Learning about components

We can think of a UI as a set of components put together to build a visual unit that the user can interact with to perform some task or get some information.

The components are the building blocks of our UI, and FMX (and VCL as well) has plenty of components (usually a bit complicated). Let's start with three very common components – TLabel, TEdit, and TButton. The following diagram will help you consider the position of these three classes in the general Delphi component hierarchy, for the FMX version:

Figure 2.6

At the same time, these three classes have a corresponding version in VCL, and the following diagram provides a representation of the significant portion of the VCL class hierarchy around TEdit, TButton, and TLabel:

Figure 2.7

You can see, in Figure 2.6 and Figure 2.7, the class hierarchy structures for FMX and VCL. For convenience, we can assume TComponent as the root class and you can easily spot some homonyms...