1 /*
2 * XNap - A P2P framework and client.
3 *
4 * See the file AUTHORS for copyright information.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 package org.xnap.pkg;
21
22
23 /***
24 */
25 public abstract class AbstractDependencyNode implements DependencyNode
26 {
27
28 //--- Data Field(s) ---
29
30 private Object id;
31 private boolean required;
32
33 //--- Constructor(s) ---
34
35 public AbstractDependencyNode(Object id)
36 {
37 this.id = id;
38 }
39
40 //--- Method(s) ---
41
42 public Object getID()
43 {
44 return id;
45 }
46
47 public boolean isRequired()
48 {
49 return required;
50 }
51
52 public void require(boolean requireInstalled)
53 throws UnsatisfiedDependenciesException
54 {
55 if (required) {
56 // already visited this node
57 return;
58 }
59
60 required = true;
61 try {
62 checkDepends(requireInstalled);
63 }
64 catch (UnsatisfiedDependenciesException e) {
65 required = false;
66 throw e;
67 }
68 }
69
70 public abstract void checkDepends(boolean requireInstalled)
71 throws UnsatisfiedDependenciesException;
72
73 public void setRequired(boolean required)
74 {
75 this.required = required;
76 }
77
78 public String toString()
79 {
80 return getID().toString();
81 }
82
83 }
84