About the TQDBNavigator component

Purpose
The QDBNavigator component works with the QDB components (TQDB, TQDBItem, & TQDBView) to provide push-button access to individual items.

Tasks
You can choose the orientation of the navigator, which buttons are available, and which QDB component it acts upon. If the operating system allows, the buttons can be flat rather than raised.

It is possible to assign a hint to each button or replace a button's default glyph.

When linked to a QDB component the navigator reflects the state of the component by enabling or disabling its buttons, e.g., if the QDB is not Ready all buttons are grayed out. The navigator also responds to the BoF and EoF conditions.

When any one of the navigators buttons is pressed three things happen in sequence:

   first the BeforeAction event is triggered

   then if there is a handler assigned to that button the corresponding event is triggered
   and if not the appropriate method of the associated QDB is called

   finally the OnClick event is triggered

For example, if the associated QDB component is Q (of type TQDBView) and the post button is pressed and there is no handler for the OnPost event, Q's Post method is called to update the associated panel.