Return channel from run method

application.go

@@ -18,13 +18,13 @@ func (application *Application) SetTitle (title string) {
 	application.backend.SetTitle(title)
 }
 
-// Run initializes the application, and then calls callback. Operations inside
-// of callback are allowed to interact with the application. Depending on the
-// backend used, this function may bind to the main thread.
+// Run initializes the application, starts it, and then returns a channel that
+// broadcasts events. If no suitable backend can be found, an error is returned.
 func (application *Application) Run (
 	callback func (application *Application),
 ) (
-	err error,
+	channel chan(Event),
+	err     error,
 ) {
 	// default values for certain parameters
 	width, height := application.Size()
@@ -44,7 +44,7 @@ func (application *Application) Run (
 
 	application.backend, err = instantiateBackend(application)
 	if err != nil { return }
-	application.backend.Run(callback)
+	channel = application.backend.Run()
 
 	return
 }

backend.go

@@ -1,11 +1,10 @@
 package stone
 
-import "time"
 import "image"
 import "errors"
 
 type Backend interface {
-	Run      () (chan(Event))
+	Run      () (channel chan(Event))
 	SetTitle (title string)
 	SetIcon  (icons []image.Image)
 }

event.go

@@ -1,7 +1,8 @@
-package application
+package stone
 
 type Event interface { }
 
+type EventQuit      struct { }
 type EventPress     Button
 type EventRelease   Button
 type EventResize    struct { }

examples/hello/main.go

@@ -3,7 +3,7 @@ package main
 import "fmt"
 import "time"
 import "git.tebibyte.media/sashakoshka/stone"
-import _ "git.tebibyte.media/sashakoshka/stone/backends/pixel"
+// import _ "git.tebibyte.media/sashakoshka/stone/backends/x"
 
 func main () {
 	application := stone.Application { }