1 /*
2 * Entreri, an entity-component framework in Java
3 *
4 * Copyright (c) 2013, Michael Ludwig
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without modification,
8 * are permitted provided that the following conditions are met:
9 *
10 * Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 * Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
23 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27 package com.lhkbob.entreri.property;
28
29 /**
30 * ShareableProperty designates a special type of property that can mutate a shared
31 * instance to a specific component's value, instead of returning internal references.
32 * Often, shareable properties are capable of actually unpacking the type into primitive
33 * arrays and restoring the value into the shared instance for improved cache coherence.
34 * <p/>
35 * Because simple primitives cannot be shared, ShareableProperty declares the required
36 * methods using generics.
37 *
38 * @param <T> The type stored by the property
39 *
40 * @author Michael Ludwig
41 */
42 public interface ShareableProperty<T> extends Property {
43 /**
44 * Create a new instance of type T for use by components that need a shareable
45 * instance to pass into {@link #get(int, Object)}.
46 *
47 * @return A new instance of type T
48 */
49 public T createShareableInstance();
50
51 /**
52 * Get the property value at <var>index</var>, but instead of returning a new instance
53 * or the value, the <var>result</var> parameter is mutated to equal the property
54 * value. It can be assumed the instance was previously created by a call to {@link
55 * #createShareableInstance()}.
56 *
57 * @param index The index to access
58 * @param result The instance of T to modify
59 */
60 public void get(int index, T result);
61 }