HIDDEN attribute

Indicates whether to “hide” a widget.

Data type: LOGICAL

Access: Readable/Writeable

Applies to: BROWSE widget, BUTTON widget, COMBO-BOX widget, CONTROL-FRAME widget, DIALOG-BOX widget, EDITOR widget, FILL-IN widget, FRAME widget, IMAGE widget, LITERAL widget, RADIO-SET widget, RECTANGLE widget, SELECTION-LIST widget, SLIDER widget, TEXT widget, TOGGLE-BOX widget, WINDOW widget

Setting the HIDDEN attribute to TRUE prevents the widget from being displayed implicitly. For a field-level widget, child frame, or child window, this means that the widget is not automatically made visible when the containing frame or parent window becomes visible. The widget does not appear unless one of the following occurs:

It is forced to receive user input (for example, using a SET or PAUSE statement).
It is explicitly displayed using a VIEW statement or by setting its VISIBLE attribute to TRUE.

Any action that explicitly displays the widget also resets the HIDDEN attribute to FALSE. If the widget is already visible, setting its HIDDEN attribute to TRUE makes that widget and any widgets it parents (and their descendants) invisible (VISIBLE is set to FALSE). The default value of the HIDDEN attribute is FALSE for all widgets.

In windows, setting the HIDDEN attribute to TRUE prevents implicit display of the hidden window when you:

Invoke DISPLAY, ENABLE, and VIEW statements for frames of the window
View an ancestor or descendant window of the hidden window

This limits flashing side effects caused during set up of the application user interface. In windows, this attribute is not supported in character mode.

For frames and dialog boxes, setting the HIDDEN attribute to TRUE prevents implicit display of the frame or dialog box when you invoke DISPLAY or ENABLE statements for the widget or its descendant frames. This allows the frame or dialog box to remain invisible during actions that set it up. The HIDDEN attribute has no effect on DISPLAY statements directed to a file, pipe, or printer.

Note: Setting a frame or field-level widget’s VISIBLE attribute to TRUE also displays any parent or ancestor frames, even if their HIDDEN attributes are set to TRUE (resetting the HIDDEN attributes, if necessary). However, setting a window’s VISIBLE attribute to TRUE only displays the window if there are no ancestor windows with their HIDDEN attribute set to TRUE. In any case, the window’s own HIDDEN attribute is set to FALSE.

For field-level widgets and frames parented by other frames, setting the HIDDEN attribute to TRUE prevents implicit display of the field-level widget or child frame when its containing frame or dialog box is displayed. If the frame or dialog box containing the widget is visible, setting HIDDEN to FALSE for the widget makes the widget visible (the VISIBLE attribute is set to TRUE). If the containing frame or dialog box is not visible, setting HIDDEN to FALSE has no effect on the VISIBLE attribute of the widget.

Note: The HIDE statement sets the VISIBLE attribute for the widget to FALSE. It only sets the HIDDEN attribute to TRUE if you hide a field-level widget or child frame whose containing frame is still visible.

OpenEdge Release 10.2B

Copyright © 2009 Progress Software Corporation