/*
 * StoJ.java - stella to java conversion program
 * Copyright 1999-2003 David A. Joiner and the Shodor Edcuation
 * Foundation, Inc.
 */

import java.awt.*;
import java.applet.Applet;
import com.helplets.awt.*;
import java.awt.event.*;

public class StoJ extends Applet implements Runnable,ActionListener,ItemListener
{
    // Graphic display uses graphPaper class, with modifications
    LineGraphPaper graphs;
    AnimatedGraphPaper animation;
    String gr_title;
    String gr_depLabel;
    String gr_type;
    String gr_auto;
    
    // Model class is an extension of Diffeq, with overrides
    // for problem setup and differential equation calculation
    Model my_eq;
    
    // Model_running is the thread, which runs continously,
    // try_model tracks actual solution of model
    Thread model_running;
    int try_model; 
    int start_model;
    
    // User controls contains sliderbar controls for variables
    // and parameters
    Panel user_controls;
    
    // Text output is given as an option for users to cut
    // and paste a model solution into Excel or another spreadsheet.
    GEchoDlg text_out2;
    
    // Model controls holds numerical solution and model
    // run options.
    Panel model_controls;
    
    // graph_key controls what will be displayed on the
    // graph.
    Panel graph_key;
    
    // Panels to assist in layout, many choices for different layout
    // possibilities

    Panel panelKeyModelSwitch;
    Panel panelGraphSwitch;

    // add user controls
    // text field variable names start with tf_
    // NumInput variable names start with ni_
    // ScrollBar variable names start with sb_
    TextField [] tf_varlabel;
    TextField [] tf_ratelabel;
    NumSlider [] ns_var;
    NumSlider [] ns_rate;
    
    // user control labels
    TextField uclabel1;
    TextField uclabel2;

    // variables (stocks) and rates (converters) controlled
    // by scrollbars
    double [] x_var;
    double [] x_rate;

    // add graph_key controls
    // check_var stores the state of the display boolean
    // check_colors stores the colors used for display
    // check_key is a series of panels which are painted to
    // give a key for the display
    // autoscale changes the range of display so that all
    // are displayed from min to max
    // show_text allows the user to get text output.
    // ch_trace allows the user to turn tracing on
    Checkbox [] check_var;
    Color [] check_colors;
    Panel [] check_key;
    Checkbox ch_autoscale;
    Checkbox ch_trace;
    Button show_text;

    // add model controls
    TextField tf_itlabel;
    TextField tf_ftlabel;
    TextField tf_stlabel;
    TextField tf_imlabel;
    TextField tf_yminlabel;
    TextField tf_ymaxlabel;
    TextField tf_status;
    NumInput ni_it;
    NumInput ni_ft;
    NumInput ni_st;
    NumInput ni_ymin;
    NumInput ni_ymax;
    Choice ch_method;
    Checkbox ch_adaptive;
    Button stop_model;
    double x_it,x_ft,x_st,x_ymin,x_ymax;
    
    // CardLayout controls
    // For the many sliders view, a cardlayout is used to switch back
    // and forth between display controls and model controls
    CardLayout cardLayoutKey;
    Choice choiceCardLayoutKey;
    CardLayout cardLayoutGraph;
    Choice choiceCardLayoutGraph;

    // xtemp is used to create a single array to pass to
    // graphpaper
    //double [] xtemp;
    //int ntemp=0;

    int redraw=0;
    int textbox=0;
    
    // Display types are
    // STANDARD - 2 X 2 - graph, user controls, model controls
    // display controls
    // LIMITED - 2 X 1 - graph, user controls
    // MANY_SPLIDERS - 2 left, 1 right - switch between model
    // and graph controls
    final static int DISPLAY_STANDARD=0;
    final static int DISPLAY_LIMITED=1;
    final static int DISPLAY_MANY_SLIDERS=2;
    int display_type=DISPLAY_STANDARD;
    
    Color bg_color;
    Color text_bg_color;
    Color label_bg_color;

    public void init() {
    
    
        // define model
        my_eq=new Model();
        my_eq.init_problem(0.25);
        
        String paramstring;

        
        //Check for parameter modifications
        
        paramstring = getParameter("GRAPHS_TITLE");
        if (paramstring != null) {
            gr_title = new String(paramstring);
        } else {
            gr_title = my_eq.gr_title;
        }
        paramstring = getParameter("GRAPHS_DEPLABEL");
        if (paramstring != null) {
            gr_depLabel = new String(paramstring);
        } else {
            gr_depLabel = my_eq.gr_depLabel;
        }
        paramstring = getParameter("GRAPHS_AUTO");
        if (paramstring != null) {
            gr_auto = new String(paramstring);
            if (!gr_auto.equalsIgnoreCase("TRUE")) {
                gr_auto = new String("FALSE");
            }
        } else {
            gr_auto = new String("FALSE");
        }
        paramstring = getParameter("GRAPHS_TYPE");
        if (paramstring != null) {
            gr_type = new String(paramstring);
            if (!gr_type.equalsIgnoreCase("Bar")) {
                gr_type = new String("Line");
            }
        } else {
            gr_type = new String("Line");
        }
        //Graphs to be allowed - beware, if they allow too
        // many, an error could result due to too many colors
        // make sure that the display section cuts it off
        // appropriately
        // maybe there needs to be an internal check
        paramstring = getParameter("GRAPHS_ALLOW");
        // This gets a little nasty, since everything is
        // contained on one string, we have to parse it all
        // out, and check each occurence. This is a
        // serious candidate for a subroutine at some point.
        if (paramstring != null) {
            String rest = paramstring;
            String first = null;
            String arg = null;
            while (rest!=null) {
                int index = rest.indexOf(";");
                if (index<0) {
                    first = rest;
                    rest = null;
                } else {
                    first = rest.substring(0,index);
                    rest = rest.substring(index+1,rest.length());
                }
                // loop through all possible labels, and search for
                // a match (do not ignore case)
                // If a match occurs, change as appropriate
                index = first.indexOf(",");
                if (index>-1) {
                    arg = first.substring(index+1,first.length());
                    first = first.substring(0,index);
                } else {
                    arg = new String("true");
                }
                boolean done=false;
                int imatch=-1;
                // loop through all of the things which can
                // be displayed, and check for a match.
                for(int i=0;i<my_eq.n_tot&&!done;i++) {
                    int j=0;
                    if(i<my_eq.n_vars) {
                        j=i;
                        if (first.equals(my_eq.var_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else if (i<my_eq.n_vartot) {
                        j=i-my_eq.n_vars;
                        if (first.equals(my_eq.varf_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else if (i<my_eq.n_vartot+my_eq.n_rates) {
                        j=i-my_eq.n_vars-my_eq.n_varfs;
                        if (first.equals(my_eq.rate_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else if (i<my_eq.n_vartot+my_eq.n_rates+my_eq.n_convs) {
                        j=i-my_eq.n_vars-my_eq.n_varfs-my_eq.n_rates;
                        if (first.equals(my_eq.conv_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else {
                        j=i-my_eq.n_vars-my_eq.n_varfs-my_eq.n_convs-my_eq.n_rates;
                        if (first.equals(my_eq.flow_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    }
                    // if a match was found, go ahead and make
                    // the change.
                    if (done) {
                        if(arg.equalsIgnoreCase("true")) {
                            my_eq.allow_display[imatch]=true;
                        } else {
                            my_eq.allow_display[imatch]=false;
                        }
                    }
                }
            }
        }


        //Also allow the user to use parameters to override
        //whether a graph which CAN be displayed actually
        //is displayed.
        paramstring = getParameter("GRAPHS_DISPLAY");
        if (paramstring != null) {
            String rest = paramstring;
            String first = null;
            String arg = null;
            while (rest!=null) {
                int index = rest.indexOf(";");
                if (index<0) {
                   first = rest;
                   rest = null;
                } else {
                    first = rest.substring(0,index);
                    rest = rest.substring(index+1,rest.length());
                }
                // loop through all possible labels, and search for
                // a match (do not ignore case)
                // If a match occurs, change as appropriate
                index = first.indexOf(",");
                if (index>-1) {
                    arg = first.substring(index+1,first.length());
                    first = first.substring(0,index);
                } else {
                    arg = new String("true");
                }
                boolean done=false;
                int imatch=-1;
                for(int i=0;i<my_eq.n_tot&&!done;i++) {
                    int j=0;
                    if(i<my_eq.n_vars) {
                        j=i;
                        if (first.equals(my_eq.var_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else if (i<my_eq.n_vartot) {
                        j=i-my_eq.n_vars;
                        if (first.equals(my_eq.varf_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else if (i<my_eq.n_vartot+my_eq.n_rates) {
                        j=i-my_eq.n_vars-my_eq.n_varfs;
                        if (first.equals(my_eq.rate_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else if (i<my_eq.n_vartot+my_eq.n_rates+my_eq.n_convs) {
                        j=i-my_eq.n_vars-my_eq.n_varfs-my_eq.n_rates;
                        if (first.equals(my_eq.conv_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    } else {
                        j=i-my_eq.n_vars-my_eq.n_varfs-my_eq.n_convs-my_eq.n_rates;
                        if (first.equals(my_eq.flow_label[j])) {
                            imatch=i;
                            done=true;
                        }
                    }
                    if (done) {
                        if(arg.equalsIgnoreCase("true")) {
                            my_eq.default_display[imatch]=true;
                        } else {
                            my_eq.default_display[imatch]=false;
                        }
                    }
                }
            }
        }

    
        //Check parameters for display type
        // Display type can be STANDARD, LIMITED, or MANY_SLIDERS
        paramstring = getParameter("DISPLAY");
        if (paramstring!=null) {
            if (paramstring.equalsIgnoreCase("LIMITED")) {
                display_type=DISPLAY_LIMITED;
            } else if (paramstring.equalsIgnoreCase("MANY_SLIDERS")) {
                display_type=DISPLAY_MANY_SLIDERS;
            }
        }
        //bg_color = new Color(225,225,255);
        bg_color = getBackground();
        text_bg_color = new Color(225,225,225);
        label_bg_color = new Color(200,200,200);
        paramstring = getParameter("BGCOLOR");
        if (paramstring!=null) {
            if (paramstring.charAt(0)=='#') {
                paramstring=paramstring.substring(1);
                bg_color = new Color(Integer.parseInt(paramstring,16));
            } else {
                bg_color = new Color((new Integer(paramstring)).intValue());
            }
        }
        paramstring = getParameter("LABEL_BGCOLOR");
        if (paramstring!=null) {
            if (paramstring.charAt(0)=='#') {
                paramstring=paramstring.substring(1);
                label_bg_color = new Color(Integer.parseInt(paramstring,16));
            } else {
                label_bg_color = new Color((new Integer(paramstring)).intValue());
            }
        }
        paramstring = getParameter("TEXT_BGCOLOR");
        if (paramstring!=null) {
            if (paramstring.charAt(0)=='#') {
                paramstring=paramstring.substring(1);
                text_bg_color = new Color(Integer.parseInt(paramstring,16));
            } else {
                text_bg_color = new Color((new Integer(paramstring)).intValue());
            }
        }

        paramstring = getParameter("TSTEP");
        if (paramstring!=null) {
            my_eq.tstep_default= new Double(paramstring).doubleValue();
        }
        paramstring = getParameter("TINIT");
        if (paramstring!=null) {
            my_eq.tinitial= new Double(paramstring).doubleValue();
        }
        paramstring = getParameter("TFINAL");
        if (paramstring!=null) {
            my_eq.tfinal= new Double(paramstring).doubleValue();
        }
        paramstring = getParameter("YMIN");
        if (paramstring!=null) {
            my_eq.ymin_default= new Double(paramstring).doubleValue();
        }
        paramstring = getParameter("YMAX");
        if (paramstring!=null) {
            my_eq.ymax_default= new Double(paramstring).doubleValue();
        }
        paramstring = getParameter("ADAPTIVE");
        if (paramstring!=null) {
            if (paramstring.equalsIgnoreCase("YES")) {
                my_eq.adap_default=true;
            } else {
                my_eq.adap_default=false;
            }
        }
        paramstring = getParameter("INT_METHOD");
        if (paramstring!=null) {
            if (paramstring.equalsIgnoreCase("EULER")) {
                my_eq.method=Diffeq.EULER;
            } else if(paramstring.equalsIgnoreCase("RK2")) {
                my_eq.method=Diffeq.IEULER;
            } else {
                my_eq.method=Diffeq.RKUTTA4;
            }
        }

        // Set up graphical display
        graphs=new LineGraphPaper();
        graphs.setEditable(false);
        graphs.setTitle(gr_title);
        graphs.setDepLabel(gr_depLabel);
        animation=new AnimatedGraphPaper();
        animation.setTitle(gr_title);
        animation.setUnit(gr_depLabel);
        
        // define thread
        model_running=new Thread(this);
        my_eq.try_model=0;
        start_model=1;
        

        
        
        //set up model parameter controls
        user_controls=new Panel();
        user_controls.setBackground(bg_color);
        tf_varlabel=new TextField[my_eq.n_vars];
        for (int i =0;i<my_eq.n_vars;i++) {
            tf_varlabel[i]=new TextField(my_eq.var_label[i]);
            tf_varlabel[i].setEditable(false);
            tf_varlabel[i].setForeground(graphs.getColor(i));
            tf_varlabel[i].setBackground(text_bg_color);
        }
        tf_ratelabel=new TextField[my_eq.n_rates];
        for (int i =0;i<my_eq.n_rates;i++) {
            tf_ratelabel[i]=new TextField(my_eq.rate_label[i]);
            tf_ratelabel[i].setEditable(false);
            tf_ratelabel[i].setBackground(text_bg_color);
        }

        ns_var = new NumSlider[my_eq.n_vars];
        ns_rate = new NumSlider[my_eq.n_rates];
        for(int i=0;i<my_eq.n_vars;i++) {
            ns_var[i]=new NumSlider(30,my_eq.var_stylesb[i],my_eq.var_defaultsb[i],
                my_eq.var_minsb[i],my_eq.var_maxsb[i]);
        }
        for(int i=0;i<my_eq.n_rates;i++) {
            ns_rate[i]=new NumSlider(30,my_eq.rate_stylesb[i],my_eq.rate_defaultsb[i],
                my_eq.rate_minsb[i],my_eq.rate_maxsb[i]);
        }
        


        uclabel1 = new TextField("Initial Conditions",34);
        uclabel1.setBackground(label_bg_color);
        uclabel2 = new TextField("Parameters",34);
        uclabel2.setBackground(label_bg_color);
        setFont(new Font("Dialog", Font.PLAIN , 10));
        uclabel1.setEditable(false);
        uclabel2.setEditable(false);
                
        cardLayoutKey = new CardLayout();
        choiceCardLayoutKey = new Choice();
        choiceCardLayoutKey.setBackground(bg_color);
        choiceCardLayoutKey.addItem("Graph Controls");
        choiceCardLayoutKey.addItem("Model Controls");

        user_controls.setLayout(new PercentLayout());
        int ratespace=1;
        int varspace=1;
        if(my_eq.n_rates==0) ratespace=0;
        if(my_eq.n_vars==0) varspace=0;
        int componentHeight=9;
        int sliderHeight=componentHeight;
        if (display_type==DISPLAY_MANY_SLIDERS) sliderHeight=4;

        int numElements=0;
        if (varspace == 1) numElements++;
        numElements+=my_eq.n_vars;
        if(ratespace==1) numElements++;
        numElements+=my_eq.n_rates;
        if (numElements==0) numElements=1;
        if (80/(numElements) < sliderHeight) sliderHeight = 
            80/(numElements);
        if (sliderHeight<2) sliderHeight=2;

        int pos = 10;
        int left = 10;
        int right = 90;
        int numBorder = 40;
        if (varspace == 1) {
            user_controls.add("left="+left+", right="+right+
                ", top="+pos+", bottom="+(pos+sliderHeight),uclabel1);
            pos+=sliderHeight;
        }
        for(int i=varspace;i<my_eq.n_vars+varspace;i++) {
            user_controls.add("left="+left+", right="+numBorder+
                ", top="+pos+", bottom="+(pos+sliderHeight),
                tf_varlabel[i-varspace]);
            user_controls.add("left="+numBorder+", right="+right+
                ", top="+pos+", bottom="+
                (pos+sliderHeight),ns_var[i-varspace]);
            pos+=sliderHeight;
        }
        if(ratespace==1) {
            user_controls.add("left="+left+", right="+right+
                ", top="+pos+", bottom="+(pos+sliderHeight),uclabel2);
            pos+=sliderHeight;
        }
        for(int i=0;i<my_eq.n_rates;i++) {
            user_controls.add("left="+left+", right="+numBorder+
                ", top="+pos+", bottom="+(pos+sliderHeight),tf_ratelabel[i]);
            user_controls.add("left="+numBorder+", right="+right+
                ", top="+pos+", bottom="+
                (pos+sliderHeight),ns_rate[i]);
            pos+=sliderHeight;
        }

        text_out2 = new GEchoDlg(graphs,GetFrame(this),"Text Output",true);
        
        //Initialize graph key.
        graph_key=new Panel();
        graph_key.setBackground(bg_color);
        check_var = new Checkbox[my_eq.n_tot];
        check_key = new Panel[my_eq.n_tot];
        check_colors=new Color[my_eq.n_tot];
        int ccount=0;
        for(int i=0;i<my_eq.n_tot;i++) {
            check_colors[i]=graphs.getColor(ccount);
            if(my_eq.allow_display[i]) ccount++;
            if(i<my_eq.n_vars) {
                check_var[i]=new Checkbox(my_eq.var_label[i]);
                check_var[i].setForeground(check_colors[i]);
                check_var[i].setLabel(my_eq.var_label[i]);
                check_var[i].setState(my_eq.default_display[i]);
                check_key[i]=new Panel();
                check_key[i].setBackground(check_colors[i]);
            } else if (i<my_eq.n_vartot) {
                check_var[i]=new Checkbox(my_eq.varf_label[i-my_eq.n_vars]);
                check_var[i].setForeground(check_colors[i]);
                check_var[i].setLabel(my_eq.varf_label[i-my_eq.n_vars]);
                check_var[i].setState(my_eq.default_display[i]);
                check_key[i]=new Panel();
                check_key[i].setBackground(check_colors[i]);
            } else if (i<my_eq.n_vartot+my_eq.n_rates) {
                check_var[i]=new Checkbox(my_eq.rate_label[i-my_eq.n_vartot]);
                check_var[i].setForeground(check_colors[i]);
                check_var[i].setLabel(my_eq.rate_label[i-my_eq.n_vartot]);
                check_var[i].setState(my_eq.default_display[i]);
                check_key[i]=new Panel();
                check_key[i].setBackground(check_colors[i]);
            } else if (i<my_eq.n_vartot+my_eq.n_rates+my_eq.n_convs) {
                check_var[i]=new Checkbox(my_eq.conv_label[i-my_eq.n_vartot-my_eq.n_rates]);
                check_var[i].setForeground(check_colors[i]);
                check_var[i].setLabel(my_eq.conv_label[i-my_eq.n_vartot-my_eq.n_rates]);
                check_var[i].setState(my_eq.default_display[i]);
                check_key[i]=new Panel();
                check_key[i].setBackground(check_colors[i]);
            } else {
                check_var[i]=new Checkbox(my_eq.flow_label[i-(my_eq.n_vartot+my_eq.n_rates+my_eq.n_convs)]);
                check_var[i].setForeground(check_colors[i]);
                check_var[i].setLabel(my_eq.flow_label[i-(my_eq.n_vartot+my_eq.n_rates+my_eq.n_convs)]);
                check_var[i].setState(my_eq.default_display[i]);
                check_key[i]=new Panel();
                check_key[i].setBackground(check_colors[i]);
            }
        }

        ch_autoscale=new Checkbox("Autoscale");
        if(gr_auto.equalsIgnoreCase("TRUE")) {
            ch_autoscale.setState(true);
        } else {
            ch_autoscale.setState(false);
        }
        ch_trace=new Checkbox("Trace");
        ch_trace.setState(false);
        show_text=new Button("Text Output");
        
        Label graphlabel = new Label("Check to display:");
        graph_key.setLayout(new PercentLayout());
        pos = 5;
        left = 10;
        right = 90;
        int keyBorder = 20;
        numElements = 3; // count total number of items on panel
        for(int i=0;i<my_eq.n_tot;i++) {
            if(my_eq.allow_display[i]) {
                numElements++;
            }
        }
        int cboxHeight = 90/numElements;
        if (cboxHeight>componentHeight) cboxHeight=componentHeight;
        if (cboxHeight<2) cboxHeight=2;

        graph_key.add("left="+left+", right="+right+
                    ", top="+pos+", bottom="+(pos+cboxHeight),graphlabel);
        pos+=cboxHeight;
        for(int i=0;i<my_eq.n_tot;i++) {
            if(my_eq.allow_display[i]) {
                graph_key.add("left="+left+", right="+keyBorder+
                    ", top="+pos+", bottom="+(pos+cboxHeight),check_key[i]);
                graph_key.add("left="+keyBorder+", right="+right+
                    ", top="+pos+", bottom="+(pos+cboxHeight),check_var[i]);
                pos+=cboxHeight;
            }
        }
        graph_key.add("left="+keyBorder+", right="+right+
                    ", top="+pos+", bottom="+(pos+cboxHeight),ch_autoscale);
        pos+=cboxHeight;
        graph_key.add("left="+keyBorder+", right="+right+
                    ", top="+pos+", bottom="+(pos+cboxHeight),ch_trace);
        pos+=cboxHeight;
        graph_key.add("left="+left+", right="+right+
                    ", top="+pos+", bottom="+(pos+cboxHeight),show_text);
        pos+=cboxHeight;

        // Initialize model control options
        model_controls=new Panel();
        model_controls.setBackground(bg_color);
        tf_itlabel=new TextField("Initial Time:",20);
        tf_itlabel.setBackground(text_bg_color);
        tf_ftlabel=new TextField("Final Time:",20);
        tf_ftlabel.setBackground(text_bg_color);
        tf_stlabel=new TextField("Time Step:",20);
        tf_stlabel.setBackground(text_bg_color);
        tf_imlabel=new TextField("Integration Method:",20);
        tf_imlabel.setBackground(text_bg_color);
        tf_yminlabel=new TextField("Y-min Value:",20);
        tf_yminlabel.setBackground(text_bg_color);
        tf_ymaxlabel=new TextField("Y-max Value:",20);
        tf_ymaxlabel.setBackground(text_bg_color);
                tf_status=new TextField("Program Status: IDLE");
        tf_status.setBackground(text_bg_color);
        stop_model=new Button("Stop Model");
        tf_itlabel.setEditable(false);
        tf_ftlabel.setEditable(false);
        tf_stlabel.setEditable(false);
        tf_imlabel.setEditable(false);
        tf_yminlabel.setEditable(false);
        tf_ymaxlabel.setEditable(false);
                tf_status.setEditable(false);
        ni_it=new NumInput(StrLib.expNotation(my_eq.tinitial),8);
        ni_ft=new NumInput(StrLib.expNotation(my_eq.tfinal),8);
        ni_st=new NumInput(StrLib.expNotation(my_eq.tstep_default),8);
        ni_ymin=new NumInput(StrLib.expNotation(my_eq.ymin_default),8);
        ni_ymax=new NumInput(StrLib.expNotation(my_eq.ymax_default),8);
        x_it = ni_it.getDouble();
        x_ft = ni_ft.getDouble();
        x_st = ni_st.getDouble();
        x_ymin = ni_ymin.getDouble();
        x_ymax = ni_ymax.getDouble();
        ch_method=new Choice();
        ch_method.setBackground(bg_color);
        ch_method.addItem("Euler");
        ch_method.addItem("RK2");
        ch_method.addItem("RK4");
        switch (my_eq.method) {
            case Diffeq.EULER:
                ch_method.select(0);
            break;
            
            case Diffeq.IEULER:
                ch_method.select(1);
            break;
            
            case Diffeq.RKUTTA4:
            default:
                ch_method.select(2);
            break;
        }
        ch_adaptive=new Checkbox("Attempt Adaptive");
        ch_adaptive.setState(my_eq.adap_default);

        
        
        model_controls.setLayout(new PercentLayout());
        pos = 10;
        left = 10;
        right = 90;
        int inputBorder = 50;

        numElements=1;
        if (my_eq.it_enable) numElements++;
        if (my_eq.ft_enable) numElements++;
        if (my_eq.st_enable) numElements++;
        if (my_eq.imeth_enable) numElements++;
        if (my_eq.ymin_enable) numElements++;
        if (my_eq.ymax_enable) numElements++;
        if (my_eq.adap_enable) numElements++;
        int controlHeight = 80/numElements;
        if (controlHeight>componentHeight) controlHeight=componentHeight;
        if (controlHeight<2) controlHeight=2;

        if (my_eq.it_enable) {
            model_controls.add("left="+left+", right="+inputBorder+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_itlabel);
            model_controls.add("left="+inputBorder+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ni_it);
            pos+=controlHeight;
        }
        if (my_eq.ft_enable) {
            model_controls.add("left="+left+", right="+inputBorder+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_ftlabel);
            model_controls.add("left="+inputBorder+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ni_ft);
            pos+=controlHeight;
        }
        if (my_eq.st_enable) {
            model_controls.add("left="+left+", right="+inputBorder+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_stlabel);
            model_controls.add("left="+inputBorder+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ni_st);
            pos+=controlHeight;
        }
        if (my_eq.imeth_enable) {
            model_controls.add("left="+left+", right="+inputBorder+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_imlabel);
            model_controls.add("left="+inputBorder+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ch_method);
            pos+=controlHeight;
        }
        if (my_eq.ymin_enable) {
            model_controls.add("left="+left+", right="+inputBorder+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_yminlabel);
            model_controls.add("left="+inputBorder+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ni_ymin);
            pos+=controlHeight;
        }
        if (my_eq.ymax_enable) {
            model_controls.add("left="+left+", right="+inputBorder+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_ymaxlabel);
            model_controls.add("left="+inputBorder+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ni_ymax);
            pos+=controlHeight;
        }
        if (my_eq.adap_enable) {
            model_controls.add("left="+left+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),ch_adaptive);
            pos+=controlHeight;
        }
        model_controls.add("left="+left+", right="+right+
                ", top="+pos+", bottom="+(pos+controlHeight),tf_status);
        pos+=controlHeight;



        cardLayoutGraph = new CardLayout();
        choiceCardLayoutGraph = new Choice();
        choiceCardLayoutGraph.setBackground(bg_color);
        choiceCardLayoutGraph.addItem("Line Graph");
        choiceCardLayoutGraph.addItem("Bar Graph");
        if (gr_type.equalsIgnoreCase("Bar")) {
            choiceCardLayoutGraph.select(1);
        }
        
        panelGraphSwitch = new Panel();
        panelGraphSwitch.setBackground(bg_color);
        panelGraphSwitch.setLayout(cardLayoutGraph);
        panelGraphSwitch.add("Line Graph",graphs);
        panelGraphSwitch.add("Bar Graph",animation);
        cardLayoutGraph.show(panelGraphSwitch,
            choiceCardLayoutGraph.getSelectedItem());


        
        // set up basic applet layout
        if (display_type == DISPLAY_STANDARD) {
            // standard layout, top panel contains graph and sliders
            // bottom panel contains controls
            setLayout(new PercentLayout());
            //add("left=0, right=50, top=0, bottom=50",graphs);
            add("left=0, right=50, top=0, bottom=10",choiceCardLayoutGraph);
            add("left=0, right=50, top=10, bottom=50",panelGraphSwitch);
            add("left=50, right=100, top=0, bottom=50",user_controls);
            add("left=0, right=50, top=50, bottom=100",graph_key);
            add("left=50, right=100, top=50, bottom=100",model_controls);
        } else if (display_type == DISPLAY_LIMITED) {
            // limited layout, do not include controls
            setLayout(new PercentLayout());
            add("left=0, right=50, top=0, bottom=20", choiceCardLayoutGraph);
            add("left=0, right=50, top=20, bottom=100", panelGraphSwitch);
            add("left=50, right=100, top=0, bottom=100", user_controls);
        } else {
            // many slider layout, graph and controls are on left, sliders are
            // on right
            panelKeyModelSwitch = new Panel();
            panelKeyModelSwitch.setBackground(bg_color);
            panelKeyModelSwitch.setLayout(cardLayoutKey);
            panelKeyModelSwitch.add("Graph Controls",graph_key);
            panelKeyModelSwitch.add("Model Controls",model_controls);
            setLayout(new PercentLayout());
            add("left=0, right=50, top=0, bottom=10",choiceCardLayoutGraph);
            add("left=0, right=50, top=10, bottom=50",panelGraphSwitch);
            add("left=0, right=50, top=50, bottom=60",choiceCardLayoutKey);
            add("left=0, right=50, top=60, bottom=100", panelKeyModelSwitch);
            add("left=50, right=100, top=0, bottom=100", user_controls);
            cardLayoutKey.show(panelKeyModelSwitch,"Graph Controls");
        }
        

        
        // initialize arrays and set here
        x_var=new double[my_eq.n_vars];
        x_rate=new double[my_eq.n_rates];
        for(int i=0;i<my_eq.n_vars;i++) {x_var[i]=ns_var[i].getRealValue();}
        for(int i=0;i<my_eq.n_rates;i++) {x_rate[i]=ns_rate[i].getRealValue();}

        //Set up listeners
        for (int i=0; i<my_eq.n_vars; i++) {
            ns_var[i].addActionListener(this);
        }
        for (int i=0; i<my_eq.n_rates; i++) {
            ns_rate[i].addActionListener(this);
        }
        ni_it.addActionListener(this);
        ni_ft.addActionListener(this);
        ni_st.addActionListener(this);
        ni_ymin.addActionListener(this);
        ni_ymax.addActionListener(this);
        for (int i=0; i<my_eq.n_tot; i++) {
            check_var[i].addItemListener(this);
        }
        ch_autoscale.addItemListener(this);
        ch_trace.addItemListener(this);
        ch_adaptive.addItemListener(this);
        ch_method.addItemListener(this);
        choiceCardLayoutKey.addItemListener(this);
        choiceCardLayoutGraph.addItemListener(this);
        stop_model.addActionListener(this);
        show_text.addActionListener(this);

        //start model thread
        model_running.start();
        my_eq.try_model=1;
        


    }

    public void fix_labels() {
        for (int i =0;i<my_eq.n_vars;i++) {
            tf_varlabel[i].setText(my_eq.var_label[i]);
        }
        for (int i =0;i<my_eq.n_rates;i++) {
            tf_ratelabel[i].setText(my_eq.rate_label[i]);
        }
        uclabel1.setText("Initial Conditions");
        uclabel2.setText("Parameters");
        tf_itlabel.setText("Initial Time:");
        tf_ftlabel.setText("Final Time:");
        tf_stlabel.setText("Time Step:");
        tf_imlabel.setText("Integration Method:");
        tf_yminlabel.setText("Y-min Value:");
        tf_ymaxlabel.setText("Y-max Value:");
    }

    public void start() {
        if(model_running==null){
            model_running = new Thread(this);
            model_running.start();
        }
    }
    public void stop(){
        if(model_running!=null){
            model_running.stop();
            model_running=null;
        }
    }
    
    // OK, so right now I need to let the user control how the
    // model runs. currently I solve it all at once,
    // display it, and let the user change parameters.
    
    // This could be called immediate mode.
    
    // "real-time" mode would be to watch the model evolve.
    // In real-time mode, I would want the user to
    // have control over the wait time between steps, and
    // have the option of changing parameters "on the fly"
    // as in Stella's flight simulator mode.


    //public void reset_xtemp(int nnew) {
    //    if(nnew==ntemp) return;
    //    ntemp=nnew;
    //    xtemp = new double[ntemp];
    //}


    public void draw_graphs(){
        graphs.setTrace(ch_trace.getState());
        graphs.reset();
        animation.reset();
        //reset_xtemp(my_eq.ntime);
        double truemax=1.0;
        double truemin=0.0;
        for (int j=0;j<(my_eq.n_tot);j++) {
            if(my_eq.allow_display[j]) {
                double [] xtemp = new double[my_eq.ntime];
                double xmax=my_eq.xtime[(j+1)*my_eq.ntime];
                double xmin=xmax;
                for (int i=0;i<my_eq.ntime;i++) {
                    xtemp[i]=my_eq.xtime[(j+1)*my_eq.ntime+i];
                    if (xmax<xtemp[i]) xmax=xtemp[i];
                    if (xmin>xtemp[i]) xmin=xtemp[i];
                }
                if (ch_autoscale.getState()) {
                    if (xmin!=xmax) {
                        //xtemp = new double[my_eq.ntime];
                        double tempmax=xmax;
                        double tempmin=xmin;
                        xmin = Math.abs(xmin);
                        xmax = Math.abs(xmax);
                        tempmax/=xmax;
                        tempmin/=xmin;
                        if (xmin>xmax) xmax=xmin;
                        for(int i=0;i<my_eq.ntime;i++) {
                            xtemp[i]=(xtemp[i])/(xmax);
                            if (tempmax>truemax) truemax=tempmax;
                            if (tempmin<truemin) truemin=tempmin;
                        }
                    } else {
                        for(int i=0;i<my_eq.ntime;i++) {
                            xtemp[i]=0.5;
                        }
                    }
                }
                if(check_var[j].getState()){
                    graphs.setValues(my_eq.ntime, my_eq.xtime,
                        xtemp, check_colors[j], check_var[j].getLabel());
                    animation.setValues(my_eq.ntime,check_colors[j],
                        my_eq.xtime, xtemp, null);
                }
            }
        }
        graphs.setIndMin(my_eq.tinitial);
        graphs.setIndMax(my_eq.tfinal);
        if(ch_autoscale.getState()) {
            graphs.setDepMin(truemin);
            graphs.setDepMax(truemax);
            animation.setGraphMin(truemin);
            animation.setGraphMax(truemax);
        } else {
            graphs.setDepMin(x_ymin);
            graphs.setDepMax(x_ymax);
            animation.setGraphMin(x_ymin);
            animation.setGraphMax(x_ymax);
        }
        graphs.drawAll();
        animation.drawAll();
        redraw=0;
    }
    
    public void run() {
        int labelcount=0;
        while(model_running!=null){
            try {
                int runmode=0;
                if(my_eq.try_model==1) { 
                    labelcount++;
                    if(labelcount>50) {
                        labelcount=0;
                        fix_labels();
                    }
                    tf_status.setText("Program Status: RUNNING");
                    if(runmode==0) {
                        // if in immediate mode
                        my_eq.solve(x_var,x_rate,
                            x_it,x_ft,
                            x_st,
                            ch_adaptive.getState());
                        my_eq.try_model=0;
                        redraw=1;
                        tf_status.setText("Program Status: IDLE");
                    } else {
                // this will one day be slow mode
                    }
                }
                if (redraw==1) {
                    draw_graphs();
                }
                if(textbox==1) {
                    textbox=0;
                    tf_status.setText("Program Status: TEXT");
                    text_out2.updateText();
                    text_out2.show();
                    tf_status.setText("Program Status: IDLE");
                }
                        
                model_running.sleep(50);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
        
    public void itemStateChanged(ItemEvent e) {
        for (int i=0; i<my_eq.n_tot; i++) {
            if (e.getSource() == check_var[i]) {
                redraw=1;
            }
        }
        if (e.getSource() == ch_autoscale) {
            redraw=1;
        }
        if (e.getSource() == ch_trace) {
            redraw=1;
        }
        if (e.getSource() == ch_adaptive) {
            my_eq.try_model=1;
        }
        if (e.getSource() == ch_method) {
            String method=ch_method.getSelectedItem();
            if(method=="Euler") {
                my_eq.method=Diffeq.EULER;
            } else if (method=="RK2") {
                my_eq.method=Diffeq.IEULER;
            } else {
                my_eq.method=Diffeq.RKUTTA4;
            }
            my_eq.try_model=1;
        }
        if (e.getSource() == choiceCardLayoutKey) {
            cardLayoutKey.show(panelKeyModelSwitch,choiceCardLayoutKey.getSelectedItem());
        }
        if (e.getSource() == choiceCardLayoutGraph) {
            cardLayoutGraph.show(panelGraphSwitch,choiceCardLayoutGraph.getSelectedItem());
            graphs.drawAll();
            animation.drawAll();
        }
    }
    
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == show_text) {
            textbox=1;
        }
        if (e.getSource() == stop_model) {
            my_eq.try_model=0;
        }
        for (int i=0;i<my_eq.n_vars;i++) {
            if (e.getSource()==ns_var[i]) {
                x_var[i]=ns_var[i].getRealValue();
                my_eq.try_model=1;
            }
        }
        for (int i=0;i<my_eq.n_rates;i++) {
            if (e.getSource()==ns_rate[i]) {
                x_rate[i]=ns_rate[i].getRealValue();
                my_eq.try_model=1;
            }
        }
        if (e.getSource() == ni_it) {
            x_it = ni_it.getDouble();
            my_eq.try_model=1;
        }
        if (e.getSource() == ni_ft) {
            x_ft = ni_ft.getDouble();
            my_eq.try_model=1;
        }
        if (e.getSource() == ni_st) {
            x_st = ni_st.getDouble();
            my_eq.try_model=1;
        }
        if (e.getSource() == ni_ymin) {
            x_ymin = ni_ymin.getDouble();
            redraw=1;
        }
        if (e.getSource() == ni_ymax) {
            x_ymax = ni_ymax.getDouble();
            redraw=1;
        }
    }
    
    public Frame GetFrame(Object o) {
      Object anchorpoint = o;
      while (! ( anchorpoint instanceof Frame))
         anchorpoint = ((Component)anchorpoint).getParent();
      return ((Frame)anchorpoint);
   }
    
}

class GEchoDlg extends Dialog {

    TextArea echotext;
    Button close_wind;
    LineGraphPaper theParent;

    GEchoDlg(LineGraphPaper lgp,Frame f, String s, boolean b) {
        super(f,s,b);
        theParent = lgp;

        //set up components
        resize(200,200);

        setLayout(new FlowLayout());

        echotext = new TextArea("",6,20);
        echotext.resize(100,100);

        echotext.setText(theParent.getValues(4));

        close_wind = new Button("Close Window");

        setLayout(new PercentLayout());
        add("left=0, right=100, top=0, bottom=20",close_wind);
        add("left=0, right=100, top=21, bottom=100",echotext);

        /* This makes it possible for the user to close the window */
        addWindowListener(new WindowAdapter() {
                           public void windowClosing(WindowEvent e) {
                               setVisible(false);
                               dispose();
                           }
        });

    }
    
    public void updateText(){
        echotext.setText(theParent.getValues(4));
        hide();
    }

    public boolean action(Event evt, Object arg) {
        if (evt.target instanceof Button) {
            String labl = (String)arg;
            if(labl.equals("Close Window")) {
                hide();
                return true;
            }
        }
        return super.action(evt,arg);
    }

}