no mutex, only channel

main.go

@@ -2,7 +2,6 @@ package fyneflow
 
 import (
 	"errors"
-	"sync"
 
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/data/binding"
@@ -16,13 +15,10 @@ type FlowItem struct {
 
 type Flow struct {
 	window  fyne.Window
-	flowMut sync.Mutex
 	current string
-	next    string
-	signal  chan struct{}
+	next    chan string
 	items   map[string]*FlowItem
 
-	stateMut sync.Mutex
 	strState map[string]binding.String
 	intState map[string]binding.Int
 	close    bool
@@ -36,19 +32,16 @@ type Flow struct {
 func NewFlow(w fyne.Window) *Flow {
 	f := new(Flow)
 	f.window = w
-	f.flowMut = sync.Mutex{}
 	f.items = make(map[string]*FlowItem)
-	f.signal = make(chan struct{}, 1)
+	f.next = make(chan string, 1)
 	go f.loop()
 	return f
 }
 
 // Close closes the Flow.
 // This will not close the associated fyne.Window!
 func (f *Flow) Close() {
-	f.signal <- struct{}{}
-	f.flowMut.Lock()
-	defer f.flowMut.Unlock()
+	f.next <- ""
 
 	f.close = true
 	for k := range f.items {
@@ -58,88 +51,63 @@ func (f *Flow) Close() {
 
 func (f *Flow) loop() {
 	for !f.close {
-		<-f.signal
-		if f.next != f.current {
-			f.apply()
+		next := <-f.next
+		if next != f.current {
+			f.apply(next)
 		}
 	}
 }
 
 // Set adds a FlowItem to the Flow.
 // If the key already exists, the FlowItem will be overwritten.
 func (f *Flow) Set(key string, generator FlowItemGenerator) *FlowItem {
-	f.flowMut.Lock()
-	defer f.flowMut.Unlock()
-
 	fi := new(FlowItem)
 	fi.generator = generator
 	apply := len(f.items) == 0
 	f.items[key] = fi
 	if apply {
-		f.next = key
+		f.next <- key
 	}
-	f.signal <- struct{}{}
 	return fi
 }
 
 // GoTo sets the content of the window to the content of the FlowItem associated with the given key.
 // If the key is not found, an error is returned.
 func (f *Flow) GoTo(key string) error {
-	f.flowMut.Lock()
-	defer f.flowMut.Unlock()
-
 	if f.current == key {
 		return nil
 	}
 
 	if _, ok := f.items[key]; ok {
-		f.next = key
-		f.signal <- struct{}{}
+		f.next <- key
 		return nil
 	} else {
 		return errors.New("flow: key not found")
 	}
 }
 
-func (f *Flow) apply() {
-	f.flowMut.Lock()
-	defer f.flowMut.Unlock()
-
-	fi, ok := f.items[f.next]
+func (f *Flow) apply(next string) {
+	fi, ok := f.items[next]
 	if !ok || fi == nil {
 		return
 	}
 
 	obj := fi.generator()
 
 	f.window.SetContent(obj)
-	f.current = f.next
+	f.current = next
 }
 
 // Current returns the key of the FlowItem that is currently displayed.
 func (f *Flow) Current() string {
-	f.flowMut.Lock()
-	defer f.flowMut.Unlock()
-
 	return f.current
 }
 
-// Next returns the key of the FlowItem that will be displayed next.
-func (f *Flow) Next() string {
-	f.flowMut.Lock()
-	defer f.flowMut.Unlock()
-
-	return f.next
-}
-
 // UseStateStr returns a binding.String that is associated with the given key.
 // If the key does not exist, a new binding.String is created with the given default value.
 // If the key does exist, the default value is ignored.
 // The returned binding.String is shared between all FlowItems of the Flow.
 func (f *Flow) UseStateStr(key string, def string) binding.String {
-	f.stateMut.Lock()
-	defer f.stateMut.Unlock()
-
 	if f.strState == nil {
 		f.strState = make(map[string]binding.String)
 	}
@@ -157,9 +125,6 @@ func (f *Flow) UseStateStr(key string, def string) binding.String {
 // If the key does exist, the default value is ignored.
 // The returned binding.Int is shared between all FlowItems of the Flow.
 func (f *Flow) UseStateInt(key string, def int) binding.Int {
-	f.stateMut.Lock()
-	defer f.stateMut.Unlock()
-
 	if f.intState == nil {
 		f.intState = make(map[string]binding.Int)
 	}