01: /*
02: * <copyright>
03: *
04: * Copyright 1997-2004 BBNT Solutions, LLC
05: * under sponsorship of the Defense Advanced Research Projects
06: * Agency (DARPA).
07: *
08: * You can redistribute this software and/or modify it under the
09: * terms of the Cougaar Open Source License as published on the
10: * Cougaar Open Source Website (www.cougaar.org).
11: *
12: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
13: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
14: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
15: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
16: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
17: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
18: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
22: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: *
24: * </copyright>
25: */
26: package org.cougaar.core.component;
27:
28: import java.util.Comparator;
29:
30: /**
31: * A BinderFactory provides Binder instances
32: * on behalf of a ContainingComponent or ServiceProvider to wrap
33: * Child components.
34: * <p>
35: * BinderFactories are generally themselves specially bound by only by
36: * a trivial binder, so the "parent" component link is supplied shortly after
37: * construction by a call to the setContainer method. This may change
38: * to something closer to the way that any other component is bound at
39: * some point.
40: **/
41: public interface BinderFactory extends Component {
42: /** Lowest-priority for a BinderFactory. Default infrastructure
43: * BinderFactories are generally at this level.
44: **/
45: int MIN_PRIORITY = 0;
46:
47: /** Typical intermediate priority for "real-world" BinderFactories.
48: * Higher priorities should be used mainly for BinderFactoryWrappers.
49: **/
50: int NORM_PRIORITY = 50;
51:
52: /** Highest priority, for use by very important specific
53: * BinderFactoryWrappers.
54: **/
55: int MAX_PRIORITY = 100;
56:
57: /** The priority of this binder factory. The range of values
58: * is specified by the MIN_PRIORITY to MAX_PRIORITY.
59: * This value determines stacking order, with MAX_PRIORITY factories
60: * getting first chance to construct binders. Generally,
61: * the first one to respond wins.
62: * <p>
63: * This is pretty half-baked, but we need some policy to resolve
64: * ambiguity. Perhaps a two-level approach would be sufficient,
65: * e.g. built-in versus dynamically loaded factory. Also an
66: * option is to logically try all available binder factories and
67: * then resolve any conflicts which might arise.
68: **/
69: int getPriority();
70:
71: /** Get or Construct a binder for a child component.
72: * The returned value will be a Binder
73: * customized for use by the child Component. The
74: * Factory may impose any restrictions deemed neccessary on
75: * the client object. Most commonly, the child will often
76: * be required to implement a client-side interface of a
77: * service protocol.
78: **/
79: Binder getBinder(Object child);
80:
81: final class BFComparator implements Comparator {
82: public int compare(Object o1, Object o2) {
83: return ((BinderFactory) o2).getPriority()
84: - ((BinderFactory) o1).getPriority();
85: }
86: }
87:
88: /** a comparator for keeping Binder Factories sorted **/
89: Comparator comparator = new BFComparator();
90:
91: /** Get the BinderFactory's ComponentFactory.
92: * May return null if the BinderFactory doesn't make components.
93: **/
94: ComponentFactory getComponentFactory();
95: }
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