TComponent

TComponent is the foundational class for components in the Delphi and C++Builder frameworks. Defined in the system library, it serves as the common ancestor for both visual and non-visual components and provides the core infrastructure that descendant components build upon. As the base of the component hierarchy, TComponent exposes essential functionality around lifetime management, ownership, and persistence, while leaving specialized behavior to more specific descendants such as TControl or TDataSource.

Ownership and lifetime management are central to TComponent. Components are typically created with an AOwner parameter, and the owner is responsible for freeing its owned components when it is destroyed. This ownership model helps manage memory automatically and allows components to form hierarchical relationships.

Persistence and streaming are another key role. The Delphi streaming system saves and loads component properties to and from form and project files. Because TComponent participates in this system, components can be instantiated and their properties restored at design-time and run-time. The naming and streaming identifiers used by components assist the integrated development environment in representing the form hierarchy.

Notification and lifecycle state are supported through a small set of mechanisms. Components can notify others about changes or removal, allowing references to be cleaned up to prevent access to freed objects. TComponentState includes flags used during the component’s creation, loading, and destruction phases.

Common non-visual descendants include data sources and timers, while visual descendants originate from TControl. TComponent thus provides the essential, framework-wide features that enable Delphi’s component model to function coherently.