1 /*
2  * Copyright (C) 2023 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 package com.android.systemui.keyguard.ui.viewmodel
18 
19 import com.android.app.animation.Interpolators.EMPHASIZED_ACCELERATE
20 import com.android.systemui.dagger.SysUISingleton
21 import com.android.systemui.keyguard.domain.interactor.FromGoneTransitionInteractor.Companion.TO_DREAMING_DURATION
22 import com.android.systemui.keyguard.domain.interactor.KeyguardTransitionInteractor
23 import com.android.systemui.keyguard.ui.KeyguardTransitionAnimationFlow
24 import javax.inject.Inject
25 import kotlin.time.Duration.Companion.milliseconds
26 import kotlinx.coroutines.flow.Flow
27 
28 /** Breaks down GONE->DREAMING transition into discrete steps for corresponding views to consume. */
29 @SysUISingleton
30 class GoneToDreamingTransitionViewModel
31 @Inject
32 constructor(
33     private val interactor: KeyguardTransitionInteractor,
34 ) {
35 
36     private val transitionAnimation =
37         KeyguardTransitionAnimationFlow(
38             transitionDuration = TO_DREAMING_DURATION,
39             transitionFlow = interactor.goneToDreamingTransition,
40         )
41 
42     /** Lockscreen views y-translation */
43     fun lockscreenTranslationY(translatePx: Int): Flow<Float> {
44         return transitionAnimation.createFlow(
45             duration = 500.milliseconds,
46             onStep = { it * translatePx },
47             // Reset on cancel or finish
48             onFinish = { 0f },
49             onCancel = { 0f },
50             interpolator = EMPHASIZED_ACCELERATE,
51         )
52     }
53 
54     /** Lockscreen views alpha */
55     val lockscreenAlpha: Flow<Float> =
56         transitionAnimation.createFlow(
57             duration = 250.milliseconds,
58             onStep = { 1f - it },
59         )
60 }
61