invoke-into

invoke-into Function

Summary

Invokes an Objective-C method that returns a specific type or fills a specific object.

Package

objc

Signature

invoke-into result class-or-object-pointer method &rest args => value

Arguments

`result`⇩	A symbol or list naming the return type or an object to contain the returned value.
`class-or-object-pointer`⇩
	A string naming an Objective-C class, a pointer to an Objective-C foreign object or the result of calling current-super.
`method`⇩	A string naming the method to invoke or a list as specified by invoke.
`args`⇩	Arguments to the method.

Values

value

The value returned by the method.

Description

The function invoke-into is used to call Objective-C instance and class methods that return specific types which are not supported directly by invoke or for methods that return values of some foreign structure type where an existing object should be filled with the value. The meaning of class-or-object-pointer, method and args is identical to invoke.

The value of result controls how the value of the method is converted and returned as follows:

the symbol string	If the result type of the method is `id`, then the value is assumed to be an Objective-C object of class `NSString` and is converted a string and returned. Otherwise no special conversion is performed.
the symbol array	If the result type of the method is `id`, then the value is assumed to be an Objective-C object of class `NSArray` and is converted a vector and returned. Otherwise no special conversion is performed.
a list of the form `(array elt-type)`
	If the result type of the method is `id`, then the value is assumed to be an Objective-C object of class `NSArray` and is recursively converted a vector and returned. The component `elt-type` should be either string, array or another list of the form `(array sub-elt-type)` and is used to control the conversion of the elements. Otherwise no special conversion is performed.
the symbol `:pointer`	If the result type of the method is `unsigned char *`, then the value is returned as a pointer of type objc-c-string. Otherwise no special conversion is performed.
a list of the form `(:pointer elt-type)`
	If the result type of the method is `unsigned char *`, then the value is returned as a pointer with element type `elt-type`. Otherwise no special conversion is performed.
a pointer to a foreign structure
	If the result type of the method is a foreign structure type defined with define-objc-struct or a built-in structure type such as `NSRect`, the value is copied into the structure pointed to by `result` and the pointer is returned. Otherwise no special conversion is performed.
an object of type vector
	If the result type of the method is `id`, then the value is assumed to be an Objective-C object of class `NSArray` and is converted to fill the vector, which must be at least as long as the `NSArray`. The vector is returned. If the result type of the method is `NSRect`, `NSSize` or `NSPoint` then the first 4, 2 or 2 elements respectively of the vector are set to the corresponding components of the result. The vector is returned. Otherwise no special conversion is performed.
an object of type cons
	If the result type of the method is `NSRange` then the car of the cons is set to the `location` of the range and the cdr of the cons is set to the `length` of the range. The cons is returned. Otherwise no special conversion is performed.