GUI ScreenIO for Windows

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Listview Control Properties

Listview properties are collected on several property sheets and popups.  You can jump directly to the page of interest using the links below.

The items are arranged in alphabetical order by page.

General

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Item Significance
Caching Method:

Accumulate Cache

Selects accumulate caching.  If you load the listview from the start of the list, the listview will return listview-GET-NEXT events only when more data is needed.

It does not discard cached records, so your program does not need to handle listview-GET-PRIOR and listview-START-AT events.   (Note: Get-Prior events may be returned if you violate one of the rules for listview loading, See Common Problems).

 If the file is large, and the user drags the scrollbar thumb a long way into the file, there could be a long delay while the records are requested sequentially via multiple GET-NEXT requests, plus your program needs to know when it has reached the percentage into the file that matches the scrollbar thumb.

As a result, this is only appropriate for small data files; in most cases, preload caching would be simpler to implement.

Caching Method:

Normal

Recommended caching method.  GUI ScreenIO maintains a cache of records that are near the current position in the list, which gives best performance and versatility.

Requires that your program can handle listview-GET-NEXT, listview-GET-PRIOR, and listview-START-AT events.  See also listview events.

Caching Method:

Preload Cache

Selects preload caching.  When you load the listview the first time, it will return a series of listview-GET-NEXT events until all of the records have been loaded to the list. (Note: Get-Prior events may be returned if you violate one of the rules for listview loading, See Common Problems).

Not useful for large lists, since there is a delay while the list is being loaded, but nice because your program only needs to handle the listview-GET-NEXT event.

COBOL field name COBOL name of your control.  All of the fields in the panel copybook for this control will be prefaced with this name.
Column headings:

Return event when clicked

Causes a listview-CLICKCOLn event to be returned when the user clicks on a column heading.
Column headings:

Do not return events

Suppresses listview-CLICKCOLn events when a column heading is clicked.
Column headings:

No column headings

Displays the listview with no column headings.
Listview type:

Large icons

Similar to List, except that the text is arranged a bit differently.  GUI ScreenIO does not presently support icons (e.g., images) within a listview.
Listview type:

List

Displays only the contents of the first column, with the list wrapping into as many columns as will fit within the area you defined for your listview.
Listview type:

Report

Most common form of a listview; displays one record per row, with fields within the record arranged as columns.

A listview may contain from 1 to 15 columns.

Listview type:

Small icons

Similar to List, except that the text is arranged more densely.  GUI ScreenIO does not presently support icons (e.g., images) within a listview.
Presentation:

Has a border

Draws a dark line around the control.
Presentation:

Multiple selections

Allows the user to select more than one item in the list.

Not implemented.

Presentation:

Sunken appearance

Has a border that makes the control appear sunken.

Listview elements

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Defining listview columns

The listview on this page displays information about the columns in your listview. 

The invisible key column is special; it will contain data which is not displayed, but which is associated with each listview record.  Double-click its entry to define the field properties of the invisible key column.

To update the column heading text, click the entry in the "Column Heading Text" column, then click it again.

Type the column heading you want and press Enter to update it.  You can also slow-click the heading on the listview itself to modify the column heading.

To define the properties of each individual column, double-click its entry in the list.  This will display the field properties panel, which collects the field specifications for each column.

Item Significance
Column heading Click the item in this column, pause, then click it again.  An edit control will appear.  Type the text for the column heading.

Double-click the item to define the field properties for a column.

Event IDs:

Assign event IDs automatically

Default; the panel editor will assign the numeric event-IDs to listview events.  Unless you have very good reasons to manually assign these values, you should let the panel editor assign event-IDs to avoid conflicts with other events assigned to the panel. 

The number assigned to the event ID is not significant because you should always use the 88-level items to evaluate events.

Event IDs:

listview-EDITED event

Event ID assigned to the listview-EDITED event.
Event IDs:

listview-GET-NEXT and GET-PRIOR events

Event ID assigned to the listview-GET-NEXT and listview-GET-PRIOR events.
Event IDs:

listview-SELECTION event

Event ID assigned to the listview-SELECTION event.
Event IDs:

listview-START-AT event

Event ID assigned to the listview-START-AT event.
Number of columns in listview Specifies the number of columns your listview will display (from 1 to 15).
Number of rows in table used to pass data to the listview Specifies the number of entries in the listview buffer, which is used to pass blocks of data to the listview.

This may be from 2 to 100; larger values generally yield better performance.  We suggest a minimum of 20.

Resequence Columns Displays a popup that lets you rearrange the columns in a listview.

Listview behavior

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Item Significance
? Displays a popup that collects text that is displayed in a ToolTip when the user places the mouse cursor over the control and pauses briefly.
Return to program when:

Each time selection changes

Causes GUI ScreenIO to return a listview-SELECTION event when the user selects a different record in the listview. 
Return to program when:

Entering field

Causes GUI ScreenIO to return an event when the user activates this control.  See hot fields.
Return to program when:

Leaving (always)

Causes GUI ScreenIO to return an event when the user activates a different control on the panel.  See hot fields.
Return to program when:

Leaving (if selection changed)

Causes GUI ScreenIO to return an event when the user activates a different control on the panel, but only if a different item was selected.  See hot fields.
Runtime behavior:

Column 1 text can be edited in-place

Allows the user to slow-click column 1 to change the data.  Also enables the listview-EDITED event.
Runtime behavior:

Flat Scroll Bars

Specifies Flat scrollbar style; appearance only, has no effect on how scrollbars operate.
Runtime behavior:

Full row highlighted when selected

Highlights the entire row of a selected record.
Runtime behavior:

Grid Lines

Listview control shows gridlines to separate columns and rows.
Runtime behavior:

Selection persists when control loses focus

The selected item in a listview remains visible even though another control has the keyboard focus.
Runtime behavior:

Show long content in popup Tip window

If the column is too narrow to display the content, it will appear in a popup Tip window when the user pauses the mouse cursor over the item.
Runtime behavior:

Tab stops here

Makes it possible to use the Tab key to navigate to this control.

Related topics:


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