Browse Prior Art Database

Expanding Listbox Items in a Standard Presentation Manager Listbox

IP.com Disclosure Number: IPCOM000121686D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Jefferson, KJ: AUTHOR [+2]

Abstract

This article discusses a technique to expand listbox items in a standard Presentation Manager* (PM) listbox. Because a listbox can only display a single line of information at a time, another window is generally used to display item details. Expanding and collapsing listbox entries allows a single window to display item information for a single item.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 80% of the total text.

Expanding Listbox Items in a Standard Presentation Manager Listbox

      This article discusses a technique to expand listbox
items in a standard Presentation Manager* (PM) listbox.  Because a
listbox can only display a single line of information at a time,
another window is generally used to display item details.  Expanding
and collapsing listbox entries allows a single window to display item
information for a single item.

      A standard listbox does not take advantage of mouse button 2
processing.  By utilizing mouse button 2, the index of a listbox item
can be determined and extra processing beyond selection and entry can
take place.

      In order to expand a listbox item, the following steps need to
be followed:
1.   Determine the item index when a mouse button 2 down is
processed.
2.   Change the text of the listbox item to reflect expansion.
3.   Insert additional item information at the index of the item + 1.
Continue inserting detail lines until all lines have been inserted.
4.   Insert a line to reflect expansion completion.

      In order to collapse an expanded listbox item, the following
steps need to be followed:
1.   Determine the item index when a mouse button 2 down is
processed.
2.   Verify that this is a valid item to collapse.
3.   Reset the test of the listbox item to reflect the collapsed
state.
4.   Remove all lines at item + 1 until the completion line is
reached.
5.   Remove the expansion completion line.

 ...