☜	Error Code M49 M[UMPS] by Example					☞

M49, Invalid attempt to set focus

Introduced in the 1995 ANSI M[UMPS] Windowing Application Programmers’ Interface.

If an application attempts to set focus to a window or gadget that is not currently capable of receiving focus, this error will occur. After this, special variable $ERef will contain a value that indicates the reference to the structured system variable for which the error occurred.

There are many reasons why a window or gadget may be unable to receive focus: it may be invisible, not active, disabled by the value of its MODAL attribute, or reside on a different display.

If an application attempts to assign a value to a NEXTG attribute that does not identify a gadget that has been defined for the window in question, this error will occur. After this, special variable $ERef will contain a value that indicates the reference to the structured system variable for which the error occurred.

In earlier printed versions of the 1995 ANSI M[UMPS] Windowing Application Programmers’ Interface, this error was identified as M?4.

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Copyright © Examples: 1995-2024 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2024 Ed de Moel.

The information in this page is NOT authoritative and subject to be modified at any moment.
Please consult the appropriate (draft) language standard for an authoritative definition.

Some specifications are "approved for inclusion in a future standard". Note that the MUMPS Development Committee cannot guarantee that such future standards will indeed be published.

This page most recently updated on 16-Nov-2023, 14:49:09.

For comments, contact Ed de Moel (demoel@jacquardsystems.com)