#
Chapter 38
`sendevent.ss`: AppleEvents

To load: `(require (lib "sendevent.ss"))`

## 38.1 AppleEvents

`(send-event``` `receiver-byte-string event-class-byte-string event-id-byte-string``` [`direct-argument-v argument-list`]`)` PROCEDURE

Sends an AppleEvent or raises `exn:fail:unsupported`. Currently AppleEvents are supported only within MrEd under Mac OS X.

The `receiver-byte-string`, `event-class-byte-string`, and `event-id-byte-string` arguments specify the signature of the receiving application, the class of the AppleEvent, and the ID of the AppleEvent. Each of these must be a four-character byte string, otherwise the `exn:fail:contract` exception is raised.

The `direct-argument-v` value is converted (see below) and passed as the main argument of the event; if `direct-argument-v` is void, no main argument is sent in the event. The `argument-list` argument is a list of two-element lists containing a typestring and value; each typestring is used ad the keyword name of an AppleEvent argument for the associated converted value. Each typestring must be a four-character string, otherwise the `exn:fail:contract` exception is raised. The default values for `direct-argument` and `arguments` are void and ``null``, respectively.

The following types of MzScheme values can be converted to AppleEvent values passed to the receiver:

`#t` or `#f` | Boolean
small integer | Long Integer
inexact real number | Double
string | Characters
list of convertible values | List of converted values
`#(`file` pathname)` | Alias (file exists) or FSSpec (does not exist)
`#(`record` (typestring v) `···`)` | Record of keyword-tagged values

If other types of values are passed to ``send-event`` for conversion, the `exn:fail:unsupported` exception is raised.

The ``send-event`` procedure does not return until the receiver of the AppleEvent replies. The result of ``send-event`` is the reverse-converted reply value (see below), or the `exn:fail` exception is raised if there is an error. If there is no error or return value, ``send-event`` returns void.

The following types of AppleEvent values can be reverse-converted into a MzScheme value returned by ``send-event``:

Boolean | `#t` or `#f`
Signed Integer | integer
Float, Double, or Extended | inexact real number
Characters | string
list of reverse-convertible values | List of reverse-converted values
Alias or FSSpec | `#(`file` pathname)`
Record of keyword-tagged values | `#(`record` (typestring v) `···`)`

If the AppleEvent reply contains a value that cannot be reverse-converted, the `exn:fail` exception is raised.