UIDemo.java

// Graphic User Interface Demo program.  This AWT program shows
// how to use various Components and how to add a "wallpaper"
// effect by overriding paint.
//
// Written 2003 by Wayne Pollock, Tampa Florida USA.
// Updated 2011 to replace Vector with ArrayList.

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

public class UIDemo extends Frame
{
   private java.util.List<Component> components = new ArrayList<Component>();
   private boolean done = false;
   private MenuBar mb;

   public static void main ( String [] args )
   {
      UIDemo myFrame = new UIDemo("UI Demo");
      myFrame.addWindowListener( new WindowAdapter()
         {  public void windowClosing ( WindowEvent e )
            {  System.exit( 0 );
            }
         }
      );

      myFrame.runDemo();
   }

   public UIDemo ( String title )
   {
      super( title );
      setSize( 450, 300 );
      setLayout( new FlowLayout( FlowLayout.CENTER, 10, 10 ) );

         mb = new MenuBar();
         Menu fileMenu = new Menu( "File" );
         Menu editMenu = new Menu( "Edit" );
         Menu fruitMenu = new Menu( "Fruit" );
         mb.add( fileMenu );
         mb.add( editMenu );
         fileMenu.add( new MenuItem( "New..." ) );
         fileMenu.add( new MenuItem( "Open..." ) );
         fileMenu.addSeparator();  // add( "-" ); works too.
         fileMenu.add( fruitMenu );
         editMenu.add( "Cut" );
         editMenu.add( "Copy" );
         editMenu.add( "Paste" );
         fruitMenu.add( "Apple" );
         fruitMenu.add( "Orange" );
         fruitMenu.add( "Mango" );

      components.add( new Label( "I'm a Label!" ) );
      components.add( new Button( "Do nothing Button" ) );
      components.add( new TextField( "A TextField" ) );
      components.add( new TextArea( "A 2 x 20 TextArea", 2, 20 ) );
         java.awt.List lst = new java.awt.List();
         lst.add( "A List");
         lst.add( "by default has" );
         lst.add( "4 lines showing," );
         lst.add( "only one item" );
         lst.add( "can be selected." );
      components.add( lst );
         Choice myChoice = new Choice();
         myChoice.add( "A Choice");
         myChoice.add( "Apples" );
         myChoice.add( "Oranges" );
         myChoice.add( "Mangos" );
         components.add( myChoice );
      components.add( new Checkbox( "A Checkbox item" ) );
         Panel radioBtns = new Panel();
         CheckboxGroup cbg = new CheckboxGroup();
         radioBtns.add(new Checkbox("Radio Btn 1", cbg, true));
         radioBtns.add(new Checkbox("Radio Btn 2", cbg, false));
      components.add( radioBtns );
   }


   private void runDemo ()
   {
      setVisible( true );
      pause( 3 );
      setMenuBar( mb );
      validate();
      Iterator<Component> it = components.iterator();
      while ( it.hasNext() )
      {
         repaint();  // Shouldn't be needed but it is.
         pause( 3 );
         Component c = it.next();
         add( c );
         validate();
      }
      done = true;
      repaint();
   }


   public void paint ( Graphics g )
   {
      wallpaper( g );

      if ( ! done )
         g.drawString( "Running Demo...", 180, getHeight() - 20 );
      else
         g.drawString( "Demo  Finished!", 180, getHeight() - 20 );

      super.paint( g ); // Paint lightweight components (if any)
   }


   private void wallpaper ( Graphics g )
   {
      Toolkit tk = Toolkit.getDefaultToolkit();
      Image tile = tk.getImage( "backgrnd.gif" );

      int tileHeight = tile.getHeight( this );
      int tileWidth = tile.getWidth( this );
      if ( tileHeight == -1 || tileWidth == -1 )
         return;  // Must wait for image to fully load.

      int frameHeight = getHeight();
      int frameWidth = getWidth();

      for ( int y = 0; y < frameHeight; y += tileHeight )
      {  for ( int x = 0; x < frameWidth; x += tileWidth )
         {  g.drawImage( tile, x, y, this );
         }
      }
   }


   // The loop to sleep is better than trying to sleep the
   // whole interval in one shot, because most system clocks
   // are just not accurate enough!

   private void pause ( int seconds )
   {
      long now = System.currentTimeMillis();
      long stopTime = now + ( seconds * 1000 );

      while ( now < stopTime )
      {
         try { Thread.sleep( 50 ); }
         catch ( InterruptedException ignored ) {}
         now = System.currentTimeMillis();
      }
   }
}