Allow disabling of the thread checks as a "migration" - a pattern we can re-use

app.go

@@ -118,11 +118,14 @@ type AppMetadata struct {
 	// Icon contains, if present, a resource of the icon that was bundled at build time.
 	Icon Resource
 	// Release if true this binary was build in release mode
-	// Since 2.3
+	// Since: 2.3
 	Release bool
 	// Custom contain the custom metadata defined either in FyneApp.toml or on the compile command line
-	// Since 2.3
+	// Since: 2.3
 	Custom map[string]string
+	// Migrations allows an app to opt into features before they are standard
+	// Since: 2.6
+	Migrations map[string]bool
 }
 
 // Lifecycle represents the various phases that an app can transition through.

app/meta.go

@@ -5,12 +5,13 @@ import (
 )
 
 var meta = fyne.AppMetadata{
-	ID:      "",
-	Name:    "",
-	Version: "0.0.1",
-	Build:   1,
-	Release: false,
-	Custom:  map[string]string{},
+	ID:         "",
+	Name:       "",
+	Version:    "0.0.1",
+	Build:      1,
+	Release:    false,
+	Custom:     map[string]string{},
+	Migrations: map[string]bool{},
 }
 
 // SetMetadata overrides the packaged application metadata.
@@ -21,6 +22,9 @@ func SetMetadata(m fyne.AppMetadata) {
 	if meta.Custom == nil {
 		meta.Custom = map[string]string{}
 	}
+	if meta.Migrations == nil {
+		meta.Migrations = map[string]bool{}
+	}
 }
 
 func (a *fyneApp) Metadata() fyne.AppMetadata {

app/meta_development.go

@@ -43,6 +43,7 @@ func checkLocalMetadata() {
 
 	meta.Release = false
 	meta.Custom = data.Development
+	meta.Migrations = data.Migrations
 }
 
 func getProjectPath() string {

cmd/fyne/internal/commands/build.go

@@ -230,6 +230,9 @@ func (b *Builder) build() error {
 	if b.release {
 		tags = append(tags, "release")
 	}
+	if ok, set := b.appData.Migrations["fyneDo"]; ok && set {
+		tags = append(tags, "migrated_fynedo")
+	}
 	if len(tags) > 0 {
 		args = append(args, "-tags", strings.Join(tags, ","))
 	}

cmd/fyne/internal/commands/data.go

@@ -9,6 +9,7 @@ type appData struct {
 	ResGoString       string
 	Release, rawIcon  bool
 	CustomMetadata    map[string]string
+	Migrations        map[string]bool
 	VersionAtLeast2_3 bool
 }
 
@@ -47,4 +48,5 @@ func (a *appData) mergeMetadata(data *metadata.FyneApp) {
 	} else {
 		a.appendCustomMetadata(data.Development)
 	}
+	a.Migrations = data.Migrations
 }

cmd/hello/FyneApp.toml

@@ -4,3 +4,6 @@
   ID = "io.fyne.hello"
   Version = "2.5.3"
   Build = 2
+
+[Migrations]
+  fyneDo = true

internal/async/goroutine.go

@@ -30,7 +30,7 @@ func IsMainGoroutine() bool {
 //
 // This will be removed later and should never be public
 func EnsureNotMain(fn func()) {
-	if build.DisableThreadChecks || !IsMainGoroutine() {
+	if build.MigratedToFyneDo() || !build.HasHints || !IsMainGoroutine() {
 		fn()
 		return
 	}
@@ -47,7 +47,7 @@ func EnsureNotMain(fn func()) {
 //
 // This will be removed later and should never be public
 func EnsureMain(fn func()) {
-	if build.DisableThreadChecks || IsMainGoroutine() {
+	if build.MigratedToFyneDo() || !build.HasHints || IsMainGoroutine() {
 		fn()
 		return
 	}

internal/build/build.go

@@ -1,4 +1,29 @@
 // Package build contains information about they type of build currently running.
 package build
 
-const DisableThreadChecks = false
+import (
+	"sync"
+
+	"fyne.io/fyne/v2"
+)
+
+var (
+	migrateCheck sync.Once
+
+	migratedFyneDo bool
+)
+
+func MigratedToFyneDo() bool {
+	if DisableThreadChecks {
+		return true
+	}
+
+	migrateCheck.Do(func() {
+		v, ok := fyne.CurrentApp().Metadata().Migrations["fyneDo"]
+		if ok {
+			migratedFyneDo = v
+		}
+	})
+
+	return migratedFyneDo
+}

internal/build/migrated_fynedo.go

@@ -0,0 +1,6 @@
+//go:build migrated_fynedo
+
+package build
+
+// DisableThreadChecks disables the thread safety checks for performance.
+const DisableThreadChecks = true

internal/build/migrated_notfynedo.go

@@ -0,0 +1,6 @@
+//go:build !migrated_fynedo
+
+package build
+
+// DisableThreadChecks set to false enables the thread safety checks for logging of incorrect usage.
+const DisableThreadChecks = false

internal/metadata/data.go

@@ -9,6 +9,7 @@ type FyneApp struct {
 	Source      *AppSource        `toml:",omitempty"`
 	LinuxAndBSD *LinuxAndBSD      `toml:",omitempty"`
 	Languages   []string          `toml:",omitempty"`
+	Migrations  map[string]bool   `toml:",omitempty"`
 }
 
 // AppDetails describes the build information, this group may be OS or arch specific

widget/widget.go

@@ -4,6 +4,7 @@ package widget // import "fyne.io/fyne/v2/widget"
 import (
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/internal/async"
 	"fyne.io/fyne/v2/internal/cache"
 	internalWidget "fyne.io/fyne/v2/internal/widget"
 	"fyne.io/fyne/v2/theme"
@@ -111,14 +112,16 @@ func (w *BaseWidget) Hide() {
 
 // Refresh causes this widget to be redrawn in its current state
 func (w *BaseWidget) Refresh() {
-	impl := w.super()
-	if impl == nil {
-		return
-	}
+	async.EnsureMain(func() {
+		impl := w.super()
+		if impl == nil {
+			return
+		}
 
-	w.themeCache = nil
+		w.themeCache = nil
 
-	cache.Renderer(impl).Refresh()
+		cache.Renderer(impl).Refresh()
+	})
 }
 
 // Theme returns a cached Theme instance for this widget (or its extending widget).