001package bradleyross.library.applets;
002//  colorsSample.java
003//  A simple Java applet
004//
005import java.awt.*;
006import java.applet.*;
007import java.awt.Button;
008import java.awt.event.ActionListener;
009import java.awt.event.ActionEvent;
010//
011/**
012* Demonstrates the use of buttons to change the colors on the
013* items in a graphic item.
014* <p>This Java file can be compiled using
015*    <nobr><code>-source 1.3 -target 1.3</code></nobr>
016*    so that it will run with browsers using Java Run-Time
017*    Enviroments as early as Java 1.3.  However, the standard
018*    script now uses version 1.5 as the standard.</p>
019* @see java.awt.Button
020* @see java.awt.Canvas
021* @see java.awt.Panel
022* @see java.awt.GridBagConstraints
023* @see java.awt.GridBagLayout
024* @author Bradley Ross
025*/
026public class ColorsSample  extends Applet implements ActionListener 
027{
028/**
029         * 
030         */
031        private static final long serialVersionUID = 1L;
032/** 
033* The inner class colorSet represents the buttons in the panel 
034* which the user sees.
035* <p>Each of the buttons is defined as a public field in the inner class, with each 
036*    field belonging to the class java.awt.Button.  The entire panel containing
037*    the buttons is also defined as a public field, with the field of type
038*    java.awt.Panel.</p>
039*/
040class colorSet extends Component
041   {
042
043/**
044         * 
045         */
046        private static final long serialVersionUID = 1L;
047/**
048   * Integer value representing the button that
049   * was depressed.
050   */
051   public int ColorChoice;
052   /**
053   * Object defining the panel of buttons.
054   */
055   Panel colorPanel = new Panel();
056   /**
057   * Object for the "black" button.
058   *<p>The other buttons are defined in the same manner.</p>
059   */
060   public Button blackButton = new Button("black");
061   /**
062   * Object for the "blue" button.
063   *<p>The actions in the constructor for blueButton
064   *   differ from the other in that the label is 
065   *   changed to " Blue " while the message returned
066   *   to the listener is still "blue".</p>
067   */
068   public Button blueButton = new Button("blue");
069   /** See the description of blackButton */
070   public Button cyanButton = new Button("cyan");
071   /** See the description of blackButton */
072   public Button darkGrayButton = new Button("darkGray");
073   /** See the description of blackButton */
074   public Button grayButton = new Button("gray");
075   /** See the description of blackButton */
076   public Button lightGrayButton = new Button("lightGray");
077   /** See the description of blackButton */
078   public Button  magentaButton = new Button("magenta");
079   /** See the description of blackButton */
080   public Button orangeButton = new Button("orange");
081   /** See the description of blackButton */
082   public Button pinkButton = new Button("pink");
083   /** See the description of blackButton */
084   public Button redButton = new Button("red");
085   /** See the description of blackButton */
086   public Button whiteButton = new Button("white");
087   /** See the description of blackButton */
088   public Button yellowButton = new Button("yellow");
089   /** See the description of blackButton */
090   public Button greenButton = new Button("green");
091   /**
092   * This is the constructor for the colorSet class
093   * which defines the buttons.
094   *<p>For blackButton, the setLabel and setActionCommand
095   *   methods are used to set the values.</p>
096   *<p>For the other buttons, label for the button and
097   *   the message returned when the button is depressed
098   *   are set equal to the string used in the constructor
099   *   for the java.awt.Button object.</p>
100   *<p>The add method for the colorPanel object places the
101   *   various buttons in the panel according to the
102   *   GridBagLayout and GridBagConstraints classes.</p>
103   */
104   public colorSet()
105      {
106      ColorChoice = 1;
107      setBackground(Color.white);
108      GridBagLayout layout = new GridBagLayout();
109      GridBagConstraints constraints = new GridBagConstraints();
110      colorPanel.setLayout(layout);
111      constraints.insets = new Insets (5, 5, 5, 5);
112      constraints.fill = GridBagConstraints.BOTH;
113      constraints.anchor = GridBagConstraints.SOUTHWEST;
114      constraints.weightx = 0; constraints.weighty = 0;
115      constraints.gridwidth = 1; constraints.gridheight = 1;
116      //
117      constraints.gridx = 1; constraints.gridy = 1;
118      colorPanel.add(blackButton, constraints);
119      //
120      constraints.gridx = 2; constraints.gridy = 1;
121      colorPanel.add(blueButton, constraints);
122      blueButton.setLabel("  Blue  ");
123      blueButton.setActionCommand("blue");
124      //
125      constraints.gridx = 3; constraints.gridy = 1;
126      colorPanel.add(cyanButton, constraints);
127      //
128      constraints.gridx = 4; constraints.gridy = 1;
129      colorPanel.add(darkGrayButton, constraints);
130      //
131      constraints.gridx = 5; constraints.gridy = 1;
132      colorPanel.add(grayButton, constraints);
133      //
134      constraints.gridx = 1; constraints.gridy = 2;
135      colorPanel.add(greenButton, constraints);
136      //
137      constraints.gridx = 2; constraints.gridy = 2;
138      colorPanel.add(lightGrayButton, constraints);
139      //
140      constraints.gridx = 3; constraints.gridy = 2;
141      colorPanel.add(magentaButton, constraints);
142      //
143      constraints.gridx = 4; constraints.gridy = 2;
144      colorPanel.add(orangeButton, constraints);
145      //
146      constraints.gridx = 5; constraints.gridy = 2;
147      colorPanel.add(pinkButton, constraints);
148      //
149      constraints.gridx = 1; constraints.gridy = 3;
150      colorPanel.add(redButton, constraints);
151      //
152      constraints.gridx = 2; constraints.gridy = 3;
153      colorPanel.add(whiteButton, constraints);
154      //
155      constraints.gridx = 3; constraints.gridy = 3;
156      colorPanel.add(yellowButton, constraints);
157      }
158   } // This is the end of the inner class
159static final String message = "Hello World!";
160static final String errorMessage = "Illegal Code";
161private Font font = new Font("serif", Font.ITALIC + Font.BOLD, 36);
162/**
163* The buttons object is the instantiation of the inner class colorSet.
164*/
165colorSet buttons = new colorSet();
166/**
167* Initialize the applet.
168*<p>The class colorsSample implements the interface
169*   java.awt.ActionListener as well as extending the
170*   class java.applet.Applet.</p>
171*<p>The addActionListener methods arrange for the
172*   colorsSample class to receive the messages
173*   when the buttons are depressed.  This means that
174*   that the ActionPerformed method for the class
175*   is executed whenever a button is depressed.</p>
176* @see java.awt.event.ActionListener
177* @see java.applet.Applet
178*/
179public void init() 
180   {
181   FlowLayout layout = new FlowLayout();
182   setLayout(layout);
183   setBackground(Color.white);
184   add(buttons.colorPanel);
185   buttons.blackButton.addActionListener(this);
186   buttons.blueButton.addActionListener(this);
187   buttons.cyanButton.addActionListener(this);
188   buttons.darkGrayButton.addActionListener(this);
189   buttons.grayButton.addActionListener(this);
190   buttons.greenButton.addActionListener(this);
191   buttons.lightGrayButton.addActionListener(this);
192   buttons.magentaButton.addActionListener(this);
193   buttons.orangeButton.addActionListener(this);
194   buttons.pinkButton.addActionListener(this);
195   buttons.redButton.addActionListener(this);
196   buttons.whiteButton.addActionListener(this);
197   buttons.yellowButton.addActionListener(this);
198   doLayout();
199   } // End of init
200/**
201* The paint method is called whenever it is necessary to
202* redraw the contents of the applet.
203* <p>The paint method is called whenever it is necessary
204*    redraw the image.  It can be called by the window manager
205*    when a window is resized, covered, or uncovered or when it
206*    detects that another method has executed the repaint method.</p>
207* @param g The graphics item which is to be redrawn.
208*/
209public void paint (Graphics g) 
210   {
211   switch (buttons.ColorChoice) 
212      {
213      case 1:
214         g.setColor(Color.black);
215         break;
216      case 2:
217         g.setColor(Color.blue);
218         break;
219      case 3:
220         g.setColor(Color.cyan);
221         break;
222      case 4:
223         g.setColor(Color.darkGray);
224         break;
225      case 5:
226         g.setColor(Color.gray);
227         break;
228      case 6:
229         g.setColor(Color.green);
230         break;
231      case 7:
232         g.setColor(Color.lightGray);
233         break;
234      case 8:
235         g.setColor(Color.magenta);
236         break;
237      case 9:
238         g.setColor(Color.orange);
239         break;
240      case 10:
241         g.setColor(Color.pink);
242         break;
243      case 11:
244         g.setColor(Color.red);
245         break;
246      case 12:
247         g.setColor(Color.yellow);
248         break;
249      case 13:
250         g.setColor(Color.gray);
251         g.fillRect(40, 130, 280, 75);
252         g.setColor(Color.black);
253         g.fillRect(40, 205, 40, 40);
254         g.setColor(Color.darkGray);
255         g.fillRect(80, 205, 40, 40);
256         g.setColor(Color.gray);
257         g.fillRect(120, 205, 40, 40);
258         g.setColor(Color.lightGray);
259         g.fillRect(160, 205, 40, 40);
260         g.setColor(Color.white);
261         g.fillRect(200, 205, 40, 40);
262         g.setColor(Color.lightGray);
263         g.fillRect(240, 205, 40, 40);
264         g.setColor(Color.gray);
265         g.fillRect(280, 205, 40, 40);
266         g.setColor(Color.white);
267         break;
268      default:
269         g.setColor(Color.pink);
270      }
271   g.setFont(font);
272   if (buttons.ColorChoice < 50)
273      {g.drawString(message, 40, 180);}
274   else
275      {g.drawString(errorMessage, 40, 180);}
276   System.out.println("Executing paint");
277   } // end of paint
278/**
279* The actionPerformed method is executed whenever
280*    an action is taken by the user.
281*<p>The event created by depressing the
282*   the button is passed as argument of
283*   the method and the getActionCommand method
284*   obtains the character string associated
285*   with the button as defined by the constructor
286*   and other methods for the button.</p>
287*<p>This method then sets the ColorChoice field
288*   in the buttons object according to which 
289*   button was depressed and then uses the
290*   repaint method to cause the graphics on the
291*   applet to be redrawn.</p>
292*/
293public void actionPerformed (ActionEvent e)
294   {
295   String command = new String();
296   command = e.getActionCommand();
297   System.out.println("ActionEvent **" + command + "**");
298   if (command.equals("black"))
299      { buttons.ColorChoice = 1; }
300   else if (command.equals("blue"))
301      { buttons.ColorChoice = 2; }
302   else if (command.equals("cyan"))
303      { buttons.ColorChoice = 3; }
304   else if (command.equals("darkGray"))
305      { buttons.ColorChoice = 4; }
306   else if (command.equals("gray"))
307      { buttons.ColorChoice = 5; }
308   else if (command.equals("green"))
309      { buttons.ColorChoice = 6; }
310   else if (command.equals("lightGray"))
311      { buttons.ColorChoice = 7; }
312   else if (command.equals("magenta"))
313      { buttons.ColorChoice = 8; }
314   else if (command.equals("orange"))
315      { buttons.ColorChoice = 9; }
316   else if (command.equals("pink"))
317      { buttons.ColorChoice = 10; }
318   else if (command.equals("red"))   
319      { buttons.ColorChoice = 11; }
320   else if (command.equals("yellow"))
321      { buttons.ColorChoice = 12; }
322   else if (command.equals("white"))
323      { buttons.ColorChoice = 13; }
324   else
325      { buttons.ColorChoice = 99; }
326   repaint();
327   } // end of actionPerformed
328}