1 files changed, 35 insertions, 49 deletions

diff --git a/uitask_darwin.go b/uitask_darwin.go
index 3a6d633..2fb6b45 100644
--- a/uitask_darwin.go
+++ b/uitask_darwin.go
@@ -17,7 +17,6 @@ We will create an Objective-C class goAppDelegate. It contains two methods:
 
 // #cgo LDFLAGS: -lobjc -framework Foundation -framework AppKit
 // #include "objc_darwin.h"
-// extern void appDelegate_applicationDidFinishLaunching(id, SEL, id);
 // extern void appDelegate_uitask(id, SEL, id);
 import "C"
 
@@ -27,8 +26,6 @@ func msgBoxError(string, string){}
 
 var uitask chan func()
 
-var mtret chan interface{}
-
 var (
 	_NSAutoreleasePool = objc_getClass("NSAutoreleasePool")
 	_NSValue = objc_getClass("NSValue")
@@ -38,36 +35,44 @@ var (
 	_performSelectorOnMainThread =
 		sel_getUid("performSelectorOnMainThread:withObject:waitUntilDone:")
 	_pointerValue = sel_getUid("pointerValue")
+	_run = sel_getUid("run")
 )
 
-func ui(initDone chan error) {
+func ui(main func()) error {
 	runtime.LockOSThread()
 
 	uitask = make(chan func())
-	mtret = make(chan interface{})
-	go mainThread()
-	v := <-mtret
-	if err, ok := v.(error); ok {
-		initDone <- fmt.Errorf("error initializing Cocoa: %v", err)
-		return
-	}
-	appDelegate := v.(C.id)
 
-	for f := range uitask {
-		// we need to make an NSAutoreleasePool, otherwise we get leak warnings on stderr
-		pool := objc_new(_NSAutoreleasePool)
-		fp := C.objc_msgSend_ptr(_NSValue, _valueWithPointer,
-			unsafe.Pointer(&f))
-		C.objc_msgSend_sel_id_bool(
-			appDelegate,
-			_performSelectorOnMainThread,
-			_uitask,
-			fp,
-			C.BOOL(C.YES))			// wait so we can properly drain the autorelease pool; on other platforms we wind up waiting anyway (since the main thread can only handle one thing at a time) so
-		objc_release(pool)
+	NSApp, appDelegate, err := initCocoa()
+	if err != nil {
+		return err
 	}
+
+	// Cocoa must run on the first thread created by the program, so we run our dispatcher on another thread instead
+	go func() {
+		for f := range uitask {
+			// we need to make an NSAutoreleasePool, otherwise we get leak warnings on stderr
+			pool := objc_new(_NSAutoreleasePool)
+			fp := C.objc_msgSend_ptr(_NSValue, _valueWithPointer,
+				unsafe.Pointer(&f))
+			C.objc_msgSend_sel_id_bool(
+				appDelegate,
+				_performSelectorOnMainThread,
+				_uitask,
+				fp,
+				C.BOOL(C.YES))			// wait so we can properly drain the autorelease pool; on other platforms we wind up waiting anyway (since the main thread can only handle one thing at a time) so
+			objc_release(pool)
+		}
+	}()
+
+	go main()
+
+	C.objc_msgSend_noargs(NSApp, _run)
+	return nil
 }
 
+// TODO move to init_darwin.go?
+
 const (
 	_goAppDelegate = "goAppDelegate"
 )
@@ -76,41 +81,22 @@ var (
 	_NSApplication = objc_getClass("NSApplication")
 
 	_sharedApplication = sel_getUid("sharedApplication")
-	_applicationDidFinishLaunching = sel_getUid("applicationDidFinishLaunching:")
-	_run = sel_getUid("run")
 )
 
-func mainThread() {
-	runtime.LockOSThread()
+func initCocoa() (NSApp C.id, appDelegate C.id, err error) {
+	var appdelegateclass C.Class
 
-	_NSApp := C.objc_msgSend_noargs(_NSApplication, _sharedApplication)
-	appdelegateclass, err := makeDelegateClass(_goAppDelegate)
-	if err != nil {
-		mtret <- fmt.Errorf("error creating NSApplication delegate: %v", err)
-		return
-	}
-	err = addDelegateMethod(appdelegateclass, _applicationDidFinishLaunching,
-		C.appDelegate_applicationDidFinishLaunching)
-	if err != nil {
-		mtret <- fmt.Errorf("error adding NSApplication delegate applicationDidFinishLaunching: method (to start UI loop): %v", err)
-		return
-	}
+	NSApp = C.objc_msgSend_noargs(_NSApplication, _sharedApplication)
 	err = addDelegateMethod(appdelegateclass, _uitask, C.appDelegate_uitask)
 	if err != nil {
-		mtret <- fmt.Errorf("error adding NSApplication delegate uitask: method (to do UI tasks): %v", err)
+		err = fmt.Errorf("error adding NSApplication delegate uitask: method (to do UI tasks): %v", err)
 		return
 	}
 	// TODO using objc_new() causes a segfault; find out why
 	// TODO make alloc followed by init (I thought NSObject provided its own init?)
-	appDelegate := objc_alloc(objc_getClass(_goAppDelegate))
-	objc_setDelegate(_NSApp, appDelegate)
-	// and that's it, really
-	C.objc_msgSend_noargs(_NSApp, _run)
-}
+	appDelegate = objc_alloc(objc_getClass(_goAppDelegate))
 
-//export appDelegate_applicationDidFinishLaunching
-func appDelegate_applicationDidFinishLaunching(self C.id, sel C.SEL, arg C.id) {
-	mtret <- self
+	return
 }
 
 //export appDelegate_uitask