1 /*
2  * Copyright 2024 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 namespace android {
20 
21 /**
22  * The InputFilter policy interface.
23  *
24  * This is the interface that InputFilter uses to talk to Input Manager and other system components.
25  */
26 class InputFilterPolicyInterface {
27 public:
28     virtual ~InputFilterPolicyInterface() = default;
29 
30     /**
31      * A callback to notify about sticky modifier state changes when Sticky keys feature is enabled.
32      *
33      * modifierState: Current sticky modifier state which will be sent with all subsequent
34      * KeyEvents. This only includes modifiers that can be 'Sticky' which includes: Meta, Ctrl,
35      * Shift, Alt and AltGr.
36      *
37      * lockedModifierState: Current locked modifier state representing modifiers that don't get
38      * cleared after non-modifier key press. This only includes modifiers that can be 'Sticky' which
39      * includes: Meta, Ctrl, Shift, Alt and AltGr.
40      *
41      * For more information {@see sticky_keys_filter.rs}
42      */
43     virtual void notifyStickyModifierStateChanged(uint32_t modifierState,
44                                                   uint32_t lockedModifierState) = 0;
45 };
46 
47 } // namespace android
48