axis.java

java 作图的程序

package graph;

import java.awt.*;
import java.applet.*;
import java.util.Vector;
import java.util.Enumeration;
import java.lang.*;


/*
**************************************************************************
**
**    Class  Axis            
**
**************************************************************************
**    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.
**************************************************************************
**
**    This class is designed to be used in conjunction with 
**    the Graph2D class and DataSet class for plotting 2D graphs.
**
*************************************************************************/



/**
 * This class controls the look and feel of axes. 
 * It is designed to be used in conjunction with 
 * the Graph2D class and DataSet class for plotting 2D graphs.
 *
 * To work with the other classes a system of registration is used.
 * The axes have to be attached to the controlling Graph2D class
 * and the DataSet's have to be attached to both the Graph2D class
 * and the Axis class.
 *
 * This way the 3 main classes Graph2D, Axis and DataSet know of each
 * others existence.
 *
 * This does not mean the classes cannot be used independently, they can
 * but in this mode nothing is automated, the user must code everything
 * manually
 *
 * @version  $Revision: 1.12 $, $Date: 1996/09/12 03:27:07 $.
 * @author   Leigh Brookshaw
 */ 

public class Axis extends Object {
    
/*
***************************
** Public Static Values     
**************************/

/**
 *    Constant flagging Horizontal Axis
 */
      static final int  HORIZONTAL = 0;
/**
 *    Constant flagging Vertical Axis
 */
      static final int  VERTICAL   = 1;
/**
 *    Constant flagging Axis position on the graph. 
 *    Left side => Vertical
 */
      public static final int  LEFT       = 2;
/**
 *    Constant flagging Axis position on the graph. 
 *    Right side => Vertical
 */
      public static final int  RIGHT      = 3;
/**
 *    Constant flagging Axis position on the graph. 
 *    Top side => Horizontal
 */
      public static final int  TOP        = 4;
/**
 *    Constant flagging Axis position on the graph. 
 *    Bottom side => Horizontal
 */
      public static final int  BOTTOM     = 5;
/**
 *    The first guess on the number of Labeled Major tick marks.
 */
      static final int  NUMBER_OF_TICS = 4;

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

  /**
   *    If <i>true</i> draw a grid positioned on major ticks over the graph
   */
      public boolean  drawgrid        = false;
  /**
   *    If <i>true</i> draw a line positioned on the Zero label tick mark.
   */
      public boolean  drawzero        = false;
  /**
   * Color of the grid
   */
      public Color   gridcolor        = null;
  /**
   * Color of the line at the Zero label
   */
      public Color   zerocolor        = null;
  /**
   * Default value <i>true</i>. Normally never changed. If set <i>false</I>
   * the Axis draw method exits without drawing the axis.
   * @see Axis#drawAxis()
   */
      public boolean redraw           = true;
  /**
   * Rescale the axis so that labels fall at the end of the Axis. Default
   * value <i>false</i>.
   */
      public boolean force_end_labels = false;
  /**
   * Size in pixels of the major tick marks
   */
      public int     major_tic_size = 10;
  /**
   * Size in pixels of the minor tick marks
   */
      public int     minor_tic_size  = 5;
  /**
   * Number of minor tick marks between major tick marks
   */
      public int     minor_tic_count = 1;
  /**
   * Color of the Axis.
   */
      public Color   axiscolor;
  /**
   * Minimum data value of the axis. This is the value used to scale
   * data into the data window. This is the value to alter to force
   * a rescaling of the data window.
   */
      public double minimum;
  /**
   * Maximum data value of the axis. This is the value used to scale
   * data into the data window. This is the value to alter to force
   * a rescaling of the data window.
   */
      public double maximum;
  /**
   * Before the Axis can be positioned correctly and drawn the data window
   * needs to be calculated and passed to the Axis.
   */
      public Dimension data_window = new Dimension(0,0);

  /**
   * The graph canvas this axis is attached to (if it is attached to any)
   * @see graph.Graph2D
   */
      public Graph2D g2d = null;



/*
***********************
** Protected Variables      
**********************/
  /**
   * The position in pixels of the minimum point of the axis line
   */
      protected Point amin;

  /**
   * The position in pixels of the maximum point of the axis line
   */
      protected Point amax;

  /**
   * The orientation of the axis. Either Axis.HORIZONTAL or
   * Axis.VERTICAL
   */
      protected int orientation;

  /**
   * The position of the axis. Either Axis.LEFT, Axis.RIGHT, Axis.TOP, or
   * Axis.BOTTOM
   */
      protected int position;

  /**
   * The width of the Axis. Where width for a horizontal axis is really 
   * the height
   */
      protected int width = 0;

  /**
   * Textline class to contain the title of the axis.
   */
      protected RTextLine title    = new RTextLine();

  /**
   * Textline class to hold the labels before printing.
   */
      protected RTextLine label    = new RTextLine("0");
  /**
   * Textline class to hold the label's exponent (if it has one).
   */
      protected RTextLine exponent = new RTextLine();
  /**
   * The width of the maximum label. Used to position a Vertical Axis.
   */
      protected int max_label_width     = 0;
  /**
   * Vector containing a list of attached DataSets
   */
      protected Vector dataset = new Vector();
  /**
   * String to contain the labels.
   */  
      protected String label_string[]     = null;
  /**
   * The actual values of the axis labels
   */
      protected float  label_value[]      = null;
  /**
   * The starting value of the labels
   */
      protected double label_start        = 0.0;
  /**
   * The increment between labels
   */
      protected double label_step         = 0.0;
  /**
   * The label exponent
   */
      protected int    label_exponent     = 0;
  /**
   * The number of labels required
   */
      protected int    label_count        = 0;
  /**
   * Initial guess for the number of labels required
   */
      protected int    guess_label_number = 4;

  /**
   * If true the axis range must be manually set by setting the
   * Axis.minimum and Axis.maximum variables. The default is false.
   * The default action is for the axis range to be calculated everytime
   * a dataset is attached.
   */
     protected boolean manualRange = false;

/*
*********************
** Constructors
********************/

  /**
   *  Instantiate the class. The defalt type is a Horizontal axis
   *  positioned at the bottom of the graph.
   */
      public Axis() {
                 orientation = HORIZONTAL;
                 position    = BOTTOM;
      }           

  /**
   * Instantiate the class. Setting the position.
   * @param p Set the axis position. Must be one of Axis.BOTTOM,
   * Axis.TOP, Axis.LEFT, Axis.RIGHT, Axis.HORIZONTAL or Axis.VERTICAL.
   * If one of the latter two are used then Axis.BOTTOM or 
   * Axis.LEFT is assumed.
   */
      public Axis(int p) {

           setPosition(p);

           switch (position) {
              case LEFT: case VERTICAL:
                          title.setRotation(90);
                          break;
              case RIGHT:
                          title.setRotation(-90);
                          break;
              default:
                          title.setRotation(0);
                          break;
           }


      }

/*
*******************
** Public Methods
******************/

  /**
   * Set the axis position.
   * @param p Must be one of Axis.BOTTOM,
   * Axis.TOP, Axis.LEFT, Axis.RIGHT, Axis.HORIZONTAL or Axis.VERTICAL.
   * If one of the latter two are used then Axis.BOTTOM or 
   * Axis.LEFT is assumed.
   */
      public void setPosition(int p) {
           position = p;

           switch (position) {
              case LEFT:
                          orientation = VERTICAL;
                          break;
              case RIGHT:
                          orientation = VERTICAL;
                          break;

              case TOP:
                          orientation = HORIZONTAL;
                          break;
              case BOTTOM:
                          orientation = HORIZONTAL;
                          break;
              case HORIZONTAL:
                          orientation = HORIZONTAL;
                          position    = BOTTOM;
                          break;
              case VERTICAL:
                          orientation = VERTICAL;
                          position    = LEFT;
                          break;
              default:
                          orientation = HORIZONTAL;
                          position    = BOTTOM;
                          break;
           }
      }
      
  /**
   * Attach a DataSet for the Axis to manage.
   * @param d dataSet to attach
   * @see graph.DataSet
   */
      public void attachDataSet( DataSet d ) {
            if( orientation == HORIZONTAL )   attachXdata( d );
            else                              attachYdata( d );
      }
  /**
   * Detach an attached DataSet
   * @param d dataSet to detach
   * @see graph.DataSet
   */
      public void detachDataSet( DataSet d ) {
           int i = 0;

           if( d == null ) return;

           if( orientation == HORIZONTAL ) {
               d.xaxis = null;
           } else {
               d.yaxis = null;
           }
           dataset.removeElement(d);

           if(!manualRange) resetRange();
      }
  /**