GUIBaseContext :: doAfterHandleOpen - Post-event handler after opening control
The handler handles the DEV_Opened data event. The event is fired after opening or setting the data source for a control. When the event is fired, the property handle is already opened and data in the property handles can be accessed. Data sources (property handles) for subordinated controls are, usually, not yet opened.
The event is fired also when reopening a data source, which might become necessary when the parent changes its type or data source. Hence, the handler might be called several times for a control. In contrast to the doAfterHandleActivated() handler, which is called only ones, when activating a data source.
The event is typically used to set button or control states. The event cannot handle selection of instances in a control, since data might have been already filled into control areas. Instance selection must be handled in the DEV_Activated event handler (doAfterHandleActivated()).
Usually, the data sources are opened after all controls have been opened, but this is not for sure. Hence, when your application or window needs to start with an initial action, this should be called in the doAfterShow() handler but not in this handler.