50 lines
1.3 KiB
Go
50 lines
1.3 KiB
Go
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// 27 february 2014
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package main
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import (
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"fmt"
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"unsafe"
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)
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// #cgo LDFLAGS: -lobjc -framework Foundation
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// #include <stdlib.h>
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// #include "objc_darwin.h"
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// /* because cgo doesn't like Nil */
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// Class NilClass = Nil;
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import "C"
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var (
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_NSObject_Class = C.object_getClass(_NSObject)
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)
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func newDelegateClass(name string) (C.Class, error) {
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cname := C.CString(name)
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defer C.free(unsafe.Pointer(cname))
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c := C.objc_allocateClassPair(_NSObject_Class, cname, 0)
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if c == C.NilClass {
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return fmt.Errorf("unable to create Objective-C class %s; reason unknown", name)
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}
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C.objc_registerClassPair(c)
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return c, nil
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}
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// according to errors spit out by cgo, C function pointers are unsafe.Pointer
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func addDelegateMethod(class C.Class, sel C.SEL, imp unsafe.Pointer) error {
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// maps to void (*)(id, SEL, id)
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ty := []C.char{'v', '@', ':', '@', 0}
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// clas methods get stored in the metaclass; the objc_allocateClassPair() docs say this will work
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// metaclass := C.object_getClass(C.id(unsafe.Pointer(class)))
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// we're adding instance methods, so just class will do
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ok := C.class_addMethod(class,
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sel,
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C.IMP(imp),
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&ty[0])
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if ok == C.BOOL(C.NO) {
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// TODO get function name
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return fmt.Errorf("unable to add selector %v/imp %v (reason unknown)", sel, imp)
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}
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return nil
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}
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