How to improve the performance of your application by making your Tab-Control a container.

When the allow-container style is set, a tab control becomes a container control.

   03 screen1-tc-1 tab-control
       tab-to-add ("Page1", "Page2")
       allow-container.

By making the tab control a container, you remove the need to manage the tab switch by intercepting the CMD-TABCHANGED event and updating the screen with the DISPLAY verb. The tab switch is automatically managed by the runtime Framework. This simplifies your coding and also reduces traffic in thin client and WebClient environments, which improves performance.

There are two ways to add controls to a Tab-Control with the Allow-Container style:

by using a Format 2 DISPLAY statement. E.g.

display scr-page-1 upon screen1-tc-1(1)

by setting the attributes TAB-GROUP and TAB-GROUP-VALUE on the screen entry. E.g.

      03 scr-page-1 tab-group screen1-tc-1, tab-group-value 1.
           05 entry-field
              ...
      03 scr-page-2 tab-group screen1-tc-1, tab-group-value 2.
           05 list-box
              ...

Example – Here’s a tab-control with two pages with the allow-container style

      SCREEN SECTION.

       01 Mask.
           03 Tb1-container
              tab-control
              line                 2
              col                  2
              lines                17 cells
              size                 68 cells
              allow-container
              .
           03 tb1-container-page1
              tab-group Tb1-container tab-group-value 1.
              05 label
                 line           4
                 col            4
                 title          "This is the first page"
                 .
              05 ef1-container
                 entry-field
                 line           6
                 col            4
                 .
           03 tb1-container-page2
              tab-group Tb1-container tab-group-value 2.
              05 label
                 line           4
                 col            4
                 title          "This is the second page"
                 .
              05 cb1-container
                 combo-box
                 line           6
                 col            4.

       PROCEDURE DIVISION.
       MAIN.
          ...

           display Mask

           modify Tb1-container tab-to-add ("Page1", "Page2")
           modify Cb1-container item-to-add ("item1", "item2")

           . . .

           perform until crt-status = 27
              accept Mask
                 on exception
                    continue
              end-accept
              if crt-status = 2
                 . . .
              end-if
           end-perform.