From ffa1bbe0b91a8c812ddcea5c5d65e55f60d07f33 Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Mon, 30 Jun 2014 22:48:12 -0400
Subject: Restored the previous new API. I'm going to change it so that events
 are callbacks rather than using a window handler, but other than that...
 yeah.

---
 init.go | 61 +++++++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 43 insertions(+), 18 deletions(-)

(limited to 'init.go')

diff --git a/init.go b/init.go
index 2e59301..72f24ef 100644
--- a/init.go
+++ b/init.go
@@ -2,28 +2,53 @@
 
 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.
-//
-// It is not safe to call ui.Go() in a goroutine. It must be called directly from main().
+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.
 //
-// This model is undesirable, but Cocoa limitations require it.
+// 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.)
 //
-// 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(); err != nil {
+		return err
+	}
+	Ready <- struct{}{}
+	close(Ready)
+	ui()
+	return nil
 }
 
-// AppQuit is pulsed when the user decides to quit the program if their operating system provides a facility for quitting an entire application, rather than merely close all windows (for instance, Mac OS X via the Dock icon).
-// You should assign one of your Windows's Closing to this variable so the user choosing to quit the application is treated the same as closing that window.
-// If you do not respond to this signal, nothing will happen; regardless of whether or not you respond to this signal, the application will not quit.
-// Do not merely check this channel alone; it is not guaranteed to be pulsed on all systems or in all conditions.
-var AppQuit chan struct{}
+// 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{})
 
-func init() {
-	// don't expose this in the documentation
-	AppQuit = newEvent()
+// 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.
+// TODO make sure this acts sanely if called from uitask itself
+func touitask(f func()) {
+	done := make(chan struct{})
+	defer close(done)
+	go func() {		// to avoid locking uitask itself
+		done2 := make(chan struct{})		// make the chain uitask <- f <- uitask to avoid deadlocks
+		defer close(done2)
+		uitask <- func() {
+			f()
+			done2 <- struct{}{}
+		}
+		done <- <-done2
+	}()
+	<-done
 }
-- 
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