[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Controls' (#lcl)

# TWinControl.UpdateShowing

Updates the Showing property with the visibility for the control, its Parents, and its child controls.

## Declaration

Source position: controls.pp line 2313

`protected procedure TWinControl.UpdateShowing; virtual;`

## Description

UpdateShowing is a method used to determine the visibility for the Handle in the control. It calls HandleObjectShouldBeVisible to check the handle state and visibility for both the control and each of its Parent controls. If the control should be showing and Handle has not already been allocated, CreateHandle is called.

When child controls exist in the Controls property, they are visited to call the UpdatingShowing method for each of the TWinControl instances.

If an auto-sizing request is not active, a CM_SHOWINGCHANGED message is performed to apply the new visibility for the control(s). The Showing property is updated prior to exiting from the method.

## See also

TWinControl.Showing |  | Cached visibility for the widget. Not necessarily in sync with the widget.
TWinControl.CreateHandle |  | Creates the Handle for the widget, if not already created.
TWinControl.AutoSizeDelayed |  | Returns True if auto-sizing has been delayed until some other process is completed.
TWinControl.AutoSizePhases |  | Translates control state flags into AutoSizePhases.
TControl.HandleObjectShouldBeVisible |  | True if the control should be visible, unless it's being destroyed.