import java.awt.*;
import java.awt.event.*;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

import java.util.Vector;

public class GraphicsCanvas extends Frame {

    static final Color[] color_types = {
	Color.black    ,
	Color.blue     ,
	Color.cyan     ,
	Color.darkGray ,
	Color.gray     ,
	Color.green    ,
	Color.lightGray,
	Color.magenta  ,
	Color.orange   ,
	Color.pink     ,
	Color.red      ,
	Color.white    ,
	Color.yellow
    };

    static final String[] color_names = {
	"Black"     ,
	"Blue"      ,
	"Cyan"      ,
	"Dark Gray" ,
	"Gray"      ,
	"Green"     ,
	"Light Gray",
	"Magenta"   ,
	"Orange"    ,
	"Pink"      ,
	"Red"       ,
	"White"     ,
	"Yello"
    };


    Vector objects = new Vector( );

    String whichFunc  = null;
    Color  whichColor = Color.black;



    ActionListener objectListener = new ActionListener( ) {

	public void actionPerformed( ActionEvent e ) {
	    GraphicsCanvas.this.whichFunc  = e.getActionCommand( );
	}
    };

    ActionListener colorListener  = new ActionListener( ) {

	public void actionPerformed( ActionEvent e ) {
	    GraphicsCanvas.this.whichColor = Color.decode(
		e.getActionCommand( ) );
	}
    };




    public GraphicsCanvas ( ) {
	super( "Paint Program" );

	////////////////////////////////////////
	// Set the MenuBar for this Frame.

	MenuBar menuBar = new MenuBar( );
	Menu    objMenu = new Menu( "Objects" );
	Menu    colMenu = new Menu( "Colors" );

	////////////////////////////////////////
	// Open configuration file and read in
	// Class names.

	try {

	    FileReader     fRead = new FileReader( "Config.txt" );
	    BufferedReader rRead = new BufferedReader( fRead );

	    String tempString = null;

	    while( (tempString = rRead.readLine( )) != null) {

		MenuItem item = new MenuItem( tempString );

		item.setActionCommand( tempString );
		item.addActionListener( objectListener );

		objMenu.add( item );
	    }

	    rRead.close( );

	} catch (FileNotFoundException e) {

	    System.err.println( "Can't find Config.txt" );
	    System.exit( 1 );

	} catch (IOException e) {

	    System.err.println( "Error in file stream" );
	    System.exit( 2 );
	}

	    
	for (int i = 0; i < color_types.length; i++ ) {
	    
	    MenuItem item = new MenuItem( color_names[i] );

	    item.setActionCommand( "" + color_types[i].getRGB( ) );
	    item.addActionListener( colorListener );

	    colMenu.add( item );
	}

	menuBar.add( objMenu );
	menuBar.add( colMenu );

	setMenuBar( menuBar );


	////////////////////////////////////////
	// Add WindowListener to allow closing 
	// of Window.
 
	addWindowListener( new WindowAdapter( ) {

	    public void windowClosing( WindowEvent e ) {
		
		GraphicsCanvas.this.dispose( );
		System.exit( 0 );
	    }
	});


	////////////////////////////////////////
	// Add MouseListener to create and reg-
	// ister new GraphicsObjects when the
	// mouse button is pressed within the
	// Frame.

	addMouseListener( new MouseAdapter( ) {

	    public void mousePressed( MouseEvent e ) {

		if (whichFunc != null) {

		    ////////////////////////////////////////
		    // If a GraphicsObject has been speci-
		    // fied create, initialize, and register
		    // the object.
		    //
		    // Note that this is done dynamically so
		    // that new GraphicsObjects can be made
		    // and easily utilized by the Graphics-
		    // Canvas.

		    try {
			Class          c = Class.forName( whichFunc );
			GraphicsObject f = (GraphicsObject) c.newInstance( );

			f.setColor( GraphicsCanvas.this.whichColor );
			f.setContainer( GraphicsCanvas.this );
			f.setLocation( e.getX( ), e.getY( ) );

			GraphicsCanvas.this.objects.addElement( f );

		    } catch (ClassNotFoundException excep) {
			
			System.err.println( "No such graphics class" );
			
			GraphicsCanvas.this.dispose( );
			System.exit( 1 );

		    } catch (InstantiationException excep) {

			System.err.println( "Could not create class " + 
					    whichFunc );
			
			GraphicsCanvas.this.dispose( );
			System.exit( 2 );

		    } catch (IllegalAccessException excep) {
		
			System.err.println( "No default constructor for " + 
					    whichFunc );

			GraphicsCanvas.this.dispose( );
			System.exit( 3 );
		    }
		}
	    }
	});


	setSize( 300, 400 );
	show();
    }


    public void update( Graphics g) { paint( g ); }

    public void paint( Graphics g ) {
	for( int i = 0; i < objects.size( ); i++ )
	    ((GraphicsFunction) objects.elementAt( i )).draw( );
    }

    
    ////////////////////////////////////////
    // Start application via main.

    public static void main( String[] args ) {
	new GraphicsCanvas();
    }
}