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.settings.biometrics.fingerprint2.domain.interactor
18 
19 import android.content.Context
20 import com.android.settingslib.display.DisplayDensityUtils
21 import kotlinx.coroutines.CoroutineScope
22 import kotlinx.coroutines.flow.Flow
23 import kotlinx.coroutines.flow.MutableStateFlow
24 import kotlinx.coroutines.flow.SharingStarted
25 import kotlinx.coroutines.flow.asStateFlow
26 import kotlinx.coroutines.flow.flowOf
27 import kotlinx.coroutines.flow.shareIn
28 import kotlinx.coroutines.flow.update
29 
30 /**
31  * This class is responsible for handling updates to fontScale and displayDensity and forwarding
32  * these events to classes that need them
33  */
34 interface DisplayDensityInteractor {
35   /** Indicates the display density has been updated. */
updateDisplayDensitynull36   fun updateDisplayDensity(density: Int)
37 
38   /** Indicates the font scale has been updates. */
39   fun updateFontScale(fontScale: Float)
40 
41   /** A flow that propagates fontscale. */
42   val fontScale: Flow<Float>
43 
44   /** A flow that propagates displayDensity. */
45   val displayDensity: Flow<Int>
46 
47   /** A flow that propagates the default display density. */
48   val defaultDisplayDensity: Flow<Int>
49 }
50 
51 /**
52  * Implementation of the [DisplayDensityInteractor]. This interactor is used to forward activity
53  * information to the rest of the application.
54  */
55 class DisplayDensityInteractorImpl(context: Context, scope: CoroutineScope) :
56   DisplayDensityInteractor {
57 
58   val displayDensityUtils = DisplayDensityUtils(context)
59 
60   override fun updateDisplayDensity(density: Int) {
61     _displayDensity.update { density }
62   }
63 
64   override fun updateFontScale(fontScale: Float) {
65     _fontScale.update { fontScale }
66   }
67 
68   private val _fontScale = MutableStateFlow(context.resources.configuration.fontScale)
69   private val _displayDensity =
70     MutableStateFlow(
71       displayDensityUtils.defaultDisplayDensityValues[
72           displayDensityUtils.currentIndexForDefaultDisplay]
73     )
74 
75   override val fontScale: Flow<Float> = _fontScale.asStateFlow()
76 
77   override val displayDensity: Flow<Int> = _displayDensity.asStateFlow()
78 
79   override val defaultDisplayDensity: Flow<Int> =
80     flowOf(displayDensityUtils.defaultDensityForDefaultDisplay)
81       .shareIn(scope, SharingStarted.Eagerly, 1)
82 }
83