/09/24 05:23:41 $
 * @author   Leigh Brookshaw
 */

public class Graph2D extends Canvas {


/*
** Default Background Color
*/
    private Color DefaultBackground = null;



/*
*********************
**
** Protected Variables
**
*********************/

/**
 *  A vector list of All the axes attached
 *  @see Graph2d#attachAxis()
 */

    protected Vector axis          = new Vector(4);

/**
 *  A vector list of All the DataSets attached
 *  @see Graph2d#attachDataSet()
 *  @see DataSet
 */

    protected Vector dataset       = new Vector(10);

/**
 *  The markers that may have been loaded
 *  @see Graph2D#setMarkers()
 */

    protected Markers markers = null;

/**
 * The blinking "data loading" thread
 * @see Graph2D#startedloading()
 */

    protected LoadMessage load_thread = null;

/**
 * The background color for the data window
 */
    protected Color DataBackground = null;

/*
**********************
**
** Public Variables
**
*********************/

/**
 *  If this is greater than zero it means that
 *  data loading threads are active so the message "loading data"
 *  is flashed on the plot canvas. When it is back to zero the plot
 *  progresses normally
 */
    public int  loadingData  = 0;


/**
 *  The width of the border at the top of the canvas. This allows 
 *  slopover from axis labels, legends etc.
 */
    public int     borderTop          = 20;
/**
 *  The width of the border at the bottom of the canvas. This allows 
 *  slopover from axis labels, legends etc.
 */
    public int     borderBottom       = 20;
/**
 *  The width of the border at the left of the canvas. This allows 
 *  slopover from axis labels, legends etc.
 */
    public int     borderLeft         = 20;
/**
 *  The width of the border at the right of the canvas. This allows 
 *  slopover from axis labels, legends etc.
 */
    public int     borderRight        = 20;

/**
 *  If set <I>true</I> a frame will be drawn around the data window.
 *  Any axes will overlay this frame.
 */
    public boolean frame        = true;
/**
 *  The color of the frame to be drawn
 */
    public Color   framecolor;
/**
 * If set <I>true</I> (the default) a grid will be drawn over the data window.
 * The grid will align with the major tic marks of the Innermost axes.
 */
    public boolean drawgrid     = true; 
/**
 * The color of the grid to be drawn
 */
    public Color   gridcolor    = Color.pink;
/**
 *  If set <I>true</I> (the default) a grid line will be drawn 
 *  across the data window
 *  at the zeros of the innermost axes.
 */
    public boolean drawzero     = true;
/**
 *  The color of the zero grid lines.
 */ 
    public Color   zerocolor    = Color.orange;
/**
 *  The rectangle that the data will be plotted within. This is an output
 *  variable only.
*/
    public Rectangle datarect   = new Rectangle();
/**
 *  If set <I>true</I> (the default) the canvas will be set to the background
 *  color (erasing the plot) when the update method is called.
 *  This would only be changed for special effects.
 */
    public boolean clearAll     = true;
/**
 *  If set <I>true</I> (the default) everything associated with the plot
 *  will be drawn when the update method or paint method are called.
 *  Normally
 *  only modified for special effects
*/
    public boolean paintAll     = true;

/**
 *  Modify the position of the axis and the range of the axis so that
 *  the aspect ratio of the major tick marks are 1 and the plot is square
 *  on the screen
*/
    public boolean square = false;

  /**
   * Text to be painted Last onto the Graph Canvas.
   */
    public TextLine lastText = null;
/*
*******************
**
**  Public Methods
**
*******************/


/**
 *  Load and Attach a DataSet from a File. 
 *  The method loads the data into a DataSet class
 *  and attaches the class to the graph for plotting.
 *
 *  The data is assumed to consist
 *  (at this stage) 2 ASCII columns of numbers x, y. As always blank lines
 *  are ignored and everything following # is ignored as a comment.
 *
 *  @param file    The URL of the data file to read.
 *  @return        The DataSet constructed containing the data read.
 */
    public DataSet loadFile( URL file) {
           byte b[] = new byte[50];
           int nbytes = 0;
           int max  = 100;
           int inc  = 100;
           int n    = 0;
           double data[] = new double[max];
           InputStream is = null;
           boolean comment    = false;
           int c;

           try {
                 is = file.openStream();

                 while( (c=is.read()) > -1 ) {
                     
                     switch (c) {
                     
                         case '#':
                                    comment = true;
                                    break;
                         case '\r': case '\n':
                                    comment = false;
                         case ' ': case '\t':
                                if( nbytes > 0 ) {
                                   String s = new String(b,0,0,nbytes);
                                   data[n] = Double.valueOf(s).doubleValue();
                                   n++;
                                   if( n >= max ) {
                                       max += inc;
                                       double d[] = new double[max];
                                       System.arraycopy(data, 0, d, 0, n);
                                       data = d;
                                   }

                                   nbytes = 0;
                                }
                                break;
                         default:
                                   if( !comment ) {
                                        b[nbytes] = (byte)c;
                                        nbytes++;
                                   }
                                   break;
                      }

                  }

                if (is != null) is.close();
        } catch(Exception e) {
          System.out.println("Failed to load Data set from file ");
          e.printStackTrace();
          if (is != null) try { is.close(); } catch (Exception ev) { }
          return null;
        }

        return loadDataSet(data,n/2);
        
    }

/**
 *  Load and Attach a DataSet from an array. 
 *  The method loads the data into a DataSet class
 *  and attaches the class to the graph for plotting.
 *
 *  The data is assumed to be stored
 *  in the form  x,y,x,y,x,y.... A local copy of the data is made.
 *
 *  @param  data   The data to be loaded in the form x,y,x,y,...
 *  @param  n      The number of (x,y) data points. This means that the
 *                 minimum length of the data array is 2*n.
 *  @return        The DataSet constructed containing the data read.
 */
    public DataSet loadDataSet( double data[], int n ) {
       DataSet d;
       try { 
             d =  new DataSet(data, n);
             dataset.addElement( d );
             d.g2d = this;
            }
       catch (Exception e) { 
         System.out.println("Failed to load Data set ");
         e.printStackTrace();
         return null;
       }
       return d;
    }

/**
 *   Attach a DataSet to the graph. By attaching the data set the class
 *   can draw the data through its paint method.
 */

    public void attachDataSet( DataSet d ) {

       if( d != null) {
             dataset.addElement( d );
             d.g2d = this;
       }
    }
/**
 *    Detach the DataSet from the class. Data associated with the DataSet
 *    will nolonger be plotted.
 *
 *    @param d    The DataSet to detach.
 */

    public void detachDataSet( DataSet d ) {
       if(d != null) {
                      if(d.xaxis != null) d.xaxis.detachDataSet(d);
                      if(d.yaxis != null) d.yaxis.detachDataSet(d);
                      dataset.removeElement(d);
       }
    }
/**
 *    Detach All the DataSets from the class.
*/

    public void detachDataSets() {
           DataSet d;
           int i;

           if(dataset == null | dataset.isEmpty() ) return;

           for (i=0; i<dataset.size(); i++) {
             d = ((DataSet)dataset.elementAt(i));
             if(d.xaxis != null) d.xaxis.detachDataSet(d);
             if(d.yaxis != null) d.yaxis.detachDataSet(d);
           }

           dataset.removeAllElements();
    }


/**
 *    Create and attach an Axis to the graph. The position of the axis
 *    is one of Axis.TOP, Axis.BOTTOM, Axis.LEFT or Axis.RIGHT.
 *
 *    @param position   Position of the axis in the drawing window.
 *
*/
    public Axis createAxis( int position ) {
       Axis a;

       try { 
             a =  new Axis(position);
             a.g2d = this;
             axis.addElement( a );
            }
       catch (Exception e) { 
         System.out.println("Failed to create Axis");
         e.printStackTrace();
         return null;
       }

       return a;
    }
/**
 *  Attach a previously created Axis. Only Axes that have been attached will
 *  be drawn 
 *
 *    @param the Axis to attach.
*/
    public void attachAxis( Axis a ) {

       if(a == null) return;
       
       try { 
             axis.addElement( a );
             a.g2d = this;
            }