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Browse Prior Art Database

Application-Wide Modality in a Presentation Manager Application

IP.com Disclosure Number: IPCOM000115173D
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 140K

Publishing Venue

IBM

Related People

Banda, VP: AUTHOR [+4]

Abstract

Disclosed is a technique that an application can implement in order to manually provide application-wide modality when the needs of the application require it, thus enhancing the usability of the Graphical User Interface.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 44% of the total text.

Application-Wide Modality in a Presentation Manager Application

      Disclosed is a technique that an application can implement in
order to manually provide application-wide modality when the needs of
the application require it, thus enhancing the usability of the
Graphical User Interface.

      An application written for the OS/2* Presentation Manager* (PM)
GUI is provided by the system with two kinds of modality for its
modal windows:  system modality and application modality.  Modality
in a graphical user interface is a description of what other windows
the user can interface with when the modal window is displayed on the
screen.

      PM provides the capability for a window to be system modal.
This means that when the system modal window is displayed, the user
cannot interact with any other window in the system.  This should
only be used by an application for situations where the user needs to
be notified of some event that places the entire system at risk.

      PM also provides application modality.  This form of modality
disallows the user from interacting with the window that is the owner
of the application modal window only.  The owner of a given window is
specified by the application when the window is created and must be
another window in the same application.

      These two types of modality provided by PM leave a large gap in
the modality requirements of applications.  PM does not provide the
ability for a window to be modal to every other window in its
application.  This type of modality is true application-wide
modality.

      An example of the need for application-wide modality can be
seen in LAN Server* 4.0.  Users who are interfacing with LAN Server
using the graphical user interface portion can have many windows open
at a given time.  These users can then switch to a windowed command
prompt and log off using the command line interface also provided to
LAN Server.  If users then switch back to the graphical user
interface portion of LAN Server, they will be presented with a
message box telling them that they have logged off and that when they
dismiss the message box, all of the windows currently open for LAN
Server will be closed.  This message box must display
application-wide modality to prevent users from ignoring the message
box and continuing to interact with the LAN Server windows.  This
produces unpredictable results, because the users have already logged
off.  PM does not provide any modality support for this type of
application-wide modality.

      A window must be disabled in order to keep a user from
interacting with it.  This can be achieved by calling the
WinEnableWindow API, passing the window handle and a flag indicating
that the window should be disabled.  In a disabled state, all user
input is ignored.  This is how PM internally implements the modality
between a window and its owner--the owner is disabled by PM.

      To provide application-wide modal...