Changed the way drawRect: was being added to our Mac OS X Area such that we no longer need a separate function to add it to the class.

area_darwin.go

@@ -3,7 +3,6 @@
 package ui
 
 import (
-	"fmt"
 	"unsafe"
 	"image"
 )
@@ -12,7 +11,6 @@ import (
 // #include <stdlib.h>
 //// #include <HIToolbox/Events.h>
 // #include "objc_darwin.h"
-// extern void areaView_drawRect(id, struct xrect);
 // extern BOOL areaView_isFlipped_acceptsFirstResponder(id, SEL);
 // extern void areaView_mouseMoved(id, SEL, id);
 // extern void areaView_mouseDown_mouseDragged(id, SEL, id);
@@ -29,11 +27,11 @@ const (
 var (
 	_goArea C.id
 	_NSView = objc_getClass("NSView")
-
-	_drawRect = sel_getUid("drawRect:")
 )
 
 var goAreaSels = []selector{
+	selector{"drawRect:", uintptr(C._areaView_drawRect), sel_void_rect,
+		"actually drawing Areas"},
 	selector{"isFlipped", uintptr(C.areaView_isFlipped_acceptsFirstResponder), sel_bool,
 		"ensuring that an Area's coordinate system has (0,0) at the top-left corner"},
 	selector{"acceptsFirstResponder", uintptr(C.areaView_isFlipped_acceptsFirstResponder), sel_bool,
@@ -67,16 +65,11 @@ var goAreaSels = []selector{
 }
 
 func mkAreaClass() error {
-	id, class, err := makeClass(__goArea, _NSView, goAreaSels,
+	id, err := makeClass(__goArea, _NSView, goAreaSels,
 		"the implementation of Area on Mac OS X")
 	if err != nil {
 		return err
 	}
-	// addAreaViewDrawMethod() is in bleh_darwin.m
-	ok := C.addAreaViewDrawMethod(class)
-	if ok != C.BOOL(C.YES) {
-		return fmt.Errorf("unable to add selector drawRect: to class %s (needed for actually drawing Areas; reason unknown)", __goArea)
-	}
 	_goArea = id
 	return nil
 }

bleh_darwin.m

@@ -210,7 +210,7 @@ id makeDummyEvent()
 
 extern void areaView_drawRect(id, struct xrect);
 
-static void _areaView_drawRect(id self, SEL sel, NSRect r)
+static void __areaView_drawRect(id self, SEL sel, NSRect r)
 {
 	struct xrect t;
 
@@ -221,21 +221,15 @@ static void _areaView_drawRect(id self, SEL sel, NSRect r)
 	areaView_drawRect(self, t);
 }
 
-/* the only objective-c feature you'll see here */
+void *_areaView_drawRect = (void *) __areaView_drawRect;
-/* TODO correct? "v@:" @encode(NSRect) complained about missing ; */
-static char *avdrType = @encode(void(id, SEL, NSRect));
 
-static SEL drawRect;
+/* the only objective-c feature you'll see here
-static BOOL drawRect_init = NO;
 
-BOOL addAreaViewDrawMethod(Class what)
+unfortunately NSRect both varies across architectures and is passed as just a structure, so its encoding has to be computed at compile time
-{
+because @encode() is NOT A LITERAL, we're going to just stick it all the way back in objc_darwin.go
-	if (drawRect_init == NO) {
+see also: http://stackoverflow.com/questions/6812035/adding-methods-dynamically
-		drawRect = sel_getUid("drawRect:");
+*/
-		drawRect_init = YES;
+char *encodedNSRect = @encode(NSRect);
-	}
-	return class_addMethod(what, drawRect, (IMP) _areaView_drawRect, avdrType);
-}
 
 /*
 the NSBitmapImageRep constructor is complex; put it here

delegate_darwin.go

@@ -48,7 +48,7 @@ var appDelegateSels = []selector{
 }
 
 func mkAppDelegate() error {
-	id, _, err := makeClass(_goAppDelegate, _NSObject, appDelegateSels,
+	id, err := makeClass(_goAppDelegate, _NSObject, appDelegateSels,
 		"application delegate (handles events)")
 	if err != nil {
 		return err

objc_darwin.go

@@ -68,6 +68,7 @@ const (
 	sel_void_id itype = iota
 	sel_bool_id
 	sel_bool
+	sel_void_rect
 	nitypes
 )
 
@@ -75,9 +76,22 @@ var itypes = [nitypes][]C.char{
 	sel_void_id:	[]C.char{'v', '@', ':', '@', 0},
 	sel_bool_id:	[]C.char{'c', '@', ':', '@', 0},
 	sel_bool:		[]C.char{'c', '@', ':', 0},
+	sel_void_rect:	nil,			// see init() below
 }
 
-func makeClass(name string, super C.id, sels []selector, desc string) (id C.id, class C.Class, err error) {
+func init() {
+	// see encodedNSRect in bleh_darwin.m
+	x := make([]C.char, 0, 256)	// more than enough
+	x = append(x, 'v', '@', ':')
+	y := C.GoString(C.encodedNSRect)
+	for _, b := range y {
+		x = append(x, C.char(b))
+	}
+	x = append(x, 0)
+	itypes[sel_void_rect] = x
+}
+
+func makeClass(name string, super C.id, sels []selector, desc string) (id C.id, err error) {
 	cname := C.CString(name)
 	defer C.free(unsafe.Pointer(cname))
 
@@ -97,5 +111,5 @@ func makeClass(name string, super C.id, sels []selector, desc string) (id C.id,
 			return
 		}
 	}
-	return objc_getClass(name), c, nil
+	return objc_getClass(name), nil
 }

objc_darwin.h

@@ -113,10 +113,13 @@ extern uintptr_t *NSIndexSetEntries(id, uintptr_t);
 extern id makeDummyEvent();
 
 /* for area_darwin.go */
-extern BOOL addAreaViewDrawMethod(Class);
+extern void *_areaView_drawRect;
 extern void drawImage(void *, int64_t, int64_t, int64_t, int64_t, int64_t);
 extern struct xpoint getTranslatedEventPoint(id, id);
 
+/* for objc_darwin.go */
+extern char *encodedNSRect;
+
 /* for sysdata_darwin.go */
 extern void objc_setFont(id, unsigned int);