ImageMapArea


1   /*
2    * @(#)ImageMapArea.java    1.19 06/02/22
3    * 
4    * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
5    * 
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7    * modification, are permitted provided that the following conditions are met:
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10   *  list of conditions and the following disclaimer.
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12   * -Redistribution in binary form must reproduce the above copyright notice, 
13   *  this list of conditions and the following disclaimer in the documentation
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20   * This software is provided "AS IS," without a warranty of any kind. ALL 
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22   * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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33   * for use in the design, construction, operation or maintenance of any
34   * nuclear facility.
35   */
36  
37  /*
38   * @(#)ImageMapArea.java    1.19 06/02/22
39   */
40  
41  import java.awt.Graphics  ;
42  import java.awt.Image  ;
43  import java.awt.image.*;
44  import java.util.StringTokenizer  ;
45  import java.net.URL  ;
46  import java.net.MalformedURLException  ;
47  
48  /**
49   * The base ImageArea class.
50   * This class performs the basic functions that most ImageArea
51   * classes will need and delegates specific actions to the subclasses.
52   *
53   * @author  Jim Graham
54   * @version     1.19, 02/22/06
55   */
56  class ImageMapArea implements ImageObserver {
57      /** The applet parent that contains this ImageArea. */
58      ImageMap parent;
59      /** The X location of the area (if rectangular). */
60      int X;
61      /** The Y location of the area (if rectangular). */
62      int Y;
63      /** The size().width of the area (if rectangular). */
64      int W;
65      /** The size().height of the area (if rectangular). */
66      int H;
67      /**
68       * This flag indicates whether the user was in this area during the
69       * last scan of mouse locations.
70       */
71      boolean entered = false;
72      /** This flag indicates whether the area is currently highlighted. */
73      boolean active = false;
74  
75      /**
76       * This is the default highlight image if no special effects are
77       * needed to draw the highlighted image.  It is created by the
78       * default "makeImages()" method.
79       */
80      Image   hlImage;
81  
82      /**
83       * This is the status string requested by this area.  Only the
84       * status string from the topmost area which has requested one
85       * will be displayed.
86       */
87      String   status;
88  
89      /**
90       * Initialize this ImageArea as called from the applet.
91       * If the subclass does not override this initializer, then it
92       * will perform the basic functions of setting the parent applet
93       * and parsing out 4 numbers from the argument string which specify
94       * a rectangular region for the ImageArea to act on.
95       * The remainder of the argument string is passed to the handleArg()
96       * method for more specific handling by the subclass.
97       */
98      public void init(ImageMap parent, String   args) {
99      this.parent = parent;
100     StringTokenizer   st = new StringTokenizer  (args, ", ");
101     X = Integer.parseInt(st.nextToken());
102     Y = Integer.parseInt(st.nextToken());
103     W = Integer.parseInt(st.nextToken());
104     H = Integer.parseInt(st.nextToken());
105     if (st.hasMoreTokens()) {
106         handleArg(st.nextToken(","));
107     } else {
108         handleArg(null);
109     }
110     makeImages();
111     }
112 
113     /**
114      * This method handles the remainder of the argument string after
115      * the standard initializer has parsed off the 4 rectangular
116      * parameters.  If the subclass does not override this method,
117      * the remainder will be ignored.
118      */
119     public void handleArg(String   s) {
120     }
121 
122     /**
123      * This method loads any additional media that the ImageMapArea
124      * may need for its animations.
125      */
126     public void getMedia() {
127     }
128 
129     /**
130      * This method is called every animation cycle if there are any
131      * active animating areas.
132      * @return true if this area requires further animation notifications
133      */
134     public boolean animate() {
135     return false;
136     }
137 
138     /**
139      * This method sets the image to be used to render the ImageArea
140      * when it is highlighted.
141      */
142     public void setHighlight(Image   img) {
143     hlImage = img;
144     }
145 
146     /**
147      * This method handles the construction of the various images
148      * used to highlight this particular ImageArea when the user
149      * interacts with it.
150      */
151     public void makeImages() {
152     setHighlight(parent.getHighlight(X, Y, W, H));
153     }
154 
155     /**
156      * The repaint method causes the area to be repainted at the next
157      * opportunity.
158      */
159     public void repaint() {
160     parent.repaint(0, X, Y, W, H);
161     }
162 
163     /**
164      * This method tests to see if a point is inside this ImageArea.
165      * The standard method assumes a rectangular area as parsed by
166      * the standard initializer.  If a more complex area is required
167      * then this method will have to be overridden by the subclass.
168      */
169     public boolean inside(int x, int y) {
170     return (x >= X && x < (X + W) && y >= Y && y < (Y + H));
171     }
172 
173     /**
174      * This utility method draws a rectangular subset of a highlight
175      * image.
176      */
177     public void drawImage(Graphics   g, Image   img, int imgx, int imgy,
178               int x, int y, int w, int h) {
179     Graphics   ng = g.create();
180     try {
181         ng.clipRect(x, y, w, h);
182         ng.drawImage(img, imgx, imgy, this);
183     } finally {
184         ng.dispose();
185     }
186     }
187 
188     /**
189      * This method handles the updates from drawing the images.
190      */
191     public boolean imageUpdate(Image   img, int infoflags,
192                    int x, int y, int width, int height) {
193     if (img == hlImage) {
194         return parent.imageUpdate(img, infoflags, x + X, y + Y,
195                       width, height);
196     } else {
197         return (infoflags & (ALLBITS | ERROR)) == 0;
198     }
199     }
200 
201     /**
202      * This utility method records a string to be shown in the status bar.
203      */
204     public void showStatus(String   msg) {
205     status = msg;
206     parent.newStatus();
207     }
208 
209     /**
210      * This utility method returns the status string this area wants to
211      * put into the status bar.  If no previous area (higher in the
212      * stacking order) has yet returned a status message, prevmsg will
213      * be null and this area will then return its own message, otherwise
214      * it will leave the present message alone.
215      */
216     public String   getStatus(String   prevmsg) {
217     return (prevmsg == null) ? status : prevmsg;
218     }
219 
220     /**
221      * This utility method tells the browser to visit a URL.
222      */
223     public void showDocument(URL   u) {
224     parent.getAppletContext().showDocument(u);
225     }
226 
227     /**
228      * This method highlights the specified area when the user enters
229      * it with his mouse.  The standard highlight method is to replace
230      * the indicated rectangular area of the image with the primary
231      * highlighted image.
232      */
233     public void highlight(Graphics   g) {
234     }
235 
236     /**
237      * The checkEnter method is called when the mouse is inside the
238      * region to see if the area needs to have its enter method called.
239      * The default implementation simply checks if the entered flag is
240      * set and only calls enter if it is false.
241      */
242     public boolean checkEnter(int x, int y) {
243     if (!entered) {
244         entered = true;
245         enter(x, y);
246     }
247     return isTerminal();
248     }
249 
250     /**
251      * The checkExit method is called when the mouse is outside the
252      * region to see if the area needs to have its exit method called.
253      * The default implementation simply checks if the entered flag is
254      * set and only calls exit if it is true.
255      */
256     public void checkExit() {
257     if (entered) {
258         entered = false;
259         exit();
260     }
261     }
262 
263     /**
264      * The isTerminal method controls whether events propagate to the
265      * areas which lie beneath this one.
266      * @return true if the events should be propagated to the underlying
267      * areas.
268      */
269     public boolean isTerminal() {
270     return false;
271     }
272 
273     /**
274      * The enter method is called when the mouse enters the region.
275      * The location is supplied, but the standard implementation is
276      * to call the overloaded method with no arguments.
277      */
278     public void enter(int x, int y) {
279     enter();
280     }
281 
282     /**
283      * The overloaded enter method is called when the mouse enters
284      * the region.  This method can be overridden if the ImageArea
285      * does not need to know where the mouse entered.
286      */
287     public void enter() {
288     }
289 
290     /**
291      * The exit method is called when the mouse leaves the region.
292      */
293     public void exit() {
294     }
295 
296     /**
297      * The press method is called when the user presses the mouse
298      * button inside the ImageArea.  The location is supplied, but
299      * the standard implementation is to call the overloaded method
300      * with no arguments.
301      * @return true if this ImageMapArea wants to prevent any underlying
302      * areas from seeing the press
303      */
304     public boolean press(int x, int y) {
305     return press();
306     }
307 
308     /**
309      * The overloaded press method is called when the user presses the
310      * mouse button inside the ImageArea.  This method can be overridden
311      * if the ImageArea does not need to know the location of the press.
312      * @return true if this ImageMapArea wants to prevent any underlying
313      * areas from seeing the press
314      */
315     public boolean press() {
316     return isTerminal();
317     }
318 
319     /**
320      * The lift method is called when the user releases the mouse button.
321      * The location is supplied, but the standard implementation is to
322      * call the overloaded method with no arguments.  Only those ImageAreas
323      * that were informed of a press will be informed of the corresponding
324      * release.
325      * @return true if this ImageMapArea wants to prevent any underlying
326      * areas from seeing the lift
327      */
328     public boolean lift(int x, int y) {
329     return lift();
330     }
331 
332     /**
333      * The overloaded lift method is called when the user releases the
334      * mouse button.  This method can be overridden if the ImageArea
335      * does not need to know the location of the release.
336      * @return true if this ImageMapArea wants to prevent any underlying
337      * areas from seeing the lift
338      */
339     public boolean lift() {
340     return isTerminal();
341     }
342 
343     /**
344      * The drag method is called when the user moves the mouse while
345      * the button is pressed.  Only those ImageAreas that were informed
346      * of a press will be informed of the corresponding mouse movements.
347      * @return true if this ImageMapArea wants to prevent any underlying
348      * areas from seeing the drag
349      */
350     public boolean drag(int x, int y) {
351     return isTerminal();
352     }
353 
354   public String   getAppletInfo() {
355     return "Title: ImageArea \nAuthor: Jim Graham \nThis class performs the basic functions that most ImageArea classes will need and delegates specific actions to the subclasses.";
356   }
357 }
358 
359
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