THintWindow = class(TCustomControl)
class PASCALIMPLEMENTATION THintWindow : public TCustomControl
THintWindow implements the small pop-up window that appears over a control at run time, when the control has its ShowHint property set to True.
Use objects of the THintWindow class to display a Help Hint pop-up window directly from an application. Override THintWindow to customize the window that appears automatically for controls with their ShowHint property set to True. After overriding THintWindow to create a new derived type, assign the new type to the global HintWindowClass variable at application start-up time, so that the new hint window type is used for Help Hints.
The Hint window's BiDiMode is always set to the BiDiMode of the control that activates it. If the mode is
bdRightToLeft, then the Hint is left-aligned to the cursor.