Use std::string in logger.

23 files changed, 122 insertions, 115 deletions

diff --git a/src/base/log/Logger.cpp b/src/base/log/Logger.cpp
index 8aa8915c..c195cd87 100644
--- a/src/base/log/Logger.cpp
+++ b/src/base/log/Logger.cpp
@@ -3,6 +3,7 @@
 
 #include <algorithm>
 #include <ctime>
+#include <format>
 
 #ifdef CRU_PLATFORM_WINDOWS
 #include "cru/base/platform/win/DebugLogTarget.h"
@@ -35,32 +36,32 @@ void Logger::RemoveLogTarget(ILogTarget *target) {
 }
 
 namespace {
-String LogLevelToString(LogLevel level) {
+const char *LogLevelToString(LogLevel level) {
   switch (level) {
     case LogLevel::Debug:
-      return u"DEBUG";
+      return "DEBUG";
     case LogLevel::Info:
-      return u"INFO";
+      return "INFO";
     case LogLevel::Warn:
-      return u"WARN";
+      return "WARN";
     case LogLevel::Error:
-      return u"ERROR";
+      return "ERROR";
     default:
       std::terminate();
   }
 }
 
-String GetLogTime() {
+std::string GetLogTime() {
   auto time = std::time(nullptr);
   auto calendar = std::localtime(&time);
-  return Format(u"{}:{}:{}", calendar->tm_hour, calendar->tm_min,
-                calendar->tm_sec);
+  return std::format("{}:{}:{}", calendar->tm_hour, calendar->tm_min,
+                     calendar->tm_sec);
 }
 
-String MakeLogFinalMessage(const LogInfo &log_info) {
-  return Format(u"[{}] {} {}: {}\n", GetLogTime(),
-                LogLevelToString(log_info.level), log_info.tag,
-                log_info.message);
+std::string MakeLogFinalMessage(const LogInfo &log_info) {
+  return std::format("[{}] {} {}: {}\n", GetLogTime(),
+                     LogLevelToString(log_info.level), log_info.tag,
+                     log_info.message);
 }
 }  // namespace
 
@@ -86,18 +87,19 @@ void Logger::Log(LogInfo log_info) {
   log_queue_.Push(std::move(log_info));
 }
 
-LoggerCppStream::LoggerCppStream(Logger *logger, LogLevel level, String tag)
+LoggerCppStream::LoggerCppStream(Logger *logger, LogLevel level,
+                                 std::string tag)
     : logger_(logger), level_(level), tag_(std::move(tag)) {}
 
 LoggerCppStream LoggerCppStream::WithLevel(LogLevel level) const {
   return LoggerCppStream(this->logger_, level, this->tag_);
 }
 
-LoggerCppStream LoggerCppStream::WithTag(String tag) const {
+LoggerCppStream LoggerCppStream::WithTag(std::string tag) const {
   return LoggerCppStream(this->logger_, this->level_, std::move(tag));
 }
 
-void LoggerCppStream::Consume(StringView str) {
-  this->logger_->Log(this->level_, this->tag_, str.ToString());
+void LoggerCppStream::Consume(std::string_view str) {
+  this->logger_->Log(this->level_, this->tag_, std::string(str));
 }
 }  // namespace cru::log
diff --git a/src/base/log/StdioLogTarget.cpp b/src/base/log/StdioLogTarget.cpp
index 64ddcacc..45203f2c 100644
--- a/src/base/log/StdioLogTarget.cpp
+++ b/src/base/log/StdioLogTarget.cpp
@@ -7,20 +7,19 @@ StdioLogTarget::StdioLogTarget() {}
 
 StdioLogTarget::~StdioLogTarget() {}
 
-void StdioLogTarget::Write(log::LogLevel level, StringView s) {
+void StdioLogTarget::Write(log::LogLevel level, std::string message) {
 #ifdef CRU_PLATFORM_WINDOWS
+  String s = String::FromUtf8(message);
   if (level == log::LogLevel::Error) {
     std::wcerr.write(reinterpret_cast<const wchar_t*>(s.data()), s.size());
   } else {
     std::wcout.write(reinterpret_cast<const wchar_t*>(s.data()), s.size());
   }
 #else
-  std::string m = s.ToUtf8();
-
   if (level == log::LogLevel::Error) {
-    std::cerr << m;
+    std::cerr << message;
   } else {
-    std::cout << m;
+    std::cout << message;
   }
 #endif
 }
diff --git a/src/base/platform/unix/PosixSpawnSubProcess.cpp b/src/base/platform/unix/PosixSpawnSubProcess.cpp
index f7d2e855..f99d3224 100644
--- a/src/base/platform/unix/PosixSpawnSubProcess.cpp
+++ b/src/base/platform/unix/PosixSpawnSubProcess.cpp
@@ -145,14 +145,14 @@ SubProcessExitResult PosixSpawnSubProcessImpl::PlatformWaitForProcess() {
 
   while (waitpid(pid_, &wstatus, 0) == -1) {
     if (errno == EINTR) {
-      CRU_LOG_TAG_INFO(u"Waitpid is interrupted by a signal. Call it again.");
+      CRU_LOG_TAG_INFO("Waitpid is interrupted by a signal. Call it again.");
       continue;
     }
 
     std::unique_ptr<ErrnoException> inner(new ErrnoException(errno));
 
-    throw SubProcessInternalException(
-        u"Failed to call waitpid on a subprocess.", std::move(inner));
+    throw SubProcessInternalException("Failed to call waitpid on a subprocess.",
+                                      std::move(inner));
   }
 
   if (WIFEXITED(wstatus)) {
diff --git a/src/base/platform/unix/UnixFile.cpp b/src/base/platform/unix/UnixFile.cpp
index 9d4db949..00ed3b9c 100644
--- a/src/base/platform/unix/UnixFile.cpp
+++ b/src/base/platform/unix/UnixFile.cpp
@@ -19,10 +19,10 @@ UnixFileDescriptor::UnixFileDescriptor(int descriptor, bool auto_close,
       close_(std::move(close)) {}
 
 UnixFileDescriptor::~UnixFileDescriptor() {
-  constexpr auto kLogTag = u"cru::platform::unix::UnixFileDescriptor";
+  constexpr auto kLogTag = "cru::platform::unix::UnixFileDescriptor";
   if (this->IsValid() && this->IsAutoClose()) {
     if (!this->DoClose()) {
-      CRU_LOG_TAG_ERROR(u"Failed to close file descriptor {}, errno {}.",
+      CRU_LOG_TAG_ERROR("Failed to close file descriptor {}, errno {}.",
                         descriptor_, errno);
     }
   }
diff --git a/src/platform/graphics/direct2d/Painter.cpp b/src/platform/graphics/direct2d/Painter.cpp
index ec96080a..a505e46e 100644
--- a/src/platform/graphics/direct2d/Painter.cpp
+++ b/src/platform/graphics/direct2d/Painter.cpp
@@ -22,7 +22,7 @@ D2DDeviceContextPainter::D2DDeviceContextPainter(
 
 D2DDeviceContextPainter::~D2DDeviceContextPainter() {
   if (is_drawing_) {
-    CRU_LOG_TAG_INFO(u"You may forget to call EndDraw before destroying painter.");
+    CRU_LOG_TAG_INFO("You may forget to call EndDraw before destroying painter.");
   }
 
   if (release_) {
diff --git a/src/platform/gui/osx/Clipboard.mm b/src/platform/gui/osx/Clipboard.mm
index db5f6ed3..d87ab7e3 100644
--- a/src/platform/gui/osx/Clipboard.mm
+++ b/src/platform/gui/osx/Clipboard.mm
@@ -25,7 +25,7 @@ OsxClipboardPrivate::~OsxClipboardPrivate() {}
 String OsxClipboardPrivate::GetText() {
   auto result = [pasteboard_ readObjectsForClasses:@[ NSString.class ] options:nil];
   if (result == nil) {
-    CRU_LOG_TAG_WARN(u"Failed to get text from clipboard");
+    CRU_LOG_TAG_WARN("Failed to get text from clipboard");
     return u"";
   } else {
     if (result.count == 0) {
diff --git a/src/platform/gui/osx/ClipboardPrivate.h b/src/platform/gui/osx/ClipboardPrivate.h
index 766026b6..41554297 100644
--- a/src/platform/gui/osx/ClipboardPrivate.h
+++ b/src/platform/gui/osx/ClipboardPrivate.h
@@ -7,7 +7,7 @@
 namespace cru::platform::gui::osx {
 namespace details {
 class OsxClipboardPrivate : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"OsxClipboardPrivate")
+  CRU_DEFINE_CLASS_LOG_TAG("OsxClipboardPrivate")
  public:
   explicit OsxClipboardPrivate(NSPasteboard* pasteboard);
 
diff --git a/src/platform/gui/win/Clipboard.cpp b/src/platform/gui/win/Clipboard.cpp
index 9e305d1c..5525cb40 100644
--- a/src/platform/gui/win/Clipboard.cpp
+++ b/src/platform/gui/win/Clipboard.cpp
@@ -13,25 +13,25 @@ String WinClipboard::GetText() {
   auto god_window = application_->GetGodWindow();
 
   if (!::OpenClipboard(god_window->GetHandle())) {
-    CRU_LOG_TAG_WARN(u"Failed to open clipboard.");
+    CRU_LOG_TAG_WARN("Failed to open clipboard.");
     return {};
   }
 
   if (!::IsClipboardFormatAvailable(CF_UNICODETEXT)) {
-    CRU_LOG_TAG_WARN(u"Clipboard format for text is not available.");
+    CRU_LOG_TAG_WARN("Clipboard format for text is not available.");
     return {};
   }
 
   auto handle = ::GetClipboardData(CF_UNICODETEXT);
 
   if (handle == nullptr) {
-    CRU_LOG_TAG_WARN(u"Failed to get clipboard data.");
+    CRU_LOG_TAG_WARN("Failed to get clipboard data.");
     return {};
   }
 
   auto ptr = ::GlobalLock(handle);
   if (ptr == nullptr) {
-    CRU_LOG_TAG_WARN(u"Failed to lock clipboard data.");
+    CRU_LOG_TAG_WARN("Failed to lock clipboard data.");
     ::CloseClipboard();
     return {};
   }
@@ -48,21 +48,21 @@ void WinClipboard::SetText(String text) {
   auto god_window = application_->GetGodWindow();
 
   if (!::OpenClipboard(god_window->GetHandle())) {
-    CRU_LOG_TAG_WARN(u"Failed to open clipboard.");
+    CRU_LOG_TAG_WARN("Failed to open clipboard.");
     return;
   }
 
   auto handle = GlobalAlloc(GMEM_MOVEABLE, (text.size() + 1) * sizeof(wchar_t));
 
   if (handle == nullptr) {
-    CRU_LOG_TAG_WARN(u"Failed to allocate clipboard data.");
+    CRU_LOG_TAG_WARN("Failed to allocate clipboard data.");
     ::CloseClipboard();
     return;
   }
 
   auto ptr = ::GlobalLock(handle);
   if (ptr == nullptr) {
-    CRU_LOG_TAG_WARN(u"Failed to lock clipboard data.");
+    CRU_LOG_TAG_WARN("Failed to lock clipboard data.");
     ::GlobalFree(handle);
     ::CloseClipboard();
     return;
@@ -73,7 +73,7 @@ void WinClipboard::SetText(String text) {
   ::GlobalUnlock(handle);
 
   if (::SetClipboardData(CF_UNICODETEXT, handle) == nullptr) {
-    CRU_LOG_TAG_WARN(u"Failed to set clipboard data.");
+    CRU_LOG_TAG_WARN("Failed to set clipboard data.");
   }
 
   ::CloseClipboard();
diff --git a/src/platform/gui/win/Cursor.cpp b/src/platform/gui/win/Cursor.cpp
index e6cce5b9..24e9c2fc 100644
--- a/src/platform/gui/win/Cursor.cpp
+++ b/src/platform/gui/win/Cursor.cpp
@@ -16,7 +16,7 @@ WinCursor::~WinCursor() {
     if (!::DestroyCursor(handle_)) {
       // This is not a fetal error but might still need notice because it may
       // cause leak.
-      CRU_LOG_TAG_WARN(u"Failed to destroy a cursor. Last error code: {}",
+      CRU_LOG_TAG_WARN("Failed to destroy a cursor. Last error code: {}",
                    ::GetLastError());
     }
   }
diff --git a/src/platform/gui/win/GodWindow.cpp b/src/platform/gui/win/GodWindow.cpp
index c969df8f..485eae72 100644
--- a/src/platform/gui/win/GodWindow.cpp
+++ b/src/platform/gui/win/GodWindow.cpp
@@ -43,7 +43,7 @@ GodWindow::GodWindow(WinUiApplication* application) {
 GodWindow::~GodWindow() {
   if (!::DestroyWindow(hwnd_)) {
     // Although this could be "safely" ignore.
-    CRU_LOG_TAG_WARN(u"Failed to destroy god window.");
+    CRU_LOG_TAG_WARN("Failed to destroy god window.");
   }
 }
 
diff --git a/src/platform/gui/win/InputMethod.cpp b/src/platform/gui/win/InputMethod.cpp
index 306dc3fa..94795c8c 100644
--- a/src/platform/gui/win/InputMethod.cpp
+++ b/src/platform/gui/win/InputMethod.cpp
@@ -35,7 +35,7 @@ AutoHIMC& AutoHIMC::operator=(AutoHIMC&& other) {
 AutoHIMC::~AutoHIMC() {
   if (handle_) {
     if (!::ImmReleaseContext(hwnd_, handle_))
-      CRU_LOG_TAG_WARN(u"Failed to release HIMC.");
+      CRU_LOG_TAG_WARN("Failed to release HIMC.");
   }
 }
 
@@ -156,7 +156,7 @@ WinInputMethodContext::~WinInputMethodContext() {}
 void WinInputMethodContext::EnableIME() {
   const auto hwnd = native_window_->GetWindowHandle();
   if (::ImmAssociateContextEx(hwnd, nullptr, IACE_DEFAULT) == FALSE) {
-    CRU_LOG_TAG_WARN(u"Failed to enable ime.");
+    CRU_LOG_TAG_WARN("Failed to enable ime.");
   }
 }
 
@@ -167,21 +167,21 @@ void WinInputMethodContext::DisableIME() {
   ::ImmNotifyIME(himc.Get(), NI_COMPOSITIONSTR, CPS_COMPLETE, 0);
 
   if (::ImmAssociateContextEx(hwnd, nullptr, 0) == FALSE) {
-    CRU_LOG_TAG_WARN(u"Failed to disable ime.");
+    CRU_LOG_TAG_WARN("Failed to disable ime.");
   }
 }
 
 void WinInputMethodContext::CompleteComposition() {
   auto himc = GetHIMC();
   if (!::ImmNotifyIME(himc.Get(), NI_COMPOSITIONSTR, CPS_COMPLETE, 0)) {
-    CRU_LOG_TAG_WARN(u"Failed to complete composition.");
+    CRU_LOG_TAG_WARN("Failed to complete composition.");
   }
 }
 
 void WinInputMethodContext::CancelComposition() {
   auto himc = GetHIMC();
   if (!::ImmNotifyIME(himc.Get(), NI_COMPOSITIONSTR, CPS_CANCEL, 0)) {
-    CRU_LOG_TAG_WARN(u"Failed to complete composition.");
+    CRU_LOG_TAG_WARN("Failed to complete composition.");
   }
 }
 
@@ -200,7 +200,7 @@ void WinInputMethodContext::SetCandidateWindowPosition(const Point& point) {
   form.ptCurrentPos = native_window_->DipToPixel(point);
 
   if (!::ImmSetCandidateWindow(himc.Get(), &form))
-    CRU_LOG_TAG_DEBUG(u"Failed to set input method candidate window position.");
+    CRU_LOG_TAG_DEBUG("Failed to set input method candidate window position.");
 }
 
 IEvent<std::nullptr_t>* WinInputMethodContext::CompositionStartEvent() {
@@ -228,8 +228,8 @@ void WinInputMethodContext::OnWindowNativeMessage(
         // should only trigger ascci character. If it is a charater from
         // supplementary planes, it should be handled with ime messages.
         CRU_LOG_TAG_WARN(
-            u"A WM_CHAR message for character from supplementary "
-            u"planes is ignored.");
+            "A WM_CHAR message for character from supplementary "
+            "planes is ignored.");
       } else {
         if (c != '\b') {            // ignore backspace
           if (c == '\r') c = '\n';  // Change \r to \n
@@ -245,8 +245,8 @@ void WinInputMethodContext::OnWindowNativeMessage(
       composition_event_.Raise(nullptr);
       auto composition_text = GetCompositionText();
       if constexpr (DebugFlags::input_method) {
-        CRU_LOG_TAG_DEBUG(u"WM_IME_COMPOSITION composition text:\n{}",
-                      composition_text);
+        CRU_LOG_TAG_DEBUG("WM_IME_COMPOSITION composition text:\n{}",
+                          composition_text);
       }
       if (message.l_param & GCS_RESULTSTR) {
         auto result_string = GetResultString();
@@ -256,14 +256,14 @@ void WinInputMethodContext::OnWindowNativeMessage(
     }
     case WM_IME_STARTCOMPOSITION: {
       if constexpr (DebugFlags::input_method) {
-        CRU_LOG_TAG_DEBUG(u"WM_IME_STARTCOMPOSITION received.");
+        CRU_LOG_TAG_DEBUG("WM_IME_STARTCOMPOSITION received.");
       }
       composition_start_event_.Raise(nullptr);
       break;
     }
     case WM_IME_ENDCOMPOSITION: {
       if constexpr (DebugFlags::input_method) {
-        CRU_LOG_TAG_DEBUG(u"WM_IME_ENDCOMPOSITION received.");
+        CRU_LOG_TAG_DEBUG("WM_IME_ENDCOMPOSITION received.");
       }
       composition_end_event_.Raise(nullptr);
       break;
diff --git a/src/platform/gui/win/Window.cpp b/src/platform/gui/win/Window.cpp
index 690e56de..5bd14323 100644
--- a/src/platform/gui/win/Window.cpp
+++ b/src/platform/gui/win/Window.cpp
@@ -207,7 +207,7 @@ bool WinNativeWindow::ReleaseMouse() {
 
 void WinNativeWindow::RequestRepaint() {
   if constexpr (DebugFlags::paint) {
-    CRU_LOG_TAG_DEBUG(u"A repaint is requested.");
+    CRU_LOG_TAG_DEBUG("A repaint is requested.");
   }
   if (!::InvalidateRect(hwnd_, nullptr, FALSE))
     throw Win32Error(::GetLastError(), u"Failed to invalidate window.");
@@ -235,8 +235,8 @@ void WinNativeWindow::SetCursor(std::shared_ptr<ICursor> cursor) {
   if (!::SetClassLongPtrW(hwnd_, GCLP_HCURSOR,
                           reinterpret_cast<LONG_PTR>(cursor_->GetHandle()))) {
     CRU_LOG_TAG_WARN(
-        u"Failed to set cursor because failed to set class long. Last "
-        u"error code: {}.",
+        "Failed to set cursor because failed to set class long. Last "
+        "error code: {}.",
         ::GetLastError());
     return;
   }
@@ -477,7 +477,7 @@ void WinNativeWindow::RecreateWindow() {
   if (dpi == 0)
     throw Win32Error(::GetLastError(), u"Failed to get dpi of window.");
   dpi_ = static_cast<float>(dpi);
-  CRU_LOG_TAG_DEBUG(u"Dpi of window is {}.", dpi_);
+  CRU_LOG_TAG_DEBUG("Dpi of window is {}.", dpi_);
 
   window_manager->RegisterWindow(hwnd_, this);
 
@@ -507,7 +507,7 @@ void WinNativeWindow::OnPaintInternal() {
   paint_event_.Raise(nullptr);
   ValidateRect(hwnd_, nullptr);
   if constexpr (DebugFlags::paint) {
-    CRU_LOG_TAG_DEBUG(u"A repaint is finished.");
+    CRU_LOG_TAG_DEBUG("A repaint is finished.");
   }
 }
 
diff --git a/src/ui/ThemeResourceDictionary.cpp b/src/ui/ThemeResourceDictionary.cpp
index fff25e09..421723f5 100644
--- a/src/ui/ThemeResourceDictionary.cpp
+++ b/src/ui/ThemeResourceDictionary.cpp
@@ -47,10 +47,11 @@ void ThemeResourceDictionary::UpdateResourceMap(xml::XmlElementNode* xml_root) {
 
         resource_map_[entry.name] = std::move(entry);
       } else {
-        CRU_LOG_TAG_DEBUG(u"Ignore unknown element {} of theme.", c->GetTag());
+        CRU_LOG_TAG_DEBUG("Ignore unknown element {} of theme.",
+                          c->GetTag().ToUtf8());
       }
     } else {
-      CRU_LOG_TAG_DEBUG(u"Ignore text or comment node of theme.");
+      CRU_LOG_TAG_DEBUG("Ignore text or comment node of theme.");
     }
   }
 }
diff --git a/src/ui/controls/Control.cpp b/src/ui/controls/Control.cpp
index d6770684..3218f185 100644
--- a/src/ui/controls/Control.cpp
+++ b/src/ui/controls/Control.cpp
@@ -31,7 +31,7 @@ Control::Control() {
 Control::~Control() {
   if (host::WindowHost::IsInEventHandling()) {
     CRU_LOG_TAG_ERROR(
-        u"Control destroyed during event handling. Please use DeleteLater.");
+        "Control destroyed during event handling. Please use DeleteLater.");
   }
 
   in_destruction_ = true;
diff --git a/src/ui/controls/TextHostControlService.cpp b/src/ui/controls/TextHostControlService.cpp
index bc562e88..ace02a46 100644
--- a/src/ui/controls/TextHostControlService.cpp
+++ b/src/ui/controls/TextHostControlService.cpp
@@ -227,7 +227,7 @@ void TextHostControlService::SetText(String text, bool stop_composition) {
 void TextHostControlService::InsertText(Index position, StringView text,
                                         bool stop_composition) {
   if (!Utf16IsValidInsertPosition(this->text_, position)) {
-    CRU_LOG_TAG_ERROR(u"Invalid text insert position.");
+    CRU_LOG_TAG_ERROR("Invalid text insert position.");
     return;
   }
   this->text_.insert(this->text_.cbegin() + position, text);
@@ -240,7 +240,7 @@ void TextHostControlService::InsertText(Index position, StringView text,
 
 void TextHostControlService::DeleteChar(Index position, bool stop_composition) {
   if (!Utf16IsValidInsertPosition(this->text_, position)) {
-    CRU_LOG_TAG_ERROR(u"Invalid text delete position.");
+    CRU_LOG_TAG_ERROR("Invalid text delete position.");
     return;
   }
   if (position == static_cast<Index>(this->text_.size())) return;
@@ -253,7 +253,7 @@ void TextHostControlService::DeleteChar(Index position, bool stop_composition) {
 Index TextHostControlService::DeleteCharPrevious(Index position,
                                                  bool stop_composition) {
   if (!Utf16IsValidInsertPosition(this->text_, position)) {
-    CRU_LOG_TAG_ERROR(u"Invalid text delete position.");
+    CRU_LOG_TAG_ERROR("Invalid text delete position.");
     return 0;
   }
   if (position == 0) return 0;
@@ -269,11 +269,11 @@ void TextHostControlService::DeleteText(TextRange range,
   if (range.count == 0) return;
   range = range.Normalize();
   if (!Utf16IsValidInsertPosition(this->text_, range.GetStart())) {
-    CRU_LOG_TAG_ERROR(u"Invalid text delete start position.");
+    CRU_LOG_TAG_ERROR("Invalid text delete start position.");
     return;
   }
   if (!Utf16IsValidInsertPosition(this->text_, range.GetStart())) {
-    CRU_LOG_TAG_ERROR(u"Invalid text delete end position.");
+    CRU_LOG_TAG_ERROR("Invalid text delete end position.");
     return;
   }
   this->text_.erase(this->text_.cbegin() + range.GetStart(),
@@ -465,7 +465,7 @@ void TextHostControlService::UpdateInputMethodPosition() {
     right_bottom.y += 5;
 
     if constexpr (debug_flags::text_service) {
-      CRU_LOG_TAG_DEBUG(u"Calculate input method candidate window position: {}.",
+      CRU_LOG_TAG_DEBUG("Calculate input method candidate window position: {}.",
                     right_bottom);
     }
 
diff --git a/src/ui/helper/ClickDetector.cpp b/src/ui/helper/ClickDetector.cpp
index b7e800a8..2e3dc1a0 100644
--- a/src/ui/helper/ClickDetector.cpp
+++ b/src/ui/helper/ClickDetector.cpp
@@ -58,7 +58,7 @@ ClickDetector::ClickDetector(controls::Control* control) {
                 this->state_ == ClickState::Hover) {
               if (!this->control_->CaptureMouse()) {
                 if constexpr (debug_flags::click_detector) {
-                  CRU_LOG_TAG_DEBUG(u"Failed to capture mouse when begin click.");
+                  CRU_LOG_TAG_DEBUG("Failed to capture mouse when begin click.");
                 }
                 return;
               }
@@ -137,7 +137,7 @@ void ClickDetector::SetState(ClickState state) {
           UnreachableCode();
       }
     };
-    CRU_LOG_TAG_DEBUG(u"Click state changed, new state: {}.", to_string(state));
+    CRU_LOG_TAG_DEBUG("Click state changed, new state: {}.", to_string(state));
   }
 
   state_ = state;
diff --git a/src/ui/helper/ShortcutHub.cpp b/src/ui/helper/ShortcutHub.cpp
index c413ab2a..e3a06e8c 100644
--- a/src/ui/helper/ShortcutHub.cpp
+++ b/src/ui/helper/ShortcutHub.cpp
@@ -64,7 +64,7 @@ const std::vector<ShortcutInfo>& ShortcutHub::GetShortcutByKeyBind(
 
 void ShortcutHub::Install(controls::Control* control) {
   if (!event_guard_.IsEmpty()) {
-    CRU_LOG_TAG_ERROR(u"Shortcut hub is already installed. Failed to install.");
+    CRU_LOG_TAG_ERROR("Shortcut hub is already installed. Failed to install.");
     return;
   }
 
@@ -74,7 +74,7 @@ void ShortcutHub::Install(controls::Control* control) {
 
 void ShortcutHub::Uninstall() {
   if (event_guard_.IsEmpty()) {
-    CRU_LOG_TAG_WARN(u"Shortcut hub is not installed. Failed to uninstall.");
+    CRU_LOG_TAG_WARN("Shortcut hub is not installed. Failed to uninstall.");
     return;
   }
 
@@ -89,17 +89,18 @@ void ShortcutHub::OnKeyDown(events::KeyEventArgs& event) {
 
   if constexpr (debug_flags::shortcut) {
     if (shortcut_list.empty()) {
-      CRU_LOG_TAG_DEBUG(u"No shortcut for key bind {}.", key_bind.ToString());
+      CRU_LOG_TAG_DEBUG("No shortcut for key bind {}.",
+                        key_bind.ToString().ToUtf8());
     }
-    CRU_LOG_TAG_DEBUG(u"Begin to handle shortcut for key bind {}.",
-                  key_bind.ToString());
+    CRU_LOG_TAG_DEBUG("Begin to handle shortcut for key bind {}.",
+                      key_bind.ToString());
   }
 
   for (const auto& shortcut : shortcut_list) {
     auto is_handled = shortcut.handler();
     if (is_handled) {
       if constexpr (debug_flags::shortcut) {
-        CRU_LOG_TAG_DEBUG(u"Handle {} handled it.", shortcut.name);
+        CRU_LOG_TAG_DEBUG("Handle {} handled it.", shortcut.name.ToUtf8());
       }
 
       handled = true;
@@ -108,23 +109,24 @@ void ShortcutHub::OnKeyDown(events::KeyEventArgs& event) {
       break;
     } else {
       if constexpr (debug_flags::shortcut) {
-        CRU_LOG_TAG_DEBUG(u"Handle {} didn't handle it.", shortcut.name);
+        CRU_LOG_TAG_DEBUG("Handle {} didn't handle it.",
+                          shortcut.name.ToUtf8());
       }
     }
   }
 
   if constexpr (debug_flags::shortcut) {
     if (!shortcut_list.empty()) {
-      CRU_LOG_TAG_DEBUG(u"End handling shortcut for key bind {}.",
-                    key_bind.ToString());
+      CRU_LOG_TAG_DEBUG("End handling shortcut for key bind {}.",
+                        key_bind.ToString().ToUtf8());
     }
   }
 
   if (!handled) {
     if constexpr (debug_flags::shortcut) {
       CRU_LOG_TAG_DEBUG(
-          u"Raise fallback event for unhandled shortcut of key bind {}.",
-          key_bind.ToString());
+          "Raise fallback event for unhandled shortcut of key bind {}.",
+          key_bind.ToString().ToUtf8());
     }
     fallback_event_.Raise(event);
   }
diff --git a/src/ui/host/RoutedEventDispatch.h b/src/ui/host/RoutedEventDispatch.h
index 6677deea..4efc9208 100644
--- a/src/ui/host/RoutedEventDispatch.h
+++ b/src/ui/host/RoutedEventDispatch.h
@@ -26,7 +26,7 @@ void DispatchEvent(
     const String& event_name, controls::Control* const original_sender,
     events::RoutedEvent<EventArgs>* (controls::Control::*event_ptr)(),
     controls::Control* const last_receiver, Args&&... args) {
-  constexpr auto kLogTag = u"DispatchEvent";
+  constexpr auto kLogTag = "DispatchEvent";
 
   if (original_sender == nullptr) return;
 
@@ -35,9 +35,9 @@ void DispatchEvent(
   if (original_sender == last_receiver) {
     if constexpr (debug_flags::routed_event)
       CRU_LOG_TAG_DEBUG(
-          u"Routed event {} no need to dispatch (original_sender == "
+          "Routed event {} no need to dispatch (original_sender == "
           "last_receiver). Original sender is {}.",
-          event_name, original_sender->GetControlType());
+          event_name.ToUtf8(), original_sender->GetControlType().ToUtf8());
     return;
   }
 
@@ -54,16 +54,16 @@ void DispatchEvent(
   }
 
   if constexpr (debug_flags::routed_event) {
-    String log = u"Dispatch routed event ";
-    log += event_name;
-    log += u". Path (parent first): ";
+    std::string log = "Dispatch routed event ";
+    log += event_name.ToUtf8();
+    log += ". Path (parent first): ";
     auto i = receive_list.crbegin();
     const auto end = --receive_list.crend();
     for (; i != end; ++i) {
-      log += i->Resolve()->GetControlType();
-      log += u" -> ";
+      log += i->Resolve()->GetControlType().ToUtf8();
+      log += " -> ";
     }
-    log += i->Resolve()->GetControlType();
+    log += i->Resolve()->GetControlType().ToUtf8();
     CRU_LOG_TAG_DEBUG(log);
   }
 
@@ -83,8 +83,8 @@ void DispatchEvent(
       handled = true;
       if constexpr (debug_flags::routed_event)
         CRU_LOG_TAG_DEBUG(
-            u"Routed event is short-circuit in TUNNEL at {}-st control (count "
-            u"from parent).",
+            "Routed event is short-circuit in TUNNEL at {}-st control (count "
+            "from parent).",
             count);
       break;
     }
@@ -103,8 +103,8 @@ void DispatchEvent(
       if (event_args.IsHandled()) {
         if constexpr (debug_flags::routed_event)
           CRU_LOG_TAG_DEBUG(
-              u"Routed event is short-circuit in BUBBLE at {}-st control "
-              u"(count from parent).",
+              "Routed event is short-circuit in BUBBLE at {}-st control "
+              "(count from parent).",
               count);
         break;
       }
@@ -121,7 +121,7 @@ void DispatchEvent(
   }
 
   if constexpr (debug_flags::routed_event)
-    CRU_LOG_TAG_DEBUG(u"Routed event dispatch finished.");
+    CRU_LOG_TAG_DEBUG("Routed event dispatch finished.");
 
   WindowHost::LeaveEventHandling();
 }
diff --git a/src/ui/host/WindowHost.cpp b/src/ui/host/WindowHost.cpp
index 9d0e2006..59e383c5 100644
--- a/src/ui/host/WindowHost.cpp
+++ b/src/ui/host/WindowHost.cpp
@@ -202,7 +202,7 @@ void WindowHost::RelayoutWithSize(const Size& available_size,
   for (auto& action : after_layout_stable_action_) action();
   after_layout_event_.Raise(AfterLayoutEventArgs{});
   after_layout_stable_action_.clear();
-  if constexpr (debug_flags::layout) CRU_LOG_TAG_DEBUG(u"A relayout is finished.");
+  if constexpr (debug_flags::layout) CRU_LOG_TAG_DEBUG("A relayout is finished.");
 }
 
 void WindowHost::Repaint() {
diff --git a/src/ui/render/BorderRenderObject.cpp b/src/ui/render/BorderRenderObject.cpp
index 0e97c5e8..03fdff24 100644
--- a/src/ui/render/BorderRenderObject.cpp
+++ b/src/ui/render/BorderRenderObject.cpp
@@ -82,11 +82,13 @@ RenderObject* BorderRenderObject::HitTest(const Point& point) {
 void BorderRenderObject::Draw(platform::graphics::IPainter* painter) {
   if constexpr (debug_flags::draw) {
     CRU_LOG_TAG_DEBUG(
-        u"BorderRenderObject draw, background: {}, foreground: {}.",
-        background_brush_ == nullptr ? u"NONE"
-                                     : background_brush_->GetDebugString(),
-        foreground_brush_ == nullptr ? u"NONE"
-                                     : foreground_brush_->GetDebugString());
+        "BorderRenderObject draw, background: {}, foreground: {}.",
+        background_brush_ == nullptr
+            ? "NONE"
+            : background_brush_->GetDebugString().ToUtf8(),
+        foreground_brush_ == nullptr
+            ? "NONE"
+            : foreground_brush_->GetDebugString().ToUtf8());
   }
 
   if (background_brush_ != nullptr)
@@ -95,7 +97,7 @@ void BorderRenderObject::Draw(platform::graphics::IPainter* painter) {
 
   if (is_border_enabled_) {
     if (border_brush_ == nullptr) {
-      CRU_LOG_TAG_WARN(u"Border is enabled but border brush is null.");
+      CRU_LOG_TAG_WARN("Border is enabled but border brush is null.");
     } else {
       painter->FillGeometry(geometry_.get(), border_brush_.get());
     }
diff --git a/src/ui/render/FlexLayoutRenderObject.cpp b/src/ui/render/FlexLayoutRenderObject.cpp
index 588c379b..efc98602 100644
--- a/src/ui/render/FlexLayoutRenderObject.cpp
+++ b/src/ui/render/FlexLayoutRenderObject.cpp
@@ -90,7 +90,7 @@ Size FlexLayoutMeasureContentImpl(
     const MeasureRequirement& requirement, const MeasureSize& preferred_size,
     const std::vector<RenderObject*>& children,
     const std::vector<FlexChildLayoutData>& layout_data,
-    Alignment item_cross_align, String kLogTag) {
+    Alignment item_cross_align, std::string kLogTag) {
   Expects(children.size() == layout_data.size());
 
   direction_tag_t direction_tag;
@@ -301,7 +301,7 @@ Size FlexLayoutMeasureContentImpl(
   if (max_main_length.IsSpecified() &&
       total_length > max_main_length.GetLengthOrUndefined()) {
     CRU_LOG_TAG_WARN(
-        u"(Measure) Children's main axis length exceeds required max length.");
+        "(Measure) Children's main axis length exceeds required max length.");
     total_length = max_main_length.GetLengthOrUndefined();
   } else if (min_main_length.IsSpecified() &&
              total_length < min_main_length.GetLengthOrUndefined()) {
diff --git a/src/ui/render/RenderObject.cpp b/src/ui/render/RenderObject.cpp
index b3a28d6d..1803a131 100644
--- a/src/ui/render/RenderObject.cpp
+++ b/src/ui/render/RenderObject.cpp
@@ -119,16 +119,16 @@ void RenderObject::Measure(const MeasureRequirement& requirement,
       preferred_size.OverrideBy(preferred_size_);
 
   if constexpr (cru::ui::debug_flags::layout) {
-    CRU_LOG_TAG_DEBUG(u"{} Measure begins :\nrequirement: {}\npreferred size: {}",
-                  this->GetDebugPathInTree(), requirement.ToDebugString(),
-                  preferred_size.ToDebugString());
+    CRU_LOG_TAG_DEBUG("{} Measure begins :\nrequirement: {}\npreferred size: {}",
+                  this->GetDebugPathInTree().ToUtf8(), requirement.ToDebugString().ToUtf8(),
+                  preferred_size.ToDebugString().ToUtf8());
   }
 
   desired_size_ = OnMeasureCore(merged_requirement, merged_preferred_size);
 
   if constexpr (cru::ui::debug_flags::layout) {
-    CRU_LOG_TAG_DEBUG(u"{} Measure ends :\nresult size: {}",
-                  this->GetDebugPathInTree(), desired_size_);
+    CRU_LOG_TAG_DEBUG("{} Measure ends :\nresult size: {}",
+                  this->GetDebugPathInTree().ToUtf8(), desired_size_);
   }
 
   Ensures(desired_size_.width >= 0);
@@ -144,8 +144,8 @@ Size RenderObject::Measure1(const BoxConstraint& constraint) {
 
 void RenderObject::Layout(const Point& offset) {
   if constexpr (cru::ui::debug_flags::layout) {
-    CRU_LOG_TAG_DEBUG(u"{} Layout :\noffset: {} size: {}",
-                  this->GetDebugPathInTree(), offset, desired_size_);
+    CRU_LOG_TAG_DEBUG("{} Layout :\noffset: {} size: {}",
+                  this->GetDebugPathInTree().ToUtf8(), offset, desired_size_);
   }
   offset_ = offset;
   size_ = desired_size_;
@@ -192,14 +192,14 @@ Size RenderObject::OnMeasureCore1(const BoxConstraint& constraint) {
 
   if (space_size.width > merged_constraint.max.width) {
     space_size.width = merged_constraint.max.width;
-    CRU_LOG_TAG_WARN(u"{} space width is over constraint.max.width",
-                 this->GetDebugPathInTree());
+    CRU_LOG_TAG_WARN("{} space width is over constraint.max.width",
+                 this->GetDebugPathInTree().ToUtf8());
   }
 
   if (space_size.height > merged_constraint.max.height) {
     space_size.height = merged_constraint.max.height;
-    CRU_LOG_TAG_WARN(u"{} space height is over constraint.max.height",
-                 this->GetDebugPathInTree());
+    CRU_LOG_TAG_WARN("{} space height is over constraint.max.height",
+                 this->GetDebugPathInTree().ToUtf8());
   }
 
   BoxConstraint content_constraint{merged_constraint.max - space_size,
diff --git a/src/ui/render/TextRenderObject.cpp b/src/ui/render/TextRenderObject.cpp
index 8a579041..346b4957 100644
--- a/src/ui/render/TextRenderObject.cpp
+++ b/src/ui/render/TextRenderObject.cpp
@@ -178,10 +178,11 @@ RenderObject* TextRenderObject::HitTest(const Point& point) {
 void TextRenderObject::Draw(platform::graphics::IPainter* painter) {
   if constexpr (debug_flags::draw) {
     CRU_LOG_TAG_DEBUG(
-        u"Begin to paint, total_offset: {}, size: {}, text_layout: "
-        u"{}, brush: {}.",
+        "Begin to paint, total_offset: {}, size: {}, text_layout: "
+        "{}, brush: {}.",
         this->GetTotalOffset(), this->GetDesiredSize(),
-        this->text_layout_->GetDebugString(), this->brush_->GetDebugString());
+        this->text_layout_->GetDebugString().ToUtf8(),
+        this->brush_->GetDebugString().ToUtf8());
   }
 
   if (this->selection_range_.has_value()) {