move shared data structures to external module

3 files changed, 8 insertions, 58 deletions

diff --git a/go.mod b/go.mod
index 6f9d95c..758b712 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/faiface/gui
 go 1.22.4
 
 require (
+	git.samanthony.xyz/share v0.0.0
 	github.com/faiface/mainthread v0.0.0-20171120011319-8b78f0a41ae3
 	github.com/fogleman/gg v1.3.0
 	github.com/go-gl/gl v0.0.0-20231021071112-07e5d0ea2e71
diff --git a/mux.go b/mux.go
index f4eb6d1..b1375a8 100644
--- a/mux.go
+++ b/mux.go
@@ -3,6 +3,8 @@ package gui
 import (
 	"image"
 	"image/draw"
+
+	"git.samanthony.xyz/share"
 )
 
 // Mux can be used to multiplex an Env, let's call it a root Env. Mux implements a way to
@@ -10,7 +12,7 @@ import (
 // events and their draw functions get redirected to the root Env.
 type Mux struct {
 	addEventsIn chan<- chan<- Event
-	size        sharedVal[image.Rectangle]
+	size        share.Val[image.Rectangle]
 	draw        chan<- func(draw.Image) image.Rectangle
 }
 
@@ -20,7 +22,7 @@ type Mux struct {
 // created by the Mux.
 func NewMux(env Env) (mux *Mux, master Env) {
 	addEventsIn := make(chan chan<- Event)
-	size := newSharedVal[image.Rectangle]()
+	size := share.NewVal[image.Rectangle]()
 	drawChan := make(chan func(draw.Image) image.Rectangle)
 	mux = &Mux{
 		addEventsIn: addEventsIn,
@@ -33,7 +35,7 @@ func NewMux(env Env) (mux *Mux, master Env) {
 
 		defer close(env.Draw())
 		defer close(addEventsIn)
-		defer size.close()
+		defer size.Close()
 		defer func() {
 			for _, eventsIn := range eventsIns {
 				close(eventsIn)
@@ -52,7 +54,7 @@ func NewMux(env Env) (mux *Mux, master Env) {
 					return
 				}
 				if resize, ok := e.(Resize); ok {
-					size.set <- resize.Rectangle
+					size.Set <- resize.Rectangle
 				}
 				for _, eventsIn := range eventsIns {
 					eventsIn <- e
@@ -89,7 +91,7 @@ func (mux *Mux) makeEnv(master bool) Env {
 
 	mux.addEventsIn <- eventsIn
 	// make sure to always send a resize event to a new Env
-	eventsIn <- Resize{mux.size.get()}
+	eventsIn <- Resize{mux.size.Get()}
 
 	go func() {
 		func() {
diff --git a/share.go b/share.go
deleted file mode 100644
index 36b903b..0000000
--- a/share.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package gui
-
-// sharedVal is a concurrent interface to a piece of shared data.
-//
-// A client can read the data by sending a channel via request, and the stored value will
-// be sent back via the channel. The client is responsible for closing the channel.
-//
-// The stored value can be changed by sending the new value via set. Requests block until
-// the first value is received on set.
-//
-// A sharedVal should be closed after use.
-type sharedVal[T any] struct {
-	request chan<- chan T
-	set     chan<- T
-}
-
-func newSharedVal[T any]() sharedVal[T] {
-	request := make(chan chan T)
-	set := make(chan T)
-	go func() {
-		val := <-set // wait for initial value
-		for {
-			select {
-			case v, ok := <-set:
-				if !ok { // closed
-					return
-				}
-				val = v
-			case req, ok := <-request:
-				if !ok { // closed
-					return
-				}
-				go func() { // don't wait for client to receive
-					req <- val
-				}()
-			}
-		}
-	}()
-	return sharedVal[T]{request, set}
-}
-
-// get makes a synchronous request and returns the stored value.
-func (sv sharedVal[T]) get() T {
-	c := make(chan T)
-	defer close(c)
-	sv.request <- c
-	return <-c
-}
-
-func (sv sharedVal[T]) close() {
-	close(sv.request)
-	close(sv.set)
-}