wrap glfw.PostEmptyEvent funcion to prevent panic (#579)

Author: pchampio

application.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"runtime"
+	"runtime/debug"
 	"time"
 	"unsafe"
 
@@ -62,6 +63,17 @@ func NewApplication(opt ...Option) *Application {
 	return app
 }
 
+func postEmptyEvent() {
+	defer func() {
+		p := recover()
+		if p != nil {
+			fmt.Printf("go-flutter: recovered from panic 'glfw.PostEmptyEvent()': %v\n", p)
+			debug.PrintStack()
+		}
+	}()
+	glfw.PostEmptyEvent()
+}
+
 // createResourceWindow creates an invisible GLFW window that shares the 'view'
 // window's resource context. This window is used to upload resources in the
 // background. Must be call after the 'view' window is created.
@@ -124,7 +136,7 @@ func (a *Application) Run() error {
 		// TODO(drakirus): Delete this when https://github.com/go-gl/glfw/issues/272 is resolved.
 		// Post an empty event from the main thread before it can happen in a non-main thread,
 		// to work around https://github.com/glfw/glfw/issues/1649.
-		glfw.PostEmptyEvent()
+		postEmptyEvent()
 	}
 
 	if a.config.windowInitialLocation.xpos != 0 {
@@ -204,8 +216,8 @@ func (a *Application) Run() error {
 
 	// Create a new eventloop
 	eventLoop := newEventLoop(
-		glfw.PostEmptyEvent, // Wakeup GLFW
-		a.engine.RunTask,    // Flush tasks
+		postEmptyEvent,   // Wakeup GLFW
+		a.engine.RunTask, // Flush tasks
 	)
 	// Attach TaskRunner callback functions onto the engine
 	a.engine.TaskRunnerRunOnCurrentThread = eventLoop.RunOnCurrentThread

messenger.go

@@ -8,7 +8,6 @@ import (
 	"github.com/go-flutter-desktop/go-flutter/embedder"
 	"github.com/go-flutter-desktop/go-flutter/internal/tasker"
 	"github.com/go-flutter-desktop/go-flutter/plugin"
-	"github.com/go-gl/glfw/v3.3/glfw"
 )
 
 type messenger struct {
@@ -62,7 +61,7 @@ func (m *messenger) SendWithReply(channel string, binaryMessage []byte) (binaryR
 		replyErr := make(chan error)
 		defer close(replyErr)
 
-		glfw.PostEmptyEvent()
+		postEmptyEvent()
 		go m.engineTasker.Do(func() {
 			replyErr <- m.engine.SendPlatformMessage(msg)
 		})
@@ -87,7 +86,7 @@ func (m *messenger) Send(channel string, binaryMessage []byte) (err error) {
 		replyErr := make(chan error)
 		defer close(replyErr)
 
-		glfw.PostEmptyEvent()
+		postEmptyEvent()
 		go m.engineTasker.Do(func() {
 			replyErr <- m.engine.SendPlatformMessage(msg)
 		})
@@ -147,7 +146,7 @@ func (r responseSender) Send(binaryReply []byte) {
 	// TODO: detect multiple responses on the same message and spam the log
 	// about it.
 
-	glfw.PostEmptyEvent()
+	postEmptyEvent()
 	go r.engineTasker.Do(func() {
 		err := r.engine.SendPlatformMessageResponse(r.message.ResponseHandle, binaryReply)
 		if err != nil {