Extending VCL to Mobile with App Tethering

App Tethering was first introduced in RAD Studio XE6 as a way to extend your VCL and FireMonkey (FMX) apps to other companion applications.  The companion apps can be Windows, Mac OS X and/or FMX multi-device apps.

With App Tethering, you can breathe new life into your existing Windows VCL apps! You can extend Windows VCL and FMX apps connecting them to other devices, sensors, data and services to build connected apps to add to a distributed Internet of Things (IoT) solution!

RAD Studio 10.1 Berlin added these App Tethering Improvements:

App tethering gains the following features:

• Two new network adapters that provide multicast support for IPv4 and IPv6. You can configure your manager to use them.

• You can specify a range of IPv4 addresses as the target of a remote manager discovery.

       procedure DiscoverManagers(const ATargetList: TTetheringTargetHosts); overload;

• Log filtering support. You can enable of disable logging for specific items of the app tethering architecture.
• Profiles can now control whether or not they allow connection requests from remote profiles. As a result:
• The TTetheringProfile.OnConnectProfile event has been divided in OnBeforeConnectProfile and OnAfterConnectProfile.
• The TTetheringDisconnectEvent event type has been renamed as TTetheringProfileEvent.

For security, you can encrypt the data or streams before sending to any connected app, and then you decrypt the data or streams when it’s received by any of the connected apps as I described in this post, App Tethering using Encryption Hooks.

The RAD Studio 10.1 Berlin sample PhotoWall app shows AppTethering sending streams between other paired profiles. 

The Photo Wall app has a DesktopWall viewer app is a Multi-Device app to display photos taken with its mobile counterpart application.

The Mobile app from the PhotoWall lets you take a photo with your Android or iOS device and display it on one or more DesktopWall instances over the network.

This sample app demonstrates how to scan for App Tethering enabled Remote Instances across a network, pair with individual Remote Instances, and send Temporary Resources to those individual Remote Instances.