The easiest and fastest way to find out if the Windows taskbar’s auto hide feature is on is to use the Windows SHAppBarMessage() function. Here’s the Object Pascal code port:
uses ShellAPI;
…
function TaskbarAutoHide: Boolean;
var
ABData: TAppBarData;
begin
ABData.cbSize := SizeOf(ABData);
Result := ((SHAppBarMessage(ABM_GETSTATE, ABData) and ABS_AUTOHIDE) > 0);
end;
Merlin’s Delphi Forge