Added new MsgBox() behavior on Mac OS X. Now we can finally remove MsgBox() from the TODOs! :D

delegateuitask_darwin.m

@@ -108,8 +108,9 @@ extern NSRect dummyRect;
 	return NSTerminateCancel;
 }
 
-- (void)alertDidEnd:(NSAlert *)alert returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo
+- (void)alertDidEnd:(NSAlert *)alert returnCode:(NSInteger)returnCode contextInfo:(void *)chan
 {
+	dialog_send(chan, (uintptr_t) returnCode);
 }
 
 @end

dialog_darwin.go

@@ -3,19 +3,26 @@
 package ui
 
 import (
-	// ...
+	"unsafe"
 )
 
 // #include "objc_darwin.h"
 import "C"
 
-func _msgBox(parent *Window, primarytext string, secondarytext string, style uintptr) {
-	ret := make(chan struct{})
-	defer close(ret)
+//export dialog_send
+func dialog_send(pchan unsafe.Pointer, res C.intptr_t) {
+	rchan := (*chan int)(pchan)
+	go func() {		// send it in a new goroutine like we do with everything else
+		*rchan <- int(res)
+	}()
+}
+
+func _msgBox(parent *Window, primarytext string, secondarytext string, style uintptr) chan int {
+	ret := make(chan int)
 	uitask <- func() {
 		var pwin C.id = nil
 
-		if parent != nil {
+		if parent != dialogWindow {
 			pwin = parent.sysData.id
 		}
 		primary := toNSString(primarytext)
@@ -25,19 +32,28 @@ func _msgBox(parent *Window, primarytext string, secondarytext string, style uin
 		}
 		switch style {
 		case 0:		// normal
-			C.msgBox(pwin, primary, secondary)
+			C.msgBox(pwin, primary, secondary, unsafe.Pointer(&ret))
 		case 1:		// error
-			C.msgBoxError(pwin, primary, secondary)
+			C.msgBoxError(pwin, primary, secondary, unsafe.Pointer(&ret))
 		}
-		ret <- struct{}{}
 	}
-	<-ret
+	return ret
 }
 
-func msgBox(parent *Window, primarytext string, secondarytext string) {
-	_msgBox(parent, primarytext, secondarytext, 0)
+func (w *Window) msgBox(primarytext string, secondarytext string) (done chan struct{}) {
+	done = make(chan struct{})
+	go func() {
+		<-_msgBox(w, primarytext, secondarytext, 0)
+		done <- struct{}{}
+	}()
+	return done
 }
 
-func msgBoxError(parent *Window, primarytext string, secondarytext string) {
-	_msgBox(parent, primarytext, secondarytext, 1)
+func (w *Window) msgBoxError(primarytext string, secondarytext string) (done chan struct{}) {
+	done = make(chan struct{})
+	go func() {
+		<-_msgBox(w, primarytext, secondarytext, 1)
+		done <- struct{}{}
+	}()
+	return done
 }

dialog_darwin.m

@@ -1,6 +1,7 @@
 // 15 may 2014
 
 #include "objc_darwin.h"
+#include "_cgo_export.h"
 #import <AppKit/NSAlert.h>
 
 // see delegateuitask_darwin.m
@@ -23,7 +24,7 @@
 #define to(T, x) ((T *) (x))
 #define toNSWindow(x) to(NSWindow, (x))
 
-static void alert(id parent, NSString *primary, NSString *secondary, NSAlertStyle style)
+static void alert(id parent, NSString *primary, NSString *secondary, NSAlertStyle style, void *chan)
 {
 	NSAlert *box;
 
@@ -35,20 +36,20 @@ static void alert(id parent, NSString *primary, NSString *secondary, NSAlertStyl
 	// TODO is there a named constant? will also need to be changed when we add different dialog types
 	[box addButtonWithTitle:@"OK"];
 	if (parent == nil)
-		[box runModal];
+		dialog_send(chan, (intptr_t) [box runModal]);
 	else
 		[box beginSheetModalForWindow:toNSWindow(parent)
 			modalDelegate:[NSApp delegate]
 			didEndSelector:@selector(alertDidEnd:returnCode:contextInfo:)
-			contextInfo:NULL];
+			contextInfo:chan];
 }
 
-void msgBox(id parent, id primary, id secondary)
+void msgBox(id parent, id primary, id secondary, void *chan)
 {
-	alert(parent, (NSString *) primary, (NSString *) secondary, NSInformationalAlertStyle);
+	alert(parent, (NSString *) primary, (NSString *) secondary, NSInformationalAlertStyle, chan);
 }
 
-void msgBoxError(id parent, id primary, id secondary)
+void msgBoxError(id parent, id primary, id secondary, void *chan)
 {
-	alert(parent, (NSString *) primary, (NSString *) secondary, NSCriticalAlertStyle);
+	alert(parent, (NSString *) primary, (NSString *) secondary, NSCriticalAlertStyle, chan);
 }

objc_darwin.h

@@ -63,8 +63,8 @@ extern void breakMainLoop(void);
 extern void cocoaMainLoop(void);
 
 /* dialog_darwin.m */
-extern void msgBox(id, id, id);
-extern void msgBoxError(id, id, id);
+extern void msgBox(id, id, id, void *);
+extern void msgBoxError(id, id, id, void *);
 
 /* listbox_darwin.m */
 extern id toListboxItem(id, id);

todo.md

@@ -24,4 +24,3 @@ ALL PLATFORMS:
 	- will require moving dialog behavior to the package overview
 - make sure MouseEvent's documentation has dragging described correctly (both Windows and GTK+ do)
 - make all widths and heights parameters in constructors in the same place (or drop the ones in Window entirely?)
-- Message boxes that belong to agiven parent are still application-modal on all platforms except Mac OS X because the whole system waits... we'll need to use a channel for this, I guess :S