Inheriting members

The following figure shows the inheritance of TInputDialog.

As you can see, TInputDialog is derived from TDialog, which is derived from TWindow, which is in turn derived from TEventHandler and TStreamable. Inheritance lets you add more specialized behavior as you move further along the hierarchy.

TDialog inheritance

The following table shows the public data members of each class, including those inherited from the TDialog and TWindow base classes:

TWindow	TDialog	TInputDialog
Status	Status	Status
HWindow	HWindow	HWindow
Title	Title	Title
Parent	Parent	Parent
Attr	Attr	Attr
DefaultProc	DefaultProc	DefaultProc
Scroller	Scroller	Scroller
	IsModal	IsModal
		Prompt
		Buffer
		BufferSize

TInputDialog inherits all the data members of TDialog and TWindow and adds the data members it needs to be an input dialog box.

To fully understand what you can do with TInputDialog, you have to understand its inheritance: a TInputDialog object is both a dialog box (TDialog) and a window (TWindow). TDialog adds the concept of modality to the TWindow class. TInputDialog extends that by adding the ability to store and retrieve user-input data.