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OS/2 Presentation Manager: API for Setting System Value Change Notifications

IP.com Disclosure Number: IPCOM000107959D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 43K

Publishing Venue

IBM

Related People

Smith, MD: AUTHOR [+2]

Abstract

OS/2* Presentation Manager* provides no method for applications to know when system values have changed. If an application performs some amount of work depending on a system value setting, the application must query the setting repeatedly. Applications need the ability to set system notifications which are attached to specific system values.

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OS/2 Presentation Manager: API for Setting System Value Change Notifications

       OS/2* Presentation Manager* provides no method for
applications to know when system values have changed.  If an
application performs some amount of work depending on a system value
setting, the application must query the setting repeatedly.
Applications need the ability to set system notifications which are
attached to specific system values.

      This article describes a new OS/2 Presentation Manager API
which sets a notification alarm for a system value. When the system
value changes, the application which set the alarm is notified of the
change. The API name suggested is WinNotifySysValue.

      The API which sets the notification alarm receives among its
arguments a handle to a window and the requested system value
identifier (SV_x) defined by OS/2 Presentation Manager.  When the
system value changes, the application receives notification through a
message to its window.  The application will know what system value
has changed through inspection of one of the message parameters.  The
notification alarm does not need resetting because it stays
activated.

      For example, if an application currently queries the system
value SV_MOUSEPRESENT and a mouse is present and operable, the
application can either assume that the mouse will stay that way or it
must frequently repeat the query. With the ability to set a
notification alarm, the application can set up the query...