IBase.hal revision 2cd440cf0c589e89d0d4509d273142a35b5ef81c 
1/*
2 * Copyright (C) 2016 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
17package android.hidl.base@1.0;
18
19/*
20 * The ancestor for all interfaces.
21 *
22 * All HAL files will have this interface implicitly imported. If an interface
23 * does not explicitly extend from another interface, it will implicitly extend
24 * from IBase. (This is like java.lang.Object in Java.)
25 *
26 * Methods defined here are shared by all interfaces (this is like
27 * java.lang.Object.notify(), for example.) However, the behavior of these
28 * functions cannot be overridden.
29 */
30interface IBase {
31
32    /*
33     * Provides run-time type information for this object.
34     * For example, for the following interface definition:
35     *     package android.hardware.foo@1.0;
36     *     interface IParent {};
37     *     interface IChild {};
38     * Calling interfaceChain on an IChild object will yield the following:
39     *     ["android.hardware.foo@1.0::IChild",
40     *      "android.hardware.foo@1.0::IParent"
41     *      "android.hidl.base@1.0::IBase"]
42     *
43     * @return indicator a vector of descriptors of the run-time type of the
44     *         object.
45     */
46    interfaceChain() generates (vec<string> indicator);
47
48    /*
49     * This method notifies the interface that one or more system properties
50     * have changed. The default implementation calls
51     * (C++)  report_sysprop_change() in libcutils or
52     * (Java) android.os.SystemProperties.reportSyspropChanged,
53     * which in turn calls a set of registered callbacks (eg to update trace
54     * tags).
55     */
56    oneway notifySyspropsChanged();
57};
58