implement auto-freeze on lock

app/src/main/AndroidManifest.xml

@@ -111,6 +111,9 @@
         <!-- A hack service to ensure every ShelterService is killed when App is removed -->
         <!-- from recent tasks -->
         <service android:name=".services.KillerService" />
+
+        <!-- Service to freeze apps on screen lock -->
+        <service android:name=".services.FreezeService" />
     </application>
 
 </manifest>

app/src/main/java/net/typeblog/shelter/services/FreezeService.java

@@ -0,0 +1,70 @@
+package net.typeblog.shelter.services;
+
+import android.app.Service;
+import android.app.admin.DevicePolicyManager;
+import android.content.BroadcastReceiver;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.IBinder;
+
+import net.typeblog.shelter.receivers.ShelterDeviceAdminReceiver;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import androidx.annotation.Nullable;
+
+// This service simply registers a screen-off listener that will be called
+// when the user locks the screen. When this happens, this service
+// will freeze all the apps that the user launched through Unfreeze & Launch
+// during the last session.
+public class FreezeService extends Service {
+    // Use a static variable and static methods to store the current list to be frozen
+    // We don't need to run this service in another process, so the static context should
+    // be sufficient for this. DummyActivity will use these static methods to add more apps
+    // to the list
+    private static List<String> sAppToFreeze = new ArrayList<>();
+    public static synchronized void registerAppToFreeze(String app) {
+        if (!sAppToFreeze.contains(app)) {
+            sAppToFreeze.add(app);
+        }
+    }
+
+    public static synchronized boolean hasPendingAppToFreeze() {
+        return sAppToFreeze.size() > 0;
+    }
+
+    // The actual receiver of the screen-off event
+    private BroadcastReceiver mLockReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            synchronized (FreezeService.class) {
+                if (sAppToFreeze.size() > 0) {
+                    DevicePolicyManager dpm = getSystemService(DevicePolicyManager.class);
+                    ComponentName adminComponent = new ComponentName(FreezeService.this, ShelterDeviceAdminReceiver.class);
+                    for (String app : sAppToFreeze) {
+                        dpm.setApplicationHidden(adminComponent, app, true);
+                    }
+                    sAppToFreeze.clear();
+                }
+                unregisterReceiver(this);
+                stopSelf();
+            }
+        }
+    };
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        // This is the only thing that we do
+        registerReceiver(mLockReceiver, new IntentFilter(Intent.ACTION_SCREEN_OFF));
+    }
+
+    @Nullable
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+}

app/src/main/java/net/typeblog/shelter/services/ShelterService.java

@@ -58,8 +58,8 @@ public class ShelterService extends Service {
 
                 ((ShelterApplication) getApplication()).unbindShelterService();
 
-                if (kill) {
-                    // Just kill the entire process if this signal is received
+                if (kill && !(mIsProfileOwner && FreezeService.hasPendingAppToFreeze())) {
+                    // Just kill the entire process if this signal is received and the process has nothing to do
                     System.exit(0);
                 }
             }).start();

app/src/main/java/net/typeblog/shelter/ui/DummyActivity.java

@@ -21,6 +21,7 @@ import androidx.annotation.Nullable;
 import net.typeblog.shelter.R;
 import net.typeblog.shelter.ShelterApplication;
 import net.typeblog.shelter.receivers.ShelterDeviceAdminReceiver;
+import net.typeblog.shelter.services.FreezeService;
 import net.typeblog.shelter.services.IAppInstallCallback;
 import net.typeblog.shelter.services.IFileShuttleService;
 import net.typeblog.shelter.services.IFileShuttleServiceCallback;
@@ -312,7 +313,12 @@ public class DummyActivity extends Activity {
             // Forward it to work profile
             Intent intent = new Intent(UNFREEZE_AND_LAUNCH);
             Utility.transferIntentToProfile(this, intent);
-            intent.putExtra("packageName", getIntent().getStringExtra("packageName"));
+            String packageName = getIntent().getStringExtra("packageName");
+            intent.putExtra("packageName", packageName);
+            intent.putExtra("shouldFreeze",
+                    SettingsManager.getInstance().getAutoFreezeServiceEnabled() &&
+                            LocalStorageManager.getInstance()
+                                .stringListContains(LocalStorageManager.PREF_AUTO_FREEZE_LIST_WORK_PROFILE, packageName));
             startActivity(intent);
             finish();
             return;
@@ -329,6 +335,10 @@ public class DummyActivity extends Activity {
         Intent launchIntent = getPackageManager().getLaunchIntentForPackage(packageName);
 
         if (launchIntent != null) {
+            if (getIntent().getBooleanExtra("shouldFreeze", false)) {
+                FreezeService.registerAppToFreeze(packageName);
+                startService(new Intent(this, FreezeService.class));
+            }
             startActivity(launchIntent);
         }
 

app/src/main/java/net/typeblog/shelter/ui/SettingsFragment.java

@@ -17,10 +17,12 @@ public class SettingsFragment extends PreferenceFragmentCompat implements Prefer
     private static final String SETTINGS_SOURCE_CODE = "settings_source_code";
     private static final String SETTINGS_BUG_REPORT = "settings_bug_report";
     private static final String SETTINGS_CROSS_PROFILE_FILE_CHOOSER = "settings_cross_profile_file_chooser";
+    private static final String SETTINGS_AUTO_FREEZE_SERVICE = "settings_auto_freeze_service";
 
     private SettingsManager mManager = SettingsManager.getInstance();
 
     private CheckBoxPreference mPrefCrossProfileFileChooser = null;
+    private CheckBoxPreference mPrefAutoFreezeService = null;
 
     @Override
     public void onCreatePreferences(Bundle bundle, String s) {
@@ -45,6 +47,11 @@ public class SettingsFragment extends PreferenceFragmentCompat implements Prefer
         mPrefCrossProfileFileChooser = (CheckBoxPreference) findPreference(SETTINGS_CROSS_PROFILE_FILE_CHOOSER);
         mPrefCrossProfileFileChooser.setChecked(mManager.getCrossProfileFileChooserEnabled());
         mPrefCrossProfileFileChooser.setOnPreferenceChangeListener(this);
+
+        // === Services ===
+        mPrefAutoFreezeService = (CheckBoxPreference) findPreference(SETTINGS_AUTO_FREEZE_SERVICE);
+        mPrefAutoFreezeService.setChecked(mManager.getAutoFreezeServiceEnabled());
+        mPrefAutoFreezeService.setOnPreferenceChangeListener(this);
     }
 
     private boolean openSummaryUrl(Preference pref) {
@@ -59,6 +66,9 @@ public class SettingsFragment extends PreferenceFragmentCompat implements Prefer
         if (preference == mPrefCrossProfileFileChooser) {
             mManager.setCrossProfileFileChooserEnabled((boolean) newState);
             return true;
+        } else if (preference == mPrefAutoFreezeService) {
+            mManager.setAutoFreezeServiceEnabled((boolean) newState);
+            return true;
         } else {
             return false;
         }

app/src/main/java/net/typeblog/shelter/util/LocalStorageManager.java

@@ -14,6 +14,7 @@ public class LocalStorageManager {
     public static final String PREF_AUTO_FREEZE_LIST_WORK_PROFILE = "auto_freeze_list_work_profile";
     public static final String PREF_CROSS_PROFILE_FILE_CHOOSER = "cross_profile_file_chooser";
     public static final String PREF_AUTH_KEY = "auth_key";
+    public static final String PREF_AUTO_FREEZE_SERVICE = "auto_freeze_service";
 
     private static final String LIST_DIVIDER = ",";
 

app/src/main/java/net/typeblog/shelter/util/SettingsManager.java

@@ -59,4 +59,15 @@ public class SettingsManager {
     public boolean getCrossProfileFileChooserEnabled() {
         return mStorage.getBoolean(LocalStorageManager.PREF_CROSS_PROFILE_FILE_CHOOSER);
     }
+
+    // Set the enabled state of the auto freeze service
+    // This does NOT need to be synchronized nor applied across profile
+    public void setAutoFreezeServiceEnabled(boolean enabled) {
+        mStorage.setBoolean(LocalStorageManager.PREF_AUTO_FREEZE_SERVICE, enabled);
+    }
+
+    // Get the enabled state of the auto freeze service
+    public boolean getAutoFreezeServiceEnabled() {
+        return mStorage.getBoolean(LocalStorageManager.PREF_AUTO_FREEZE_SERVICE);
+    }
 }

app/src/main/res/values-zh-rCN/strings.xml

@@ -37,6 +37,9 @@
     <string name="settings_interaction">交互</string>
     <string name="settings_cross_profile_file_chooser">文件穿梭</string>
     <string name="settings_cross_profile_file_chooser_desc">打开以后，您将可以且仅可以从系统的 Documents UI (启动器上的名称为 文件 或 下载) 或支持 Documents UI 的 APP 中 浏览 / 查看 / 选择 / 复制 Shelter 内的文件到主用户，反之亦然。这不会影响对文件系统的隔离。即使是支持 Documents UI 的 App 也只能临时获取您选择的文件的访问权限。</string>
+    <string name="settings_services">服务</string>
+    <string name="settings_auto_freeze_service">自动冻结服务</string>
+    <string name="settings_auto_freeze_service_desc">在您锁屏时，自动冻结您通过 \"解冻并运行\" 启动的应用</string>
     <string name="settings_about">关于</string>
     <string name="settings_version">版本</string>
     <string name="settings_source_code">源代码</string>

app/src/main/res/values/strings.xml

@@ -39,6 +39,9 @@
     <string name="settings_interaction">Interaction</string>
     <string name="settings_cross_profile_file_chooser">File Shuttle</string>
     <string name="settings_cross_profile_file_chooser_desc">When enabled, you\'ll be able to browse / view / pick / copy files in Shelter from main profile and vice-versa, ONLY through Documents UI (named Files or Documents on your launcher) or apps with Documents UI support (they only gain temporary access to files you choose in Documents UI), while still pertaining the filesystem isolation.</string>
+    <string name="settings_services">Services</string>
+    <string name="settings_auto_freeze_service">Auto Freeze Service</string>
+    <string name="settings_auto_freeze_service_desc">Automatically freeze apps you launched from \"Unfreeze &amp; Launch Shortcut\" when you lock your screen.</string>
     <string name="settings_about">About</string>
     <string name="settings_version">Version</string>
     <string name="settings_source_code">Source Code</string>

app/src/main/res/xml/preferences_settings.xml

@@ -12,6 +12,16 @@
 
     </androidx.preference.PreferenceCategory>
 
+    <androidx.preference.PreferenceCategory
+        android:title="@string/settings_services">
+
+        <androidx.preference.CheckBoxPreference
+            android:key="settings_auto_freeze_service"
+            android:title="@string/settings_auto_freeze_service"
+            android:summary="@string/settings_auto_freeze_service_desc" />
+
+    </androidx.preference.PreferenceCategory>
+
     <androidx.preference.PreferenceCategory
         android:title="@string/settings_about">