vlr-undo-reactor (AutoLISP/ActiveX)

Constructs an editor reactor object that notifies of an undo event

Supported Platforms: Windows only

Signature

(vlr-undo-reactor data callbacks)
data

Type: Integer, Real, String, List, VLA-object, safearray, variant, T, or nil

Any AutoLISP data to be associated with the reactor object; otherwise nil if no data.

callbacks

Type: List

A list of pairs of the following form:

(event-name . callback_function)

  • event-name is one of the following Undo reactor events:

    Undo reactor events

    Event name

    Description

    :vlr-undoSubcommandAuto

    The UNDO command's Auto option has been executed.

    :vlr-undoSubcommandControl

    The UNDO command's Control option has been executed.

    :vlr-undoSubcommandBegin

    The UNDO command's BEGIN or GROUP option is being performed. BEGIN and GROUP mark the beginning of a series of commands that can be undone as one unit.

    :vlr-undoSubcommandEnd

    The UNDO command's END option is being performed. UNDO/END marks the end of a series of commands that can be undone as one unit.

    :vlr-undoSubcommandMark

    The UNDO command's MARK option is about to be executed. This places a marker in the undo file so UNDO/BACK can undo back to the marker.

    :vlr-undoSubcommandBack

    The UNDO command's BACK option is about to be performed. UNDO/BACK undoes everything back to the most recent MARK marker or back to the beginning of the undo file if no MARK marker exists.

    :vlr-undoSubcommandNumber

    The UNDO command's NUMBER option is about to be executed (the default action of the UNDO command).

  • and callback_function is a symbol representing a function to be called when the event fires. Each callback function accepts two arguments:

    reactor_object -- The VLR object that called the callback function.

    list -- A list of extra data elements associated with the particular event. The contents of this list for particular events are shown in the “Undo reactor callback data” table.

    Undo reactor callback data

    Name

    List length

    Parameters

    :vlr-undoSubcommandAuto

    2

    First parameter is an integer indicating the activity. The value is always 4, indicating that notification occurred after the operation was performed.

    Second parameter is a symbol indicating the state of Auto mode. Value is T if Auto mode is turned on, nil if Auto mode is turned off.

    :vlr-undoSubcommandControl

    2

    First parameter is an integer indicating the activity. The value is always 4, indicating that notification occurred after the operation was performed.

    Second parameter is an integer indicating the Control option selected. This can be one of the following:

    0 -- NONE was selected

    1 -- ONE was selected

    2 -- ALL was selected

    :vlr-undoSubcommandBegin

    :vlr-undoSubcommandEnd

    :vlr-undoSubcommandMark

    :vlr-undoSubcommandBack

    1

    An integer value of 0, indicating that notification occurs before the actual operation is performed.

    :vlr-undoSubcommandNumber

    2

    First parameter is an integer indicating the activity. The value is always 0, indicating that notification occurs before the actual operation is performed.

    Second parameter is an integer indicating the number of steps being undone.

Return Values

Type: VLR object

The reactor_object argument from the callback_function.

Examples

N/A

Related Concepts