[webview_flutter_lwe] Fix "channel sent a message from native to Flutter on a non-platform thread" error

packages/webview_flutter_lwe/tizen/src/message_dispatcher.cc

@@ -0,0 +1,28 @@
+// Copyright 2025 Samsung Electronics Co., Ltd. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "message_dispatcher.h"
+
+#include <Ecore.h>
+
+MessageDispatcher::MessageDispatcher() { ecore_init(); }
+MessageDispatcher::~MessageDispatcher() { ecore_shutdown(); }
+
+void MessageDispatcher::dispatchTaskOnMainThread(std::function<void()> fn) {
+  struct Param {
+    std::function<void()> fn;
+  };
+
+  Param* p = new Param;
+  p->fn = fn;
+
+  ecore_main_loop_thread_safe_call_sync(
+      [](void* data) -> void* {
+        Param* p = (Param*)data;
+        p->fn();
+        delete p;
+        return nullptr;
+      },
+      p);
+}

packages/webview_flutter_lwe/tizen/src/message_dispatcher.h

@@ -0,0 +1,18 @@
+// Copyright 2025 Samsung Electronics Co., Ltd. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_PLUGIN_MESSAGE_DISPATCHER_H_
+#define FLUTTER_PLUGIN_MESSAGE_DISPATCHER_H_
+
+#include <functional>
+
+class MessageDispatcher {
+ public:
+  MessageDispatcher();
+  ~MessageDispatcher();
+
+  void dispatchTaskOnMainThread(std::function<void()> fn);
+};
+
+#endif  // FLUTTER_PLUGIN_MESSAGE_DISPATCHER_H_

packages/webview_flutter_lwe/tizen/src/webview.cc

@@ -125,6 +125,8 @@ WebView::WebView(flutter::PluginRegistrar* registrar, int view_id,
 
   InitWebView();
 
+  dispatcher = new MessageDispatcher();
+
   webview_channel_ = std::make_unique<FlMethodChannel>(
       GetPluginRegistrar()->messenger(), GetWebViewChannelName(),
       &flutter::StandardMethodCodec::GetInstance());
@@ -148,53 +150,65 @@ WebView::WebView(flutter::PluginRegistrar* registrar, int view_id,
 
   webview_instance_->RegisterOnPageStartedHandler(
       [this](LWE::WebContainer* container, const std::string& url) {
-        flutter::EncodableMap args = {
-            {flutter::EncodableValue("url"), flutter::EncodableValue(url)}};
-        navigation_delegate_channel_->InvokeMethod(
-            "onPageStarted", std::make_unique<flutter::EncodableValue>(args));
+        dispatcher->dispatchTaskOnMainThread([&]() {
+          flutter::EncodableMap args = {
+              {flutter::EncodableValue("url"), flutter::EncodableValue(url)}};
+          navigation_delegate_channel_->InvokeMethod(
+              "onPageStarted", std::make_unique<flutter::EncodableValue>(args));
+        });
       });
   webview_instance_->RegisterOnPageLoadedHandler(
       [this](LWE::WebContainer* container, const std::string& url) {
-        flutter::EncodableMap args = {
-            {flutter::EncodableValue("url"), flutter::EncodableValue(url)}};
-        navigation_delegate_channel_->InvokeMethod(
-            "onPageFinished", std::make_unique<flutter::EncodableValue>(args));
+        dispatcher->dispatchTaskOnMainThread([&]() {
+          flutter::EncodableMap args = {
+              {flutter::EncodableValue("url"), flutter::EncodableValue(url)}};
+          navigation_delegate_channel_->InvokeMethod(
+              "onPageFinished",
+              std::make_unique<flutter::EncodableValue>(args));
+        });
       });
   webview_instance_->RegisterOnProgressChangedHandler(
       [this](LWE::WebContainer* container, int progress) {
-        flutter::EncodableMap args = {{flutter::EncodableValue("progress"),
-                                       flutter::EncodableValue(progress)}};
-        navigation_delegate_channel_->InvokeMethod(
-            "onProgress", std::make_unique<flutter::EncodableValue>(args));
+        dispatcher->dispatchTaskOnMainThread([&]() {
+          flutter::EncodableMap args = {{flutter::EncodableValue("progress"),
+                                         flutter::EncodableValue(progress)}};
+          navigation_delegate_channel_->InvokeMethod(
+              "onProgress", std::make_unique<flutter::EncodableValue>(args));
+        });
       });
   webview_instance_->RegisterOnReceivedErrorHandler(
       [this](LWE::WebContainer* container, LWE::ResourceError error) {
-        flutter::EncodableMap args = {
-            {flutter::EncodableValue("errorCode"),
-             flutter::EncodableValue(error.GetErrorCode())},
-            {flutter::EncodableValue("description"),
-             flutter::EncodableValue(error.GetDescription())},
-            {flutter::EncodableValue("failingUrl"),
-             flutter::EncodableValue(error.GetUrl())},
-        };
-        navigation_delegate_channel_->InvokeMethod(
-            "onWebResourceError",
-            std::make_unique<flutter::EncodableValue>(args));
+        dispatcher->dispatchTaskOnMainThread([&]() {
+          flutter::EncodableMap args = {
+              {flutter::EncodableValue("errorCode"),
+               flutter::EncodableValue(error.GetErrorCode())},
+              {flutter::EncodableValue("description"),
+               flutter::EncodableValue(error.GetDescription())},
+              {flutter::EncodableValue("failingUrl"),
+               flutter::EncodableValue(error.GetUrl())},
+          };
+          navigation_delegate_channel_->InvokeMethod(
+              "onWebResourceError",
+              std::make_unique<flutter::EncodableValue>(args));
+        });
       });
   webview_instance_->RegisterShouldOverrideUrlLoadingHandler(
       [this](LWE::WebContainer* view, const std::string& url) -> bool {
         if (!has_navigation_delegate_) {
           return false;
         }
-        flutter::EncodableMap args = {
-            {flutter::EncodableValue("url"), flutter::EncodableValue(url)},
-            {flutter::EncodableValue("isForMainFrame"),
-             flutter::EncodableValue(true)},
-        };
-        auto result = std::make_unique<NavigationRequestResult>(url, this);
-        navigation_delegate_channel_->InvokeMethod(
-            "navigationRequest",
-            std::make_unique<flutter::EncodableValue>(args), std::move(result));
+        dispatcher->dispatchTaskOnMainThread([&]() {
+          flutter::EncodableMap args = {
+              {flutter::EncodableValue("url"), flutter::EncodableValue(url)},
+              {flutter::EncodableValue("isForMainFrame"),
+               flutter::EncodableValue(true)},
+          };
+          auto result = std::make_unique<NavigationRequestResult>(url, this);
+          navigation_delegate_channel_->InvokeMethod(
+              "navigationRequest",
+              std::make_unique<flutter::EncodableValue>(args),
+              std::move(result));
+        });
         return true;
       });
 }
@@ -212,9 +226,11 @@ void WebView::RegisterJavaScriptChannelName(const std::string& name) {
         {flutter::EncodableValue("channel"), flutter::EncodableValue(name)},
         {flutter::EncodableValue("message"), flutter::EncodableValue(message)},
     };
-    webview_channel_->InvokeMethod(
-        "javaScriptChannelMessage",
-        std::make_unique<flutter::EncodableValue>(args));
+    dispatcher->dispatchTaskOnMainThread([&]() {
+      webview_channel_->InvokeMethod(
+          "javaScriptChannelMessage",
+          std::make_unique<flutter::EncodableValue>(args));
+    });
     return "success";
   };
   webview_instance_->AddJavaScriptInterface(name, "postMessage", on_message);
@@ -238,6 +254,11 @@ void WebView::Dispose() {
     webview_instance_->Destroy();
     webview_instance_ = nullptr;
   }
+
+  if (dispatcher) {
+    delete dispatcher;
+    dispatcher = nullptr;
+  }
 }
 
 void WebView::Resize(double width, double height) {
@@ -622,7 +643,9 @@ void WebView::HandleWebViewMethodCall(const FlMethodCall& method_call,
           delete result;
         }
       };
+
       webview_instance_->EvaluateJavaScript(*javascript, on_result);
+
     } else {
       result->Error("Invalid argument", "The argument must be a string.");
     }

packages/webview_flutter_lwe/tizen/src/webview.h

@@ -17,6 +17,8 @@
 #include <mutex>
 #include <string>
 
+#include "message_dispatcher.h"
+
 typedef flutter::MethodCall<flutter::EncodableValue> FlMethodCall;
 typedef flutter::MethodResult<flutter::EncodableValue> FlMethodResult;
 typedef flutter::MethodChannel<flutter::EncodableValue> FlMethodChannel;
@@ -66,6 +68,7 @@ class WebView : public PlatformView {
   void InitWebView();
 
   LWE::WebContainer* webview_instance_ = nullptr;
+  MessageDispatcher* dispatcher = nullptr;
   flutter::TextureRegistrar* texture_registrar_;
   double width_;
   double height_;