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 @file:OptIn(ExperimentalCoroutinesApi::class)
18 
19 package com.android.systemui.scene.data.repository
20 
21 import com.android.systemui.dagger.qualifiers.Application
22 import com.android.systemui.scene.shared.model.ObservableTransitionState
23 import com.android.systemui.scene.shared.model.SceneContainerConfig
24 import com.android.systemui.scene.shared.model.SceneKey
25 import com.android.systemui.scene.shared.model.SceneModel
26 import javax.inject.Inject
27 import kotlinx.coroutines.CoroutineScope
28 import kotlinx.coroutines.ExperimentalCoroutinesApi
29 import kotlinx.coroutines.flow.Flow
30 import kotlinx.coroutines.flow.MutableStateFlow
31 import kotlinx.coroutines.flow.SharingStarted
32 import kotlinx.coroutines.flow.StateFlow
33 import kotlinx.coroutines.flow.asStateFlow
34 import kotlinx.coroutines.flow.flatMapLatest
35 import kotlinx.coroutines.flow.flowOf
36 import kotlinx.coroutines.flow.stateIn
37 
38 /** Source of truth for scene framework application state. */
39 class SceneContainerRepository
40 @Inject
41 constructor(
42     @Application applicationScope: CoroutineScope,
43     private val config: SceneContainerConfig,
44 ) {
45     private val _desiredScene = MutableStateFlow(SceneModel(config.initialSceneKey))
46     val desiredScene: StateFlow<SceneModel> = _desiredScene.asStateFlow()
47 
48     private val _isVisible = MutableStateFlow(true)
49     val isVisible: StateFlow<Boolean> = _isVisible.asStateFlow()
50 
51     private val defaultTransitionState = ObservableTransitionState.Idle(config.initialSceneKey)
52     private val _transitionState = MutableStateFlow<Flow<ObservableTransitionState>?>(null)
53     val transitionState: StateFlow<ObservableTransitionState> =
54         _transitionState
55             .flatMapLatest { innerFlowOrNull -> innerFlowOrNull ?: flowOf(defaultTransitionState) }
56             .stateIn(
57                 scope = applicationScope,
58                 started = SharingStarted.Eagerly,
59                 initialValue = defaultTransitionState,
60             )
61 
62     /**
63      * Returns the keys to all scenes in the container.
64      *
65      * The scenes will be sorted in z-order such that the last one is the one that should be
66      * rendered on top of all previous ones.
67      */
68     fun allSceneKeys(): List<SceneKey> {
69         return config.sceneKeys
70     }
71 
72     fun setDesiredScene(scene: SceneModel) {
73         check(allSceneKeys().contains(scene.key)) {
74             """
75                 Cannot set the desired scene key to "${scene.key}". The configuration does not
76                 contain a scene with that key.
77             """
78                 .trimIndent()
79         }
80 
81         _desiredScene.value = scene
82     }
83 
84     /** Sets whether the container is visible. */
85     fun setVisible(isVisible: Boolean) {
86         _isVisible.value = isVisible
87     }
88 
89     /**
90      * Binds the given flow so the system remembers it.
91      *
92      * Note that you must call is with `null` when the UI is done or risk a memory leak.
93      */
94     fun setTransitionState(transitionState: Flow<ObservableTransitionState>?) {
95         _transitionState.value = transitionState
96     }
97 }
98