Get gadget's state of visibility (hidden?, disabled?)

[c4s]

Getting the gadget state of visibility could be useful sometimes: Is it hidden or disabled by the program itself (using DisableGadget() or HideGadget())? Maybe even checks if it's really not visible by the user (window minimized, covered by something).
On Windows we can use IsWindowEnabled_() / IsWindowVisible_() but what about a cross-platform solution build into PureBasic?!