backgroundBehavior

Specifies whether a group behaves as a background and come after it's card on the message path.

# Metadata

Platforms: desktop, server, mobile OS: mac, windows, linux, ios, android Introduced: 1.1 Security:

# Syntax

set the backgroundBehavior of group to {true | false}

# Examples

set the backgroundBehavior of group 1 to false

set the backgroundBehavior of the last group to true

if the backgroundBehavior of group "backgroundObjects" is true then -- do something end if

# Description

Use the backgroundBehavior property to make groups behave like backgrounds and to automatically place groups on newly created cards.

Only top-level groups may be background groups; an attempt to set the backgroundBehavior of a nested group to true throws an error.

A background group differs from a normal group in the following ways:

* The group's script is placed behind the card in the message path for any message not originating from a control within it. * The group can be referred to using the 'background' chunk. * The card on which the group is placed receives preOpenBackground / openBackground / closeBackground messages (these messages occur instead of preOpenControl / openControl / closeControl being sent to the group itself). * The group can be placed onto multiple cards. * If the group is placed on 'this card' at the time a new card is created, it is automatically placed onto the new (empty) card.

A background group is also a shared group. This means that when the backgroundBehavior is set to true, the sharedBehavior is also set to true (if it is not already).

>*Note:* Setting the backgroundBehavior of a group to false does not > affect the sharedBehavior property, in particular the latter is not > be set to false until it is explicitly done so.

>*Note:* Only groups whose backgroundBehavior is true appear in the > list reported by the backgroundNames and backgroundIDs properties.

>*Note:* If a stack created in a version of LiveCode earlier than 1.1 is > opened in 1.1 or later, the backgroundBehavior of all its groups is > set to true by default. This also applies to imported HyperCard > stacks.

# Tags

objects,

# See

- **property:** HCAddressing, sharedBehavior, backgroundNames, backgroundIDs, dynamicPaths - **message:** preOpenBackground, openControl, openBackground, closeBackground, preOpenControl, closeControl - **command:** place, send - **control structure:** pass