//
// BarChart.java - defines BarChart class
//
// Code Developed for the Java Tutor column in Java Report 
// and Datamation Magazine
//
// Copyright (c) 1995 by Philip Meese
//
import java.awt.*;      // referece to the Abstract Window Toolkit pkg
import javax.swing.*;      // referece to the Abstract Window Toolkit pkg

import NumericSet;      // ref to our own class

public class BarChart extends JPanel {
        // member data
        NumericSet      _set;
        Rectangle       _rect;          // our bounds (bounding rectangle)
        int             _margin=5;      // for t, b, l and r margins

        // member functions
        public BarChart(NumericSet set_, int width_, int height_){
                numericSet(set_);
                setBounds(0, 0, width_, height_);
        }
        public void numericSet(NumericSet set_){
                _set=set_;
                repaint();
        }
        public void paintComponent(Graphics g_){
                _rect=getBounds();
                paintBackground(g_, Color.white);
                if(_set.length()>0)
                        paintBars(g_);
        }
        public void paintBars(Graphics g_){
                int sep=2;              // interbar spacing
                Color c=g_.getColor();  // remember color for later

                // area within which the bars will be rendered
                int renderWidth=_rect.width-_margin*2-(_set.length()-1)*sep;
                int renderHeight=_rect.height-_margin*2;

                int barWidth=renderWidth/_set.length();
                
                // scaling factor so values fit in given height
                float scaleFactor=(float)renderHeight/_set.max();

                Point barOrg=new Point(_margin, _margin);
                for(int i=0; i<_set.length(); i++, barOrg.y=_margin){
                        int barHeight=(int)(_set.value(i)*scaleFactor);

                        // adjust bar rect so it grows from bottom
                        barOrg.y=_margin+renderHeight-barHeight;

                        g_.setColor(Color.black);               // outline bar
                        g_.drawRect(barOrg.x, 
                                    barOrg.y, 
                                    barWidth-sep, 
                                    barHeight);

                        g_.setColor(Color.red);                 // fill bar
                        g_.fillRect(barOrg.x+1,
                                    barOrg.y+1, 
                                    barWidth-sep-1, 
                                    barHeight-1);

                        barOrg.x += barWidth + sep;             // space between
                }
                g_.setColor(c); //reset color
        }
        public void paintBackground(Graphics g_, Color c_){
                Color c=g_.getColor();
                g_.setColor(c_);
                g_.fillRect(0, 0, _rect.width, _rect.height);
                g_.setColor(c);
        }

} // end class BarChart


// debugging code no longer needed
/*
                debugPrintln("_rect.x/y/w/h=" + _rect.x + " "+  _rect.y +
                         " "+  _rect.width + " "+  _rect.height);


        public void debugPrintln(String s_){
                if(_debug>0) System.out.println(s_);
        }

                debugPrintln("paintBars: barWidth=" + barWidth + 
                        ", _rect.height=" + _rect.height +
                        ", _rect.width=" + _rect.width);
                debugPrintln("        scaleFactor=" + scaleFactor +
                        ", _set.length()=" + _set.length() +
                        ",_set.max()=" + _set.max() );

 */