add String and Image + unit tests

CoreFoundation.go

@@ -40,7 +40,7 @@ type CFStringRef unsafe.Pointer
 // created string.
 //
 // It is the program's responsibility to release the object returned by this
-// function with a call to CFStringRelease or CFRelease.
+// function with a call to CFRelease.
 //
 // https://developer.apple.com/library/ios/documentation/CoreFoundation/Reference/CFStringRef/index.html#//apple_ref/c/func/CFStringCreateWithBytes
 func CFStringCreate(s string) CFStringRef {
@@ -54,22 +54,6 @@ func CFStringCreate(s string) CFStringRef {
 	))
 }
 
-// CFStringRetain increases the reference counter of the string object passed as
-// argument.
-//
-// https://developer.apple.com/library/mac/documentation/CoreFoundation/Reference/CFTypeRef/#//apple_ref/c/func/CFRetain
-func CFStringRetain(s CFStringRef) {
-	CFRetain(CFTypeRef(s))
-}
-
-// CFStringRelease decreases the reference counter of the string object passed
-// as argument.
-//
-// https://developer.apple.com/library/mac/documentation/CoreFoundation/Reference/CFTypeRef/#//apple_ref/c/func/CFRelease
-func CFStringRelease(s CFStringRef) {
-	CFRelease(CFTypeRef(s))
-}
-
 // GoString creates a new Go string value with a content equivalent to the
 // CFStringRef object passed as argument.
 func GoString(s CFStringRef) string {

CoreFoundation_test.go

@@ -14,11 +14,11 @@ func TestCFString(t *testing.T) {
 
 	for _, test := range tests {
 		s1 := CFStringCreate(test)
-		CFStringRetain(s1)
-		CFStringRelease(s1)
+		CFRetain(CFTypeRef(s1))
+		CFRelease(CFTypeRef(s1))
 
 		s2 := GoString(s1)
-		CFStringRelease(s1)
+		CFRelease(CFTypeRef(s1))
 
 		if test != s2 {
 			t.Errorf(test, "!=", s2)

CoreGraphics.go

@@ -18,7 +18,7 @@ type CGImageRef unsafe.Pointer
 //
 // The image content is copied by the funciton, it's the program's responsibility
 // to free the resources allocated by the returned CGImageRef with a call to
-// CGImageRelease or CFRelease.
+// CFRelease.
 //
 // The function supports any image types defined in the standard image package,
 // but will panic if the program attempts to create a CGImageRef from an
@@ -63,7 +63,7 @@ func CGImageCreate(img image.Image) CGImageRef {
 // program must ensure that the image.Image value it passed to the function is
 // referenced and unmodified for as long as the returned CGImageRef is in use.
 // It's the program's responsibility to free the resources allocated by the
-// returned CGImageRef with a call to CGImageRelease or CFRelease.
+// returned CGImageRef with a call to CFRelease.
 //
 // The function supports any image types defined in the standard image package,
 // but will panic if the program attempts to create a CGImageRef from an
@@ -99,22 +99,6 @@ func CGImageCreateNoCopy(img image.Image) CGImageRef {
 	return CGImageRef(cgimg)
 }
 
-// CGImageRetain increases the reference counter of the image object passed as
-// argument.
-//
-// https://developer.apple.com/library/mac/documentation/CoreFoundation/Reference/CFTypeRef/#//apple_ref/c/func/CFRetain
-func CGImageRetain(img CGImageRef) {
-	CFRetain(CFTypeRef(img))
-}
-
-// CFImageRelease decreases the reference counter of the image object passed
-// as argument.
-//
-// https://developer.apple.com/library/mac/documentation/CoreFoundation/Reference/CFTypeRef/#//apple_ref/c/func/CFRelease
-func CGImageRelease(img CGImageRef) {
-	CFRelease(CFTypeRef(img))
-}
-
 type imageData struct {
 	pixels []byte
 	bpc    int

CoreGraphics_test.go

@@ -3,32 +3,21 @@
 package cocoa
 
 import (
-	"bufio"
-	"image"
-	"os"
 	"testing"
 
 	_ "image/png"
 )
 
 func TestCGImageCreate(t *testing.T) {
 	img := CGImageCreate(gopher)
-	CGImageRetain(img)
-	CGImageRelease(img)
-	CGImageRelease(img)
+	CFRetain(CFTypeRef(img))
+	CFRelease(CFTypeRef(img))
+	CFRelease(CFTypeRef(img))
 }
 
 func TestCGImageCreateNoCopy(t *testing.T) {
 	img := CGImageCreateNoCopy(gopher)
-	CGImageRetain(img)
-	CGImageRelease(img)
-	CGImageRelease(img)
-}
-
-var gopher image.Image
-
-func init() {
-	f, _ := os.Open("fixtures/gopher.png")
-	gopher, _, _ = image.Decode(bufio.NewReader(f))
-	f.Close()
+	CFRetain(CFTypeRef(img))
+	CFRelease(CFTypeRef(img))
+	CFRelease(CFTypeRef(img))
 }

image.go

@@ -0,0 +1,50 @@
+// +build darwin
+
+package cocoa
+
+import (
+	"image"
+	"runtime"
+)
+
+// The Image type wraps and manages a CGImageRef value.
+//
+// The intent for Image values is to provide automatic memory management for
+// native values from the Cocoa framework by leveraging the Go GC, basically
+// the lifetime of the managed CGImageRef is bound to the lifetime of the
+// Image instance.
+//
+// The Image type also offers an API that betters integrates with Go code by
+// implementing standard interfaces and exposing methods.
+type Image struct {
+	ref CGImageRef
+}
+
+// NewImage creates a new Image value with a content equivalent to the Go
+// image passed as argument.
+func NewImage(img image.Image) *Image {
+	return NewImageWrap(CGImageCreate(img))
+}
+
+// NewImageWarp creates a new Image value that wraps the CGImageRef value
+// passed as argument.
+//
+// The returned Image value becomes the owner of the CGImageRef, it will
+// automatically release it when it gets garbage collected.
+func NewImageWrap(ref CGImageRef) *Image {
+	img := &Image{ref}
+	runtime.SetFinalizer(img, (*Image).release)
+	return img
+}
+
+// Ref returns the CGImageRef wrapped by the Image value it is called on.
+func (img *Image) Ref() CGImageRef {
+	return img.ref
+}
+
+func (img *Image) release() {
+	if ref := img.ref; ref != nil {
+		img.ref = nil
+		CFRelease(CFTypeRef(ref))
+	}
+}

image_test.go

@@ -0,0 +1,35 @@
+// +build darwin
+
+package cocoa
+
+import (
+	"bufio"
+	"image"
+	"os"
+	"testing"
+)
+
+var gopher image.Image
+
+func init() {
+	f, _ := os.Open("fixtures/gopher.png")
+	gopher, _, _ = image.Decode(bufio.NewReader(f))
+	f.Close()
+}
+
+func TestNewImage(t *testing.T) {
+	img := NewImage(gopher)
+
+	if img.Ref() == nil {
+		t.Error("invalid nil image reference")
+	}
+}
+
+func TestNewImageWrap(t *testing.T) {
+	img1 := CGImageCreate(gopher)
+	img2 := NewImageWrap(img1)
+
+	if ref := img2.Ref(); ref != img1 {
+		t.Error("invalid image reference:", ref)
+	}
+}

string.go

@@ -0,0 +1,55 @@
+// +build darwin
+
+package cocoa
+
+import "runtime"
+
+// The String type wraps and manages a CFStringRef value.
+//
+// The intent for String values is to provide automatic memory management for
+// native values from the Cocoa framework by leveraging the Go GC, basically
+// the lifetime of the managed CFStringRef is bound to the lifetime of the
+// String instance.
+//
+// The String type also offers an API that betters integrates with Go code by
+// implementing standard interfaces and exposing methods.
+type String struct {
+	ref CFStringRef
+}
+
+// NewString creates a new String value with a content equivalent to the Go
+// string passed as argument.
+func NewString(s string) *String {
+	return NewStringWrap(CFStringCreate(s))
+}
+
+// NewStringWarp creates a new String value that wraps the CFStringRef value
+// passed as argument.
+//
+// The returned String value becomes the owner of the CFStringRef, it will
+// automatically release it when it gets garbage collected.
+func NewStringWrap(ref CFStringRef) *String {
+	s := &String{ref}
+	runtime.SetFinalizer(s, (*String).release)
+	return s
+}
+
+// String returns the content of the String object as a Go string value.
+func (s *String) String() string {
+	if s.ref == nil {
+		return ""
+	}
+	return GoString(s.ref)
+}
+
+// Ref returns the CFStringRef wrapped by the String value it is called on.
+func (s *String) Ref() CFStringRef {
+	return s.ref
+}
+
+func (s *String) release() {
+	if ref := s.ref; ref != nil {
+		s.ref = nil
+		CFRelease(CFTypeRef(ref))
+	}
+}

string_test.go

@@ -0,0 +1,59 @@
+// +build darwin
+
+package cocoa
+
+import "testing"
+
+func TestNewString(t *testing.T) {
+	tests := []string{
+		"",
+		"0123456789",
+		"Hello World!",
+		"你好",
+	}
+
+	for _, test := range tests {
+		s1 := NewString(test)
+		s2 := s1.String()
+
+		if s2 != test {
+			t.Error("invalid string:", s2, "!=", test)
+		}
+	}
+}
+
+func TestNewStringWrap(t *testing.T) {
+	tests := []string{
+		"",
+		"0123456789",
+		"Hello World!",
+		"你好",
+	}
+
+	for _, test := range tests {
+		s1 := CFStringCreate(test)
+		s2 := NewStringWrap(s1)
+
+		if s2.Ref() != s1 {
+			t.Error("invalid string ref:", s1, "!=", s2)
+		}
+	}
+}
+
+func TestStringZeroValue(t *testing.T) {
+	s1 := &String{}
+	s2 := s1.String()
+
+	if s2 != "" {
+		t.Error("string zero-value produced an invalid Go string:", s2)
+	}
+}
+
+func TestStringRelease(t *testing.T) {
+	s := NewString("")
+	s.release()
+
+	if s.ref != nil {
+		t.Error("releasing didn't set the internal string reference to nil")
+	}
+}