Introduce LocalBackupPasswordPreferenceController

- Create new LocalBackupPasswordPreferenceController
 - Create controller inside the DashboardFragment
 - Port logic from DevelopmentSettings into the controller

Bug: 34203528
Test: make RunSettingsRoboTests -j40
Change-Id: I86d0d2402e8092e9f03498254ae4e3bf7bb9bf3d

src/com/android/settings/development/LocalBackupPasswordPreferenceController.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.development;
+
+import android.app.backup.IBackupManager;
+import android.content.Context;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.os.UserManager;
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.R;
+
+public class LocalBackupPasswordPreferenceController extends DeveloperOptionsPreferenceController {
+
+    private static final String LOCAL_BACKUP_PASSWORD = "local_backup_password";
+
+    private final UserManager mUserManager;
+    private final IBackupManager mBackupManager;
+
+    public LocalBackupPasswordPreferenceController(Context context) {
+        super(context);
+
+        mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
+        mBackupManager = IBackupManager.Stub.asInterface(
+                ServiceManager.getService(Context.BACKUP_SERVICE));
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return LOCAL_BACKUP_PASSWORD;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        updatePasswordSummary(preference);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchEnabled() {
+        // intentional no-op
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        // intentional no-op
+    }
+
+    private void updatePasswordSummary(Preference preference) {
+        preference.setEnabled(isAdminUser() && mBackupManager != null);
+        if (mBackupManager == null) {
+            return;
+        }
+        try {
+            if (mBackupManager.hasBackupPassword()) {
+                preference.setSummary(R.string.local_backup_password_summary_change);
+            } else {
+                preference.setSummary(R.string.local_backup_password_summary_none);
+            }
+        } catch (RemoteException e) {
+            // Not much we can do here
+        }
+    }
+
+    @VisibleForTesting
+    boolean isAdminUser() {
+        return mUserManager.isAdminUser();
+    }
+}