Delay the large FyneDo warning unless hints is on

Author: andydotxyz

app/app.go

@@ -5,12 +5,12 @@ package app // import "fyne.io/fyne/v2/app"
 
 import (
 	"fmt"
-	"log"
 	"time"
 
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/internal"
 	"fyne.io/fyne/v2/internal/app"
+	"fyne.io/fyne/v2/internal/async"
 	"fyne.io/fyne/v2/internal/build"
 	intRepo "fyne.io/fyne/v2/internal/repository"
 	"fyne.io/fyne/v2/internal/scheduler"
@@ -80,10 +80,8 @@ func (a *fyneApp) Run() {
 		a.settings.watchSettings()
 	}
 
-	if !build.MigratedToFyneDo() {
-		log.Println("*** This application has not been migrated to the fyne.Do threading model ***")
-		log.Println("*** The next major Fyne release will remove this safety! ***")
-		log.Println("*** Read more at https://docs.fyne.io/started/goroutines ***")
+	if !build.MigratedToFyneDo() && build.HasHints {
+		async.PrintFyneDoWarning()
 	}
 	a.driver.Run()
 }

internal/async/goroutine.go

@@ -10,10 +10,14 @@ import (
 	"fyne.io/fyne/v2/internal/build"
 )
 
-// mainGoroutineID stores the main goroutine ID.
-// This ID must be initialized during setup by calling `SetMainGoroutine` because
-// a main goroutine may not equal to 1 due to the influence of a garbage collector.
-var mainGoroutineID atomic.Uint64
+var (
+	// mainGoroutineID stores the main goroutine ID.
+	// This ID must be initialized during setup by calling `SetMainGoroutine` because
+	// a main goroutine may not equal to 1 due to the influence of a garbage collector.
+	mainGoroutineID atomic.Uint64
+
+	warnedNotMigrated bool
+)
 
 func SetMainGoroutine() {
 	mainGoroutineID.Store(goroutineID())
@@ -29,6 +33,7 @@ func EnsureNotMain(fn func()) {
 		fn()
 		return
 	}
+	PrintFyneDoWarning()
 
 	log.Println("*** Error in Fyne call thread, fyne.Do[AndWait] called from main goroutine ***")
 	log.Println("*** This error needs to be addressed as it will become a deadlock soon ***")
@@ -48,6 +53,7 @@ func EnsureMain(fn func()) {
 		fn()
 		return
 	}
+	PrintFyneDoWarning()
 
 	log.Println("*** Error in Fyne call thread, this should have been called in fyne.Do[AndWait] ***")
 	log.Println("*** This error needs to be addressed as it could cause concurrent errors soon ***")
@@ -89,3 +95,14 @@ func goroutineID() (id uint64) {
 
 	return id
 }
+
+func PrintFyneDoWarning() {
+	if warnedNotMigrated { // shown before
+		return
+	}
+
+	warnedNotMigrated = true
+	log.Println("*** This application has not been migrated to the fyne.Do threading model ***")
+	log.Println("*** The next major Fyne release will remove this safety! ***")
+	log.Println("*** Read more at https://docs.fyne.io/started/goroutines ***")
+}