1 /**
2 * This file Copyright (c) 2018 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.ui;
35
36 import info.magnolia.ui.framework.ContextProperty;
37 import info.magnolia.ui.framework.UiComponentContext;
38
39 import java.util.Optional;
40 import java.util.Set;
41 import java.util.function.Consumer;
42 import java.util.stream.Stream;
43
44 import com.google.common.collect.Sets;
45
46 import io.reactivex.disposables.Disposable;
47
48
49 /**
50 * Ui component context holding the selection/value that the related UI components
51 * operate with.
52 *
53 * @param <T> item type.
54 */
55 public interface ValueContext<T> extends UiComponentContext {
56
57 ContextProperty<Set<T>> current();
58
59 default Optional<T> getSingle() {
60 return get().findFirst();
61 }
62
63 default T getSingleOrThrow() {
64 return get().findFirst().orElseThrow(() -> new IllegalStateException("No item in value context"));
65 }
66
67 default Stream<T> get() {
68 return current().value()
69 .map(Set::stream)
70 .orElse(Stream.empty());
71 }
72
73 default void set(Set<T> value) {
74 current().set(value, true);
75 }
76
77 default void set(T value) {
78 set(Sets.newHashSet(value));
79 }
80
81 default void clear() {
82 current().value().ifPresent(ts -> set(Sets.newHashSet()));
83 }
84
85 default Disposable observe(Consumer<Set<T>> action) {
86 return current().observe(optionalValue -> action.accept(optionalValue.orElse(Sets.newHashSet())));
87 }
88
89 default Disposable observeNullable(Consumer<Set<T>> action) {
90 return current().observeNullable(action);
91 }
92 }