Better signal handling (#1488)

* Better signal handling

* Remove waitgroup

v2/internal/appng/app_bindings.go

@@ -35,6 +35,8 @@ func (a *App) Run() error {
 	return nil
 }
 
+func (a *App) Shutdown() {}
+
 // CreateApp creates the app!
 func CreateApp(appoptions *options.App) (*App, error) {
 	// Set up logger

v2/internal/appng/app_dev.go

@@ -44,11 +44,16 @@ type App struct {
 	ctx              context.Context
 }
 
-func (a *App) Run() error {
-	err := a.frontend.Run(a.ctx)
+func (a *App) Shutdown() {
 	if a.shutdownCallback != nil {
 		a.shutdownCallback(a.ctx)
 	}
+	a.frontend.Quit()
+}
+
+func (a *App) Run() error {
+	err := a.frontend.Run(a.ctx)
+	a.Shutdown()
 	return err
 }
 

v2/internal/appng/app_production.go

@@ -34,11 +34,16 @@ type App struct {
 	ctx              context.Context
 }
 
-func (a *App) Run() error {
-	err := a.frontend.Run(a.ctx)
+func (a *App) Shutdown() {
 	if a.shutdownCallback != nil {
 		a.shutdownCallback(a.ctx)
 	}
+	a.frontend.Quit()
+}
+
+func (a *App) Run() error {
+	err := a.frontend.Run(a.ctx)
+	a.Shutdown()
 	return err
 }
 

v2/internal/signal/signal.go

@@ -1,73 +1,39 @@
 package signal
 
 import (
-	"context"
 	"os"
 	gosignal "os/signal"
 	"sync"
 	"syscall"
-
-	"github.com/wailsapp/wails/v2/internal/logger"
-	"github.com/wailsapp/wails/v2/internal/servicebus"
 )
 
-// Manager manages signals such as CTRL-C
-type Manager struct {
-	// Service Bus
-	bus *servicebus.ServiceBus
+var signalChannel = make(chan os.Signal, 2)
 
-	// logger
-	logger logger.CustomLogger
+var callbacks []func()
+var lock sync.Mutex
 
-	// signalChannel
-	signalchannel chan os.Signal
-
-	// ctx
-	ctx    context.Context
-	cancel context.CancelFunc
-
-	// Parent waitgroup
-	wg *sync.WaitGroup
-}
-
-// NewManager creates a new signal manager
-func NewManager(ctx context.Context, cancel context.CancelFunc, bus *servicebus.ServiceBus, logger *logger.Logger) (*Manager, error) {
-
-	result := &Manager{
-		bus:           bus,
-		logger:        logger.CustomLogger("Signal Manager"),
-		signalchannel: make(chan os.Signal, 2),
-		ctx:           ctx,
-		cancel:        cancel,
-		wg:            ctx.Value("waitgroup").(*sync.WaitGroup),
-	}
-
-	return result, nil
+func OnShutdown(callback func()) {
+	lock.Lock()
+	defer lock.Unlock()
+	callbacks = append(callbacks, callback)
 }
 
 // Start the Signal Manager
-func (m *Manager) Start() {
+func Start() {
 
 	// Hook into interrupts
-	gosignal.Notify(m.signalchannel, os.Interrupt, syscall.SIGTERM, syscall.SIGINT)
-
-	m.wg.Add(1)
+	gosignal.Notify(signalChannel, os.Interrupt, syscall.SIGTERM, syscall.SIGINT)
 
 	// Spin off signal listener and wait for either a cancellation
 	// or signal
 	go func() {
 		select {
-		case <-m.signalchannel:
-			println()
-			m.logger.Trace("Ctrl+C detected. Shutting down...")
-			m.bus.Publish("quit", "ctrl-c pressed")
-
-			// Start shutdown of Wails
-			m.cancel()
-
-		case <-m.ctx.Done():
+		case <-signalChannel:
+			println("")
+			println("Ctrl+C detected. Shutting down...")
+			for _, callback := range callbacks {
+				callback()
+			}
 		}
-		m.logger.Trace("Shutdown")
-		m.wg.Done()
 	}()
 }

v2/wails.go

@@ -4,6 +4,7 @@ package wails
 
 import (
 	app "github.com/wailsapp/wails/v2/internal/appng"
+	"github.com/wailsapp/wails/v2/internal/signal"
 	"github.com/wailsapp/wails/v2/pkg/options"
 )
 
@@ -30,5 +31,11 @@ func Run(options *options.App) error {
 		return err
 	}
 
+	signal.OnShutdown(func() {
+		mainapp.Shutdown()
+	})
+
+	signal.Start()
+
 	return mainapp.Run()
 }