1 /*
2  * Copyright (C) 2020 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 package com.android.launcher3.statemanager;
17 
18 import android.content.Context;
19 
20 /**
21  * Interface representing a state of a StatefulActivity
22  */
23 public interface BaseState<T extends BaseState> {
24 
25     // Flag to indicate that Launcher is non-interactive in this state
26     int FLAG_NON_INTERACTIVE = 1 << 0;
27     int FLAG_DISABLE_RESTORE = 1 << 1;
28 
getFlag(int index)29     static int getFlag(int index) {
30         // reserve few spots to base flags
31         return 1 << (index + 2);
32     }
33 
34     /**
35      * @return How long the animation to this state should take (or from this state to NORMAL).
36      */
getTransitionDuration(Context context)37     int getTransitionDuration(Context context);
38 
39     /**
40      * Returns the state to go back to from this state
41      */
getHistoryForState(T previousState)42     T getHistoryForState(T previousState);
43 
44     /**
45      * @return true if the state can be persisted across activity restarts.
46      */
shouldDisableRestore()47     default boolean shouldDisableRestore() {
48         return hasFlag(FLAG_DISABLE_RESTORE);
49     }
50 
51     /**
52      * Returns if the state has the provided flag
53      */
hasFlag(int flagMask)54     boolean hasFlag(int flagMask);
55 }
56