1 /*
2  * Copyright (C) 2018 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.utils;
18 
19 import android.text.TextUtils;
20 import android.util.ArrayMap;
21 
22 import androidx.preference.Preference;
23 import androidx.preference.PreferenceGroup;
24 
25 /**
26  * Class that helps track which {@link Preference}s in a {@link PreferenceGroup} are still being
27  * used, and remove unused ones.
28  */
29 public class PreferenceGroupChildrenCache {
30 
31     private ArrayMap<String, Preference> mPreferenceCache;
32 
cacheRemoveAllPrefs(PreferenceGroup group)33     public void cacheRemoveAllPrefs(PreferenceGroup group) {
34         mPreferenceCache = new ArrayMap<>();
35         final int N = group.getPreferenceCount();
36         for (int i = 0; i < N; i++) {
37             Preference p = group.getPreference(i);
38             if (TextUtils.isEmpty(p.getKey())) {
39                 continue;
40             }
41             mPreferenceCache.put(p.getKey(), p);
42         }
43     }
44 
removeCachedPrefs(PreferenceGroup group)45     public void removeCachedPrefs(PreferenceGroup group) {
46         for (Preference p : mPreferenceCache.values()) {
47             group.removePreference(p);
48         }
49         mPreferenceCache = null;
50     }
51 
getCachedPreference(String key)52     public Preference getCachedPreference(String key) {
53         return mPreferenceCache != null ? mPreferenceCache.remove(key) : null;
54     }
55 
getCachedCount()56     public int getCachedCount() {
57         return mPreferenceCache != null ? mPreferenceCache.size() : 0;
58     }
59 }
60