Add a screen to show OEM backup settings.

Moves the backup settings logic to BackupSettingsHelper and
BackupSettingsActivity:
- If the manufacturer provides the intent and the label for their backup
settings in the config.xml, a new intermediate fragment is shown for
Backup settings to let the user pick either standard backup settings or
OEM provided backup settings.
- If config.xml doesn't contain the intent, BackupSettingsActivity is
used as a trampoline activity to launch backup settings provided by the
backup transport of the default backup settings activity, i.e.
PrivacySettingsActivity.

Bug: 34700410
Bug: 33655074
Bug: 33654991
Test: make RunSettingsRoboTests
Change-Id: I78e340fbf926b2a9dc2c4e3942f9337c3c7a933c
diff --git a/src/com/android/settings/backup/BackupSettingsHelper.java b/src/com/android/settings/backup/BackupSettingsHelper.java
new file mode 100644
index 0000000..b0d6cf8
--- /dev/null
+++ b/src/com/android/settings/backup/BackupSettingsHelper.java
@@ -0,0 +1,237 @@
+/*
+ * 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.backup;
+
+
+import android.app.backup.BackupManager;
+import android.app.backup.IBackupManager;
+import android.content.Context;
+import android.content.Intent;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.os.UserHandle;
+import android.util.Log;
+
+import android.support.annotation.VisibleForTesting;
+
+import com.android.settings.R;
+import com.android.settings.Settings.PrivacySettingsActivity;
+import com.android.settingslib.drawer.SettingsDrawerActivity;
+import java.net.URISyntaxException;
+
+/**
+ * Helper class for {@link BackupSettingsActivity} that interacts with {@link IBackupManager}.
+ */
+public class BackupSettingsHelper {
+    private static final String TAG = "BackupSettingsHelper";
+
+    private IBackupManager mBackupManager = IBackupManager.Stub.asInterface(
+            ServiceManager.getService(Context.BACKUP_SERVICE));
+
+    private Context mContext;
+
+    public BackupSettingsHelper(Context context) {
+        mContext = context;
+    }
+
+    /**
+     * Returns an intent to launch backup settings from backup transport if the intent was provided
+     * by the transport. Otherwise returns the intent to launch the default backup settings screen.
+     *
+     * @return Intent for launching backup settings
+     */
+    public Intent getIntentForBackupSettings() {
+        Intent intent;
+        if (isIntentProvidedByTransport()) {
+            intent = getIntentForBackupSettingsFromTransport();
+        } else {
+            Log.e(TAG, "Backup transport has not provided an intent"
+                    + " or the component for the intent is not found!");
+            intent = getIntentForDefaultBackupSettings();
+        }
+        return intent;
+    }
+
+    /**
+     * Returns a label for the settings item that will point to the backup settings provided by
+     * the transport. If no label was provided by transport, returns the default string.
+     *
+     * @return Label for the backup settings item.
+     */
+    public String getLabelForBackupSettings() {
+        String label = getLabelFromBackupTransport();
+        if (label == null || label.isEmpty()) {
+            label = mContext.getString(R.string.privacy_settings_title);
+        }
+        return label;
+    }
+
+    /**
+     * Returns a summary string for the settings item that will point to the backup settings
+     * provided by the transport. If no summary was provided by transport, returns the default
+     * string.
+     *
+     * @return Summary for the backup settings item.
+     */
+    public String getSummaryForBackupSettings() {
+        String summary = getSummaryFromBackupTransport();
+        if (summary == null) {
+            summary = mContext.getString(R.string.backup_configure_account_default_summary);
+        }
+        return summary;
+    }
+
+
+    /**
+     * Checks if the manufacturer provided an intent to launch its backup settings screen
+     * in the config file.
+     */
+    public boolean isBackupProvidedByManufacturer() {
+        if (Log.isLoggable(TAG, Log.DEBUG)) {
+            Log.d(TAG, "Checking if intent provided by manufacturer");
+        }
+        String intentString =
+                mContext.getResources().getString(R.string.config_backup_settings_intent);
+
+        return intentString != null && !intentString.isEmpty();
+    }
+
+    /**
+     * Returns the label for the backup settings item provided by the manufacturer.
+     */
+    public String getLabelProvidedByManufacturer() {
+        return mContext.getResources().getString(R.string.config_backup_settings_label);
+    }
+
+    /**
+     * Returns the intent to the backup settings screen provided by the manufacturer.
+     */
+    public Intent getIntentProvidedByManufacturer() {
+        if (Log.isLoggable(TAG, Log.DEBUG)) {
+            Log.d(TAG, "Getting a backup settings intent provided by manufacturer");
+        }
+        String intentString =
+                mContext.getResources().getString(R.string.config_backup_settings_intent);
+        if (intentString != null && !intentString.isEmpty()) {
+            try {
+                return Intent.parseUri(intentString, 0);
+            } catch (URISyntaxException e) {
+                Log.e(TAG, "Invalid intent provided by the manufacturer.", e);
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Gets the intent from Backup transport and adds the extra depending on whether the user has
+     * rights to see backup settings.
+     *
+     * @return Intent to launch Backup settings provided by the Backup transport.
+     */
+    @VisibleForTesting
+    Intent getIntentForBackupSettingsFromTransport() {
+        Intent intent = getIntentFromBackupTransport();
+        if (intent != null) {
+            intent.putExtra(BackupManager.EXTRA_BACKUP_SERVICES_AVAILABLE, isBackupServiceActive());
+        }
+        return intent;
+    }
+
+    private Intent getIntentForDefaultBackupSettings() {
+        // Extra needed by {@link SettingsDrawerActivity} to show the back button navigation.
+        return new Intent(mContext, PrivacySettingsActivity.class)
+                .putExtra(SettingsDrawerActivity.EXTRA_SHOW_MENU, true);
+    }
+
+    /**
+     * Checks if the transport provided the intent to launch the backup settings and if that
+     * intent resolves to an activity.
+     */
+    @VisibleForTesting
+    boolean isIntentProvidedByTransport() {
+        Intent intent = getIntentFromBackupTransport();
+        return intent != null && intent.resolveActivity(mContext.getPackageManager()) != null;
+    }
+
+    /**
+     * Gets an intent to launch the backup settings from the current transport using
+     * {@link com.android.internal.backup.IBackupTransport#dataManagementIntent()} API.
+     *
+     * @return intent provided by transport or null if no intent was provided.
+     */
+    private Intent getIntentFromBackupTransport() {
+        try {
+            Intent intent =
+                    mBackupManager.getDataManagementIntent(mBackupManager.getCurrentTransport());
+            if (Log.isLoggable(TAG, Log.DEBUG)) {
+                if (intent != null) {
+                    Log.d(TAG, "Parsed intent from backup transport: " + intent.toString());
+                } else {
+                    Log.d(TAG, "Received a null intent from backup transport");
+                }
+            }
+            return intent;
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error getting data management intent", e);
+        }
+        return null;
+    }
+
+    /** Checks if backup service is enabled for this user. */
+    private boolean isBackupServiceActive() {
+        boolean backupOkay;
+        try {
+            backupOkay = mBackupManager.isBackupServiceActive(UserHandle.myUserId());
+        } catch (Exception e) {
+            // things go wrong talking to the backup system => ignore and
+            // pass the default 'false' as the "backup is a thing?" state.
+            backupOkay = false;
+        }
+        return backupOkay;
+    }
+
+    @VisibleForTesting
+    String getLabelFromBackupTransport() {
+        try {
+            String label =
+                    mBackupManager.getDataManagementLabel(mBackupManager.getCurrentTransport());
+            if (Log.isLoggable(TAG, Log.DEBUG)) {
+                Log.d(TAG, "Received the backup settings label from backup transport: " + label);
+            }
+            return label;
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error getting data management label", e);
+        }
+        return null;
+    }
+
+    @VisibleForTesting
+    String getSummaryFromBackupTransport() {
+        try {
+            String summary =
+                    mBackupManager.getDestinationString(mBackupManager.getCurrentTransport());
+            if (Log.isLoggable(TAG, Log.DEBUG)) {
+                Log.d(TAG,
+                        "Received the backup settings summary from backup transport: " + summary);
+            }
+            return summary;
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error getting data management summary", e);
+        }
+        return null;
+    }
+}