Name: deleteBackground

Type: message

Syntax: deleteBackground

Summary: Sent to a <group> just before it is removed from the <stack>.

Introduced: 1.0

OS: mac,windows,linux,ios,android

Platforms: desktop,server,web,mobile

Example:
on deleteBackground
  beep 2 -- warn user
  pass deleteBackground
end deleteBackground

Description:
Handle the <deleteBackground> <message> if you want to perform cleanup before a <group> is removed from the <stack>.

The actual deletion is not triggered by the <deleteBackground> <message>, so <trap|trapping> the <message> and not allowing it to <pass> does not prevent the <group> from being removed.

Deleting the last card on which a group appears does not remove the group from the stack, so it does not cause a <deleteBackground> <message> to be sent.

Ungrouping a group does not cause a <deleteBackground> <message> to be sent.

A deleteGroup <message> is sent before the <deleteBackground> <message>. (The <deleteBackground> <message> is included for compatibility with HyperCard.)

References: delete (command), group (command), stack (object), message (glossary), trap (glossary), pass (control_st)

Tags: objects
