fix crash when encoding Error object

example/windows/runner/CMakeLists.txt

@@ -1,18 +1,32 @@
-cmake_minimum_required(VERSION 3.15)
+cmake_minimum_required(VERSION 3.14)
 project(runner LANGUAGES CXX)
 
+# Define the application target. To change its name, change BINARY_NAME in the
+# top-level CMakeLists.txt, not the value here, or `flutter run` will no longer
+# work.
+#
+# Any new source files that you add to the application should be added here.
 add_executable(${BINARY_NAME} WIN32
   "flutter_window.cpp"
   "main.cpp"
-  "run_loop.cpp"
   "utils.cpp"
   "win32_window.cpp"
   "${FLUTTER_MANAGED_DIR}/generated_plugin_registrant.cc"
   "Runner.rc"
   "runner.exe.manifest"
 )
+
+# Apply the standard set of build settings. This can be removed for applications
+# that need different build settings.
 apply_standard_settings(${BINARY_NAME})
+
+# Disable Windows macros that collide with C++ standard library functions.
 target_compile_definitions(${BINARY_NAME} PRIVATE "NOMINMAX")
+
+# Add dependency libraries and include directories. Add any application-specific
+# dependencies here.
 target_link_libraries(${BINARY_NAME} PRIVATE flutter flutter_wrapper_app)
 target_include_directories(${BINARY_NAME} PRIVATE "${CMAKE_SOURCE_DIR}")
+
+# Run the Flutter tool portions of the build. This must not be removed.
 add_dependencies(${BINARY_NAME} flutter_assemble)

example/windows/runner/Runner.rc

@@ -89,11 +89,11 @@ BEGIN
     BEGIN
         BLOCK "040904e4"
         BEGIN
-            VALUE "CompanyName", "soko.ekibun" "\0"
-            VALUE "FileDescription", "A new Flutter project." "\0"
+            VALUE "CompanyName", "com.example" "\0"
+            VALUE "FileDescription", "example" "\0"
             VALUE "FileVersion", VERSION_AS_STRING "\0"
             VALUE "InternalName", "example" "\0"
-            VALUE "LegalCopyright", "Copyright (C) 2020 soko.ekibun. All rights reserved." "\0"
+            VALUE "LegalCopyright", "Copyright (C) 2022 com.example. All rights reserved." "\0"
             VALUE "OriginalFilename", "example.exe" "\0"
             VALUE "ProductName", "example" "\0"
             VALUE "ProductVersion", VERSION_AS_STRING "\0"

example/windows/runner/flutter_window.cpp

@@ -4,9 +4,8 @@
 
 #include "flutter/generated_plugin_registrant.h"
 
-FlutterWindow::FlutterWindow(RunLoop* run_loop,
-                             const flutter::DartProject& project)
-    : run_loop_(run_loop), project_(project) {}
+FlutterWindow::FlutterWindow(const flutter::DartProject& project)
+    : project_(project) {}
 
 FlutterWindow::~FlutterWindow() {}
 
@@ -26,14 +25,12 @@ bool FlutterWindow::OnCreate() {
     return false;
   }
   RegisterPlugins(flutter_controller_->engine());
-  run_loop_->RegisterFlutterInstance(flutter_controller_->engine());
   SetChildContent(flutter_controller_->view()->GetNativeWindow());
   return true;
 }
 
 void FlutterWindow::OnDestroy() {
   if (flutter_controller_) {
-    run_loop_->UnregisterFlutterInstance(flutter_controller_->engine());
     flutter_controller_ = nullptr;
   }
 
@@ -44,7 +41,7 @@ LRESULT
 FlutterWindow::MessageHandler(HWND hwnd, UINT const message,
                               WPARAM const wparam,
                               LPARAM const lparam) noexcept {
-  // Give Flutter, including plugins, an opporutunity to handle window messages.
+  // Give Flutter, including plugins, an opportunity to handle window messages.
   if (flutter_controller_) {
     std::optional<LRESULT> result =
         flutter_controller_->HandleTopLevelWindowProc(hwnd, message, wparam,

example/windows/runner/flutter_window.h

@@ -6,16 +6,13 @@
 
 #include <memory>
 
-#include "run_loop.h"
 #include "win32_window.h"
 
 // A window that does nothing but host a Flutter view.
 class FlutterWindow : public Win32Window {
  public:
-  // Creates a new FlutterWindow driven by the |run_loop|, hosting a
-  // Flutter view running |project|.
-  explicit FlutterWindow(RunLoop* run_loop,
-                         const flutter::DartProject& project);
+  // Creates a new FlutterWindow hosting a Flutter view running |project|.
+  explicit FlutterWindow(const flutter::DartProject& project);
   virtual ~FlutterWindow();
 
  protected:
@@ -26,9 +23,6 @@ class FlutterWindow : public Win32Window {
                          LPARAM const lparam) noexcept override;
 
  private:
-  // The run loop driving events for this window.
-  RunLoop* run_loop_;
-
   // The project to run.
   flutter::DartProject project_;
 

example/windows/runner/main.cpp

@@ -3,7 +3,6 @@
 #include <windows.h>
 
 #include "flutter_window.h"
-#include "run_loop.h"
 #include "utils.h"
 
 int APIENTRY wWinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev,
@@ -18,10 +17,14 @@ int APIENTRY wWinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev,
   // plugins.
   ::CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
 
-  RunLoop run_loop;
-
   flutter::DartProject project(L"data");
-  FlutterWindow window(&run_loop, project);
+
+  std::vector<std::string> command_line_arguments =
+      GetCommandLineArguments();
+
+  project.set_dart_entrypoint_arguments(std::move(command_line_arguments));
+
+  FlutterWindow window(project);
   Win32Window::Point origin(10, 10);
   Win32Window::Size size(1280, 720);
   if (!window.CreateAndShow(L"example", origin, size)) {
@@ -29,7 +32,11 @@ int APIENTRY wWinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev,
   }
   window.SetQuitOnClose(true);
 
-  run_loop.Run();
+  ::MSG msg;
+  while (::GetMessage(&msg, nullptr, 0, 0)) {
+    ::TranslateMessage(&msg);
+    ::DispatchMessage(&msg);
+  }
 
   ::CoUninitialize();
   return EXIT_SUCCESS;

example/windows/runner/run_loop.cpp

@@ -1,66 +0,0 @@
-#include "run_loop.h"
-
-#include <windows.h>
-
-#include <algorithm>
-
-RunLoop::RunLoop() {}
-
-RunLoop::~RunLoop() {}
-
-void RunLoop::Run() {
-  bool keep_running = true;
-  TimePoint next_flutter_event_time = TimePoint::clock::now();
-  while (keep_running) {
-    std::chrono::nanoseconds wait_duration =
-        std::max(std::chrono::nanoseconds(0),
-                 next_flutter_event_time - TimePoint::clock::now());
-    ::MsgWaitForMultipleObjects(
-        0, nullptr, FALSE, static_cast<DWORD>(wait_duration.count() / 1000),
-        QS_ALLINPUT);
-    bool processed_events = false;
-    MSG message;
-    // All pending Windows messages must be processed; MsgWaitForMultipleObjects
-    // won't return again for items left in the queue after PeekMessage.
-    while (::PeekMessage(&message, nullptr, 0, 0, PM_REMOVE)) {
-      processed_events = true;
-      if (message.message == WM_QUIT) {
-        keep_running = false;
-        break;
-      }
-      ::TranslateMessage(&message);
-      ::DispatchMessage(&message);
-      // Allow Flutter to process messages each time a Windows message is
-      // processed, to prevent starvation.
-      next_flutter_event_time =
-          std::min(next_flutter_event_time, ProcessFlutterMessages());
-    }
-    // If the PeekMessage loop didn't run, process Flutter messages.
-    if (!processed_events) {
-      next_flutter_event_time =
-          std::min(next_flutter_event_time, ProcessFlutterMessages());
-    }
-  }
-}
-
-void RunLoop::RegisterFlutterInstance(
-    flutter::FlutterEngine* flutter_instance) {
-  flutter_instances_.insert(flutter_instance);
-}
-
-void RunLoop::UnregisterFlutterInstance(
-    flutter::FlutterEngine* flutter_instance) {
-  flutter_instances_.erase(flutter_instance);
-}
-
-RunLoop::TimePoint RunLoop::ProcessFlutterMessages() {
-  TimePoint next_event_time = TimePoint::max();
-  for (auto instance : flutter_instances_) {
-    std::chrono::nanoseconds wait_duration = instance->ProcessMessages();
-    if (wait_duration != std::chrono::nanoseconds::max()) {
-      next_event_time =
-          std::min(next_event_time, TimePoint::clock::now() + wait_duration);
-    }
-  }
-  return next_event_time;
-}

example/windows/runner/run_loop.h

@@ -1,40 +0,0 @@
-#ifndef RUNNER_RUN_LOOP_H_
-#define RUNNER_RUN_LOOP_H_
-
-#include <flutter/flutter_engine.h>
-
-#include <chrono>
-#include <set>
-
-// A runloop that will service events for Flutter instances as well
-// as native messages.
-class RunLoop {
- public:
-  RunLoop();
-  ~RunLoop();
-
-  // Prevent copying
-  RunLoop(RunLoop const&) = delete;
-  RunLoop& operator=(RunLoop const&) = delete;
-
-  // Runs the run loop until the application quits.
-  void Run();
-
-  // Registers the given Flutter instance for event servicing.
-  void RegisterFlutterInstance(
-      flutter::FlutterEngine* flutter_instance);
-
-  // Unregisters the given Flutter instance from event servicing.
-  void UnregisterFlutterInstance(
-      flutter::FlutterEngine* flutter_instance);
-
- private:
-  using TimePoint = std::chrono::steady_clock::time_point;
-
-  // Processes all currently pending messages for registered Flutter instances.
-  TimePoint ProcessFlutterMessages();
-
-  std::set<flutter::FlutterEngine*> flutter_instances_;
-};
-
-#endif  // RUNNER_RUN_LOOP_H_

example/windows/runner/utils.cpp

@@ -20,3 +20,45 @@ void CreateAndAttachConsole() {
     FlutterDesktopResyncOutputStreams();
   }
 }
+
+std::vector<std::string> GetCommandLineArguments() {
+  // Convert the UTF-16 command line arguments to UTF-8 for the Engine to use.
+  int argc;
+  wchar_t** argv = ::CommandLineToArgvW(::GetCommandLineW(), &argc);
+  if (argv == nullptr) {
+    return std::vector<std::string>();
+  }
+
+  std::vector<std::string> command_line_arguments;
+
+  // Skip the first argument as it's the binary name.
+  for (int i = 1; i < argc; i++) {
+    command_line_arguments.push_back(Utf8FromUtf16(argv[i]));
+  }
+
+  ::LocalFree(argv);
+
+  return command_line_arguments;
+}
+
+std::string Utf8FromUtf16(const wchar_t* utf16_string) {
+  if (utf16_string == nullptr) {
+    return std::string();
+  }
+  int target_length = ::WideCharToMultiByte(
+      CP_UTF8, WC_ERR_INVALID_CHARS, utf16_string,
+      -1, nullptr, 0, nullptr, nullptr);
+  if (target_length == 0) {
+    return std::string();
+  }
+  std::string utf8_string;
+  utf8_string.resize(target_length);
+  int converted_length = ::WideCharToMultiByte(
+      CP_UTF8, WC_ERR_INVALID_CHARS, utf16_string,
+      -1, utf8_string.data(),
+      target_length, nullptr, nullptr);
+  if (converted_length == 0) {
+    return std::string();
+  }
+  return utf8_string;
+}

example/windows/runner/utils.h

@@ -1,8 +1,19 @@
 #ifndef RUNNER_UTILS_H_
 #define RUNNER_UTILS_H_
 
+#include <string>
+#include <vector>
+
 // Creates a console for the process, and redirects stdout and stderr to
 // it for both the runner and the Flutter library.
 void CreateAndAttachConsole();
 
+// Takes a null-terminated wchar_t* encoded in UTF-16 and returns a std::string
+// encoded in UTF-8. Returns an empty std::string on failure.
+std::string Utf8FromUtf16(const wchar_t* utf16_string);
+
+// Gets the command line arguments passed in as a std::vector<std::string>,
+// encoded in UTF-8. Returns an empty std::vector<std::string> on failure.
+std::vector<std::string> GetCommandLineArguments();
+
 #endif  // RUNNER_UTILS_H_

example/windows/runner/win32_window.cpp

@@ -173,7 +173,7 @@ Win32Window::MessageHandler(HWND hwnd,
 
       return 0;
     }
-    case WM_SIZE:
+    case WM_SIZE: {
       RECT rect = GetClientArea();
       if (child_content_ != nullptr) {
         // Size and position the child window.
@@ -181,6 +181,7 @@ Win32Window::MessageHandler(HWND hwnd,
                    rect.bottom - rect.top, TRUE);
       }
       return 0;
+    }
 
     case WM_ACTIVATE:
       if (child_content_ != nullptr) {