1 /*
2  * Copyright (C) 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 package com.android.systemui.keyguard.ui.viewmodel
18 
19 import android.util.MathUtils
20 import com.android.systemui.dagger.SysUISingleton
21 import com.android.systemui.keyguard.domain.interactor.FromAodTransitionInteractor
22 import com.android.systemui.keyguard.shared.model.Edge
23 import com.android.systemui.keyguard.shared.model.KeyguardState.DOZING
24 import com.android.systemui.keyguard.shared.model.KeyguardState.OCCLUDED
25 import com.android.systemui.keyguard.ui.KeyguardTransitionAnimationFlow
26 import com.android.systemui.keyguard.ui.transitions.DeviceEntryIconTransition
27 import javax.inject.Inject
28 import kotlin.time.Duration.Companion.milliseconds
29 import kotlinx.coroutines.flow.Flow
30 
31 /**
32  * Breaks down DOZING->OCCLUDED transition into discrete steps for corresponding views to consume.
33  */
34 @SysUISingleton
35 class DozingToOccludedTransitionViewModel
36 @Inject
37 constructor(
38     animationFlow: KeyguardTransitionAnimationFlow,
39 ) : DeviceEntryIconTransition {
40     private val transitionAnimation =
41         animationFlow.setup(
42             duration = FromAodTransitionInteractor.TO_OCCLUDED_DURATION,
43             edge = Edge.create(from = DOZING, to = OCCLUDED),
44         )
45 
46     /**
47      * Fade out the lockscreen during a transition to OCCLUDED.
48      *
49      * This happens when pressing the power button while a SHOW_WHEN_LOCKED activity is on the top
50      * of the task stack, as well as when the power button is double tapped on the LOCKSCREEN (the
51      * first tap transitions to DOZING, the second cancels that transition and starts DOZING ->
52      * OCCLUDED.
53      */
lockscreenAlphanull54     fun lockscreenAlpha(viewState: ViewStateAccessor): Flow<Float> {
55         var currentAlpha = 0f
56         return transitionAnimation.sharedFlow(
57             duration = 250.milliseconds,
58             startTime = 100.milliseconds, // Wait for the light reveal to "hit" the LS elements.
59             onStart = { currentAlpha = viewState.alpha() },
60             onStep = { MathUtils.lerp(currentAlpha, 0f, it) },
61             onCancel = { 0f },
62         )
63     }
64 
65     override val deviceEntryParentViewAlpha = transitionAnimation.immediatelyTransitionTo(0f)
66 }
67