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Synopsis

condition [-delete] [-dependency string] [-initialize] [-script string] [-state boolean] string

condition is undoable, queryable, and editable.

This command creates a new named condition object whose true/false value is calculated by running a mel script. This new condition can then be used for dimming, or controlling other scripts, or whatever.

Return value

None

In query mode, return type is based on queried flag.

Flags

delete, dependency, initialize, script, state
Long name (short name) Argument types Properties
-delete(-del) create
Deletes the condition.
-dependency(-d) string createmultiuse
Each -dependency flag specifies another condition that the new condition will be dependent on. When any of these conditions change, the new-state-script will run, and the state of this condition will be set accordingly. It is possible to define infinite loops, but they will be caught and handled correctly at run-time.
-initialize(-i) create
Initializes the condition, by forcing it to run its script as soon as it is created. If this flag is not specified, the script will not run until one of the dependencies is triggered.
-script(-s) string create
The script that determines the new state of the condition.
-state(-st) boolean createqueryedit
Sets the state of the condition. This can be used to create a manually triggered condition: you could create a condition without any dependencies and without a new-state-script. This condition would only change state in response to the -st/state flag.
Flag can appear in Create mode of command Flag can appear in Edit mode of command
Flag can appear in Query mode of command Flag can be used more than once in a command.

MEL examples

//    Create a new condition, called "UndoNorRedo", which is true if
//    and only if undo is not available and redo is not available:

global proc int isUndoNorRedo()
{
    return (!`isTrue UndoAvailable` && !`isTrue RedoAvailable`);
}

condition
    -initialize
    -d UndoAvailable
    -d RedoAvailable
    -s "isUndoNorRedo"
    UndoNorRedo;

// Try out the new condition
//
if ( `isTrue UndoNorRedo` ) {
    print ( "Neither undo nor redo is available\n" );
} else {
    print ( "Undo or redo is available\n" );
}

// Get rid of the condition again
//
condition -delete UndoNorRedo;