1 package cz.cuni.amis.pogamut.sposh.elements;
2
3 import java.util.List;
4 import java.util.NoSuchElementException;
5
6 /**
7 * This is class used as intermediate class between PoshElement and DataNodes of
8 * POSH elements. Some common functions are implemented here.
9 *
10 * @author HonzaH
11 */
12 public abstract class PoshDummyElement extends PoshElement {
13
14 /**
15 * Regular pattern, only text that maches this pattern can be a name of the
16 * POSH element. This pattern must be same as token
17 * <code>NAME</code> in the PoshParser.jj
18 * <p/>
19 * Because of dash (-), not all strings that match this pattern are FQN.
20 */
21 public static final String IDENT_PATTERN = "([a-zA-Z][_\\-a-zA-Z0-9]*\\.)*[a-zA-Z][_\\-a-zA-Z0-9]*";
22
23 /**
24 * Function for moving an child element in the list of children. When node
25 * wants to change position of a child, it must first change its position in
26 * the data structures of the node and then it(the parent node of a child)
27 * must notify its listeners that a child has moved. The child is not
28 * notified (unless it has a listener on its parent).
29 * <p/>
30 * This method computes new index of a child in the collection and moves it
31 * there. The child will be at the new position and the rest of elements
32 * will move in such way that they will stay in the same order as before
33 * (imagine it as a single line of balls, you take out specified ball and
34 * put it at new position and other balls will move accordingly). Once all
35 * elements are in their proper places, the method emits a notification
36 * about movement of a child.
37 *
38 * @param collection list of elements, child must be one of them
39 * @param child child element that will be moved
40 * @param relativePosition how much will child move, how much will index of
41 * a child change (new_idx = org_inx + relativePosition).
42 * @return true if child has been moved, false if new position has been
43 * illegal
44 * @throws NoSuchElementException if child is not in the collection.
45 */
46 protected final boolean moveNodeInList(List collection, PoshElement child, int relativePosition) {
47 // find index of child
48 int childIndex = collection.indexOf(child);
49 if (childIndex == -1) {
50 throw new NoSuchElementException("Child " + child + "is not in collection.");
51 }
52 int bustPos;
53 if (relativePosition > 0) {
54 bustPos = childIndex + relativePosition + 1;
55 } else {
56 bustPos = childIndex + relativePosition;
57 }
58 // check if move is even possible
59 if (bustPos < 0 || bustPos > collection.size()) {
60 return false;
61 }
62
63 collection.add(bustPos, child);
64
65 // remove former child
66 if (relativePosition > 0) {
67 collection.remove(childIndex);
68 } else {
69 collection.remove(childIndex + 1);
70 }
71
72 emitChildMove(child, relativePosition);
73 return true;
74 }
75
76 /**
77 * Is passed name used by one of elements?
78 *
79 * @param name name to be tested
80 * @param elements elements againt which the test is done
81 * @return true if name is used, false otherwise
82 */
83 protected static boolean isUsedName(String name, List<? extends NamedLapElement> elements) {
84 for (NamedLapElement element : elements) {
85 String elementName = element.getName();
86 if (elementName.equals(name)) {
87 return true;
88 }
89 }
90 return false;
91 }
92
93 /**
94 * Get valid name for new element, but name can't be same as any name used
95 * by passed elements.
96 *
97 * @param template string used as prefix of created name
98 * @param elements elements that must have different name that created name
99 * @return valid name that can be immediately used as OK name of new drive.
100 */
101 protected static String getUnusedName(String template, List<? extends NamedLapElement> elements) {
102 int i = 1;
103 while (isUsedName(template + i, elements)) {
104 i++;
105 }
106 return template + i;
107 }
108 }