1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany |
---|
2 | // |
---|
3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
---|
4 | // you may not use this file except in compliance with the License. |
---|
5 | // You may obtain a copy of the License at |
---|
6 | // |
---|
7 | // http://www.apache.org/licenses/LICENSE-2.0 |
---|
8 | // |
---|
9 | // Unless required by applicable law or agreed to in writing, software |
---|
10 | // distributed under the License is distributed on an "AS IS" BASIS, |
---|
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
---|
12 | // See the License for the specific language governing permissions and |
---|
13 | // limitations under the License. |
---|
14 | |
---|
15 | package de.ugoe.cs.autoquest.eventcore.guimodel; |
---|
16 | |
---|
17 | import java.io.OutputStream; |
---|
18 | import java.io.PrintStream; |
---|
19 | import java.io.UnsupportedEncodingException; |
---|
20 | import java.util.ArrayList; |
---|
21 | import java.util.LinkedList; |
---|
22 | import java.util.List; |
---|
23 | import java.util.Stack; |
---|
24 | import java.util.logging.Level; |
---|
25 | |
---|
26 | import de.ugoe.cs.util.console.Console; |
---|
27 | |
---|
28 | /** |
---|
29 | * <p> |
---|
30 | * A GUI model is a tree of {@link IGUIElements} and represents a complete GUI of a software. It is |
---|
31 | * platform independent. It may have several root nodes, as some GUIs are made up of several Frames |
---|
32 | * being independent from each other. The GUI model is filled using the |
---|
33 | * {@link #integratePath(List, IGUIElementFactory)} method. |
---|
34 | * </p> |
---|
35 | * |
---|
36 | * @version 1.0 |
---|
37 | * @author Patrick Harms, Steffen Herbold |
---|
38 | */ |
---|
39 | public class GUIModel { |
---|
40 | |
---|
41 | /** |
---|
42 | * <p> |
---|
43 | * The root node of the tree not provided externally. |
---|
44 | * </p> |
---|
45 | */ |
---|
46 | private TreeNode root = new TreeNode(); |
---|
47 | |
---|
48 | /** |
---|
49 | * <p> |
---|
50 | * A list with all nodes currently known |
---|
51 | * </p> |
---|
52 | */ |
---|
53 | private List<TreeNode> allNodes = new ArrayList<TreeNode>(); |
---|
54 | |
---|
55 | /** |
---|
56 | * <p> |
---|
57 | * Integrates a path of GUI elements into the GUI model. The GUI model itself is a tree and |
---|
58 | * therefore a set of different paths through the tree that start with a root node and end with |
---|
59 | * a leaf node. Such a path can be added to the tree. The method checks, if any of the GUI |
---|
60 | * elements denoted by the path already exists. If so, it reuses it. It may therefore also |
---|
61 | * return an existing GUI element being the leaf node of the provided path. If a GUI element of |
---|
62 | * the path does not exist yet, it creates a new one using the provided GUI element factory. |
---|
63 | * </p> |
---|
64 | * <p> |
---|
65 | * If a GUI element specification describes an existing GUI element or not is determined through |
---|
66 | * comparing the GUI element specifications of the existing GUI elements with the ones provided |
---|
67 | * in the path. The comparison is done using the |
---|
68 | * {@link IGUIElementSpec#getSimilarity(IGUIElementSpec)} method. The comparison is only done on |
---|
69 | * the correct levels. I.e. the currently known root elements of the tree are only compared to |
---|
70 | * the first element in the path. If the correct one is found or created, its children are |
---|
71 | * compared only to the second specification in the path, and so on. |
---|
72 | * </p> |
---|
73 | * <p> |
---|
74 | * The returned GUI elements are singletons. I.e. it is tried to return always the identical |
---|
75 | * object for the same denoted element. However, while creating the GUI model, the similarity of |
---|
76 | * GUI elements may change. Therefore, the method might determine, that two formerly different |
---|
77 | * nodes are now similar. (This may happen, e.g. if GUI elements do not have initial names which |
---|
78 | * are set afterwards. Therefore, first they are handled differently and later they can be |
---|
79 | * identified as being the same.) In such a case, there are already several GUI element objects |
---|
80 | * instantiated for the same GUI element. The singleton paradigm gets broken. Therefore, such |
---|
81 | * GUI element objects are registered with each other, so that their equal method can determine |
---|
82 | * equality again correctly, although the objects are no singletons anymore. |
---|
83 | * </p> |
---|
84 | * |
---|
85 | * @param guiElementPath |
---|
86 | * the path to integrate into the model |
---|
87 | * @param guiElementFactory |
---|
88 | * the GUI element factory to be used for instantiating GUI element objects |
---|
89 | * |
---|
90 | * @return The GUI element object representing the GUI element denoted by the provided path |
---|
91 | * |
---|
92 | * @throws GUIModelException |
---|
93 | * thrown in cases such as the GUI element object could not be instantiated |
---|
94 | * @throws IllegalArgumentException |
---|
95 | * if the provided path is invalid. |
---|
96 | */ |
---|
97 | public IGUIElement integratePath(List<? extends IGUIElementSpec> guiElementPath, |
---|
98 | IGUIElementFactory guiElementFactory) |
---|
99 | throws GUIModelException, IllegalArgumentException |
---|
100 | { |
---|
101 | if ((guiElementPath == null) || (guiElementPath.size() <= 0)) { |
---|
102 | throw new IllegalArgumentException("GUI element path must contain at least one element"); |
---|
103 | } |
---|
104 | |
---|
105 | List<IGUIElementSpec> remainingPath = new LinkedList<IGUIElementSpec>(); |
---|
106 | |
---|
107 | for (IGUIElementSpec spec : guiElementPath) { |
---|
108 | remainingPath.add(spec); |
---|
109 | } |
---|
110 | |
---|
111 | return integratePath(root, remainingPath, guiElementFactory); |
---|
112 | } |
---|
113 | |
---|
114 | /** |
---|
115 | * <p> |
---|
116 | * Returns all children of the provided GUI element or null, if it does not have any or the node |
---|
117 | * is unknown. |
---|
118 | * </p> |
---|
119 | * |
---|
120 | * @param guiElement |
---|
121 | * the GUI element of which the children shall be returned |
---|
122 | * |
---|
123 | * @return As described |
---|
124 | */ |
---|
125 | public List<IGUIElement> getChildren(IGUIElement guiElement) { |
---|
126 | List<IGUIElement> result = null; |
---|
127 | for (TreeNode node : allNodes) { |
---|
128 | if (node.guiElement.equals(guiElement)) { |
---|
129 | if (result == null) { |
---|
130 | result = new ArrayList<IGUIElement>(); |
---|
131 | |
---|
132 | if (node.children != null) { |
---|
133 | for (TreeNode child : node.children) { |
---|
134 | result.add(child.guiElement); |
---|
135 | } |
---|
136 | } |
---|
137 | } |
---|
138 | else { |
---|
139 | Console |
---|
140 | .traceln(Level.SEVERE, |
---|
141 | "Multiple nodes in the internal GUI model match the same GUI element. " |
---|
142 | + "This should not be the case and the GUI model is probably invalid."); |
---|
143 | } |
---|
144 | } |
---|
145 | } |
---|
146 | |
---|
147 | return result; |
---|
148 | } |
---|
149 | |
---|
150 | /** |
---|
151 | * <p> |
---|
152 | * Returns the parent GUI element of the provided GUI element or null, if it does not have a |
---|
153 | * parent (i.e. if it is a root node) or if the node is unknown. |
---|
154 | * </p> |
---|
155 | * |
---|
156 | * @param guiElement |
---|
157 | * the GUI element of which the parent shall be returned |
---|
158 | * |
---|
159 | * @return As described |
---|
160 | */ |
---|
161 | public IGUIElement getParent(IGUIElement guiElement) { |
---|
162 | IGUIElement parent = null; |
---|
163 | |
---|
164 | for (TreeNode node : allNodes) { |
---|
165 | for (TreeNode child : node.children) { |
---|
166 | if (child.guiElement.equals(guiElement)) { |
---|
167 | if (parent != null) { |
---|
168 | parent = node.guiElement; |
---|
169 | } |
---|
170 | else { |
---|
171 | Console |
---|
172 | .traceln(Level.SEVERE, |
---|
173 | "Multiple nodes in the internal GUI model match the same GUI element. " |
---|
174 | + "This should not be the case and the GUI model is probably invalid."); |
---|
175 | } |
---|
176 | } |
---|
177 | } |
---|
178 | } |
---|
179 | |
---|
180 | return parent; |
---|
181 | } |
---|
182 | |
---|
183 | /** |
---|
184 | * <p> |
---|
185 | * Returns all root GUI elements of the model or an empty list, if the model is empty |
---|
186 | * </p> |
---|
187 | * |
---|
188 | * @return As described |
---|
189 | */ |
---|
190 | public List<IGUIElement> getRootElements() { |
---|
191 | List<IGUIElement> roots = new ArrayList<IGUIElement>(); |
---|
192 | |
---|
193 | if (root.children != null) { |
---|
194 | for (TreeNode rootChild : root.children) { |
---|
195 | roots.add(rootChild.guiElement); |
---|
196 | } |
---|
197 | } |
---|
198 | |
---|
199 | return roots; |
---|
200 | } |
---|
201 | |
---|
202 | /** |
---|
203 | * returns a traverser for the GUI model to have efficient access to the tree of GUI elements |
---|
204 | * without having direct access. |
---|
205 | * |
---|
206 | * @return a traverser |
---|
207 | */ |
---|
208 | public Traverser getTraverser() { |
---|
209 | return new Traverser(); |
---|
210 | } |
---|
211 | |
---|
212 | /** |
---|
213 | * <p> |
---|
214 | * dumps the GUI model to the provided stream. Each node is represented through its toString() |
---|
215 | * method. If a node has children, those are dumped indented and surrounded by braces. |
---|
216 | * </p> |
---|
217 | * |
---|
218 | * @param out |
---|
219 | * The stream to dump the textual representation of the model to |
---|
220 | * @param encoding |
---|
221 | * The encoding to be used while dumping |
---|
222 | */ |
---|
223 | public void dump(OutputStream out, String encoding) { |
---|
224 | PrintStream stream; |
---|
225 | |
---|
226 | if (out instanceof PrintStream) { |
---|
227 | stream = (PrintStream) out; |
---|
228 | } |
---|
229 | else { |
---|
230 | String enc = encoding == null ? "UTF-8" : encoding; |
---|
231 | try { |
---|
232 | stream = new PrintStream(out, true, enc); |
---|
233 | } |
---|
234 | catch (UnsupportedEncodingException e) { |
---|
235 | throw new IllegalArgumentException("encodind " + enc + " not supported"); |
---|
236 | } |
---|
237 | } |
---|
238 | |
---|
239 | for (TreeNode node : root.children) { |
---|
240 | dumpGUIElement(stream, node, ""); |
---|
241 | } |
---|
242 | } |
---|
243 | |
---|
244 | /** |
---|
245 | * <p> |
---|
246 | * By calling this method, the GUIModel is traversed and similar nodes are merged. |
---|
247 | * </p> |
---|
248 | * |
---|
249 | */ |
---|
250 | public void condenseModel() { |
---|
251 | mergeSubTree(root); |
---|
252 | } |
---|
253 | |
---|
254 | /** |
---|
255 | * <p> |
---|
256 | * Merges the tree nodes of two GUI elements. The GUI elements need to have the same parent. |
---|
257 | * </p> |
---|
258 | * |
---|
259 | * @param guiElement1 |
---|
260 | * the first merge GUI element |
---|
261 | * @param guiElement2 |
---|
262 | * the second merge GUI element |
---|
263 | * @throws IllegalArgumentException |
---|
264 | * thrown if the two GUI elements do not have the same parent |
---|
265 | */ |
---|
266 | public void mergeGUIElements(IGUIElement guiElement1, IGUIElement guiElement2) |
---|
267 | throws IllegalArgumentException |
---|
268 | { |
---|
269 | // check if both nodes have the same parent |
---|
270 | IGUIElement parentElement = guiElement1.getParent(); |
---|
271 | if (parentElement != null && !parentElement.equals(guiElement2.getParent())) { |
---|
272 | throw new IllegalArgumentException("can only merge nodes with the same parent"); |
---|
273 | } |
---|
274 | |
---|
275 | // get the TreeNode of the parent of the GUI elements |
---|
276 | TreeNode parent = findNode(parentElement); |
---|
277 | |
---|
278 | // get the TreeNodes for both GUI elements |
---|
279 | TreeNode node1 = findNode(guiElement1); |
---|
280 | TreeNode node2 = findNode(guiElement2); |
---|
281 | |
---|
282 | if (node1 == null || node2 == null) { |
---|
283 | throw new IllegalArgumentException( |
---|
284 | "Error while merging nodes: one element is not part of the GUI model!"); |
---|
285 | } |
---|
286 | |
---|
287 | TreeNode replacement = mergeTreeNodes(node1, node2); |
---|
288 | |
---|
289 | if (parent != null) { |
---|
290 | // remove node1 and node2 from the parent's children and add the replacement instead |
---|
291 | // assumes that there are no duplicates of node1 and node2 |
---|
292 | if (parent.children != null) { |
---|
293 | parent.children.set(parent.children.indexOf(node1), replacement); |
---|
294 | parent.children.remove(node2); |
---|
295 | } |
---|
296 | } |
---|
297 | |
---|
298 | } |
---|
299 | |
---|
300 | /** |
---|
301 | * <p> |
---|
302 | * internally integrates a path as the children of the provided parent node. This method is |
---|
303 | * recursive and calls itself, for the child of the parent node, that matches the first element |
---|
304 | * in the remaining path. |
---|
305 | * </p> |
---|
306 | * |
---|
307 | * @param parentNode |
---|
308 | * the parent node to add children for |
---|
309 | * @param guiElementPath |
---|
310 | * the path of children to be created starting with the parent node |
---|
311 | * @param guiElementFactory |
---|
312 | * the GUI element factory to be used for instantiating GUI element objects |
---|
313 | * |
---|
314 | * @return The GUI element object representing the GUI element denoted by the provided path |
---|
315 | * |
---|
316 | * @throws GUIModelException |
---|
317 | * thrown in cases such as the GUI element object could not be instantiated |
---|
318 | */ |
---|
319 | private IGUIElement integratePath(TreeNode parentNode, |
---|
320 | List<? extends IGUIElementSpec> remainingPath, |
---|
321 | IGUIElementFactory guiElementFactory) |
---|
322 | throws GUIModelException |
---|
323 | { |
---|
324 | IGUIElementSpec specToIntegrateElementFor = remainingPath.remove(0); |
---|
325 | |
---|
326 | TreeNode child = findEqualChild(parentNode, specToIntegrateElementFor); |
---|
327 | if (child == null) { |
---|
328 | IGUIElement newElement = |
---|
329 | guiElementFactory.instantiateGUIElement(specToIntegrateElementFor, |
---|
330 | parentNode.guiElement); |
---|
331 | |
---|
332 | child = parentNode.addChild(newElement); |
---|
333 | } |
---|
334 | |
---|
335 | if (remainingPath.size() > 0) { |
---|
336 | return integratePath(child, remainingPath, guiElementFactory); |
---|
337 | } |
---|
338 | else { |
---|
339 | return child.guiElement; |
---|
340 | } |
---|
341 | } |
---|
342 | |
---|
343 | /** |
---|
344 | * <p> |
---|
345 | * Searches the children of a tree node to see if the {@link IGUIElementSpec} of equals the |
---|
346 | * specification of the {@link TreeNode#guiElement} of the child. If a match is found, the child |
---|
347 | * is returned. |
---|
348 | * </p> |
---|
349 | * |
---|
350 | * @param parentNode |
---|
351 | * parent node whose children are searched |
---|
352 | * @param specToMatch |
---|
353 | * specification that is searched for |
---|
354 | * @return matching child node or null if no child matches |
---|
355 | */ |
---|
356 | private TreeNode findEqualChild(TreeNode parentNode, IGUIElementSpec specToMatch) { |
---|
357 | if (parentNode.children != null) { |
---|
358 | for (TreeNode child : parentNode.children) { |
---|
359 | if (specToMatch.equals(child.guiElement.getSpecification())) { |
---|
360 | return child; |
---|
361 | } |
---|
362 | } |
---|
363 | } |
---|
364 | return null; |
---|
365 | } |
---|
366 | |
---|
367 | /** |
---|
368 | * <p> |
---|
369 | * Merges all similar nodes in the sub-tree of the GUI model defined by the subTreeRoot. |
---|
370 | * </p> |
---|
371 | * <p> |
---|
372 | * The merging order is a bottom-up. This means, that we first call mergeSubTree recursively for |
---|
373 | * the grand children of the subTreeRoot, before we merge subTreeRoot. |
---|
374 | * </p> |
---|
375 | * <p> |
---|
376 | * The merging strategy is top-down. This means, that every time we merge two child nodes, we |
---|
377 | * call mergeSubTree recursively for all children of the merged nodes in order to check if we |
---|
378 | * can merge the children, too. |
---|
379 | * </p> |
---|
380 | * |
---|
381 | * @param subTreeRoot |
---|
382 | * root node of the sub-tree that is merged |
---|
383 | */ |
---|
384 | private void mergeSubTree(TreeNode subTreeRoot) { |
---|
385 | if (subTreeRoot.children == null || subTreeRoot.children.isEmpty()) { |
---|
386 | return; |
---|
387 | } |
---|
388 | |
---|
389 | // lets first merge the grand children of the parentNode |
---|
390 | for (TreeNode child : subTreeRoot.children) { |
---|
391 | mergeSubTree(child); |
---|
392 | } |
---|
393 | |
---|
394 | boolean performedMerge; |
---|
395 | |
---|
396 | do { |
---|
397 | performedMerge = false; |
---|
398 | for (int i = 0; !performedMerge && i < subTreeRoot.children.size(); i++) { |
---|
399 | IGUIElementSpec elemSpec1 = |
---|
400 | subTreeRoot.children.get(i).guiElement.getSpecification(); |
---|
401 | for (int j = i + 1; !performedMerge && j < subTreeRoot.children.size(); j++) { |
---|
402 | IGUIElementSpec elemSpec2 = |
---|
403 | subTreeRoot.children.get(j).guiElement.getSpecification(); |
---|
404 | if (elemSpec1.getSimilarity(elemSpec2)) { |
---|
405 | TreeNode replacement = |
---|
406 | mergeTreeNodes(subTreeRoot.children.get(i), subTreeRoot.children.get(j)); |
---|
407 | |
---|
408 | subTreeRoot.children.set(i, replacement); |
---|
409 | subTreeRoot.children.remove(j); |
---|
410 | performedMerge = true; |
---|
411 | i--; |
---|
412 | break; |
---|
413 | } |
---|
414 | } |
---|
415 | } |
---|
416 | } |
---|
417 | while (performedMerge); |
---|
418 | } |
---|
419 | |
---|
420 | /** |
---|
421 | * <p> |
---|
422 | * merges two nodes with each other. Merging means registering the GUI element objects with each |
---|
423 | * other for equality checks. Further it add all children of both nodes to a new replacing node. |
---|
424 | * Afterwards, all similar nodes of the replacement node are merged as well. |
---|
425 | * </p> |
---|
426 | * |
---|
427 | * @param treeNode1 |
---|
428 | * the first of the two nodes to be merged |
---|
429 | * @param treeNode2 |
---|
430 | * the second of the two nodes to be merged |
---|
431 | * @return a tree node being the merge of the two provided nodes. |
---|
432 | */ |
---|
433 | private TreeNode mergeTreeNodes(TreeNode treeNode1, TreeNode treeNode2) { |
---|
434 | // the following two lines are needed to preserve the references to the existing GUI |
---|
435 | // elements. If two elements are the same, one should be deleted to make the elements |
---|
436 | // singletons again. However, there may exist references to both objects. To preserve |
---|
437 | // these, we simply register the equal GUI elements with each other so that an equals |
---|
438 | // check can return true. |
---|
439 | treeNode1.guiElement.addEqualGUIElement(treeNode2.guiElement); |
---|
440 | treeNode2.guiElement.addEqualGUIElement(treeNode1.guiElement); |
---|
441 | |
---|
442 | // and now a replacement node that is the merge of treeNode1 and treeNode2 is created |
---|
443 | TreeNode replacement = new TreeNode(); |
---|
444 | replacement.guiElement = treeNode1.guiElement; |
---|
445 | if (treeNode1.children != null) { |
---|
446 | for (TreeNode child : treeNode1.children) { |
---|
447 | replacement.addChildNode(child); |
---|
448 | } |
---|
449 | } |
---|
450 | if (treeNode2.children != null) { |
---|
451 | for (TreeNode child : treeNode2.children) { |
---|
452 | replacement.addChildNode(child); |
---|
453 | } |
---|
454 | } |
---|
455 | |
---|
456 | mergeSubTree(replacement); |
---|
457 | |
---|
458 | replacement.guiElement.updateSpecification(treeNode2.guiElement.getSpecification()); |
---|
459 | |
---|
460 | // finally, update the known nodes list |
---|
461 | // if you don't do this getChildren will return wrong things and very bad things happen! |
---|
462 | allNodes.remove(treeNode1); |
---|
463 | allNodes.remove(treeNode2); |
---|
464 | allNodes.add(replacement); |
---|
465 | |
---|
466 | return replacement; |
---|
467 | } |
---|
468 | |
---|
469 | /** |
---|
470 | * <p> |
---|
471 | * dumps a GUI element to the stream. A dump contains the toString() representation of the GUI |
---|
472 | * element as well as a indented list of its children surrounded by braces. Therefore, not the |
---|
473 | * GUI element itself but its tree node is provided to have an efficient access to its children |
---|
474 | * </p> |
---|
475 | * |
---|
476 | * @param out |
---|
477 | * {@link PrintStream} where the guiElement is dumped to |
---|
478 | * @param node |
---|
479 | * the guiElement's tree node of which the string representation is dumped |
---|
480 | * @param indent |
---|
481 | * indent string of the dumping |
---|
482 | */ |
---|
483 | private void dumpGUIElement(PrintStream out, TreeNode node, String indent) { |
---|
484 | out.print(indent); |
---|
485 | out.print(node.guiElement); |
---|
486 | |
---|
487 | if ((node.children != null) && (node.children.size() > 0)) { |
---|
488 | out.println(" {"); |
---|
489 | |
---|
490 | for (TreeNode child : node.children) { |
---|
491 | dumpGUIElement(out, child, indent + " "); |
---|
492 | } |
---|
493 | |
---|
494 | out.print(indent); |
---|
495 | out.print("}"); |
---|
496 | } |
---|
497 | |
---|
498 | out.println(); |
---|
499 | } |
---|
500 | |
---|
501 | /** |
---|
502 | * <p> |
---|
503 | * Retrieves the TreeNode associated with a GUI element. Returns null if no such TreeNode is |
---|
504 | * found. |
---|
505 | * </p> |
---|
506 | * |
---|
507 | * @param element |
---|
508 | * the GUI element |
---|
509 | * @return associated TreeNode; null if no such node exists |
---|
510 | */ |
---|
511 | private TreeNode findNode(IGUIElement element) { |
---|
512 | if (element == null) { |
---|
513 | return null; |
---|
514 | } |
---|
515 | |
---|
516 | TreeNode result = null; |
---|
517 | for (TreeNode node : allNodes) { |
---|
518 | if (node.guiElement.equals(element)) { |
---|
519 | if (result == null) { |
---|
520 | result = node; |
---|
521 | } |
---|
522 | else { |
---|
523 | Console |
---|
524 | .traceln(Level.SEVERE, |
---|
525 | "Multiple nodes in the internal GUI model match the same GUI element. " |
---|
526 | + "This should not be the case and the GUI model is probably invalid."); |
---|
527 | } |
---|
528 | } |
---|
529 | } |
---|
530 | return result; |
---|
531 | } |
---|
532 | |
---|
533 | /** |
---|
534 | * <p> |
---|
535 | * Used externally for tree traversal without providing direct access to the tree nodes |
---|
536 | * </p> |
---|
537 | * |
---|
538 | * @version 1.0 |
---|
539 | * @author Patrick Harms, Steffen Herbold |
---|
540 | */ |
---|
541 | public class Traverser { |
---|
542 | |
---|
543 | /** |
---|
544 | * <p> |
---|
545 | * the stack of nodes on which the traverser currently works |
---|
546 | * </p> |
---|
547 | */ |
---|
548 | private Stack<StackEntry> nodeStack = new Stack<StackEntry>(); |
---|
549 | |
---|
550 | /** |
---|
551 | * <p> |
---|
552 | * initializes the traverser by adding the root node of the GUI model to the stack |
---|
553 | * </p> |
---|
554 | */ |
---|
555 | private Traverser() { |
---|
556 | nodeStack.push(new StackEntry(root, 0)); |
---|
557 | } |
---|
558 | |
---|
559 | /** |
---|
560 | * <p> |
---|
561 | * returns the first child of the current GUI element. On the first call of this method on |
---|
562 | * the traverser the first of the root GUI elements of the GUI model is returned. If the |
---|
563 | * current GUI element does not have children, the method returns null. If the GUI model |
---|
564 | * is empty, then a call to this method will return null. The returned GUI element is the |
---|
565 | * next one the traverser points to. |
---|
566 | * </p> |
---|
567 | * |
---|
568 | * @return as described. |
---|
569 | */ |
---|
570 | public IGUIElement firstChild() { |
---|
571 | return pushChild(0); |
---|
572 | } |
---|
573 | |
---|
574 | /** |
---|
575 | * <p> |
---|
576 | * returns true, if the current GUI element has a first child, i.e. if the next call to the |
---|
577 | * method {@link #firstChild()} would return a GUI element or null. |
---|
578 | * </p> |
---|
579 | * |
---|
580 | * @return as described |
---|
581 | */ |
---|
582 | public boolean hasFirstChild() { |
---|
583 | return |
---|
584 | (nodeStack.peek().treeNode.children != null) && |
---|
585 | (nodeStack.peek().treeNode.children.size() > 0); |
---|
586 | } |
---|
587 | |
---|
588 | /** |
---|
589 | * <p> |
---|
590 | * returns the next sibling of the current GUI element. If there is no further sibling, |
---|
591 | * null is returned. If the current GUI element is one of the root nodes, the next root |
---|
592 | * node of the GUI model is returned. The returned GUI element is the next one the |
---|
593 | * traverser points to. |
---|
594 | * </p> |
---|
595 | * |
---|
596 | * @return as described |
---|
597 | */ |
---|
598 | public IGUIElement nextSibling() { |
---|
599 | int lastIndex = nodeStack.pop().index; |
---|
600 | |
---|
601 | IGUIElement retval = pushChild(lastIndex + 1); |
---|
602 | if (retval == null) { |
---|
603 | pushChild(lastIndex); |
---|
604 | } |
---|
605 | |
---|
606 | return retval; |
---|
607 | } |
---|
608 | |
---|
609 | /** |
---|
610 | * <p> |
---|
611 | * returns true, if the current GUI element has a further sibling, i.e. if a call to the |
---|
612 | * method {@link #nextSibling()} will return a GUI element; |
---|
613 | * </p> |
---|
614 | * |
---|
615 | * @return as described |
---|
616 | */ |
---|
617 | public boolean hasNextSibling() { |
---|
618 | StackEntry entry = nodeStack.pop(); |
---|
619 | boolean result = nodeStack.peek().treeNode.children.size() > (entry.index + 1); |
---|
620 | pushChild(entry.index); |
---|
621 | return result; |
---|
622 | } |
---|
623 | |
---|
624 | /** |
---|
625 | * <p> |
---|
626 | * returns the parent GUI element of the current GUI element. If the current GUI element |
---|
627 | * is a root node, null is returned. If there is no current GUI element yet as the method |
---|
628 | * {@link #firstChild()} was not called yet, null is returned. |
---|
629 | * </p> |
---|
630 | * |
---|
631 | * @return as described |
---|
632 | */ |
---|
633 | public IGUIElement parent() { |
---|
634 | IGUIElement retval = null; |
---|
635 | |
---|
636 | if (nodeStack.size() > 1) { |
---|
637 | nodeStack.pop(); |
---|
638 | retval = nodeStack.peek().treeNode.guiElement; |
---|
639 | } |
---|
640 | |
---|
641 | return retval; |
---|
642 | } |
---|
643 | |
---|
644 | /** |
---|
645 | * <p> |
---|
646 | * internal method used for changing the state of the traverser. I.e. to switch to a |
---|
647 | * specific child GUI element of the current one. |
---|
648 | * </p> |
---|
649 | */ |
---|
650 | private IGUIElement pushChild(int index) { |
---|
651 | IGUIElement retVal = null; |
---|
652 | |
---|
653 | if ((nodeStack.peek().treeNode.children != null) && |
---|
654 | (nodeStack.peek().treeNode.children.size() > index)) |
---|
655 | { |
---|
656 | nodeStack.push |
---|
657 | (new StackEntry(nodeStack.peek().treeNode.children.get(index), index)); |
---|
658 | retVal = nodeStack.peek().treeNode.guiElement; |
---|
659 | } |
---|
660 | |
---|
661 | return retVal; |
---|
662 | } |
---|
663 | |
---|
664 | /** |
---|
665 | * <p> |
---|
666 | * internal class needed to fill the stack with nodes of the GUI models and their |
---|
667 | * respective index in the children of the parent node. |
---|
668 | * </p> |
---|
669 | */ |
---|
670 | private class StackEntry { |
---|
671 | |
---|
672 | /** */ |
---|
673 | private TreeNode treeNode; |
---|
674 | |
---|
675 | /** */ |
---|
676 | private int index; |
---|
677 | |
---|
678 | /** |
---|
679 | * <p> |
---|
680 | * creates a new stack entry. |
---|
681 | * </p> |
---|
682 | */ |
---|
683 | private StackEntry(TreeNode treeNode, int index) { |
---|
684 | this.treeNode = treeNode; |
---|
685 | this.index = index; |
---|
686 | } |
---|
687 | } |
---|
688 | } |
---|
689 | |
---|
690 | /** |
---|
691 | * <p> |
---|
692 | * Used internally for building up the tree of GUI elements. |
---|
693 | * </p> |
---|
694 | * |
---|
695 | * @version 1.0 |
---|
696 | * @author Patrick Harms, Steffen Herbold |
---|
697 | */ |
---|
698 | private class TreeNode { |
---|
699 | |
---|
700 | /** |
---|
701 | * <p> |
---|
702 | * GUI element associated with the TreeNode. |
---|
703 | * </p> |
---|
704 | */ |
---|
705 | private IGUIElement guiElement; |
---|
706 | |
---|
707 | /** |
---|
708 | * <p> |
---|
709 | * Children of the TreeNode. |
---|
710 | * </p> |
---|
711 | */ |
---|
712 | private List<TreeNode> children; |
---|
713 | |
---|
714 | /** |
---|
715 | * <p> |
---|
716 | * Adds a child to the current node while keeping all lists of nodes up to date |
---|
717 | * </p> |
---|
718 | * |
---|
719 | * @param guiElement |
---|
720 | * GUI element that will be associated with the new child |
---|
721 | * @return the added child |
---|
722 | */ |
---|
723 | private TreeNode addChild(IGUIElement guiElement) { |
---|
724 | if (children == null) { |
---|
725 | children = new ArrayList<TreeNode>(); |
---|
726 | } |
---|
727 | |
---|
728 | TreeNode child = new TreeNode(); |
---|
729 | child.guiElement = guiElement; |
---|
730 | children.add(child); |
---|
731 | |
---|
732 | allNodes.add(child); |
---|
733 | |
---|
734 | return child; |
---|
735 | } |
---|
736 | |
---|
737 | /** |
---|
738 | * |
---|
739 | * <p> |
---|
740 | * Adds a TreeNode as child to the current node. This way, the whole sub-tree is added. |
---|
741 | * </p> |
---|
742 | * |
---|
743 | * @param node |
---|
744 | * child node that is added |
---|
745 | * @return node that has been added |
---|
746 | */ |
---|
747 | private TreeNode addChildNode(TreeNode node) { |
---|
748 | if (children == null) { |
---|
749 | children = new ArrayList<TreeNode>(); |
---|
750 | } |
---|
751 | children.add(node); |
---|
752 | return node; |
---|
753 | } |
---|
754 | |
---|
755 | /* |
---|
756 | * (non-Javadoc) |
---|
757 | * |
---|
758 | * @see java.lang.Object#toString() |
---|
759 | */ |
---|
760 | @Override |
---|
761 | public String toString() { |
---|
762 | return guiElement.toString(); |
---|
763 | } |
---|
764 | } |
---|
765 | } |
---|