Even though many current prototyping tools tend to see an application as a bunch of views, we all know that a real application is not made only of a set of mere visual assets.
While building a cross-platform application, you obviously wish your visual application framework (FMX in the case) to deal with visual aspects but at the same time, to provide actual functionalities. This is because you will end up needing some level of interaction with the platform your application is running on.
Modern applications have to provide advanced functionalities, including some that are really basic (not always trivial, though), such as (multi-)touch support, and interaction with the system clipboard or with the filesystem. There are some possibly more specific topics, such as sensor integration (camera and positioning, for example), or other device-/platform-specifics such as notification systems, voice recognition, text-to-speech, and other advanced capabilities.
What I am trying to say is that FMX (and the Delphi RTL parts added by Embarcadero in recent years, available both for FMX and VCL) is much more than a visual framework, that is, it provides powerful abstractions that a developer can use to implement functionalities in a real cross-platform way.
This is true and evident in many areas we will cover throughout this book. Starting from behavioral services, with the aim of abstracting some device-/platform-specific behaviors (such as tab positioning in tab control or the default presentation mode of some components such as TMultiView, commonly used to implement mobile app menus). We could also abstract audio/video services, where a single, shared interface lets you access device cameras, microphones, or other common (but specific) aspects related to the multimedia area.
Just as a simple example, iOS and Android use different file formats for audio and video, thus to have a single TMediaPlayer component leveraging this difference is very convenient for the developer, that is, just ask the component to play or record audio/video with the same code.
Accessing the storage of the device (the camera roll for iOS or the Gallery/Photos apps for Android) is another great example. There are many functionalities (the device contact list to name another one), and it is hard to provide an exhaustive list.
You may think this list would represent the playground for the app developer but this is only partially true, that is, the VCL has a great level of abstraction over most Windows controls and APIs. Though, you always had a chance to go back to the metal, breaking this generally convenient abstraction and tweaking your code, adding low-level Windows API calls (without confining your possibilities to what the framework offers) and this is true also in the FMX framework, as we will see in the next section.
