XtAppAddBlockHook, XtRemoveBlockHook - register a block hook procedure
XtAppAddBlockHook(app_context, proc, client_data)
Specifies the application context.
Specifies the block hook procedure.
Specifies the application-specific data to be passed to the
XtAppAddBlockHook registers the specified procedure and returns an identifier for it. The hook is called at any time in the future when the Intrinsics are about to block pending some input.
Block hook procedures are removed automatically and the XtBlockHookId is destroyed when the application context in which they were added is destroyed.
removes the specified block hook
procedure from the list in which it was registered.
X Toolkit Intrinsics -- C Language Interface
Xlib -- C Language X Interface