isCOBOL Evolve : User Interface : Controls Reference : TAB-CONTROL : Styles : Allow-Container
Allow-Container
When this style is set, the Tab-Control becomes a real container control. There is no 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. It simplifies the coding and also reduces traffic in thin client environment.
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)
or
• by setting the attributes TAB-GROUP and TAB-GROUP-VALUE on the screen entry. E.g.
       03  screen1-tc-1 tab-control
           tab-to-add ("Page1", "Page2")
           allow-container.
       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 
              ...
By default, LINE and COLUMN coordinates of controls displayed on the Tab-Control are relative to the window top-left border. To make them relative to the tab top-left border, apply the Relative-Offset style as well.
 
Example - Define a tab-control with two pages with the allow-container style
screen section.
...
          03  screen-1-tc-1
              tab-control
              line                 2 
              col                  2
              lines                17 cells
              size                 68 cells
              allow-container
              .
           03 screen-1-tc-1-page1 
              tab-group screen-1-tc-1 tab-group-value 1.
              05 label 
                 line           4
                 col            4
                 title          "This is the first page"
                 .
              05 entry-field
                 line           6
                 col            4
                 .
           03 screen-1-tc-1-page2 
              tab-group screen-1-tc-1 tab-group-value 2.
              05 label
                 line           4
                 col            4 
                 title          "This is the second page"
                 .
              05 combo-box
                 line           6
                 col            4
                 .