Rebuild runners (#1725)

experimental/context_menus/windows/CMakeLists.txt

@@ -52,6 +52,7 @@ add_subdirectory(${FLUTTER_MANAGED_DIR})
 # Application build; see runner/CMakeLists.txt.
 add_subdirectory("runner")
 
+
 # Generated plugin build rules, which manage building the plugins and adding
 # them to the application.
 include(flutter/generated_plugins.cmake)

experimental/context_menus/windows/runner/CMakeLists.txt

@@ -33,6 +33,7 @@ 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_link_libraries(${BINARY_NAME} PRIVATE "dwmapi.lib")
 target_include_directories(${BINARY_NAME} PRIVATE "${CMAKE_SOURCE_DIR}")
 
 # Run the Flutter tool portions of the build. This must not be removed.

experimental/context_menus/windows/runner/Runner.rc

@@ -93,7 +93,7 @@ BEGIN
             VALUE "FileDescription", "context_menus" "\0"
             VALUE "FileVersion", VERSION_AS_STRING "\0"
             VALUE "InternalName", "context_menus" "\0"
-            VALUE "LegalCopyright", "Copyright (C) 2022 com.example. All rights reserved." "\0"
+            VALUE "LegalCopyright", "Copyright (C) 2023 com.example. All rights reserved." "\0"
             VALUE "OriginalFilename", "context_menus.exe" "\0"
             VALUE "ProductName", "context_menus" "\0"
             VALUE "ProductVersion", VERSION_AS_STRING "\0"

experimental/context_menus/windows/runner/utils.cpp

@@ -47,16 +47,17 @@ std::string Utf8FromUtf16(const wchar_t* utf16_string) {
   }
   int target_length = ::WideCharToMultiByte(
       CP_UTF8, WC_ERR_INVALID_CHARS, utf16_string,
-      -1, nullptr, 0, nullptr, nullptr);
+      -1, nullptr, 0, nullptr, nullptr)
+    -1; // remove the trailing null character
+  int input_length = (int)wcslen(utf16_string);
   std::string utf8_string;
-  if (target_length == 0 || target_length > utf8_string.max_size()) {
+  if (target_length <= 0 || target_length > utf8_string.max_size()) {
     return 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);
+      input_length, utf8_string.data(), target_length, nullptr, nullptr);
   if (converted_length == 0) {
     return std::string();
   }

experimental/context_menus/windows/runner/win32_window.cpp

@@ -1,13 +1,31 @@
 #include "win32_window.h"
 
+#include <dwmapi.h>
 #include <flutter_windows.h>
 
 #include "resource.h"
 
 namespace {
 
+/// Window attribute that enables dark mode window decorations.
+///
+/// Redefined in case the developer's machine has a Windows SDK older than
+/// version 10.0.22000.0.
+/// See: https://docs.microsoft.com/windows/win32/api/dwmapi/ne-dwmapi-dwmwindowattribute
+#ifndef DWMWA_USE_IMMERSIVE_DARK_MODE
+#define DWMWA_USE_IMMERSIVE_DARK_MODE 20
+#endif
+
 constexpr const wchar_t kWindowClassName[] = L"FLUTTER_RUNNER_WIN32_WINDOW";
 
+/// Registry key for app theme preference.
+///
+/// A value of 0 indicates apps should use dark mode. A non-zero or missing
+/// value indicates apps should use light mode.
+constexpr const wchar_t kGetPreferredBrightnessRegKey[] =
+  L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
+constexpr const wchar_t kGetPreferredBrightnessRegValue[] = L"AppsUseLightTheme";
+
 // The number of Win32Window objects that currently exist.
 static int g_active_window_count = 0;
 
@@ -42,7 +60,7 @@ class WindowClassRegistrar {
  public:
   ~WindowClassRegistrar() = default;
 
-  // Returns the singleton registar instance.
+  // Returns the singleton registrar instance.
   static WindowClassRegistrar* GetInstance() {
     if (!instance_) {
       instance_ = new WindowClassRegistrar();
@@ -126,6 +144,8 @@ bool Win32Window::Create(const std::wstring& title,
     return false;
   }
 
+  UpdateTheme(window);
+
   return OnCreate();
 }
 
@@ -192,6 +212,10 @@ Win32Window::MessageHandler(HWND hwnd,
         SetFocus(child_content_);
       }
       return 0;
+
+    case WM_DWMCOLORIZATIONCOLORCHANGED:
+      UpdateTheme(hwnd);
+      return 0;
   }
 
   return DefWindowProc(window_handle_, message, wparam, lparam);
@@ -247,3 +271,18 @@ bool Win32Window::OnCreate() {
 void Win32Window::OnDestroy() {
   // No-op; provided for subclasses.
 }
+
+void Win32Window::UpdateTheme(HWND const window) {
+  DWORD light_mode;
+  DWORD light_mode_size = sizeof(light_mode);
+  LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
+                               kGetPreferredBrightnessRegValue,
+                               RRF_RT_REG_DWORD, nullptr, &light_mode,
+                               &light_mode_size);
+
+  if (result == ERROR_SUCCESS) {
+    BOOL enable_dark_mode = light_mode == 0;
+    DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
+                          &enable_dark_mode, sizeof(enable_dark_mode));
+  }
+}

experimental/context_menus/windows/runner/win32_window.h

@@ -77,7 +77,7 @@ class Win32Window {
   // OS callback called by message pump. Handles the WM_NCCREATE message which
   // is passed when the non-client area is being created and enables automatic
   // non-client DPI scaling so that the non-client area automatically
-  // responsponds to changes in DPI. All other messages are handled by
+  // responds to changes in DPI. All other messages are handled by
   // MessageHandler.
   static LRESULT CALLBACK WndProc(HWND const window,
                                   UINT const message,
@@ -87,6 +87,9 @@ class Win32Window {
   // Retrieves a class instance pointer for |window|
   static Win32Window* GetThisFromHandle(HWND const window) noexcept;
 
+  // Update the window frame's theme to match the system theme.
+  static void UpdateTheme(HWND const window);
+
   bool quit_on_close_ = false;
 
   // window handle for top level window.