////////////////////////////////////////////////////////////////////////////////////
//   Title:        A drawing program
//   Filename:     DrawingApplet.java
//
//   Description:  Draws lines, squares and circles
//
//   Input:        Users mouse movements
//   Output:       Picture on screen
//   Process:      Draws appropriate image
//
//   Written by:    ...                                          Date:     ...
////////////////////////////////////////////////////////////////////////////////////

import java.awt.*;                            // Include the graphics package
import java.applet.*;                         // and the applet package

public class DrawingApplet
                 extends Applet {

    public static final int MAX_OBJECTS = 100;

    Button circleButton, lineButton, rectangleButton, clearButton;
    Canvas drawingCanvas;
    Label  actionChosen,  promptUser;
    int shapeChosen;
    boolean firstCoord;
    int numObjects = 0;
    Object figureArray [ ]	= new Object [ MAX_OBJECTS ];
    int    figType [ ]		= new int [ MAX_OBJECTS ];

    public void init ( ) {
        circleButton 	= new Button ( "    Circle    " );
        lineButton   	= new Button ( "    Line      " );
        rectangleButton	= new Button ( "    Rectangle " );
        clearButton	= new Button ( "    Clear     " );
        // drawingCanvas	= new Canvas ( );
        actionChosen	= new Label ( "Figure chosen: none;      " );
        promptUser	= new Label ( "Click on a button         " );

        // drawingCanvas.resize ( 500, 500 );

        add ( circleButton );
        add ( lineButton );
        add ( rectangleButton );
        add ( clearButton );
        // add ( drawingCanvas );
        add ( actionChosen );
        add ( promptUser );

        shapeChosen = 0;
    }

    public void paint ( Graphics g ) {
        int i;
        Object curObj;
     
        g.setColor ( Color.black );
        g.fillRect ( 0, 0, this.size ( ).width - 1, this.size ( ).height - 1);
        g.setColor ( Color.red );
        g.drawRect ( 1, 1, this.size ( ).width - 2, this.size ( ).height - 2);

        for ( i = 0; i < numObjects; i ++ ) {
            curObj = figureArray [ i ];
            switch ( figType [ i ] ) {
                case 1:  ( ( CircleFig ) curObj ).display ( g );
                         break;
                case 2:  ( ( LineFig ) curObj ).display ( g );
                         break;
                case 3:  ( ( RectangleFig ) curObj ).display ( g );
                         break;
            }
        }
    }

    public boolean handleEvent ( Event e ) {

        Object curFig = new Object ( );

        if ( e.id == Event.ACTION_EVENT ) {
            if ( e.target == circleButton ){
                shapeChosen = 1;
                figureArray [ numObjects ] = new CircleFig ( );
                actionChosen.setText ( "Figure chosen: Circle;   " );
                promptUser.setText   ( "Click for Center" );
                figType [ numObjects ] = 1;
                firstCoord = true;
                numObjects = numObjects + 1;
            }
            else if ( e.target == lineButton ){
                shapeChosen = 2;
                figureArray [ numObjects ] = new LineFig ( );
                actionChosen.setText ( "Figure chosen: Line;     " );
                promptUser.setText   ( "Click for first point" );
                figType [ numObjects ] = 2;
                firstCoord = true;
                numObjects = numObjects + 1;
            }
            else if ( e.target == rectangleButton ){
                shapeChosen = 3;
                figureArray [ numObjects ] = new RectangleFig ( );
                actionChosen.setText ( "Figure chosen: Rectangle; " );
                promptUser.setText   ( "Click for top left" );
                figType [ numObjects ] = 3;
                firstCoord = true;
                numObjects = numObjects + 1;
            }
            else if ( e.target == clearButton ) {
                numObjects = 0;
                repaint ( );
            }
            return false;
        }

        if ( numObjects > 0 )
            curFig = figureArray [ numObjects - 1 ];

        // if ( e.id == Event.MOUSE_DOWN && e.target == drawingCanvas )
        if ( e.id == Event.MOUSE_DOWN )
            switch ( shapeChosen ) {
                case 1: if ( firstCoord ) {
                            ( ( CircleFig ) curFig ).setCenter ( e.x, e.y );
                            firstCoord = false;
                            promptUser.setText ( "Click for perimeter" );
                        }
                        else {
                            ( ( CircleFig ) curFig ).setPerimeter ( e.x, e.y );
                            shapeChosen = 0;
                            actionChosen.setText ( "Figure chosen: none;      " );
                            promptUser.setText ( "Click on a button" );
                            repaint ( );
                        }
                        break;

                case 2: if ( firstCoord ) {
                            ( ( LineFig ) curFig ).setStart ( e.x, e.y );
                            firstCoord = false;
                            promptUser.setText ( "Click for second point" );
                        }
                        else {
                            ( ( LineFig ) curFig ).setEnd ( e.x, e.y );
                            shapeChosen = 0;
                            actionChosen.setText ( "Figure chosen: none;      " );
                            promptUser.setText ( "Click on a button" );
                            repaint ( );
                        }
                        break;

                case 3: if ( firstCoord ) {
                            ( ( RectangleFig ) curFig ).setTopLeft ( e.x, e.y );
                            firstCoord = false;
                            promptUser.setText ( "Click for bottom right" );
                        }
                        else {
                            ( ( RectangleFig ) curFig ).setBottomRight ( e.x, e.y );
                            shapeChosen = 0;
                            actionChosen.setText ( "Figure chosen: none;      " );
                            promptUser.setText ( "Click on a button" );
                            repaint ( );
                        }
                        break;

            }
            return false;
    }
}

class CircleFig {
    int centerX, centerY, radius;
    Color objColor;

    public void setCenter ( int x, int y ) { 
        centerX = x;
        centerY = y;
    }
    public void setPerimeter ( int x, int y ) { 
        radius = ( int ) Math.sqrt ( ( double ) ( ( x - centerX ) * ( x - centerX ) +
                                          ( y - centerY ) * ( y - centerY ) ) );
    }
    public void display ( Graphics g ) { 
        g.drawOval ( centerX - radius, centerY - radius, 2 * radius, 2 * radius );
    }
}

class LineFig {
    int startX, startY, endX, endY;
    Color objColor;

    public void setStart ( int x, int y ) { 
        startX = x;
        startY = y;
    }
    public void setEnd ( int x, int y ) { 
        endX = x;
        endY = y;
    }
    public void display ( Graphics g ) { 
        g.drawLine ( startX, startY, endX, endY );
    }

}

class RectangleFig {
    int startX, startY, endX, endY;
    Color objColor;
    
    public void setTopLeft ( int x, int y ) { 
        startX = x;
        startY = y;
    }
    public void setBottomRight ( int x, int y ) { 
        endX = x;
        endY = y;
        if ( startX >= endX ) {
            int temp = startX;
            startX = endX;
            endX = temp;
        }
        if ( startY >= endY ) {
            int temp = startY;
            startY = endY;
            endY = temp;
        }
    }
    public void display ( Graphics g ) { 
        g.drawRect ( startX, startY, endX - startX, endY - startY );
    }

}