package freegraph;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import freegraph.GraphPlaneListener;

/***
 * Applet for GraphPlane.  Provides an text field to enter functions, and
 * a list box to view them.  The applet can either be "in line," or drawn on
 * the HTML page, or can be just a button which will create a separate
 * frame for the graphing. (Because of re-draw problems on IE, it works better
 * as a separate frame...plus it can be resized.)
 */
public class GraphingApplet extends Applet
    implements ActionListener, GraphPlaneListener
{
    private GraphPlane graphPlane;
    private Panel pnlGraph;
    private Panel pnlXYLocation;
    private Panel pnlToolbar;
    private Panel pnlMain;
    private Panel pnlList;
    private Panel pnlWestList;
    private Panel pnlSouthList;
    private Label lblXLocation;
    private Label lblYLocation;
    private Button btnAdd;
    private Button btnReset;
    private Button btnZoomin;
    private Button btnZoomout;
    private Button btnClear;
    private Button btnRemove;
    private Button btnJumpOutClose;
    private Button btnSeparateWindow;
    private TextField txtFunction;
    private List lstFunctions;
    private ExpressionEvaluator expr[] = new ExpressionEvaluator[5];
    private Color clrs[] = {Color.red, Color.blue, Color.darkGray,
        Color.green, Color.orange};
    private boolean isInFrame = false;
    private boolean nostub = false;

    /**
     * Creates a new GraphingApplet, with the provided InFrame property.
     * @param inFrame   sets the InFrame property for the Applet. If inFrame
     * is true, the applet does not try to access the Applet's stub because
     * it is null
     */
    public GraphingApplet(boolean inFrame)
    {
        if (inFrame) nostub = true;
        this.isInFrame = inFrame;
    }

    /**
     * constructs a new GraphingApplet
     */
    public GraphingApplet()
    {
    }

    /**
     * initializes the Applet by calling internalInit which sets up the GUI
     */
    public void init()
    {
        try
        {
            internalInit();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }


    /**
     * sets up GUI.  Applet parameter "justwindowbutton" is used to
     * determine if only a button to launch the separate window should be
     * displayed (if set to "true" then just the button is displayed).
     * The parameter "bgcolor" is used to set the color as a HEX number.
     */
    private void internalInit() throws Exception
    {
        if (!isInFrame)
            setBackground(
                new Color(getParameterAsInt("bgcolor", 0xFFFFFF, 16)));


        if (getParameter("justwindowbutton", "false").equals("true"))
        {
            btnSeparateWindow = new Button("Start Grapher");
            btnSeparateWindow.setFont(new Font("SansSerif", Font.PLAIN, 16));
            this.setLayout(new BorderLayout());
            this.add(btnSeparateWindow, BorderLayout.CENTER);
            btnSeparateWindow.addActionListener(this);
        }
        else
        {
            graphPlane = new GraphPlane();
            graphPlane.setBackground(Color.white);

            btnAdd = new Button("Add");
            btnReset = new Button("Reset");
            btnZoomin = new Button("+");
            btnZoomout = new Button("-");
            btnClear = new Button("Clear All");
            btnRemove = new Button("Remove");
            txtFunction = new TextField();
            pnlGraph = new Panel();
            pnlMain = new Panel();
            pnlList = new Panel();
            pnlWestList = new Panel();
            pnlSouthList = new Panel();
            pnlXYLocation = new Panel();
            pnlToolbar = new Panel();
            lblXLocation = new Label("X = ");
            lblYLocation = new Label("Y = ");
            lstFunctions = new List();

            btnJumpOutClose = new Button("Close");
            btnSeparateWindow = new Button("Separate Window");

            pnlToolbar.setLayout(new BorderLayout());
            pnlToolbar.add(btnZoomout, BorderLayout.WEST);
            pnlToolbar.add(btnReset, BorderLayout.CENTER);
            pnlToolbar.add(btnZoomin, BorderLayout.EAST);

            pnlXYLocation.setLayout(new GridLayout(1, 2));
            pnlXYLocation.add(lblXLocation);
            pnlXYLocation.add(lblYLocation);


            pnlGraph.setLayout(new BorderLayout());
            pnlGraph.add(pnlXYLocation, BorderLayout.NORTH);
            pnlGraph.add(btnAdd,  BorderLayout.WEST);
            pnlGraph.add(txtFunction, BorderLayout.CENTER);

            pnlMain.setLayout(new BorderLayout());
            pnlMain.add(pnlGraph,BorderLayout.SOUTH);
            pnlMain.add(graphPlane, BorderLayout.CENTER);
            pnlMain.add(pnlToolbar, BorderLayout.NORTH);

            pnlWestList.setLayout(new GridLayout(2, 1));
            pnlWestList.add(btnRemove);
            pnlWestList.add(btnClear);

            pnlSouthList.setBackground(Color.lightGray);
            pnlSouthList.setLayout(new BorderLayout());
            if (isInFrame)
                pnlSouthList.add(btnJumpOutClose, BorderLayout.EAST);
            else
                pnlSouthList.add(btnSeparateWindow, BorderLayout.EAST);

            pnlList.setLayout(new BorderLayout());
            pnlList.add(pnlWestList, BorderLayout.WEST);
            pnlList.add(lstFunctions, BorderLayout.CENTER);
            pnlList.add(pnlSouthList, BorderLayout.SOUTH);

            this.setLayout(new BorderLayout());
            this.add(pnlMain, BorderLayout.CENTER);
            this.add(pnlList, BorderLayout.SOUTH);

            btnAdd.addActionListener(this);
            btnReset.addActionListener(this);
            btnZoomin.addActionListener(this);
            btnZoomout.addActionListener(this);
            btnClear.addActionListener(this);
            btnRemove.addActionListener(this);
            btnSeparateWindow.addActionListener(this);
            btnJumpOutClose.addActionListener(this);
            txtFunction.addActionListener(this);
            for (int i=0; i<expr.length; i++)
            {
                expr[i] = new ExpressionEvaluator();
                expr[i].setColor(clrs[i]);
                graphPlane.addGraphPlaneItem(expr[i]);
                txtFunction.requestFocus();
                graphPlane.addGraphPlaneListener(this);
            }
        }
    }

    public String getAppletInfo()
    {
        return "GraphIt Applet by Martin Lovell";
    }

    public String[][] getParameterInfo()
    {
        return null;
    }

    /**
     * adds a function to the graph if it is not already in the list. If the
     * maximum number of functions have been added, the one on the top of the
     * list is removed
     */
    void addFunction(String function)
    {
        if (function.equals("")) return;
        String functions[] = lstFunctions.getItems();
        for (int i=0; i<functions.length; i++)
        {
            if (function.equals(functions[i])) return;
        }
        if (lstFunctions.getItemCount() >= expr.length) lstFunctions.remove(0);
        lstFunctions.add(function);
        redrawGraph();
    }

    /**
     * redraws the graph with all the function in the list box.
     */
    void redrawGraph()
    {
        for (int i=0; i<expr.length; i++)
        {
            if (i<lstFunctions.getItemCount())
            try
            {
                expr[i].setExpression(lstFunctions.getItem(i));
            }
            catch (ExpressionException e)
            {
                e.printStackTrace();
            }
            else
            try
            {
                expr[i].setExpression("");
            }
            catch (ExpressionException e)
            {
                e.printStackTrace();
            }
        }
        graphPlane.repaint();
    }

    /**
     * called by buttons and other components. Reponds with appropriate action.
     */
    public void actionPerformed(ActionEvent e)
    {
        if ((e.getSource() == btnAdd) || (e.getSource() == txtFunction))
        {
            addFunction(txtFunction.getText());
            txtFunction.setText("");
        }
        else if (e.getSource() == btnReset) graphPlane.reset();
        else if (e.getSource() == btnZoomin) graphPlane.zoomin();
        else if (e.getSource() == btnZoomout) graphPlane.zoomout();
        else if (e.getSource() == btnClear)
        {
            lstFunctions.removeAll();
            redrawGraph();
        }
        else if (e.getSource() == btnRemove)
        {
            if (lstFunctions.getSelectedIndex() != -1)
            {
                lstFunctions.remove(lstFunctions.getSelectedIndex());
                redrawGraph();
            }
        }
        else if (e.getSource() == btnJumpOutClose)
        {
            if (getParent() instanceof Frame)
            {
                ((Frame)getParent()).dispose();
            }
        }
        else if (e.getSource() == btnSeparateWindow)
        {
            Frame frm = new Frame("Graphing Applet Window");
            frm.setBackground(getBackground());
            frm.setSize(new Dimension(400, 500));
            GraphingApplet gr = new GraphingApplet(true);
            frm.setLayout(new BorderLayout());
            frm.add(gr, BorderLayout.CENTER);
            gr.init();
            frm.show();
            frm.addWindowListener(
                new WindowAdapter()
                {
                    public void windowClosing(WindowEvent e)
                    {
                        ((Frame)e.getSource()).dispose();
                    }
                }
            );
        }
    }

    /**
     * called when the mouse moves on graph, the
     * position is shown on the screen
     */
    public void mousePosMoved(double xPos, double yPos)
    {
        lblXLocation.setText("X = " + Double.toString(xPos));
        lblYLocation.setText("Y = " + Double.toString(yPos));
    }

    /**
     * called when the axis change on graph
     */
    public void axisChanged(double xMin, double yMin, double xMax, double yMax)
    {
        //No display yet
    }


    /***
     * returns the value of a parameter as a String.  If the parameter
     * is not defined, def is returned.
     */
    public String getParameter(String key, String def)
    {
        if (nostub) return def;
        return (getParameter(key) != null ? getParameter(key) : def);
    }



    /***
     * returns the value of a parameter as an int.  If the parameter
     * is not defined, def is returned.  The parameter is parsed to integer
     * using the default radix of 10
     */
    public int getParameterAsInt(String key, int def)
    {
        if (nostub) return def;
        return getParameterAsInt(key, def, 10);
    }

    /***
     * returns the value of a parameter as an int.  If the parameter
     * is not defined, def is returned.  The parameter is parsed to integer
     * using the provided radix
     */
    public int getParameterAsInt(String key, int def, int radix)
    {
        try
        {
            return (getParameter(key) != null ?
                Integer.parseInt(getParameter(key), radix)
                : def);
        }
        catch (Exception e)
        {
            return def;
        }
    }

    public static void main(String args[])
    {

        Frame frm = new Frame("Graphing Applet Window");
        frm.setSize(new Dimension(400, 500));
        GraphingApplet gr = new GraphingApplet(true);
        frm.setLayout(new BorderLayout());
        frm.add(gr, BorderLayout.CENTER);
        gr.init();
        frm.show();
        frm.addWindowListener(
            new WindowAdapter()
            {
                public void windowClosing(WindowEvent e)
                {
                    ((Frame)e.getSource()).dispose();
                }
            }
        );
    }

}