1 /*
2  * Copyright (C) 2017 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.development;
18 
19 import android.app.ActivityManager;
20 import android.app.IActivityManager;
21 import android.content.Context;
22 import android.os.RemoteException;
23 
24 import androidx.annotation.VisibleForTesting;
25 import androidx.preference.ListPreference;
26 import androidx.preference.Preference;
27 
28 import com.android.settings.R;
29 import com.android.settings.core.PreferenceControllerMixin;
30 import com.android.settingslib.development.DeveloperOptionsPreferenceController;
31 
32 public class BackgroundProcessLimitPreferenceController extends
33         DeveloperOptionsPreferenceController implements Preference.OnPreferenceChangeListener,
34         PreferenceControllerMixin {
35 
36     private static final String APP_PROCESS_LIMIT_KEY = "app_process_limit";
37 
38     private final String[] mListValues;
39     private final String[] mListSummaries;
40 
BackgroundProcessLimitPreferenceController(Context context)41     public BackgroundProcessLimitPreferenceController(Context context) {
42         super(context);
43 
44         mListValues = context.getResources().getStringArray(R.array.app_process_limit_values);
45         mListSummaries = context.getResources().getStringArray(R.array.app_process_limit_entries);
46     }
47 
48     @Override
getPreferenceKey()49     public String getPreferenceKey() {
50         return APP_PROCESS_LIMIT_KEY;
51     }
52 
53     @Override
onPreferenceChange(Preference preference, Object newValue)54     public boolean onPreferenceChange(Preference preference, Object newValue) {
55         writeAppProcessLimitOptions(newValue);
56         updateAppProcessLimitOptions();
57         return true;
58     }
59 
60     @Override
updateState(Preference preference)61     public void updateState(Preference preference) {
62         updateAppProcessLimitOptions();
63     }
64 
65     @Override
onDeveloperOptionsSwitchDisabled()66     protected void onDeveloperOptionsSwitchDisabled() {
67         super.onDeveloperOptionsSwitchDisabled();
68         writeAppProcessLimitOptions(null);
69     }
70 
updateAppProcessLimitOptions()71     private void updateAppProcessLimitOptions() {
72         try {
73             final int limit = getActivityManagerService().getProcessLimit();
74             int index = 0; // default
75             for (int i = 0; i < mListValues.length; i++) {
76                 int val = Integer.parseInt(mListValues[i]);
77                 if (val >= limit) {
78                     index = i;
79                     break;
80                 }
81             }
82             final ListPreference listPreference = (ListPreference) mPreference;
83             listPreference.setValue(mListValues[index]);
84             listPreference.setSummary(mListSummaries[index]);
85         } catch (RemoteException e) {
86             // intentional no-op
87         }
88     }
89 
writeAppProcessLimitOptions(Object newValue)90     private void writeAppProcessLimitOptions(Object newValue) {
91         try {
92             final int limit = newValue != null ? Integer.parseInt(newValue.toString()) : -1;
93             getActivityManagerService().setProcessLimit(limit);
94             updateAppProcessLimitOptions();
95         } catch (RemoteException e) {
96             // intentional no-op
97         }
98     }
99 
100     @VisibleForTesting
getActivityManagerService()101     IActivityManager getActivityManagerService() {
102         return ActivityManager.getService();
103     }
104 }
105