From 4b1743bb2f7723b98cb63e580c4e38ebef305861 Mon Sep 17 00:00:00 2001
From: Roman <romanhawk@gmail.com>
Date: Fri, 26 Jun 2020 12:47:48 +0300
Subject: [PATCH] android: add serverURL configuration for MDM/EMM environments

Android for Enterprise provides special feature for applications to obtain configuration through RestrictionManager remotely by some MDM solution.

Jitsi Meet can be remotely installed and provisioned with a proper URL (making URL not editable by the user) inside the Work Profile or Fully managed device.
---
 android/app/src/main/AndroidManifest.xml      |  3 +
 .../java/org/jitsi/meet/MainActivity.java     | 88 +++++++++++++++++--
 android/app/src/main/res/values/strings.xml   |  2 +
 .../app/src/main/res/xml/app_restrictions.xml | 11 +++
 react/features/app/components/App.native.js   | 16 +++-
 react/features/base/flags/constants.js        |  6 ++
 .../components/native/SettingsView.js         | 22 ++++-
 react/features/settings/functions.js          | 16 ++++
 8 files changed, 155 insertions(+), 9 deletions(-)
 create mode 100644 android/app/src/main/res/xml/app_restrictions.xml

diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index e4411d8e9..8d805f038 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -7,6 +7,9 @@
       android:label="@string/app_name"
       android:networkSecurityConfig="@xml/network_security_config"
       android:theme="@style/AppTheme">
+    <meta-data
+        android:name="android.content.APP_RESTRICTIONS"
+        android:resource="@xml/app_restrictions" />
     <activity
         android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|screenSize|smallestScreenSize"
         android:label="@string/app_name"
diff --git a/android/app/src/main/java/org/jitsi/meet/MainActivity.java b/android/app/src/main/java/org/jitsi/meet/MainActivity.java
index 4552dced2..d420016cf 100644
--- a/android/app/src/main/java/org/jitsi/meet/MainActivity.java
+++ b/android/app/src/main/java/org/jitsi/meet/MainActivity.java
@@ -16,9 +16,15 @@
 
 package org.jitsi.meet;
 
+import android.content.BroadcastReceiver;
+import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.RestrictionEntry;
+import android.content.RestrictionsManager;
 import android.net.Uri;
 import android.os.Build;
+import android.os.Bundle;
 import android.provider.Settings;
 import android.util.Log;
 import android.view.KeyEvent;
@@ -31,6 +37,7 @@ import org.jitsi.meet.sdk.JitsiMeetConferenceOptions;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.Collection;
 import java.util.Map;
 
 /**
@@ -48,6 +55,27 @@ public class MainActivity extends JitsiMeetActivity {
     private static final int OVERLAY_PERMISSION_REQUEST_CODE
         = (int) (Math.random() * Short.MAX_VALUE);
 
+    /**
+     * ServerURL configuration key for restriction configuration using {@link android.content.RestrictionsManager}
+     */
+    public static final String RESTRICTION_SERVER_URL = "SERVER_URL";
+
+    /**
+     * Broadcast receiver for restrictions handling
+     */
+    private BroadcastReceiver broadcastReceiver;
+
+    /**
+     * Flag if configuration is provided by RestrictionManager
+     */
+    private boolean configurationByRestrictions = false;
+
+    /**
+     * Default URL as could be obtained from RestrictionManager
+     */
+    private String defaultURL;
+
+
     // JitsiMeetActivity overrides
     //
 
@@ -85,16 +113,66 @@ public class MainActivity extends JitsiMeetActivity {
 
     @Override
     protected void initialize() {
+        broadcastReceiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                // As new restrictions including server URL are received,
+                // conference should be restarted with new configuration.
+                leave();
+                recreate();
+            }
+        };
+        registerReceiver(broadcastReceiver,
+            new IntentFilter(Intent.ACTION_APPLICATION_RESTRICTIONS_CHANGED));
+
+        resolveRestrictions();
+        setJitsiMeetConferenceDefaultOptions();
+        super.initialize();
+    }
+
+    @Override
+    public void onDestroy() {
+        if (broadcastReceiver != null) {
+            unregisterReceiver(broadcastReceiver);
+            broadcastReceiver = null;
+        }
+
+        super.onDestroy();
+    }
+
+    private void setJitsiMeetConferenceDefaultOptions() {
         // Set default options
         JitsiMeetConferenceOptions defaultOptions
             = new JitsiMeetConferenceOptions.Builder()
-                .setWelcomePageEnabled(true)
-                .setServerURL(buildURL("https://meet.jit.si"))
-                .setFeatureFlag("call-integration.enabled", false)
-                .build();
+            .setWelcomePageEnabled(true)
+            .setServerURL(buildURL(defaultURL))
+            .setFeatureFlag("call-integration.enabled", false)
+            .setFeatureFlag("server-url-change.enabled", !configurationByRestrictions)
+            .build();
         JitsiMeet.setDefaultConferenceOptions(defaultOptions);
+    }
 
-        super.initialize();
+    private void resolveRestrictions() {
+        RestrictionsManager manager =
+            (RestrictionsManager) getSystemService(Context.RESTRICTIONS_SERVICE);
+        Bundle restrictions = manager.getApplicationRestrictions();
+        Collection<RestrictionEntry> entries = manager.getManifestRestrictions(
+            getApplicationContext().getPackageName());
+        for (RestrictionEntry restrictionEntry : entries) {
+            String key = restrictionEntry.getKey();
+            if (RESTRICTION_SERVER_URL.equals(key)) {
+                // If restrictions are passed to the application.
+                if (restrictions != null &&
+                    restrictions.containsKey(RESTRICTION_SERVER_URL)) {
+                    defaultURL = restrictions.getString(RESTRICTION_SERVER_URL);
+                    configurationByRestrictions = true;
+                // Otherwise use default URL from app-restrictions.xml.
+                } else {
+                    defaultURL = restrictionEntry.getSelectedString();
+                    configurationByRestrictions = false;
+                }
+            }
+        }
     }
 
     @Override
diff --git a/android/app/src/main/res/values/strings.xml b/android/app/src/main/res/values/strings.xml
index ebde5be0c..bd1265237 100644
--- a/android/app/src/main/res/values/strings.xml
+++ b/android/app/src/main/res/values/strings.xml
@@ -1,3 +1,5 @@
 <resources>
     <string name="app_name">Jitsi Meet</string>
+    <string name="restriction_server_url_description">URL of Jitsi Meet server instance to connect to</string>
+    <string name="restriction_server_url_title">Server URL</string>
 </resources>
diff --git a/android/app/src/main/res/xml/app_restrictions.xml b/android/app/src/main/res/xml/app_restrictions.xml
new file mode 100644
index 000000000..150c4c7ca
--- /dev/null
+++ b/android/app/src/main/res/xml/app_restrictions.xml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<restrictions xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <!-- Server URL configuration -->
+    <restriction
+        android:defaultValue="https://meet.jit.si"
+        android:description="@string/restriction_server_url_description"
+        android:key="SERVER_URL"
+        android:restrictionType="string"
+        android:title="@string/restriction_server_url_title"/>
+</restrictions>
diff --git a/react/features/app/components/App.native.js b/react/features/app/components/App.native.js
index f0343253e..5b692ac18 100644
--- a/react/features/app/components/App.native.js
+++ b/react/features/app/components/App.native.js
@@ -4,7 +4,7 @@ import React from 'react';
 
 import { setColorScheme } from '../../base/color-scheme';
 import { DialogContainer } from '../../base/dialog';
-import { CALL_INTEGRATION_ENABLED, updateFlags } from '../../base/flags';
+import { CALL_INTEGRATION_ENABLED, SERVER_URL_CHANGE_ENABLED, updateFlags } from '../../base/flags';
 import { Platform } from '../../base/react';
 import { DimensionsDetector, clientResized } from '../../base/responsive-ui';
 import { updateSettings } from '../../base/settings';
@@ -86,6 +86,20 @@ export class App extends AbstractApp {
             // We set these early enough so then we avoid any unnecessary re-renders.
             const { dispatch } = this.state.store;
 
+            // Check if serverURL is configured externally and not allowed to change.
+            const serverURLChangeEnabled = this.props.flags[SERVER_URL_CHANGE_ENABLED];
+
+            if (!serverURLChangeEnabled) {
+                // As serverURL is provided externally, so we push it to settings.
+                if (typeof this.props.url !== 'undefined') {
+                    const { serverURL } = this.props.url;
+
+                    if (typeof serverURL !== 'undefined') {
+                        dispatch(updateSettings({ serverURL }));
+                    }
+                }
+            }
+
             dispatch(setColorScheme(this.props.colorScheme));
             dispatch(updateFlags(this.props.flags));
             dispatch(updateSettings(this.props.userInfo || {}));
diff --git a/react/features/base/flags/constants.js b/react/features/base/flags/constants.js
index dfad73667..bc94c382d 100644
--- a/react/features/base/flags/constants.js
+++ b/react/features/base/flags/constants.js
@@ -81,6 +81,12 @@ export const RAISE_HAND_ENABLED = 'raise-hand.enabled';
  */
 export const RECORDING_ENABLED = 'recording.enabled';
 
+/**
+ * Flag indicating if server URL change is enabled.
+ * Default: enabled (true)
+ */
+export const SERVER_URL_CHANGE_ENABLED = 'server-url-change.enabled';
+
 /**
  * Flag indicating if tile view feature should be enabled.
  * Default: enabled.
diff --git a/react/features/settings/components/native/SettingsView.js b/react/features/settings/components/native/SettingsView.js
index cfa8fedf7..c5decf726 100644
--- a/react/features/settings/components/native/SettingsView.js
+++ b/react/features/settings/components/native/SettingsView.js
@@ -7,11 +7,11 @@ import { translate } from '../../../base/i18n';
 import { JitsiModal } from '../../../base/modal';
 import { connect } from '../../../base/redux';
 import { SETTINGS_VIEW_ID } from '../../constants';
-import { normalizeUserInputURL } from '../../functions';
+import { normalizeUserInputURL, isServerURLChangeEnabled } from '../../functions';
 import {
     AbstractSettingsView,
     _mapStateToProps as _abstractMapStateToProps,
-    type Props
+    type Props as AbstractProps
 } from '../AbstractSettingsView';
 
 import FormRow from './FormRow';
@@ -70,6 +70,20 @@ type State = {
     startWithVideoMuted: boolean,
 }
 
+/**
+ * The type of the React {@code Component} props of
+ * {@link SettingsView}.
+ */
+type Props = AbstractProps & {
+
+    /**
+     * Flag indicating if URL can be changed by user.
+     *
+     * @protected
+     */
+    _serverURLChangeEnabled: boolean
+}
+
 /**
  * The native container rendering the app settings page.
  *
@@ -168,6 +182,7 @@ class SettingsView extends AbstractSettingsView<Props, State> {
                         <TextInput
                             autoCapitalize = 'none'
                             autoCorrect = { false }
+                            editable = { this.props._serverURLChangeEnabled }
                             onBlur = { this._onBlurServerURL }
                             onChangeText = { this._onChangeServerURL }
                             placeholder = { this.props._serverURL }
@@ -514,7 +529,8 @@ class SettingsView extends AbstractSettingsView<Props, State> {
  */
 function _mapStateToProps(state) {
     return {
-        ..._abstractMapStateToProps(state)
+        ..._abstractMapStateToProps(state),
+        _serverURLChangeEnabled: isServerURLChangeEnabled(state)
     };
 }
 
diff --git a/react/features/settings/functions.js b/react/features/settings/functions.js
index 4dfd58e24..dcf6f6ee0 100644
--- a/react/features/settings/functions.js
+++ b/react/features/settings/functions.js
@@ -1,4 +1,6 @@
 // @flow
+
+import { SERVER_URL_CHANGE_ENABLED, getFeatureFlag } from '../base/flags';
 import { i18next, DEFAULT_LANGUAGE, LANGUAGES } from '../base/i18n';
 import { createLocalTrack } from '../base/lib-jitsi-meet/functions';
 import {
@@ -23,6 +25,20 @@ export function isSettingEnabled(settingName: string) {
     return interfaceConfig.SETTINGS_SECTIONS.includes(settingName);
 }
 
+/**
+ * Returns true if user is allowed to change Server URL.
+ *
+ * @param {(Function|Object)} stateful - The (whole) redux state, or redux's
+ * {@code getState} function to be used to retrieve the state.
+ * @returns {boolean} True to indicate that user can change Server URL, false otherwise.
+ */
+export function isServerURLChangeEnabled(stateful: Object | Function) {
+    const state = toState(stateful);
+    const flag = getFeatureFlag(state, SERVER_URL_CHANGE_ENABLED, true);
+
+    return flag;
+}
+
 /**
  * Normalizes a URL entered by the user.
  * FIXME: Consider adding this to base/util/uri.