Mercurial > hg4j

annotate src/org/tmatesoft/hg/util/Adaptable.java @ 494:2743641f2f12

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Defect: use of 0 as configuration value for mapio boundary results in every file being memmap-ed
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Thu, 18 Oct 2012 19:51:07 +0200
parents 91d75e1bac9f
children
rev   line source
148
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
1 /*
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
2 * Copyright (c) 2011 TMate Software Ltd
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
3 *
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
4 * This program is free software; you can redistribute it and/or modify
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
5 * it under the terms of the GNU General Public License as published by
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
6 * the Free Software Foundation; version 2 of the License.
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
7 *
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
8 * This program is distributed in the hope that it will be useful,
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
11 * GNU General Public License for more details.
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
12 *
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
13 * For information on how to redistribute this software under
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
14 * the terms of a license other than GNU General Public License
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
15 * contact TMate Software at support@hg4j.com
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
16 */
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
17 package org.tmatesoft.hg.util;
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
18
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
19 /**
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
20 * Extension mechanism.
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
21 *
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
22 * @author Artem Tikhomirov
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
23 * @author TMate Software Ltd.
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
24 */
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
25 public interface Adaptable {
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
26
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
27 <T> T getAdapter(Class<T> adapterClass);
356
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
28
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
29 class Factory<T> {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
30
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
31 private final Class<T> adapterClass;
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
32
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
33 public Factory(Class<T> adapterClass) {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
34 assert adapterClass != null;
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
35 this.adapterClass = adapterClass;
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
36 }
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
37
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
38 public T get(Object target) {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
39 return getAdapter(target, adapterClass, null);
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
40 }
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
41
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
42 public T get(Object target, T defaultValue) {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
43 return getAdapter(target, adapterClass, defaultValue);
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
44 }
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
45
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
46 /**
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
47 * Try to adapt target to specified class, resort to defaultValue when not possible.
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
48 * Instance lookup order is as follows: first, target is checked for being {@link Adaptable} and, if yes,
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
49 * consulted for adapter. Then, plain {@link Class#isInstance(Object) instanceof} checks if target itself is
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
50 * of desired type. {@link Adaptable} check comes first to allow classed that are in fact <code>instanceof</code>
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
51 * desired type to respond to the demand conditionally
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
52 *
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
53 * @param target object to adapt, <code>null</code> value, although meaningless, is tolerable.
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
54 * @param adapterClass desired target class
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
55 * @param defaultValue value to use if target cannot be adapted to desired class, may be <code>null</code>
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
56 * @return instance of the desired class
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
57 */
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
58 public static <C> C getAdapter(Object target, Class<C> adapterClass, C defaultValue) {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
59 if (target instanceof Adaptable) {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
60 return ((Adaptable) target).getAdapter(adapterClass);
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
61 }
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
62 if (adapterClass.isInstance(target)) {
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
63 return adapterClass.cast(target);
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
64 }
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
65 return defaultValue;
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
66 }
91d75e1bac9f Consistent approach to deal with adaptable objects. Give adaptable precedence over instanceof to allow conditional response when classes do implement desired interface
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 148
diff changeset
67 }
148
1a7a9a20e1f9 Exceptions, javadoc. Initial cancel and progress support
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
68 }