1 /* 2 * Copyright (C) 2020 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 package com.android.launcher3.model; 17 import static com.android.launcher3.util.Executors.MODEL_EXECUTOR; 18 19 import android.content.ComponentName; 20 import android.content.Context; 21 import android.content.SharedPreferences; 22 import android.os.UserHandle; 23 24 import androidx.annotation.AnyThread; 25 import androidx.annotation.WorkerThread; 26 27 import com.android.launcher3.R; 28 import com.android.launcher3.Utilities; 29 import com.android.launcher3.pm.UserCache; 30 import com.android.launcher3.util.ComponentKey; 31 import com.android.launcher3.util.Preconditions; 32 import com.android.launcher3.util.ResourceBasedOverride; 33 34 import java.util.ArrayList; 35 import java.util.List; 36 37 /** 38 * Model Helper for app predictions 39 */ 40 public class PredictionModel implements ResourceBasedOverride { 41 42 private static final String CACHED_ITEMS_KEY = "predicted_item_keys"; 43 private static final int MAX_CACHE_ITEMS = 5; 44 45 protected Context mContext; 46 private SharedPreferences mDevicePrefs; 47 private UserCache mUserCache; 48 49 50 /** 51 * Retrieve instance of this object that can be overridden in runtime based on the build 52 * variant of the application. 53 */ newInstance(Context context)54 public static PredictionModel newInstance(Context context) { 55 PredictionModel model = Overrides.getObject(PredictionModel.class, context, 56 R.string.prediction_model_class); 57 model.init(context); 58 return model; 59 } 60 init(Context context)61 protected void init(Context context) { 62 mContext = context; 63 mDevicePrefs = Utilities.getDevicePrefs(mContext); 64 mUserCache = UserCache.INSTANCE.get(mContext); 65 66 } 67 /** 68 * Formats and stores a list of component key in device preferences. 69 */ 70 @AnyThread cachePredictionComponentKeys(List<ComponentKey> componentKeys)71 public void cachePredictionComponentKeys(List<ComponentKey> componentKeys) { 72 MODEL_EXECUTOR.execute(() -> { 73 StringBuilder builder = new StringBuilder(); 74 int count = Math.min(componentKeys.size(), MAX_CACHE_ITEMS); 75 for (int i = 0; i < count; i++) { 76 builder.append(serializeComponentKeyToString(componentKeys.get(i))); 77 builder.append("\n"); 78 } 79 mDevicePrefs.edit().putString(CACHED_ITEMS_KEY, builder.toString()).apply(); 80 }); 81 } 82 83 /** 84 * parses and returns ComponentKeys saved by 85 * {@link PredictionModel#cachePredictionComponentKeys(List)} 86 */ 87 @WorkerThread getPredictionComponentKeys()88 public List<ComponentKey> getPredictionComponentKeys() { 89 Preconditions.assertWorkerThread(); 90 ArrayList<ComponentKey> items = new ArrayList<>(); 91 String cachedBlob = mDevicePrefs.getString(CACHED_ITEMS_KEY, ""); 92 for (String line : cachedBlob.split("\n")) { 93 ComponentKey key = getComponentKeyFromSerializedString(line); 94 if (key != null) { 95 items.add(key); 96 } 97 98 } 99 return items; 100 } 101 serializeComponentKeyToString(ComponentKey componentKey)102 private String serializeComponentKeyToString(ComponentKey componentKey) { 103 long userSerialNumber = mUserCache.getSerialNumberForUser(componentKey.user); 104 return componentKey.componentName.flattenToString() + "#" + userSerialNumber; 105 } 106 getComponentKeyFromSerializedString(String str)107 private ComponentKey getComponentKeyFromSerializedString(String str) { 108 int sep = str.indexOf('#'); 109 if (sep < 0 || (sep + 1) >= str.length()) { 110 return null; 111 } 112 ComponentName componentName = ComponentName.unflattenFromString(str.substring(0, sep)); 113 if (componentName == null) { 114 return null; 115 } 116 try { 117 long serialNumber = Long.parseLong(str.substring(sep + 1)); 118 UserHandle userHandle = mUserCache.getUserForSerialNumber(serialNumber); 119 return userHandle != null ? new ComponentKey(componentName, userHandle) : null; 120 } catch (NumberFormatException ex) { 121 return null; 122 } 123 } 124 } 125