150 lines
3.5 KiB
Java
150 lines
3.5 KiB
Java
Draw random lines, rectangles and ovals
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import java.awt.*;
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import java.awt.event.*;
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import javax.swing.*;
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public class DrawShapes extends JApplet
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{
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private JButton choices[];
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private String names[] = { "Line", "Rectangle", "Oval" };
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private JPanel buttonPanel;
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private DrawPanel drawingArea;
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private int width = 300, height = 200;
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public void init()
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{
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drawingArea = new DrawPanel( width, height );
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choices = new JButton[ names.length ];
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buttonPanel = new JPanel();
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buttonPanel.setLayout( new GridLayout( 1, choices.length ) );
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ButtonHandler handler = new ButtonHandler();
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for ( int i = 0; i < choices.length; i++ )
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{
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choices[ i ] = new JButton( names[ i ] );
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buttonPanel.add( choices[ i ] );
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choices[ i ].addActionListener( handler );
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}
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Container c = getContentPane();
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c.add( buttonPanel, BorderLayout.NORTH );
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c.add( drawingArea, BorderLayout.CENTER );
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}
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public void setWidth( int w )
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{
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width = ( w >= 0 ? w : 300 );
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}
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public void setHeight( int h )
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{
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height = ( h >= 0 ? h : 200 );
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}
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public static void main( String args[] )
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{
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int width, height;
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if ( args.length != 2 )
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{
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// no command-line arguments
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width = 300;
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height = 200;
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}
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else
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{
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width = Integer.parseInt( args[ 0 ] );
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height = Integer.parseInt( args[ 1 ] );
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}
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// create window in which applet will execute
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JFrame applicationWindow = new JFrame( "An applet running as an application" );
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applicationWindow.addWindowListener( new WindowAdapter()
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{
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public void windowClosing( WindowEvent e )
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{
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System.exit( 0 );
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}
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} );
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// create one applet instance
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DrawShapes appletObject = new DrawShapes();
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appletObject.setWidth( width );
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appletObject.setHeight( height );
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// call applet's init and start methods
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appletObject.init();
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appletObject.start();
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// attach applet to center of window
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applicationWindow.getContentPane().add( appletObject );
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// set the window's size
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applicationWindow.setSize( width, height );
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// showing the window causes all GUI components
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// attached to the window to be painted
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applicationWindow.show();
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}
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private class ButtonHandler implements ActionListener
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{
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public void actionPerformed( ActionEvent e )
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{
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for ( int i = 0; i < choices.length; i++ )
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if ( e.getSource() == choices[ i ] )
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{
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drawingArea.setCurrentChoice( i );
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break;
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}
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}
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}
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}
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// subclass of JPanel to allow drawing in a separate area
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class DrawPanel extends JPanel
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{
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private int currentChoice = -1; // don't draw first time
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private int width = 100, height = 100;
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public DrawPanel( int w, int h )
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{
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width = ( w >= 0 ? w : 100 );
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height = ( h >= 0 ? h : 100 );
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}
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public void paintComponent( Graphics g )
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{
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super.paintComponent( g );
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switch( currentChoice )
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{
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case 0:
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g.drawLine( randomX(), randomY(), randomX(), randomY() );
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break;
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case 1:
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g.drawRect( randomX(), randomY(), randomX(), randomY() );
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break;
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case 2:
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g.drawOval( randomX(), randomY(), randomX(), randomY() );
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break;
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}
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}
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public void setCurrentChoice( int c )
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{
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currentChoice = c;
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repaint();
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}
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private int randomX()
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{
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return (int) ( Math.random() * width );
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}
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private int randomY()
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{
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return (int) ( Math.random() * height );
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}
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}
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