Migrated init.go to the new API. This should probably be renamed now.

init.go

@@ -2,21 +2,39 @@
 
 package ui
 
-// Go sets up the UI environment and runs main in a goroutine.
-// If initialization fails, Go returns an error and main is not called.
-// Otherwise, Go does not return to its caller until main does, at which point it returns nil.
-// After it returns, you cannot call future ui functions/methods meaningfully.
+import (
+	"runtime"
+)
+
+// Go sets up the UI environment and pulses Ready.
+// If initialization fails, Go returns an error and Ready is not pulsed.
+// Otherwise, Go does not return to its caller until Stop is pulsed, at which point Go() will return nil.
+// After Go() returns, you cannot call future ui functions/methods meaningfully.
+// Pulsing Stop will cause Go() to return immediately; the programmer is responsible for cleaning up (for instance, hiding open Windows) beforehand.
 //
-// It is not safe to call ui.Go() in a goroutine. It must be called directly from main().
+// It is not safe to call ui.Go() in a goroutine. It must be called directly from main(). This means if your code calls other code-modal servers (such as http.ListenAndServe()), they must be run from goroutines. (This is due to limitations in various OSs, such as Mac OS X.)
 //
-// This model is undesirable, but Cocoa limitations require it.
-//
-// Go does not process the command line for flags (that is, it does not call flag.Parse()), nor does package ui add any of the underlying toolkit's supported command-line flags.
+// Go() does not process the command line for flags (that is, it does not call flag.Parse()), nor does package ui add any of the underlying toolkit's supported command-line flags.
 // If you must, and if the toolkit also has environment variable equivalents to these flags (for instance, GTK+), use those instead.
-func Go(main func()) error {
-	return ui(main)
+func Go() error {
+	runtime.LockOSThread()
+	if err := uiinit(main); err != nil {
+		return err
+	}
+	Ready <- struct{}{}
+	close(Ready)
+	ui()
 }
 
+// Ready is pulsed when Go() is ready to begin accepting requests to the safe methods.
+// Go() will wait for something to receive on Ready, then Ready will be closed.
+var Ready = make(chan struct{})
+
+// Stop should be pulsed when you are ready for Go() to return.
+// Pulsing Stop will cause Go() to return immediately; the programmer is responsible for cleaning up (for instance, hiding open Windows) beforehand.
+// Do not pulse Stop more than once.
+var Stop = make(chan struct{})
+
 // This function is a simple helper functionn that basically pushes the effect of a function call for later. This allows the selected safe Window methods to be safe.
 // It's also currently used by the various dialog box functions on Windows to allow them to return instantly, rather than wait for the dialog box to finish (which both GTK+ and Mac OS X let you do). I consider this a race condition bug. TODO (also TODO document the /intended/ behavior)
 func touitask(f func()) {