Sent to a group right after you go to the card that contains it or to a background group right after going from a card where it was is not placed on to one where it is.
on openControl startProgressAnimation databaseQuery end openControl
Handle the openControl message to change a group's objects or perform other updates, when a card with the group on is visited.
For groups with their backgroundBehavior property set to true, the openControl message is sent immediately after the openBackground message is sent to the card being opened. For non-background groups, it is sent after the openCard message.
For nested groups, the openControl message is sent to the parent group first, if it is passed or not handled by the parent group, then it passes though each child group in reverse layer order (i.e from highest to lowest).