1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <stdint.h>
20 #include <string>
21 #include <utils/Errors.h>
22 #include <system/audio.h>
23 #include <utils/Log.h>
24 
25 namespace android {
26 namespace audio_policy {
27 
28 template <typename Key>
29 class Element
30 {
31 public:
Element(const std::string & name)32     Element(const std::string &name)
33         : mName(name)
34     {}
~Element()35     ~Element() {}
36 
37     /**
38      * Returns identifier of this policy element
39      *
40      * @returns string representing the name of this policy element
41      */
getName()42     const std::string &getName() const { return mName; }
43 
44     /**
45     * Set the unique identifier for this policy element.
46     *
47     * @tparam Key type of the unique identifier.
48     * @param[in] identifier to be set.
49     *
50     * @return NO_ERROR if the identifier is valid and set correctly, error code otherwise.
51     */
setIdentifier(Key identifier)52     status_t setIdentifier(Key identifier)
53     {
54         mIdentifier = identifier;
55         return NO_ERROR;
56     }
57 
58     /**
59      * @return the unique identifier of this policy element.
60      */
getIdentifier()61     const Key &getIdentifier() const { return mIdentifier; }
62 
63     /**
64      * A Policy element may implement getter/setter function for a given property.
65      * Property may be audio_stream_type_t, audio_usage_t, audio_source_t
66      * or a string.
67      *
68      * @tparam Property for which this policy element has setter / getter.
69      * @return the property kept track by this policy base element.
70      */
71     template <typename Property>
72     Property get() const;
73 
74     /**
75      * A Policy element may implement getter/setter function for a given property.
76      * Property may be audio_stream_type_t, audio_usage_t, audio_source_t
77      * or a string.
78      *
79      * @tparam Property for which this policy element has setter / getter.
80      *
81      * @param[in] property value to be assigned for this policy base element.
82      *
83      * @return the property kept track by this policy base element.
84      */
85     template <typename Property>
86     status_t set(Property property);
87 
88 private:
89     /* Copy facilities are put private to disable copy. */
90     Element(const Element &object);
91     Element &operator=(const Element &object);
92 
93     std::string mName; /**< Unique literal Identifier of a policy base element*/
94     Key mIdentifier; /**< Unique numerical Identifier of a policy base element*/
95 };
96 } // namespace audio_policy
97 } // namespace android
98