objc: generic Send and SendSuper (#90)

ID.Send and ID.SendSuper can only return integer types (such as ID). These two new functions can take any return type as long as it is a type that RegisterFunc supports.

Closes #87

commit: 9246c5c809fa87320d2791d4f85e4fa870afc535
author: TotallyGamerJet · 3y ago · 2023-01-09 04:51 UTC
committer: GitHub · 3y ago · 2023-01-09 04:51 UTC
parent: 6d5fb77
signature: GPG Unverified4AEE18F83AFDEB23 The key is unknown

2 files · +45 -3

M objc/objc_runtime_darwin.go +31 -3


@@ -18,7 +18,9 @@ import (
18	18		//https://stackoverflow.com/questions/7062599/example-of-how-objective-cs-try-catch-implementation-is-executed-at-runtime
19	19
20	20		var (
	21	+	objc_msgSend_fn uintptr
21	22		objc_msgSend func(obj ID, cmd SEL, args ...interface{}) ID
	23	+	objc_msgSendSuper2_fn uintptr
22	24		objc_msgSendSuper2 func(super *objc_super, cmd SEL, args ...interface{}) ID
23	25		objc_getClass func(name string) Class
24	26		objc_getProtocol func(name string) *Protocol

@@ -37,9 +39,13 @@ var (
37	39
38	40		func init() {
39	41		objc := purego.Dlopen("/usr/lib/libobjc.A.dylib", purego.RTLD_GLOBAL)
40		-
41		-	purego.RegisterLibFunc(&objc_msgSend, objc, "objc_msgSend")
42		-	purego.RegisterLibFunc(&objc_msgSendSuper2, objc, "objc_msgSendSuper2")
	42	+	if err := purego.Dlerror(); err != "" {
	43	+	panic("objc: " + err)
	44	+	}
	45	+	objc_msgSend_fn = purego.Dlsym(objc, "objc_msgSend")
	46	+	purego.RegisterFunc(&objc_msgSend, objc_msgSend_fn)
	47	+	objc_msgSendSuper2_fn = purego.Dlsym(objc, "objc_msgSendSuper2")
	48	+	purego.RegisterFunc(&objc_msgSendSuper2, objc_msgSendSuper2_fn)
43	49		purego.RegisterLibFunc(&object_getClass, objc, "object_getClass")
44	50		purego.RegisterLibFunc(&objc_getClass, objc, "objc_getClass")
45	51		purego.RegisterLibFunc(&objc_getProtocol, objc, "objc_getProtocol")

@@ -70,6 +76,15 @@ func (id ID) Send(sel SEL, args ...interface{}) ID {
70	76		return objc_msgSend(id, sel, args...)
71	77		}
72	78
	79	+	// Send is a convenience method for sending messages to objects that can return any type.
	80	+	// This function takes a SEL instead of a string since RegisterName grabs the global Objective-C lock.
	81	+	// It is best to cache the result of RegisterName.
	82	+	func Send[T any](id ID, sel SEL, args ...any) T {
	83	+	var fn func(id ID, sel SEL, args ...any) T
	84	+	purego.RegisterFunc(&fn, objc_msgSend_fn)
	85	+	return fn(id, sel, args...)
	86	+	}
	87	+
73	88		// objc_super data structure is generated by the Objective-C compiler when it encounters the super keyword
74	89		// as the receiver of a message. It specifies the class definition of the particular superclass that should
75	90		// be messaged.

@@ -89,6 +104,19 @@ func (id ID) SendSuper(sel SEL, args ...interface{}) ID {
89	104		return objc_msgSendSuper2(super, sel, args...)
90	105		}
91	106
	107	+	// SendSuper is a convenience method for sending message to object's super that can return any type.
	108	+	// This function takes a SEL instead of a string since RegisterName grabs the global Objective-C lock.
	109	+	// It is best to cache the result of RegisterName.
	110	+	func SendSuper[T any](id ID, sel SEL, args ...any) T {
	111	+	var super = &objc_super{
	112	+	receiver: id,
	113	+	superClass: id.Class(),
	114	+	}
	115	+	var fn func(objcSuper *objc_super, sel SEL, args ...any) T
	116	+	purego.RegisterFunc(&fn, objc_msgSendSuper2_fn)
	117	+	return fn(super, sel, args...)
	118	+	}
	119	+
92	120		// SEL is an opaque type that represents a method selector
93	121		type SEL uintptr
94	122


@@ -18,7 +18,9 @@ import (
18		//https://stackoverflow.com/questions/7062599/example-of-how-objective-cs-try-catch-implementation-is-executed-at-runtime	18		//https://stackoverflow.com/questions/7062599/example-of-how-objective-cs-try-catch-implementation-is-executed-at-runtime
19			19
20		var (	20		var (
			21	+	objc_msgSend_fn uintptr
21		objc_msgSend func(obj ID, cmd SEL, args ...interface{}) ID	22		objc_msgSend func(obj ID, cmd SEL, args ...interface{}) ID
			23	+	objc_msgSendSuper2_fn uintptr
22		objc_msgSendSuper2 func(super *objc_super, cmd SEL, args ...interface{}) ID	24		objc_msgSendSuper2 func(super *objc_super, cmd SEL, args ...interface{}) ID
23		objc_getClass func(name string) Class	25		objc_getClass func(name string) Class
24		objc_getProtocol func(name string) *Protocol	26		objc_getProtocol func(name string) *Protocol

@@ -37,9 +39,13 @@ var (
37			39
38		func init() {	40		func init() {
39		objc := purego.Dlopen("/usr/lib/libobjc.A.dylib", purego.RTLD_GLOBAL)	41		objc := purego.Dlopen("/usr/lib/libobjc.A.dylib", purego.RTLD_GLOBAL)
40	-		42	+	if err := purego.Dlerror(); err != "" {
41	-	purego.RegisterLibFunc(&objc_msgSend, objc, "objc_msgSend")	43	+	panic("objc: " + err)
42	-	purego.RegisterLibFunc(&objc_msgSendSuper2, objc, "objc_msgSendSuper2")	44	+	}
			45	+	objc_msgSend_fn = purego.Dlsym(objc, "objc_msgSend")
			46	+	purego.RegisterFunc(&objc_msgSend, objc_msgSend_fn)
			47	+	objc_msgSendSuper2_fn = purego.Dlsym(objc, "objc_msgSendSuper2")
			48	+	purego.RegisterFunc(&objc_msgSendSuper2, objc_msgSendSuper2_fn)
43		purego.RegisterLibFunc(&object_getClass, objc, "object_getClass")	49		purego.RegisterLibFunc(&object_getClass, objc, "object_getClass")
44		purego.RegisterLibFunc(&objc_getClass, objc, "objc_getClass")	50		purego.RegisterLibFunc(&objc_getClass, objc, "objc_getClass")
45		purego.RegisterLibFunc(&objc_getProtocol, objc, "objc_getProtocol")	51		purego.RegisterLibFunc(&objc_getProtocol, objc, "objc_getProtocol")

@@ -70,6 +76,15 @@ func (id ID) Send(sel SEL, args ...interface{}) ID {
70		return objc_msgSend(id, sel, args...)	76		return objc_msgSend(id, sel, args...)
71		}	77		}
72			78
			79	+	// Send is a convenience method for sending messages to objects that can return any type.
			80	+	// This function takes a SEL instead of a string since RegisterName grabs the global Objective-C lock.
			81	+	// It is best to cache the result of RegisterName.
			82	+	func Send[T any](id ID, sel SEL, args ...any) T {
			83	+	var fn func(id ID, sel SEL, args ...any) T
			84	+	purego.RegisterFunc(&fn, objc_msgSend_fn)
			85	+	return fn(id, sel, args...)
			86	+	}
			87	+
73		// objc_super data structure is generated by the Objective-C compiler when it encounters the super keyword	88		// objc_super data structure is generated by the Objective-C compiler when it encounters the super keyword
74		// as the receiver of a message. It specifies the class definition of the particular superclass that should	89		// as the receiver of a message. It specifies the class definition of the particular superclass that should
75		// be messaged.	90		// be messaged.

@@ -89,6 +104,19 @@ func (id ID) SendSuper(sel SEL, args ...interface{}) ID {
89		return objc_msgSendSuper2(super, sel, args...)	104		return objc_msgSendSuper2(super, sel, args...)
90		}	105		}
91			106
			107	+	// SendSuper is a convenience method for sending message to object's super that can return any type.
			108	+	// This function takes a SEL instead of a string since RegisterName grabs the global Objective-C lock.
			109	+	// It is best to cache the result of RegisterName.
			110	+	func SendSuper[T any](id ID, sel SEL, args ...any) T {
			111	+	var super = &objc_super{
			112	+	receiver: id,
			113	+	superClass: id.Class(),
			114	+	}
			115	+	var fn func(objcSuper *objc_super, sel SEL, args ...any) T
			116	+	purego.RegisterFunc(&fn, objc_msgSendSuper2_fn)
			117	+	return fn(super, sel, args...)
			118	+	}
			119	+
92		// SEL is an opaque type that represents a method selector	120		// SEL is an opaque type that represents a method selector
93		type SEL uintptr	121		type SEL uintptr
94			122

M objc/objc_runtime_darwin_test.go +14 -0


@@ -5,6 +5,7 @@ package objc_test
5	5
6	6		import (
7	7		"fmt"
	8	+	"testing"
8	9
9	10		"github.com/ebitengine/purego"
10	11		"github.com/ebitengine/purego/objc"

@@ -73,3 +74,16 @@ func ExampleID_SendSuper() {
73	74		// Output: In Child
74	75		// In Super!
75	76		}
	77	+
	78	+	func TestSend(t *testing.T) {
	79	+	// NSNumber comes from Foundation so make sure we have linked to that framework.
	80	+	_ = purego.Dlopen("Foundation.framework/Foundation", purego.RTLD_GLOBAL)
	81	+	const double = float64(2.34)
	82	+	// Initialize a NSNumber
	83	+	NSNumber := objc.ID(objc.GetClass("NSNumber")).Send(objc.RegisterName("numberWithDouble:"), double)
	84	+	// Then get that number back using the generic Send function.
	85	+	var number = objc.Send[float64](NSNumber, objc.RegisterName("doubleValue"))
	86	+	if double != number {
	87	+	t.Failed()
	88	+	}
	89	+	}


@@ -5,6 +5,7 @@ package objc_test
5		5
6	import (	6		import (
7	"fmt"	7		"fmt"
		8	+	"testing"
8		9
9	"github.com/ebitengine/purego"	10		"github.com/ebitengine/purego"
10	"github.com/ebitengine/purego/objc"	11		"github.com/ebitengine/purego/objc"

@@ -73,3 +74,16 @@ func ExampleID_SendSuper() {
73	// Output: In Child	74		// Output: In Child
74	// In Super!	75		// In Super!
75	}	76		}
		77	+
		78	+	func TestSend(t *testing.T) {
		79	+	// NSNumber comes from Foundation so make sure we have linked to that framework.
		80	+	_ = purego.Dlopen("Foundation.framework/Foundation", purego.RTLD_GLOBAL)
		81	+	const double = float64(2.34)
		82	+	// Initialize a NSNumber
		83	+	NSNumber := objc.ID(objc.GetClass("NSNumber")).Send(objc.RegisterName("numberWithDouble:"), double)
		84	+	// Then get that number back using the generic Send function.
		85	+	var number = objc.Send[float64](NSNumber, objc.RegisterName("doubleValue"))
		86	+	if double != number {
		87	+	t.Failed()
		88	+	}
		89	+	}