1 /* 2 * Copyright (C) 2025 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.quickstep 18 19 import android.content.res.Resources 20 import com.android.quickstep.recents.data.HighResLoadingStateNotifier 21 22 /** Determines when high res or low res thumbnails should be loaded. */ 23 class HighResLoadingState : HighResLoadingStateNotifier { 24 // If the device does not support low-res thumbnails, only attempt to load high-res thumbnails 25 private val forceHighResThumbnails = !supportsLowResThumbnails() 26 var visible: Boolean = false 27 set(value) { 28 field = value 29 updateState() 30 } 31 32 var flingingFast = false 33 set(value) { 34 field = value 35 updateState() 36 } 37 38 var isEnabled: Boolean = false 39 private set 40 41 private val callbacks = ArrayList<HighResLoadingStateChangedCallback>() 42 43 interface HighResLoadingStateChangedCallback { onHighResLoadingStateChangednull44 fun onHighResLoadingStateChanged(enabled: Boolean) 45 } 46 47 override fun addCallback(callback: HighResLoadingStateChangedCallback) { 48 callbacks.add(callback) 49 } 50 removeCallbacknull51 override fun removeCallback(callback: HighResLoadingStateChangedCallback) { 52 callbacks.remove(callback) 53 } 54 updateStatenull55 private fun updateState() { 56 val prevState = isEnabled 57 isEnabled = forceHighResThumbnails || (visible && !flingingFast) 58 if (prevState != isEnabled) { 59 for (callback in callbacks.asReversed()) { 60 callback.onHighResLoadingStateChanged(isEnabled) 61 } 62 } 63 } 64 65 /** 66 * Returns Whether device supports low-res thumbnails. Low-res files are an optimization for 67 * faster load times of snapshots. Devices can optionally disable low-res files so that they 68 * only store snapshots at high-res scale. The actual scale can be configured in frameworks/base 69 * config overlay. 70 */ supportsLowResThumbnailsnull71 private fun supportsLowResThumbnails(): Boolean { 72 val res = Resources.getSystem() 73 val resId = res.getIdentifier("config_lowResTaskSnapshotScale", "dimen", "android") 74 if (resId != 0) { 75 return 0 < res.getFloat(resId) 76 } 77 return true 78 } 79 } 80