Converted the Mac OS X backend to use uitask() instead of uitask chan func().

delegateuitask_darwin.m

@@ -127,7 +127,7 @@ void douitask(id appDelegate, void *p)
 	fp = [NSValue valueWithPointer:p];
 	[appDelegate performSelectorOnMainThread:@selector(uitask:)
 		withObject:fp
-		waitUntilDone: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
+		waitUntilDone:YES];		// wait since that's what we want the Go uitask() to do
 	[pool release];
 }
 

dialog_darwin.go

@@ -19,7 +19,7 @@ func dialog_send(pchan unsafe.Pointer, res C.intptr_t) {
 
 func _msgBox(parent *Window, primarytext string, secondarytext string, style uintptr) chan int {
 	ret := make(chan int)
-	uitask <- func() {
+	uitask(func() {
 		var pwin C.id = nil
 
 		if parent != dialogWindow {
@@ -36,7 +36,7 @@ func _msgBox(parent *Window, primarytext string, secondarytext string, style uin
 		case 1: // error
 			C.msgBoxError(pwin, primary, secondary, unsafe.Pointer(&ret))
 		}
-	}
+	})
 	return ret
 }
 

sysdata_darwin.go

@@ -225,20 +225,14 @@ func (s *sysData) make(window *sysData) error {
 	if window != nil {
 		parentWindow = window.id
 	}
-	ret := make(chan C.id)
+	uitask(func() {
-	defer close(ret)
+		s.id = ct.make(parentWindow, s.alternate, s)
-	uitask <- func() {
+		if ct.getinside != nil {
-		ret <- ct.make(parentWindow, s.alternate, s)
+			addSysData(ct.getinside(s.id), s)
-	}
+		} else {
-	s.id = <-ret
+			addSysData(s.id, s)
-	if ct.getinside != nil {
-		uitask <- func() {
-			ret <- ct.getinside(s.id)
 		}
-		addSysData(<-ret, s)
+	})
-	} else {
-		addSysData(s.id, s)
-	}
 	return nil
 }
 
@@ -249,33 +243,21 @@ func (s *sysData) firstShow() error {
 }
 
 func (s *sysData) show() {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		classTypes[s.ctype].show(s.id)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) hide() {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		classTypes[s.ctype].hide(s.id)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) setText(text string) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		classTypes[s.ctype].settext(s.id, toNSString(text))
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) setRect(x int, y int, width int, height int, winheight int) error {
@@ -288,147 +270,111 @@ func (s *sysData) setRect(x int, y int, width int, height int, winheight int) er
 }
 
 func (s *sysData) isChecked() bool {
-	ret := make(chan bool)
+	var b bool
-	defer close(ret)
+
-	uitask <- func() {
+	uitask(func() {
-		ret <- C.isCheckboxChecked(s.id) != C.NO
+		b = C.isCheckboxChecked(s.id) != C.NO
-	}
+	})
-	return <-ret
+	return b
 }
 
 func (s *sysData) text() string {
-	ret := make(chan string)
+	var text string
-	defer close(ret)
+
-	uitask <- func() {
+	uitask(func() {
 		str := classTypes[s.ctype].text(s.id, s.alternate)
-		ret <- fromNSString(str)
+		text = fromNSString(str)
-	}
+	})
-	return <-ret
+	return text
 }
 
 func (s *sysData) append(what string) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		classTypes[s.ctype].append(s.id, what, s.alternate)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) insertBefore(what string, before int) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		classTypes[s.ctype].insertBefore(s.id, what, before, s.alternate)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) selectedIndex() int {
-	ret := make(chan int)
+	var i int
-	defer close(ret)
+
-	uitask <- func() {
+	uitask(func() {
-		ret <- classTypes[s.ctype].selIndex(s.id)
+		i = classTypes[s.ctype].selIndex(s.id)
-	}
+	})
-	return <-ret
+	return i
 }
 
 func (s *sysData) selectedIndices() []int {
-	ret := make(chan []int)
+	var i []int
-	defer close(ret)
+
-	uitask <- func() {
+	uitask(func() {
-		ret <- classTypes[s.ctype].selIndices(s.id)
+		i = classTypes[s.ctype].selIndices(s.id)
-	}
+	})
-	return <-ret
+	return i
 }
 
 func (s *sysData) selectedTexts() []string {
-	ret := make(chan []string)
+	var texts []string
-	defer close(ret)
+
-	uitask <- func() {
+	uitask(func() {
-		ret <- classTypes[s.ctype].selTexts(s.id)
+		texts = classTypes[s.ctype].selTexts(s.id)
-	}
+	})
-	return <-ret
+	return texts
 }
 
 func (s *sysData) setWindowSize(width int, height int) error {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		C.windowSetContentSize(s.id, C.intptr_t(width), C.intptr_t(height))
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 	return nil
 }
 
 func (s *sysData) delete(index int) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		classTypes[s.ctype].delete(s.id, index)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) setProgress(percent int) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		C.setProgress(s.id, C.intptr_t(percent))
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) len() int {
-	ret := make(chan int)
+	var i int
-	defer close(ret)
+
-	uitask <- func() {
+	uitask(func() {
-		ret <- classTypes[s.ctype].len(s.id)
+		i = classTypes[s.ctype].len(s.id)
-	}
+	})
-	return <-ret
+	return i
 }
 
 func (s *sysData) setAreaSize(width int, height int) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		C.setAreaSize(s.id, C.intptr_t(width), C.intptr_t(height))
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) repaintAll() {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		C.display(s.id)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) center() {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		C.center(s.id)
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }
 
 func (s *sysData) setChecked(checked bool) {
-	ret := make(chan struct{})
+	uitask(func() {
-	defer close(ret)
-	uitask <- func() {
 		C.setCheckboxChecked(s.id, toBOOL(checked))
-		ret <- struct{}{}
+	})
-	}
-	<-ret
 }

uitask_darwin.go

@@ -14,30 +14,25 @@ import (
 // #include "objc_darwin.h"
 import "C"
 
-var uitask chan func()
+// can be run from any thread
+// will wait for return; see delegateuitask_darwin.m
+func uitask(f func()) {
+	C.douitask(appDelegate, unsafe.Pointer(&f))
+}
 
 func ui(main func()) error {
 	runtime.LockOSThread()
 
-	uitask = make(chan func())
-
 	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 {
-			C.douitask(appDelegate, unsafe.Pointer(&f))
-		}
-	}()
-
 	go func() {
 		main()
-		uitask <- func() {
+		uitask(func() {
 			C.breakMainLoop()
-		}
+		})
 	}()
 
 	C.cocoaMainLoop()