Frame definition files

Defining a help frame for menu items or form fields

In this example let us take a look how the item descriptor lininfo and the built-in variable LININFO can be used in conjunction with the frame descriptor help to define help that is specific to the current menu item.

This example defines a menu titled TOP MENU that has three items. The first item does not have any help information. When help is requested while the cursor is on this item, the help text frame for the menu is displayed. The second and third item have help text frames associated with each item. The menu definition file for this menu is:

   menu=TOP MENU
   help=`if [ $LININFO = "" ];
           then echo open Text.gen_help;
           else echo open '$LININFO';
          fi`
   
   name=Item 1
   action=nop
   

   name=date
   action=`date | message`nop
   lininfo=Text.item2
   

   name=exit
   action=exit
   lininfo=Text.item3

Menu.lininfo: an example of defining help with LININFO

The text frame definition file Text.gen_help displays information appropriate to the menu as a whole. (Presumably this information is also sufficient for a user to understand how to use the first menu item, Item 1.)

   columns=20
   lifetime=shortterm
   title="Help on TOP MENU"
   text="This menu demonstrates the lininfo descriptor.
   The first item does not use the lininfo descriptor."

Text.gen_help: an example of a help text frame

The text frame definition files Text.item2 and Text.item3 display appropriate help information for the second and third items on the menu.

   columns=20
   lifetime=shortterm
   title="Help on date"
   text="The selection of this item will display the
   current date and time on the message line"

Text.item2: an example of a help text frame

   columns=20
   lifetime=shortterm
   title="Help on exit"
   text="This item will let you get out of the application"

Text.item3: an example of a help text frame

When this application is run, the user sees the following menu:

Menu.lininfo: screen output

If the user asks for help, either by the appropriate function key, or by the help command (from the command line or the Command Menu), the appropriate text frame will be displayed. The lifetime descriptor, defined in each of the help text frames to be shortterm, ensures that whenever the user navigates away from the help text frame, it will be removed from the work area, thus reducing screen clutter:

Menu.lininfo: screen output after requesting help on item 1

If the user navigates to the second menu item and again asks for help, the following text frame will be displayed:

Menu.lininfo: screen output after requesting help on item 2

The text defined in Text.item3 is displayed in the same manner when <HELP> is pressed while the cursor is positioned on menu item 3, exit. The display of these help frames is controlled by the lininfo descriptor and the LININFO variable.

Using the textframe command as an alternative

The previous example of defining help text frames using the LININFO variable could be coded instead using the textframe command. This would eliminate the need for 3 text frames.

To do so, you would change the line in Menu.lininfo that is coded as

   else echo open '$LININFO';

to something like

   else echo textframe -c20 '$LININFO';

Then the corresponding values for LININFO later in that file would be coded with the text values from the text descriptors in the respective text frame definition files in the example. If the different titles for each frame were to be kept as well, then the LININFO variable for each item would have to include it:

   lininfo='-t "frame title" "Text contents"'