...

56 files changed, 448 insertions, 389 deletions

diff --git a/include/cru/common/Base.h b/include/cru/common/Base.h
index 4d4d1f5f..899cfc13 100644
--- a/include/cru/common/Base.h
+++ b/include/cru/common/Base.h
@@ -94,5 +94,5 @@ inline void hash_combine(std::size_t& s, const T& v) {
 
 #define CRU_DEFINE_CLASS_LOG_TAG(tag) \
  private:                             \
-  constexpr static StringView log_tag = tag;
+  constexpr static const char16_t* kLogTag = tag;
 }  // namespace cru
diff --git a/include/cru/common/Format.h b/include/cru/common/Format.h
index 7628f07d..2b08f03b 100644
--- a/include/cru/common/Format.h
+++ b/include/cru/common/Format.h
@@ -92,7 +92,7 @@ struct FormatToken {
   String place_holder_option;
 };
 
-std::vector<FormatToken> CRU_BASE_API ParseToFormatTokenList(const String& str);
+std::vector<FormatToken> CRU_BASE_API ParseToFormatTokenList(StringView str);
 
 void CRU_BASE_API FormatAppendFromFormatTokenList(
     String& current, const std::vector<FormatToken>& format_token_list,
@@ -123,7 +123,7 @@ void FormatAppendFromFormatTokenList(
 }  // namespace details
 
 template <typename... T>
-String Format(const String& format, T&&... args) {
+String Format(StringView format, T&&... args) {
   String result;
 
   details::FormatAppendFromFormatTokenList(
diff --git a/include/cru/common/Logger.h b/include/cru/common/Logger.h
deleted file mode 100644
index 25875651..00000000
--- a/include/cru/common/Logger.h
+++ /dev/null
@@ -1,114 +0,0 @@
-#pragma once
-#include "Base.h"
-
-#include "String.h"
-#include "Format.h"
-
-#include <list>
-#include <memory>
-
-namespace cru::log {
-
-enum class LogLevel { Debug, Info, Warn, Error };
-
-struct CRU_BASE_API ILogSource : virtual Interface {
-  // Write the string s. LogLevel is just a helper. It has no effect on the
-  // content to write.
-  virtual void Write(LogLevel level, StringView s) = 0;
-};
-
-class CRU_BASE_API Logger : public Object {
- public:
-  static Logger* GetInstance();
-
- public:
-  Logger() = default;
-
-  CRU_DELETE_COPY(Logger)
-  CRU_DELETE_MOVE(Logger)
-
-  ~Logger() override = default;
-
- public:
-  void AddSource(std::unique_ptr<ILogSource> source);
-  void RemoveSource(ILogSource* source);
-
- public:
-  void Log(LogLevel level, StringView message);
-  void Log(LogLevel level, StringView tag, StringView message);
-
- private:
-  std::list<std::unique_ptr<ILogSource>> sources_;
-};
-
-// TODO: Remove argument evaluation in Debug.
-template <typename... TArgs>
-void Debug([[maybe_unused]] TArgs&&... args) {
-#ifdef CRU_DEBUG
-  Logger::GetInstance()->Log(LogLevel::Debug,
-                             Format(std::forward<TArgs>(args)...));
-#endif
-}
-
-template <typename... TArgs>
-void Info(TArgs&&... args) {
-  Logger::GetInstance()->Log(LogLevel::Info,
-                             Format(std::forward<TArgs>(args)...));
-}
-
-template <typename... TArgs>
-void Warn(TArgs&&... args) {
-  Logger::GetInstance()->Log(LogLevel::Warn,
-                             Format(std::forward<TArgs>(args)...));
-}
-
-template <typename... TArgs>
-void Error(TArgs&&... args) {
-  Logger::GetInstance()->Log(LogLevel::Error,
-                             Format(std::forward<TArgs>(args)...));
-}
-
-// TODO: Remove argument evaluation in Debug.
-template <typename... TArgs>
-void TagDebug([[maybe_unused]] StringView tag,
-              [[maybe_unused]] TArgs&&... args) {
-#ifdef CRU_DEBUG
-  Logger::GetInstance()->Log(LogLevel::Debug, tag,
-                             Format(std::forward<TArgs>(args)...));
-#endif
-}
-
-template <typename... TArgs>
-void TagInfo(StringView tag, TArgs&&... args) {
-  Logger::GetInstance()->Log(LogLevel::Info, tag,
-                             Format(std::forward<TArgs>(args)...));
-}
-
-template <typename... TArgs>
-void TagWarn(StringView tag, TArgs&&... args) {
-  Logger::GetInstance()->Log(LogLevel::Warn, tag,
-                             Format(std::forward<TArgs>(args)...));
-}
-
-template <typename... TArgs>
-void TagError(StringView tag, TArgs&&... args) {
-  Logger::GetInstance()->Log(LogLevel::Error, tag,
-                             Format(std::forward<TArgs>(args)...));
-}
-
-class StdioLogSource : public Object, public virtual ILogSource {
- public:
-  explicit StdioLogSource(bool use_lock = false);
-
-  CRU_DELETE_COPY(StdioLogSource)
-  CRU_DELETE_MOVE(StdioLogSource)
-
-  ~StdioLogSource() override;
-
- public:
-  void Write(LogLevel level, StringView s) override;
-
- private:
-  bool use_lock_;
-};
-}  // namespace cru::log
diff --git a/include/cru/common/String.h b/include/cru/common/String.h
index 0b1b031b..be886168 100644
--- a/include/cru/common/String.h
+++ b/include/cru/common/String.h
@@ -63,7 +63,7 @@ class CRU_BASE_API String {
  public:
   String() = default;
 
-  explicit String(const_pointer str);
+  String(const_pointer str);
   String(const_pointer str, size_type size);
 
   template <Index size>
diff --git a/include/cru/common/concurrent/ConcurrentQueue.h b/include/cru/common/concurrent/ConcurrentQueue.h
new file mode 100644
index 00000000..4f649a41
--- /dev/null
+++ b/include/cru/common/concurrent/ConcurrentQueue.h
@@ -0,0 +1,110 @@
+#pragma once
+#include <condition_variable>
+#include <mutex>
+#include <optional>
+#include <utility>
+
+namespace cru::concurrent {
+namespace details {
+template <typename T>
+struct ConcurrentQueueNode {
+  ConcurrentQueueNode(T&& value, ConcurrentQueueNode* next = nullptr)
+      : value(std::move(value)), next(next) {}
+
+  T value;
+  ConcurrentQueueNode* next;
+};
+}  // namespace details
+
+template <typename T>
+class ConcurrentQueue {
+ public:
+  ConcurrentQueue() {}
+
+  ConcurrentQueue(const ConcurrentQueue&) = delete;
+  ConcurrentQueue& operator=(const ConcurrentQueue&) = delete;
+
+  ConcurrentQueue(ConcurrentQueue&& other)
+      : head_(other.head_),
+        tail_(other.tail_),
+        mutex_(std::move(other.mutex_)),
+        condition_variable_(std::move(other.condition_variable_)) {
+    other.head_ = nullptr;
+    other.tail_ = nullptr;
+  }
+
+  ConcurrentQueue& operator=(ConcurrentQueue&& other) {
+    if (this != &other) {
+      head_ = other.head_;
+      tail_ = other.tail_;
+      mutex_ = std::move(other.mutex_);
+      condition_variable_ = std::move(other.condition_variable_);
+      other.head_ = nullptr;
+      other.tail_ = nullptr;
+      return *this;
+    }
+    return *this;
+  }
+
+  ~ConcurrentQueue() {
+    if (head_) {
+      auto node = head_;
+      while (node) {
+        auto next = node->next;
+        delete node;
+        node = next;
+      }
+    }
+  }
+
+ public:
+  void Push(T&& value) {
+    std::unique_lock<std::mutex> lock(mutex_);
+    if (head_ == nullptr) {
+      head_ = tail_ = new details::ConcurrentQueueNode<T>(std::move(value));
+      condition_variable_.notify_one();
+    } else {
+      tail_->next = new details::ConcurrentQueueNode<T>(std::move(value));
+      tail_ = tail_->next;
+    }
+  }
+
+  T Pull() {
+    std::unique_lock<std::mutex> lock(mutex_);
+    if (head_ == nullptr) {
+      condition_variable_.wait(lock);
+    }
+    assert(head_ != nullptr);
+    auto value = std::move(head_->value);
+    auto next = head_->next;
+    delete head_;
+    head_ = next;
+    if (next == nullptr) {
+      tail_ = nullptr;
+    }
+    return value;
+  }
+
+  std::optional<T> Poll() {
+    std::unique_lock<std::mutex> lock(mutex_);
+    if (head_ == nullptr) {
+      return std::nullopt;
+    }
+    auto value = std::move(head_->value);
+    auto next = head_->next;
+    delete head_;
+    head_ = next;
+    if (next == nullptr) {
+      tail_ = nullptr;
+    }
+    return value;
+  }
+
+ private:
+  details::ConcurrentQueueNode<T>* head_ = nullptr;
+  details::ConcurrentQueueNode<T>* tail_ = nullptr;
+
+  std::mutex mutex_;
+  std::condition_variable condition_variable_;
+};
+}  // namespace cru::concurrent
diff --git a/include/cru/common/log/Logger.h b/include/cru/common/log/Logger.h
new file mode 100644
index 00000000..25735e14
--- /dev/null
+++ b/include/cru/common/log/Logger.h
@@ -0,0 +1,88 @@
+#pragma once
+#include "../Base.h"
+
+#include "../Format.h"
+#include "../String.h"
+#include "../concurrent/ConcurrentQueue.h"
+
+#include <memory>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+namespace cru::log {
+enum class LogLevel { Debug, Info, Warn, Error };
+
+struct CRU_BASE_API LogInfo {
+  LogInfo(LogLevel level, String tag, String message)
+      : level(level), tag(std::move(tag)), message(std::move(message)) {}
+
+  CRU_DEFAULT_COPY(LogInfo)
+  CRU_DEFAULT_MOVE(LogInfo)
+
+  ~LogInfo() = default;
+
+  LogLevel level;
+  String tag;
+  String message;
+};
+
+struct CRU_BASE_API ILogTarget : virtual Interface {
+  // Write the string s. LogLevel is just a helper. It has no effect on the
+  // content to write.
+  virtual void Write(LogLevel level, StringView s) = 0;
+};
+
+class CRU_BASE_API Logger : public Object {
+ public:
+  static Logger* GetInstance();
+
+ public:
+  Logger();
+
+  CRU_DELETE_COPY(Logger)
+  CRU_DELETE_MOVE(Logger)
+
+  ~Logger() override;
+
+ public:
+  void AddLogTarget(std::unique_ptr<ILogTarget> source);
+  void RemoveLogTarget(ILogTarget* source);
+
+ public:
+  void Log(LogLevel level, String tag, String message) {
+    Log(LogInfo(level, std::move(tag), std::move(message)));
+  }
+  void Log(LogInfo log_info);
+
+  template <typename... Args>
+  void FormatLog(LogLevel level, String tag, StringView format,
+                 Args&&... args) {
+    Log(level, std::move(tag), Format(format, std::forward<Args>(args)...));
+  }
+
+ private:
+  concurrent::ConcurrentQueue<LogInfo> log_queue_;
+
+  std::mutex target_list_mutex_;
+  std::vector<std::unique_ptr<ILogTarget>> target_list_;
+
+  std::thread log_thread_;
+};
+}  // namespace cru::log
+
+#define CRU_LOG_DEBUG(...)                                              \
+  cru::log::Logger::GetInstance()->FormatLog(cru::log::LogLevel::Debug, \
+                                             kLogTag, __VA_ARGS__)
+
+#define CRU_LOG_INFO(...)                                              \
+  cru::log::Logger::GetInstance()->FormatLog(cru::log::LogLevel::Info, \
+                                             kLogTag, __VA_ARGS__)
+
+#define CRU_LOG_WARN(...)                                              \
+  cru::log::Logger::GetInstance()->FormatLog(cru::log::LogLevel::Warn, \
+                                             kLogTag, __VA_ARGS__)
+
+#define CRU_LOG_ERROR(...)                                              \
+  cru::log::Logger::GetInstance()->FormatLog(cru::log::LogLevel::Error, \
+                                             kLogTag, __VA_ARGS__)
diff --git a/include/cru/common/log/StdioLogTarget.h b/include/cru/common/log/StdioLogTarget.h
new file mode 100644
index 00000000..4123766b
--- /dev/null
+++ b/include/cru/common/log/StdioLogTarget.h
@@ -0,0 +1,17 @@
+#pragma once
+#include "Logger.h"
+
+namespace cru::log {
+class StdioLogTarget : public Object, public virtual log::ILogTarget {
+ public:
+  explicit StdioLogTarget();
+
+  CRU_DELETE_COPY(StdioLogTarget)
+  CRU_DELETE_MOVE(StdioLogTarget)
+
+  ~StdioLogTarget() override;
+
+ public:
+  void Write(log::LogLevel level, StringView s) override;
+};
+}  // namespace cru::log
diff --git a/include/cru/osx/graphics/quartz/Painter.h b/include/cru/osx/graphics/quartz/Painter.h
index 19428583..87389437 100644
--- a/include/cru/osx/graphics/quartz/Painter.h
+++ b/include/cru/osx/graphics/quartz/Painter.h
@@ -11,8 +11,7 @@
 namespace cru::platform::graphics::osx::quartz {
 class QuartzCGContextPainter : public OsxQuartzResource,
                                public virtual IPainter {
-  CRU_DEFINE_CLASS_LOG_TAG(
-      u"cru::platform::graphics::osx::quartz::QuartzCGContextPainter")
+  CRU_DEFINE_CLASS_LOG_TAG(u"QuartzCGContextPainter")
 
  public:
   explicit QuartzCGContextPainter(
diff --git a/include/cru/ui/controls/TextHostControlService.h b/include/cru/ui/controls/TextHostControlService.h
index 74da1e19..dec9b3e0 100644
--- a/include/cru/ui/controls/TextHostControlService.h
+++ b/include/cru/ui/controls/TextHostControlService.h
@@ -76,7 +76,7 @@ class TextControlMovePattern : public Object {
 };
 
 class CRU_UI_API TextHostControlService : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::controls::TextControlService")
+  CRU_DEFINE_CLASS_LOG_TAG(u"TextControlService")
 
  public:
   TextHostControlService(gsl::not_null<Control*> control);
diff --git a/include/cru/ui/helper/ClickDetector.h b/include/cru/ui/helper/ClickDetector.h
index 0d74b9c0..3bf28451 100644
--- a/include/cru/ui/helper/ClickDetector.h
+++ b/include/cru/ui/helper/ClickDetector.h
@@ -41,7 +41,7 @@ enum class ClickState {
 };
 
 class ClickDetector : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::ClickDetector")
+  CRU_DEFINE_CLASS_LOG_TAG(u"ClickDetector")
 
  public:
   explicit ClickDetector(controls::Control* control);
diff --git a/include/cru/ui/helper/ShortcutHub.h b/include/cru/ui/helper/ShortcutHub.h
index 84e786aa..28c41234 100644
--- a/include/cru/ui/helper/ShortcutHub.h
+++ b/include/cru/ui/helper/ShortcutHub.h
@@ -2,6 +2,7 @@
 #include "../Base.h"
 
 #include "../events/UiEvents.h"
+#include "cru/common/Base.h"
 #include "cru/common/Event.h"
 #include "cru/platform/gui/Keyboard.h"
 
@@ -97,6 +98,7 @@ struct ShortcutInfo {
 };
 
 class CRU_UI_API ShortcutHub : public Object {
+  CRU_DEFINE_CLASS_LOG_TAG(u"ShortcutHub")
  public:
   ShortcutHub() = default;
 
diff --git a/include/cru/ui/host/WindowHost.h b/include/cru/ui/host/WindowHost.h
index 9fe46ac0..b1d0c998 100644
--- a/include/cru/ui/host/WindowHost.h
+++ b/include/cru/ui/host/WindowHost.h
@@ -19,7 +19,7 @@ struct AfterLayoutEventArgs {};
 // The bridge between control tree and native window.
 class CRU_UI_API WindowHost : public Object {
   friend controls::Control;
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::host::WindowHost")
+  CRU_DEFINE_CLASS_LOG_TAG(u"WindowHost")
 
  public:
   explicit WindowHost(controls::Control* root_control);
diff --git a/include/cru/ui/render/BorderRenderObject.h b/include/cru/ui/render/BorderRenderObject.h
index 2fc74f0f..a71cd6a0 100644
--- a/include/cru/ui/render/BorderRenderObject.h
+++ b/include/cru/ui/render/BorderRenderObject.h
@@ -5,7 +5,7 @@
 
 namespace cru::ui::render {
 class CRU_UI_API BorderRenderObject : public SingleChildRenderObject {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::BorderRenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"BorderRenderObject")
 
  public:
   BorderRenderObject();
diff --git a/include/cru/ui/render/FlexLayoutRenderObject.h b/include/cru/ui/render/FlexLayoutRenderObject.h
index ff7340cb..4effacb1 100644
--- a/include/cru/ui/render/FlexLayoutRenderObject.h
+++ b/include/cru/ui/render/FlexLayoutRenderObject.h
@@ -93,7 +93,7 @@ struct FlexChildLayoutData {
 //
 class CRU_UI_API FlexLayoutRenderObject
     : public LayoutRenderObject<FlexChildLayoutData> {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::FlexLayoutRenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"FlexLayoutRenderObject")
 
  public:
   FlexLayoutRenderObject() = default;
diff --git a/include/cru/ui/render/RenderObject.h b/include/cru/ui/render/RenderObject.h
index 311ab044..e8dc3b17 100644
--- a/include/cru/ui/render/RenderObject.h
+++ b/include/cru/ui/render/RenderObject.h
@@ -36,7 +36,7 @@ namespace cru::ui::render {
  *  void OnLayoutContent(const Rect& content_rect) override;
  */
 class CRU_UI_API RenderObject : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::RenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"RenderObject")
 
  protected:
   RenderObject() = default;
diff --git a/include/cru/ui/render/SingleChildRenderObject.h b/include/cru/ui/render/SingleChildRenderObject.h
index cc9e4126..a98465f0 100644
--- a/include/cru/ui/render/SingleChildRenderObject.h
+++ b/include/cru/ui/render/SingleChildRenderObject.h
@@ -3,7 +3,7 @@
 
 namespace cru::ui::render {
 class CRU_UI_API SingleChildRenderObject : public RenderObject {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::SingleChildRenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"SingleChildRenderObject")
 
  public:
   SingleChildRenderObject() = default;
diff --git a/include/cru/ui/render/StackLayoutRenderObject.h b/include/cru/ui/render/StackLayoutRenderObject.h
index b522ecbb..4da63ea2 100644
--- a/include/cru/ui/render/StackLayoutRenderObject.h
+++ b/include/cru/ui/render/StackLayoutRenderObject.h
@@ -28,7 +28,7 @@ struct StackChildLayoutData {
 // to min size.
 class CRU_UI_API StackLayoutRenderObject
     : public LayoutRenderObject<StackChildLayoutData> {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render:StackLayoutRenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"StackLayoutRenderObject")
 
  public:
   StackLayoutRenderObject() = default;
diff --git a/include/cru/ui/render/TextRenderObject.h b/include/cru/ui/render/TextRenderObject.h
index db8ff0d0..079c5680 100644
--- a/include/cru/ui/render/TextRenderObject.h
+++ b/include/cru/ui/render/TextRenderObject.h
@@ -18,7 +18,7 @@ namespace cru::ui::render {
 // If the result layout box is bigger than actual text box, then text is center
 // aligned.
 class CRU_UI_API TextRenderObject : public RenderObject {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::TextRenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"TextRenderObject")
 
  public:
   constexpr static float default_caret_width = 2;
diff --git a/include/cru/ui/render/TreeRenderObject.h b/include/cru/ui/render/TreeRenderObject.h
index 4a176926..8c589d7a 100644
--- a/include/cru/ui/render/TreeRenderObject.h
+++ b/include/cru/ui/render/TreeRenderObject.h
@@ -49,7 +49,7 @@ class CRU_UI_API TreeRenderObjectItem : public Object {
 };
 
 class CRU_UI_API TreeRenderObject : public RenderObject {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render:TreeRenderObject")
+  CRU_DEFINE_CLASS_LOG_TAG(u"TreeRenderObject")
 
  public:
   TreeRenderObject();
diff --git a/include/cru/win/DebugLogger.h b/include/cru/win/DebugLogger.h
index 6a7173ea..43e08f20 100644
--- a/include/cru/win/DebugLogger.h
+++ b/include/cru/win/DebugLogger.h
@@ -1,7 +1,7 @@
 #pragma once
 #include "Base.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 
 namespace cru::platform::win {
 
diff --git a/include/cru/win/StdOutLogger.h b/include/cru/win/StdOutLogger.h
index 831d006f..d6009bb3 100644
--- a/include/cru/win/StdOutLogger.h
+++ b/include/cru/win/StdOutLogger.h
@@ -1,7 +1,7 @@
 #pragma once
 #include "Base.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 
 namespace cru::platform::win {
 class CRU_WIN_API WinStdOutLoggerSource : public ::cru::log::ILogSource {
diff --git a/include/cru/win/gui/Cursor.h b/include/cru/win/gui/Cursor.h
index 7a9a2198..f9cb0a09 100644
--- a/include/cru/win/gui/Cursor.h
+++ b/include/cru/win/gui/Cursor.h
@@ -8,7 +8,7 @@
 namespace cru::platform::gui::win {
 class CRU_WIN_GUI_API WinCursor : public WinNativeResource,
                                   public virtual ICursor {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::platform::gui::win::WinCursor")
+  CRU_DEFINE_CLASS_LOG_TAG(u"WinCursor")
 
  public:
   WinCursor(HCURSOR handle, bool auto_destroy);
diff --git a/include/cru/win/gui/GodWindow.h b/include/cru/win/gui/GodWindow.h
index 63051245..fe61c80d 100644
--- a/include/cru/win/gui/GodWindow.h
+++ b/include/cru/win/gui/GodWindow.h
@@ -9,7 +9,7 @@
 
 namespace cru::platform::gui::win {
 class CRU_WIN_GUI_API GodWindow : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::platform::gui::win::GodWindow")
+  CRU_DEFINE_CLASS_LOG_TAG(u"GodWindow")
 
  public:
   explicit GodWindow(WinUiApplication* application);
diff --git a/include/cru/win/gui/InputMethod.h b/include/cru/win/gui/InputMethod.h
index 27a621be..8e28f857 100644
--- a/include/cru/win/gui/InputMethod.h
+++ b/include/cru/win/gui/InputMethod.h
@@ -12,7 +12,7 @@
 
 namespace cru::platform::gui::win {
 class CRU_WIN_GUI_API AutoHIMC : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::platform::gui::win::AutoHIMC")
+  CRU_DEFINE_CLASS_LOG_TAG(u"AutoHIMC")
 
  public:
   explicit AutoHIMC(HWND hwnd);
@@ -36,7 +36,7 @@ class CRU_WIN_GUI_API AutoHIMC : public Object {
 class CRU_WIN_GUI_API WinInputMethodContext
     : public WinNativeResource,
       public virtual IInputMethodContext {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::platform::gui::win::WinInputMethodContext")
+  CRU_DEFINE_CLASS_LOG_TAG(u"WinInputMethodContext")
 
  public:
   WinInputMethodContext(gsl::not_null<WinNativeWindow*> window);
diff --git a/include/cru/win/gui/Window.h b/include/cru/win/gui/Window.h
index fcbe1dbd..b279a434 100644
--- a/include/cru/win/gui/Window.h
+++ b/include/cru/win/gui/Window.h
@@ -11,7 +11,7 @@
 namespace cru::platform::gui::win {
 class CRU_WIN_GUI_API WinNativeWindow : public WinNativeResource,
                                         public virtual INativeWindow {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::platform::gui::win::WinNativeWindow")
+  CRU_DEFINE_CLASS_LOG_TAG(u"WinNativeWindow")
 
  public:
   explicit WinNativeWindow(WinUiApplication* application);
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 706f0ed0..330c7226 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -2,13 +2,14 @@ add_library(cru_base SHARED
 	Base.cpp
 	Exception.cpp
 	Format.cpp
-	Logger.cpp
 	PropertyTree.cpp
 	String.cpp
 	StringUtil.cpp
 	io/Stream.cpp
 	io/Resource.cpp
 	io/MemoryStream.cpp
+	log/Logger.cpp
+	log/StdioLogTarget.cpp
 	platform/Exception.cpp
 )
 target_compile_definitions(cru_base PRIVATE CRU_BASE_EXPORT_API)
diff --git a/src/common/Format.cpp b/src/common/Format.cpp
index 3362db65..d58c90b7 100644
--- a/src/common/Format.cpp
+++ b/src/common/Format.cpp
@@ -46,7 +46,7 @@ FormatToken ParsePlaceHolder(String place_holder_string) {
   }
 }
 
-std::vector<FormatToken> ParseToFormatTokenList(const String& str) {
+std::vector<FormatToken> ParseToFormatTokenList(StringView str) {
   std::vector<FormatToken> result;
 
   auto push_char = [&result](char16_t c) {
diff --git a/src/common/Logger.cpp b/src/common/Logger.cpp
deleted file mode 100644
index 49261396..00000000
--- a/src/common/Logger.cpp
+++ /dev/null
@@ -1,108 +0,0 @@
-#include "cru/common/Logger.h"
-
-#include <array>
-#include <cstdlib>
-#include <ctime>
-#include <iostream>
-#include <memory>
-#include <mutex>
-#include <string_view>
-
-namespace cru::log {
-namespace {
-Logger *CreateLogger() {
-  const auto logger = new Logger();
-  return logger;
-}
-}  // namespace
-
-Logger *Logger::GetInstance() {
-  static std::unique_ptr<Logger> logger{CreateLogger()};
-  return logger.get();
-}
-
-void Logger::AddSource(std::unique_ptr<ILogSource> source) {
-  sources_.push_back(std::move(source));
-}
-
-void Logger::RemoveSource(ILogSource *source) {
-  sources_.remove_if([source](const std::unique_ptr<ILogSource> &s) {
-    return s.get() == source;
-  });
-}
-
-namespace {
-String LogLevelToString(LogLevel level) {
-  switch (level) {
-    case LogLevel::Debug:
-      return u"DEBUG";
-    case LogLevel::Info:
-      return u"INFO";
-    case LogLevel::Warn:
-      return u"WARN";
-    case LogLevel::Error:
-      return u"ERROR";
-    default:
-      std::terminate();
-  }
-}
-
-String GetLogTime() {
-  auto time = std::time(nullptr);
-  auto calendar = std::localtime(&time);
-  return Format(u"{}:{}:{}", calendar->tm_hour, calendar->tm_min,
-                calendar->tm_sec);
-}
-}  // namespace
-
-void Logger::Log(LogLevel level, StringView message) {
-#ifndef CRU_DEBUG
-  if (level == LogLevel::Debug) {
-    return;
-  }
-#endif
-  for (const auto &source : sources_) {
-    source->Write(level, Format(u"[{}] {}: {}\n", GetLogTime(),
-                                LogLevelToString(level), message));
-  }
-}
-
-void Logger::Log(LogLevel level, StringView tag, StringView message) {
-#ifndef CRU_DEBUG
-  if (level == LogLevel::Debug) {
-    return;
-  }
-#endif
-  for (const auto &source : sources_) {
-    source->Write(level, Format(u"[{}] {} {}: {}\n", GetLogTime(),
-                                LogLevelToString(level), tag, message));
-  }
-}
-
-namespace {
-std::mutex stdio_lock;
-
-void WriteStdio(LogLevel level, StringView s) {
-  std::string m = s.ToString().ToUtf8();
-
-  if (level == LogLevel::Error) {
-    std::cerr << m;
-  } else {
-    std::cout << m;
-  }
-}
-}  // namespace
-
-StdioLogSource::StdioLogSource(bool use_lock) : use_lock_(use_lock) {}
-
-StdioLogSource::~StdioLogSource() {}
-
-void StdioLogSource::Write(LogLevel level, StringView s) {
-  if (use_lock_) {
-    std::lock_guard<std::mutex> guard(stdio_lock);
-    WriteStdio(level, s);
-  } else {
-    WriteStdio(level, s);
-  }
-}
-}  // namespace cru::log
diff --git a/src/common/log/Logger.cpp b/src/common/log/Logger.cpp
new file mode 100644
index 00000000..bcafde21
--- /dev/null
+++ b/src/common/log/Logger.cpp
@@ -0,0 +1,86 @@
+#include "cru/common/log/Logger.h"
+#include "cru/common/log/StdioLogTarget.h"
+
+#include <array>
+#include <cstdlib>
+#include <ctime>
+
+namespace cru::log {
+Logger *Logger::GetInstance() {
+  static Logger logger;
+
+  logger.AddLogTarget(std::make_unique<StdioLogTarget>());
+
+  return &logger;
+}
+
+void Logger::AddLogTarget(std::unique_ptr<ILogTarget> target) {
+  std::lock_guard<std::mutex> lock(target_list_mutex_);
+  target_list_.push_back(std::move(target));
+}
+
+void Logger::RemoveLogTarget(ILogTarget *target) {
+  std::lock_guard<std::mutex> lock(target_list_mutex_);
+  target_list_.erase(
+      std::remove_if(target_list_.begin(), target_list_.end(),
+                     [target](const auto &t) { return t.get() == target; }),
+      target_list_.end());
+}
+
+namespace {
+String LogLevelToString(LogLevel level) {
+  switch (level) {
+    case LogLevel::Debug:
+      return u"DEBUG";
+    case LogLevel::Info:
+      return u"INFO";
+    case LogLevel::Warn:
+      return u"WARN";
+    case LogLevel::Error:
+      return u"ERROR";
+    default:
+      std::terminate();
+  }
+}
+
+String GetLogTime() {
+  auto time = std::time(nullptr);
+  auto calendar = std::localtime(&time);
+  return Format(u"{}:{}:{}", calendar->tm_hour, calendar->tm_min,
+                calendar->tm_sec);
+}
+
+String MakeLogFinalMessage(const LogInfo &log_info) {
+  if (log_info.tag.empty()) {
+    return Format(u"[{}] {}: {}", GetLogTime(),
+                  LogLevelToString(log_info.level), log_info.message);
+  } else {
+    return Format(u"[{}] {} {}: {}", GetLogTime(),
+                  LogLevelToString(log_info.level), log_info.tag,
+                  log_info.message);
+  }
+}
+}  // namespace
+
+Logger::Logger()
+    : log_thread_([this] {
+        while (true) {
+          auto log_info = log_queue_.Pull();
+          std::lock_guard<std::mutex> lock_guard{target_list_mutex_};
+          for (const auto &target : target_list_) {
+            target->Write(log_info.level, MakeLogFinalMessage(log_info));
+          }
+        }
+      }) {}
+
+Logger::~Logger() {}
+
+void Logger::Log(LogInfo log_info) {
+#ifndef CRU_DEBUG
+  if (log_info.level == LogLevel::Debug) {
+    return;
+  }
+#endif
+  log_queue_.Push(std::move(log_info));
+}
+}  // namespace cru::log
diff --git a/src/common/log/StdioLogTarget.cpp b/src/common/log/StdioLogTarget.cpp
new file mode 100644
index 00000000..ad29a3ce
--- /dev/null
+++ b/src/common/log/StdioLogTarget.cpp
@@ -0,0 +1,22 @@
+#include "cru/common/log/StdioLogTarget.h"
+
+#include <iostream>
+
+namespace cru::log {
+StdioLogTarget::StdioLogTarget() {}
+
+StdioLogTarget::~StdioLogTarget() {}
+
+void StdioLogTarget::Write(log::LogLevel level, StringView s) {
+#ifdef CRU_PLATFORM_WINDOWS
+#else
+  std::string m = s.ToUtf8();
+
+  if (level == log::LogLevel::Error) {
+    std::cerr << m;
+  } else {
+    std::cout << m;
+  }
+#endif
+}
+}  // namespace cru::log
diff --git a/src/osx/graphics/quartz/Painter.cpp b/src/osx/graphics/quartz/Painter.cpp
index d74e456b..a8c3715a 100644
--- a/src/osx/graphics/quartz/Painter.cpp
+++ b/src/osx/graphics/quartz/Painter.cpp
@@ -1,6 +1,5 @@
 #include "cru/osx/graphics/quartz/Painter.h"
 
-#include "cru/common/Logger.h"
 #include "cru/osx/graphics/quartz/Brush.h"
 #include "cru/osx/graphics/quartz/Convert.h"
 #include "cru/osx/graphics/quartz/Geometry.h"
@@ -27,10 +26,6 @@ QuartzCGContextPainter::QuartzCGContextPainter(
 
   transform_ = Matrix::Scale(1, -1) * Matrix::Translation(0, size.height);
   CGContextConcatCTM(cg_context_, Convert(transform_));
-
-  // log::TagDebug(log_tag,
-  //               u"Created with CGContext: {}, Auto Release: {},  Size: {}.",
-  //               cg_context, auto_release, size_);
 }
 
 QuartzCGContextPainter::~QuartzCGContextPainter() {
@@ -61,8 +56,6 @@ void QuartzCGContextPainter::Clear(const Color& color) {
                            color.GetFloatGreen(), color.GetFloatBlue(),
                            color.GetFloatAlpha());
   CGContextFillRect(cg_context_, Convert(Rect{Point{}, size_}));
-
-  // log::TagDebug(log_tag, u"Clear with color {}, size {}.", color, size_);
 }
 
 void QuartzCGContextPainter::DrawLine(const Point& start, const Point& end,
@@ -225,7 +218,6 @@ void QuartzCGContextPainter::DoEndDraw() {
   if (cg_context_) {
     CGContextFlush(cg_context_);
     CGContextSynchronize(cg_context_);
-    // log::TagDebug(log_tag, u"End draw and flush.");
 
     on_end_draw_(this);
   }
diff --git a/src/osx/gui/Clipboard.mm b/src/osx/gui/Clipboard.mm
index b37efce2..6e3fb076 100644
--- a/src/osx/gui/Clipboard.mm
+++ b/src/osx/gui/Clipboard.mm
@@ -1,7 +1,7 @@
 #include "cru/osx/gui/Clipboard.h"
 #include "ClipboardPrivate.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/osx/Convert.h"
 
 #include <memory>
@@ -27,7 +27,7 @@ OsxClipboardPrivate::~OsxClipboardPrivate() {}
 String OsxClipboardPrivate::GetText() {
   auto result = [pasteboard_ readObjectsForClasses:@[ NSString.class ] options:nil];
   if (result == nil) {
-    log::TagWarn(log_tag, u"Failed to get text from clipboard");
+    CRU_LOG_WARN(u"Failed to get text from clipboard");
     return u"";
   } else {
     if (result.count == 0) {
diff --git a/src/osx/gui/ClipboardPrivate.h b/src/osx/gui/ClipboardPrivate.h
index 93fe5448..63145a64 100644
--- a/src/osx/gui/ClipboardPrivate.h
+++ b/src/osx/gui/ClipboardPrivate.h
@@ -7,8 +7,7 @@
 namespace cru::platform::gui::osx {
 namespace details {
 class OsxClipboardPrivate : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(
-      u"cru::platform::gui::osx::details::OsxClipboardPrivate")
+  CRU_DEFINE_CLASS_LOG_TAG(u"OsxClipboardPrivate")
  public:
   explicit OsxClipboardPrivate(NSPasteboard* pasteboard);
 
diff --git a/src/osx/gui/InputMethod.mm b/src/osx/gui/InputMethod.mm
index 3a961209..2c19c358 100644
--- a/src/osx/gui/InputMethod.mm
+++ b/src/osx/gui/InputMethod.mm
@@ -3,7 +3,7 @@
 #import <AppKit/AppKit.h>
 #include "InputMethodPrivate.h"
 #include "WindowPrivate.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/osx/Convert.h"
 #include "cru/osx/gui/Window.h"
 
@@ -46,15 +46,9 @@ OsxInputMethodContext::OsxInputMethodContext(OsxWindow* window)
 
 OsxInputMethodContext::~OsxInputMethodContext() {}
 
-void OsxInputMethodContext::EnableIME() {
-  // log::Debug(u"Enable IME.");
-  p_->Activate();
-}
+void OsxInputMethodContext::EnableIME() { p_->Activate(); }
 
-void OsxInputMethodContext::DisableIME() {
-  // log::Debug(u"Disable IME.");
-  p_->Deactivate();
-}
+void OsxInputMethodContext::DisableIME() { p_->Deactivate(); }
 
 bool OsxInputMethodContext::ShouldManuallyDrawCompositionText() { return true; }
 
diff --git a/src/osx/gui/UiApplication.mm b/src/osx/gui/UiApplication.mm
index 20ce82d3..43c49c5c 100644
--- a/src/osx/gui/UiApplication.mm
+++ b/src/osx/gui/UiApplication.mm
@@ -1,7 +1,7 @@
 #include "cru/osx/gui/UiApplication.h"
 
 #include "ClipboardPrivate.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/common/platform/osx/Convert.h"
 #include "cru/osx/graphics/quartz/Factory.h"
 #include "cru/osx/gui/Clipboard.h"
@@ -80,9 +80,6 @@ OsxUiApplication::OsxUiApplication()
     : OsxGuiResource(this), p_(new details::OsxUiApplicationPrivate(this)) {
   [NSApplication sharedApplication];
 
-  // Add stdio logger.
-  log::Logger::GetInstance()->AddSource(std::make_unique<log::StdioLogSource>());
-
   [NSApp setDelegate:p_->app_delegate_];
   p_->quartz_graphics_factory_ = std::make_unique<graphics::osx::quartz::QuartzGraphicsFactory>();
   p_->cursor_manager_ = std::make_unique<OsxCursorManager>(this);
diff --git a/src/osx/gui/Window.mm b/src/osx/gui/Window.mm
index 403ae030..8d15ef37 100644
--- a/src/osx/gui/Window.mm
+++ b/src/osx/gui/Window.mm
@@ -3,8 +3,8 @@
 
 #include "CursorPrivate.h"
 #include "InputMethodPrivate.h"
-#include "cru/common/Logger.h"
 #include "cru/common/Range.h"
+#include "cru/common/log/Logger.h"
 #include "cru/osx/Convert.h"
 #include "cru/osx/graphics/quartz/Convert.h"
 #include "cru/osx/graphics/quartz/Painter.h"
@@ -351,7 +351,6 @@ std::unique_ptr<graphics::IPainter> OsxWindow::BeginPaint() {
   return std::make_unique<cru::platform::graphics::osx::quartz::QuartzCGContextPainter>(
       GetUiApplication()->GetGraphicsFactory(), cg_context, false, GetClientSize(),
       [this](graphics::osx::quartz::QuartzCGContextPainter*) {
-        // log::Debug(u"Finish painting and invalidate view.");
         [[p_->window_ contentView] setNeedsDisplay:YES];
       });
 }
@@ -470,7 +469,6 @@ cru::platform::gui::KeyModifier GetKeyModifier(NSEvent* event) {
 }
 
 - (void)drawRect:(NSRect)dirtyRect {
-  // cru::log::TagDebug(u"CruView", u"Begin to draw layer in view.");
   auto cg_context = [[NSGraphicsContext currentContext] CGContext];
   auto layer = _p->GetDrawLayer();
   Ensures(layer);
@@ -486,32 +484,26 @@ cru::platform::gui::KeyModifier GetKeyModifier(NSEvent* event) {
 }
 
 - (void)mouseMoved:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse move.");
   _p->OnMouseMove(cru::platform::Point(event.locationInWindow.x, event.locationInWindow.y));
 }
 
 - (void)mouseDragged:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse move.");
   _p->OnMouseMove(cru::platform::Point(event.locationInWindow.x, event.locationInWindow.y));
 }
 
 - (void)rightMouseDragged:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse move.");
   _p->OnMouseMove(cru::platform::Point(event.locationInWindow.x, event.locationInWindow.y));
 }
 
 - (void)mouseEntered:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse enter.");
   _p->OnMouseEnterLeave(cru::platform::gui::MouseEnterLeaveType::Enter);
 }
 
 - (void)mouseExited:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse exit.");
   _p->OnMouseEnterLeave(cru::platform::gui::MouseEnterLeaveType::Leave);
 }
 
 - (void)mouseDown:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse down.");
   [[self window] makeKeyWindow];
 
   auto key_modifier = GetKeyModifier(event);
@@ -521,8 +513,6 @@ cru::platform::gui::KeyModifier GetKeyModifier(NSEvent* event) {
 }
 
 - (void)mouseUp:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse up.");
-
   auto key_modifier = GetKeyModifier(event);
   cru::platform::Point p(event.locationInWindow.x, event.locationInWindow.y);
 
@@ -530,8 +520,6 @@ cru::platform::gui::KeyModifier GetKeyModifier(NSEvent* event) {
 }
 
 - (void)rightMouseDown:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved right mouse down.");
-
   auto key_modifier = GetKeyModifier(event);
   cru::platform::Point p(event.locationInWindow.x, event.locationInWindow.y);
 
@@ -539,8 +527,6 @@ cru::platform::gui::KeyModifier GetKeyModifier(NSEvent* event) {
 }
 
 - (void)rightMouseUp:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved right mouse up.");
-
   auto key_modifier = GetKeyModifier(event);
   cru::platform::Point p(event.locationInWindow.x, event.locationInWindow.y);
 
@@ -548,8 +534,6 @@ cru::platform::gui::KeyModifier GetKeyModifier(NSEvent* event) {
 }
 
 - (void)scrollWheel:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved mouse wheel.");
-
   auto key_modifier = GetKeyModifier(event);
   cru::platform::Point p(event.locationInWindow.x, event.locationInWindow.y);
 
@@ -620,10 +604,6 @@ const std::unordered_set<KeyCode> input_context_handle_codes_when_has_text{
     KeyCode::Right,     KeyCode::Up,    KeyCode::Down};
 
 - (void)keyDown:(NSEvent*)event {
-  if constexpr (key_down_debug) {
-    cru::log::TagDebug(u"CruView", u"Recieved key down.");
-  }
-
   auto key_modifier = GetKeyModifier(event);
 
   bool handled = false;
@@ -655,15 +635,11 @@ const std::unordered_set<KeyCode> input_context_handle_codes_when_has_text{
 
   if (!handled) {
     _p->OnKeyDown(c, key_modifier);
-  } else {
-    if constexpr (key_down_debug) {
-      cru::log::TagDebug(u"CruView", u"Key down is handled by input context.");
-    }
   }
 }
 
 - (void)keyUp:(NSEvent*)event {
-  // cru::log::TagDebug(u"CruView", u"Recieved key up.");
+  // cru::CRU_LOG_DEBUG(u"CruView", u"Recieved key up.");
 
   auto key_modifier = GetKeyModifier(event);
   auto c = cru::platform::gui::osx::KeyCodeFromOsxToCru(event.keyCode);
@@ -698,7 +674,7 @@ const std::unordered_set<KeyCode> input_context_handle_codes_when_has_text{
 
   auto ss = Convert(s);
 
-  // cru::log::TagDebug(u"CruView",
+  // cru::CRU_LOG_DEBUG(u"CruView",
   //                    u"Received setMarkedText string: {}, selected range: ({}, {}), "
   //                    u"replacement range: ({}, {}).",
   //                    ss, selectedRange.location, selectedRange.length, replacementRange.location,
@@ -759,7 +735,7 @@ const std::unordered_set<KeyCode> input_context_handle_codes_when_has_text{
   _input_context_p->SetCompositionText(cru::platform::gui::CompositionText());
   cru::String ss = Convert(s);
 
-  // cru::log::TagDebug(u"CruView", u"Finish composition: {}, replacement range: ({}, {})", ss,
+  // cru::CRU_LOG_DEBUG(u"CruView", u"Finish composition: {}, replacement range: ({}, {})", ss,
   //                    replacementRange.location, replacementRange.length);
 
   _input_context_p->RaiseCompositionEvent();
diff --git a/src/ui/controls/TextHostControlService.cpp b/src/ui/controls/TextHostControlService.cpp
index 81365a8b..15d9102c 100644
--- a/src/ui/controls/TextHostControlService.cpp
+++ b/src/ui/controls/TextHostControlService.cpp
@@ -2,7 +2,7 @@
 
 #include "../Helper.h"
 #include "cru/common/Base.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/common/String.h"
 #include "cru/common/StringUtil.h"
 #include "cru/platform/graphics/Font.h"
@@ -226,7 +226,7 @@ void TextHostControlService::SetText(String text, bool stop_composition) {
 void TextHostControlService::InsertText(gsl::index position, StringView text,
                                         bool stop_composition) {
   if (!Utf16IsValidInsertPosition(this->text_, position)) {
-    log::TagError(log_tag, u"Invalid text insert position.");
+    CRU_LOG_ERROR(u"Invalid text insert position.");
     return;
   }
   this->text_.insert(this->text_.cbegin() + position, text);
@@ -240,7 +240,7 @@ void TextHostControlService::InsertText(gsl::index position, StringView text,
 void TextHostControlService::DeleteChar(gsl::index position,
                                         bool stop_composition) {
   if (!Utf16IsValidInsertPosition(this->text_, position)) {
-    log::TagError(log_tag, u"Invalid text delete position.");
+    CRU_LOG_ERROR(u"Invalid text delete position.");
     return;
   }
   if (position == static_cast<gsl::index>(this->text_.size())) return;
@@ -253,7 +253,7 @@ void TextHostControlService::DeleteChar(gsl::index position,
 gsl::index TextHostControlService::DeleteCharPrevious(gsl::index position,
                                                       bool stop_composition) {
   if (!Utf16IsValidInsertPosition(this->text_, position)) {
-    log::TagError(log_tag, u"Invalid text delete position.");
+    CRU_LOG_ERROR(u"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())) {
-    log::TagError(log_tag, u"Invalid text delete start position.");
+    CRU_LOG_ERROR(u"Invalid text delete start position.");
     return;
   }
   if (!Utf16IsValidInsertPosition(this->text_, range.GetStart())) {
-    log::TagError(log_tag, u"Invalid text delete end position.");
+    CRU_LOG_ERROR(u"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) {
-      log::TagDebug(log_tag,
+      CRU_LOG_DEBUG(
                     u"Calculate input method candidate window position: {}.",
                     right_bottom);
     }
diff --git a/src/ui/helper/ClickDetector.cpp b/src/ui/helper/ClickDetector.cpp
index a10133e9..8ebdfabc 100644
--- a/src/ui/helper/ClickDetector.cpp
+++ b/src/ui/helper/ClickDetector.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/helper/ClickDetector.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/ui/DebugFlags.h"
 #include "cru/ui/controls/Control.h"
 #include "cru/ui/host/WindowHost.h"
@@ -58,7 +58,7 @@ ClickDetector::ClickDetector(controls::Control* control) {
                 this->state_ == ClickState::Hover) {
               if (!this->control_->CaptureMouse()) {
                 if constexpr (debug_flags::click_detector) {
-                  log::TagDebug(log_tag,
+                  CRU_LOG_DEBUG(
                                 u"Failed to capture mouse when begin click.");
                 }
                 return;
@@ -136,7 +136,7 @@ void ClickDetector::SetState(ClickState state) {
           UnreachableCode();
       }
     };
-    log::TagDebug(log_tag, u"Click state changed, new state: {}.",
+    CRU_LOG_DEBUG(u"Click state changed, new state: {}.",
                   to_string(state));
   }
 
diff --git a/src/ui/helper/ShortcutHub.cpp b/src/ui/helper/ShortcutHub.cpp
index 3df07409..8fbf0b8d 100644
--- a/src/ui/helper/ShortcutHub.cpp
+++ b/src/ui/helper/ShortcutHub.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/helper/ShortcutHub.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/ui/DebugFlags.h"
 #include "cru/ui/controls/Control.h"
 
@@ -64,7 +64,7 @@ const std::vector<ShortcutInfo>& ShortcutHub::GetShortcutByKeyBind(
 
 void ShortcutHub::Install(controls::Control* control) {
   if (!event_guard_.IsEmpty()) {
-    log::Error(u"Shortcut hub is already installed. Failed to install.");
+    CRU_LOG_ERROR(u"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()) {
-    log::Warn(u"Shortcut hub is not installed. Failed to uninstall.");
+    CRU_LOG_WARN(u"Shortcut hub is not installed. Failed to uninstall.");
     return;
   }
 
@@ -89,17 +89,17 @@ void ShortcutHub::OnKeyDown(events::KeyEventArgs& event) {
 
   if constexpr (debug_flags::shortcut) {
     if (shortcut_list.empty()) {
-      log::Debug(u"No shortcut for key bind {}.", key_bind.ToString());
+      CRU_LOG_DEBUG(u"No shortcut for key bind {}.", key_bind.ToString());
     }
-    log::Debug(u"Begin to handle shortcut for key bind {}.",
-               key_bind.ToString());
+    CRU_LOG_DEBUG(u"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) {
-        log::Debug(u"Handle {} handled it.", shortcut.name);
+        CRU_LOG_DEBUG(u"Handle {} handled it.", shortcut.name);
       }
 
       handled = true;
@@ -108,22 +108,23 @@ void ShortcutHub::OnKeyDown(events::KeyEventArgs& event) {
       break;
     } else {
       if constexpr (debug_flags::shortcut) {
-        log::Debug(u"Handle {} didn't handle it.", shortcut.name);
+        CRU_LOG_DEBUG(u"Handle {} didn't handle it.", shortcut.name);
       }
     }
   }
 
   if constexpr (debug_flags::shortcut) {
     if (!shortcut_list.empty()) {
-      log::Debug(u"End handling shortcut for key bind {}.",
-                 key_bind.ToString());
+      CRU_LOG_DEBUG(u"End handling shortcut for key bind {}.",
+                    key_bind.ToString());
     }
   }
 
   if (!handled) {
     if constexpr (debug_flags::shortcut) {
-      log::Debug(u"Raise fallback event for unhandled shortcut of key bind {}.",
-                 key_bind.ToString());
+      CRU_LOG_DEBUG(
+          u"Raise fallback event for unhandled shortcut of key bind {}.",
+          key_bind.ToString());
     }
     fallback_event_.Raise(event);
   }
diff --git a/src/ui/host/RoutedEventDispatch.h b/src/ui/host/RoutedEventDispatch.h
index 2ab51645..3c2a98d8 100644
--- a/src/ui/host/RoutedEventDispatch.h
+++ b/src/ui/host/RoutedEventDispatch.h
@@ -1,5 +1,5 @@
 #pragma once
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/ui/DebugFlags.h"
 #include "cru/ui/controls/Control.h"
 
@@ -21,18 +21,19 @@ namespace cru::ui {
 // as the rest arguments.
 template <typename EventArgs, typename... Args>
 void DispatchEvent(
-    const std::u16string_view& event_name,
-    controls::Control* const original_sender,
+    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";
+
   if (original_sender == nullptr) return;
 
   CRU_UNUSED(event_name)
 
   if (original_sender == last_receiver) {
     if constexpr (debug_flags::routed_event)
-      log::Debug(
-          "Routed event {} no need to dispatch (original_sender == "
+      CRU_LOG_DEBUG(
+          u"Routed event {} no need to dispatch (original_sender == "
           "last_receiver). Original sender is {}.",
           event_name, original_sender->GetControlType());
     return;
@@ -49,7 +50,7 @@ void DispatchEvent(
   }
 
   if constexpr (debug_flags::routed_event) {
-    std::u16string log = u"Dispatch routed event ";
+    String log = u"Dispatch routed event ";
     log += event_name;
     log += u". Path (parent first): ";
     auto i = receive_list.crbegin();
@@ -59,7 +60,7 @@ void DispatchEvent(
       log += u" -> ";
     }
     log += (*i)->GetControlType();
-    log::Debug(log);
+    CRU_LOG_DEBUG(log);
   }
 
   auto handled = false;
@@ -75,7 +76,7 @@ void DispatchEvent(
     if (event_args.IsHandled()) {
       handled = true;
       if constexpr (debug_flags::routed_event)
-        log::Debug(
+        CRU_LOG_DEBUG(
             u"Routed event is short-circuit in TUNNEL at {}-st control (count "
             u"from parent).",
             count);
@@ -92,7 +93,7 @@ void DispatchEvent(
           ->Raise(event_args);
       if (event_args.IsHandled()) {
         if constexpr (debug_flags::routed_event)
-          log::Debug(
+          CRU_LOG_DEBUG(
               u"Routed event is short-circuit in BUBBLE at {}-st control "
               u"(count from parent).",
               count);
@@ -109,6 +110,6 @@ void DispatchEvent(
   }
 
   if constexpr (debug_flags::routed_event)
-    log::Debug(u"Routed event dispatch finished.");
+    CRU_LOG_DEBUG(u"Routed event dispatch finished.");
 }
 }  // namespace cru::ui
diff --git a/src/ui/host/WindowHost.cpp b/src/ui/host/WindowHost.cpp
index 91b5f438..42d0945f 100644
--- a/src/ui/host/WindowHost.cpp
+++ b/src/ui/host/WindowHost.cpp
@@ -2,7 +2,7 @@
 
 #include "RoutedEventDispatch.h"
 #include "cru/common/Base.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/graphics/Painter.h"
 #include "cru/platform/gui/InputMethod.h"
 #include "cru/platform/gui/UiApplication.h"
@@ -191,7 +191,7 @@ void WindowHost::RelayoutWithSize(const Size& available_size,
   after_layout_event_.Raise(AfterLayoutEventArgs{});
   after_layout_stable_action_.clear();
   if constexpr (debug_flags::layout)
-    log::TagDebug(log_tag, u"A relayout is finished.");
+    CRU_LOG_DEBUG(u"A relayout is finished.");
 }
 
 void WindowHost::Repaint() {
diff --git a/src/ui/mapper/BorderStyleMapper.cpp b/src/ui/mapper/BorderStyleMapper.cpp
index 8daa9d1b..3dea0776 100644
--- a/src/ui/mapper/BorderStyleMapper.cpp
+++ b/src/ui/mapper/BorderStyleMapper.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/mapper/BorderStyleMapper.h"
 #include "../Helper.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/graphics/Brush.h"
 #include "cru/platform/graphics/Factory.h"
 #include "cru/ui/mapper/MapperRegistry.h"
@@ -21,7 +21,6 @@ ApplyBorderStyleInfo BorderStyleMapper::DoMapFromXml(
 
   for (auto child : node->GetChildren()) {
     if (child->GetType() == XmlNode::Type::Text) {
-      log::Debug(u"Ignore text node.");
     } else {
       auto c = child->AsElement();
       auto thickness_mapper =
@@ -43,7 +42,6 @@ ApplyBorderStyleInfo BorderStyleMapper::DoMapFromXml(
           } else if (name->CaseInsensitiveCompare(u"background") == 0) {
             result.background_brush = std::move(brush);
           } else {
-            log::Debug(u"Unknown brush name: {}", *name);
           }
         } else {
           result.border_brush = std::move(brush);
diff --git a/src/ui/render/BorderRenderObject.cpp b/src/ui/render/BorderRenderObject.cpp
index 30493a49..cbea4b81 100644
--- a/src/ui/render/BorderRenderObject.cpp
+++ b/src/ui/render/BorderRenderObject.cpp
@@ -1,7 +1,7 @@
 #include "cru/ui/render/BorderRenderObject.h"
 
 #include "../Helper.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/graphics/Factory.h"
 #include "cru/platform/graphics/Geometry.h"
 #include "cru/platform/graphics/Painter.h"
@@ -80,8 +80,8 @@ RenderObject* BorderRenderObject::HitTest(const Point& point) {
 
 void BorderRenderObject::Draw(platform::graphics::IPainter* painter) {
   if constexpr (debug_flags::draw) {
-    log::TagDebug(
-        log_tag, u"BorderRenderObject draw, background: {}, foreground: {}.",
+    CRU_LOG_DEBUG(
+        u"BorderRenderObject draw, background: {}, foreground: {}.",
         background_brush_ == nullptr ? u"NONE"
                                      : background_brush_->GetDebugString(),
         foreground_brush_ == nullptr ? u"NONE"
@@ -94,7 +94,7 @@ void BorderRenderObject::Draw(platform::graphics::IPainter* painter) {
 
   if (is_border_enabled_) {
     if (border_brush_ == nullptr) {
-      log::TagWarn(log_tag, u"Border is enabled but border brush is null.");
+      CRU_LOG_WARN(u"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 0699768a..988e7590 100644
--- a/src/ui/render/FlexLayoutRenderObject.cpp
+++ b/src/ui/render/FlexLayoutRenderObject.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/render/FlexLayoutRenderObject.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/ui/render/LayoutHelper.h"
 
 #include <algorithm>
@@ -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, StringView log_tag) {
+    Alignment item_cross_align, String kLogTag) {
   Expects(children.size() == layout_data.size());
 
   direction_tag_t direction_tag;
@@ -300,8 +300,7 @@ Size FlexLayoutMeasureContentImpl(
 
   if (max_main_length.IsSpecified() &&
       total_length > max_main_length.GetLengthOrUndefined()) {
-    log::TagWarn(
-        log_tag,
+    CRU_LOG_WARN(
         u"(Measure) Children's main axis length exceeds required max length.");
     total_length = max_main_length.GetLengthOrUndefined();
   } else if (min_main_length.IsSpecified() &&
@@ -345,11 +344,11 @@ Size FlexLayoutRenderObject::OnMeasureContent(
   if (horizontal) {
     return FlexLayoutMeasureContentImpl<tag_horizontal_t>(
         requirement, preferred_size, children, layout_data_list,
-        item_cross_align_, log_tag);
+        item_cross_align_, kLogTag);
   } else {
     return FlexLayoutMeasureContentImpl<tag_vertical_t>(
         requirement, preferred_size, children, layout_data_list,
-        item_cross_align_, log_tag);
+        item_cross_align_, kLogTag);
   }
 }
 
diff --git a/src/ui/render/LayoutHelper.cpp b/src/ui/render/LayoutHelper.cpp
index 7a82bb2d..a9121321 100644
--- a/src/ui/render/LayoutHelper.cpp
+++ b/src/ui/render/LayoutHelper.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/render/LayoutHelper.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 
 namespace cru::ui::render {
 float CalculateAnchorByAlignment(Alignment alignment, float start_point,
diff --git a/src/ui/render/RenderObject.cpp b/src/ui/render/RenderObject.cpp
index 6c09ce99..b6de5782 100644
--- a/src/ui/render/RenderObject.cpp
+++ b/src/ui/render/RenderObject.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/render/RenderObject.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/ui/DebugFlags.h"
 #include "cru/ui/controls/Control.h"
 #include "cru/ui/host/WindowHost.h"
@@ -80,16 +80,16 @@ void RenderObject::Measure(const MeasureRequirement& requirement,
       preferred_size.OverrideBy(preferred_size_);
 
   if constexpr (cru::ui::debug_flags::layout) {
-    log::Debug(u"{} Measure begins :\nrequirement: {}\npreferred size: {}",
-               this->GetDebugPathInTree(), requirement.ToDebugString(),
-               preferred_size.ToDebugString());
+    CRU_LOG_DEBUG(u"{} Measure begins :\nrequirement: {}\npreferred size: {}",
+                  this->GetDebugPathInTree(), requirement.ToDebugString(),
+                  preferred_size.ToDebugString());
   }
 
   desired_size_ = OnMeasureCore(merged_requirement, merged_preferred_size);
 
   if constexpr (cru::ui::debug_flags::layout) {
-    log::Debug(u"{} Measure ends :\nresult size: {}",
-               this->GetDebugPathInTree(), desired_size_);
+    CRU_LOG_DEBUG(u"{} Measure ends :\nresult size: {}",
+                  this->GetDebugPathInTree(), desired_size_);
   }
 
   Ensures(desired_size_.width >= 0);
@@ -98,8 +98,8 @@ void RenderObject::Measure(const MeasureRequirement& requirement,
 
 void RenderObject::Layout(const Point& offset) {
   if constexpr (cru::ui::debug_flags::layout) {
-    log::Debug(u"{} Layout :\noffset: {} size: {}", this->GetDebugPathInTree(),
-               offset, desired_size_);
+    CRU_LOG_DEBUG(u"{} Layout :\noffset: {} size: {}",
+                  this->GetDebugPathInTree(), offset, desired_size_);
   }
   offset_ = offset;
   size_ = desired_size_;
diff --git a/src/ui/render/StackLayoutRenderObject.cpp b/src/ui/render/StackLayoutRenderObject.cpp
index fda9a420..9ca9bf02 100644
--- a/src/ui/render/StackLayoutRenderObject.cpp
+++ b/src/ui/render/StackLayoutRenderObject.cpp
@@ -1,6 +1,6 @@
 #include "cru/ui/render/StackLayoutRenderObject.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/ui/render/LayoutHelper.h"
 #include "cru/ui/render/MeasureRequirement.h"
 
diff --git a/src/ui/render/TextRenderObject.cpp b/src/ui/render/TextRenderObject.cpp
index 82f314bd..0b9009c5 100644
--- a/src/ui/render/TextRenderObject.cpp
+++ b/src/ui/render/TextRenderObject.cpp
@@ -1,7 +1,7 @@
 #include "cru/ui/render/TextRenderObject.h"
 
 #include "../Helper.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/graphics/Factory.h"
 #include "cru/platform/graphics/Painter.h"
 #include "cru/platform/graphics/TextLayout.h"
@@ -176,12 +176,11 @@ RenderObject* TextRenderObject::HitTest(const Point& point) {
 
 void TextRenderObject::Draw(platform::graphics::IPainter* painter) {
   if constexpr (debug_flags::draw) {
-    log::TagDebug(log_tag,
-                  u"Begin to paint, total_offset: {}, size: {}, text_layout: "
-                  u"{}, brush: {}.",
-                  this->GetTotalOffset(), this->GetDesiredSize(),
-                  this->text_layout_->GetDebugString(),
-                  this->brush_->GetDebugString());
+    CRU_LOG_DEBUG(
+        u"Begin to paint, total_offset: {}, size: {}, text_layout: "
+        u"{}, brush: {}.",
+        this->GetTotalOffset(), this->GetDesiredSize(),
+        this->text_layout_->GetDebugString(), this->brush_->GetDebugString());
   }
 
   if (this->selection_range_.has_value()) {
diff --git a/src/win/graphics/direct/Factory.cpp b/src/win/graphics/direct/Factory.cpp
index b948c040..e8b3f107 100644
--- a/src/win/graphics/direct/Factory.cpp
+++ b/src/win/graphics/direct/Factory.cpp
@@ -1,6 +1,6 @@
 #include "cru/win/graphics/direct/Factory.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/win/graphics/direct/Brush.h"
 #include "cru/win/graphics/direct/Exception.h"
 #include "cru/win/graphics/direct/Font.h"
diff --git a/src/win/graphics/direct/TextLayout.cpp b/src/win/graphics/direct/TextLayout.cpp
index 14e2d3aa..ffef5e0c 100644
--- a/src/win/graphics/direct/TextLayout.cpp
+++ b/src/win/graphics/direct/TextLayout.cpp
@@ -1,7 +1,7 @@
 #include "cru/win/graphics/direct/TextLayout.h"
 #include <dwrite.h>
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/Check.h"
 #include "cru/win/graphics/direct/Exception.h"
 #include "cru/win/graphics/direct/Factory.h"
diff --git a/src/win/gui/Clipboard.cpp b/src/win/gui/Clipboard.cpp
index 6bb5d1c5..7ecc9dea 100644
--- a/src/win/gui/Clipboard.cpp
+++ b/src/win/gui/Clipboard.cpp
@@ -1,6 +1,6 @@
 #include "cru/win/gui/Clipboard.h"
 #include <winuser.h>
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/win/gui/GodWindow.h"
 #include "cru/win/gui/UiApplication.h"
 
diff --git a/src/win/gui/Cursor.cpp b/src/win/gui/Cursor.cpp
index 1d421b59..d85ba565 100644
--- a/src/win/gui/Cursor.cpp
+++ b/src/win/gui/Cursor.cpp
@@ -1,6 +1,6 @@
 #include "cru/win/gui/Cursor.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/win/gui/Exception.h"
 
 #include <stdexcept>
@@ -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.
-      log::TagWarn(log_tag, u"Failed to destroy a cursor. Last error code: {}",
+      CRU_LOG_WARN(u"Failed to destroy a cursor. Last error code: {}",
                    ::GetLastError());
     }
   }
diff --git a/src/win/gui/GodWindow.cpp b/src/win/gui/GodWindow.cpp
index 0c385bea..4416870f 100644
--- a/src/win/gui/GodWindow.cpp
+++ b/src/win/gui/GodWindow.cpp
@@ -1,6 +1,6 @@
 #include "cru/win/gui/GodWindow.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/win/gui/Exception.h"
 #include "cru/win/gui/UiApplication.h"
 #include "cru/win/gui/WindowClass.h"
@@ -43,7 +43,7 @@ GodWindow::GodWindow(WinUiApplication* application) {
 GodWindow::~GodWindow() {
   if (!::DestroyWindow(hwnd_)) {
     // Although this could be "safely" ignore.
-    log::TagWarn(log_tag, u"Failed to destroy god window.");
+    CRU_LOG_WARN(u"Failed to destroy god window.");
   }
 }
 
diff --git a/src/win/gui/InputMethod.cpp b/src/win/gui/InputMethod.cpp
index fedb72fe..8a54577b 100644
--- a/src/win/gui/InputMethod.cpp
+++ b/src/win/gui/InputMethod.cpp
@@ -1,6 +1,6 @@
 #include "cru/win/gui/InputMethod.h"
 
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/common/StringUtil.h"
 #include "cru/platform/Check.h"
 #include "cru/platform/gui/DebugFlags.h"
@@ -35,7 +35,7 @@ AutoHIMC& AutoHIMC::operator=(AutoHIMC&& other) {
 AutoHIMC::~AutoHIMC() {
   if (handle_) {
     if (!::ImmReleaseContext(hwnd_, handle_))
-      log::TagWarn(log_tag, u"Failed to release HIMC.");
+      CRU_LOG_WARN(u"Failed to release HIMC.");
   }
 }
 
@@ -157,7 +157,7 @@ WinInputMethodContext::~WinInputMethodContext() {}
 void WinInputMethodContext::EnableIME() {
   const auto hwnd = native_window_->GetWindowHandle();
   if (::ImmAssociateContextEx(hwnd, nullptr, IACE_DEFAULT) == FALSE) {
-    log::TagWarn(log_tag, u"Failed to enable ime.");
+    CRU_LOG_WARN(u"Failed to enable ime.");
   }
 }
 
@@ -168,21 +168,21 @@ void WinInputMethodContext::DisableIME() {
   ::ImmNotifyIME(himc.Get(), NI_COMPOSITIONSTR, CPS_COMPLETE, 0);
 
   if (::ImmAssociateContextEx(hwnd, nullptr, 0) == FALSE) {
-    log::TagWarn(log_tag, u"Failed to disable ime.");
+    CRU_LOG_WARN(u"Failed to disable ime.");
   }
 }
 
 void WinInputMethodContext::CompleteComposition() {
   auto himc = GetHIMC();
   if (!::ImmNotifyIME(himc.Get(), NI_COMPOSITIONSTR, CPS_COMPLETE, 0)) {
-    log::TagWarn(log_tag, u"Failed to complete composition.");
+    CRU_LOG_WARN(u"Failed to complete composition.");
   }
 }
 
 void WinInputMethodContext::CancelComposition() {
   auto himc = GetHIMC();
   if (!::ImmNotifyIME(himc.Get(), NI_COMPOSITIONSTR, CPS_CANCEL, 0)) {
-    log::TagWarn(log_tag, u"Failed to complete composition.");
+    CRU_LOG_WARN(u"Failed to complete composition.");
   }
 }
 
@@ -201,7 +201,7 @@ void WinInputMethodContext::SetCandidateWindowPosition(const Point& point) {
   form.ptCurrentPos = native_window_->DipToPixel(point);
 
   if (!::ImmSetCandidateWindow(himc.Get(), &form))
-    log::TagDebug(log_tag,
+    CRU_LOG_DEBUG(
                   u"Failed to set input method candidate window position.");
 }
 
@@ -229,7 +229,7 @@ void WinInputMethodContext::OnWindowNativeMessage(
         // I don't think this will happen because normal key strike without ime
         // should only trigger ascci character. If it is a charater from
         // supplementary planes, it should be handled with ime messages.
-        log::TagWarn(log_tag,
+        CRU_LOG_WARN(
                      u"A WM_CHAR message for character from supplementary "
                      u"planes is ignored.");
       } else {
@@ -247,7 +247,7 @@ void WinInputMethodContext::OnWindowNativeMessage(
       composition_event_.Raise(nullptr);
       auto composition_text = GetCompositionText();
       if constexpr (DebugFlags::input_method) {
-        log::TagDebug(log_tag, u"WM_IME_COMPOSITION composition text:\n{}",
+        CRU_LOG_DEBUG(u"WM_IME_COMPOSITION composition text:\n{}",
                       composition_text);
       }
       if (message.l_param & GCS_RESULTSTR) {
@@ -258,14 +258,14 @@ void WinInputMethodContext::OnWindowNativeMessage(
     }
     case WM_IME_STARTCOMPOSITION: {
       if constexpr (DebugFlags::input_method) {
-        log::TagDebug(log_tag, u"WM_IME_STARTCOMPOSITION received.");
+        CRU_LOG_DEBUG(u"WM_IME_STARTCOMPOSITION received.");
       }
       composition_start_event_.Raise(nullptr);
       break;
     }
     case WM_IME_ENDCOMPOSITION: {
       if constexpr (DebugFlags::input_method) {
-        log::TagDebug(log_tag, u"WM_IME_ENDCOMPOSITION received.");
+        CRU_LOG_DEBUG(u"WM_IME_ENDCOMPOSITION received.");
       }
       composition_end_event_.Raise(nullptr);
       break;
diff --git a/src/win/gui/UiApplication.cpp b/src/win/gui/UiApplication.cpp
index 59076a9c..8c2dfae7 100644
--- a/src/win/gui/UiApplication.cpp
+++ b/src/win/gui/UiApplication.cpp
@@ -2,7 +2,7 @@
 
 #include "TimerManager.h"
 #include "WindowManager.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/Check.h"
 #include "cru/win/DebugLogger.h"
 #include "cru/win/StdOutLogger.h"
diff --git a/src/win/gui/Window.cpp b/src/win/gui/Window.cpp
index ada3d59f..9c86441e 100644
--- a/src/win/gui/Window.cpp
+++ b/src/win/gui/Window.cpp
@@ -1,7 +1,7 @@
 #include "cru/win/gui/Window.h"
 
 #include "WindowManager.h"
-#include "cru/common/Logger.h"
+#include "cru/common/log/Logger.h"
 #include "cru/platform/Check.h"
 #include "cru/platform/graphics/NullPainter.h"
 #include "cru/platform/gui/Base.h"
@@ -207,7 +207,7 @@ bool WinNativeWindow::ReleaseMouse() {
 
 void WinNativeWindow::RequestRepaint() {
   if constexpr (DebugFlags::paint) {
-    log::TagDebug(log_tag, u"A repaint is requested.");
+    CRU_LOG_DEBUG(u"A repaint is requested.");
   }
   if (!::InvalidateRect(hwnd_, nullptr, FALSE))
     throw Win32Error(::GetLastError(), u"Failed to invalidate window.");
@@ -234,7 +234,7 @@ void WinNativeWindow::SetCursor(std::shared_ptr<ICursor> cursor) {
 
   if (!::SetClassLongPtrW(hwnd_, GCLP_HCURSOR,
                           reinterpret_cast<LONG_PTR>(cursor_->GetHandle()))) {
-    log::TagWarn(log_tag,
+    CRU_LOG_WARN(
                  u"Failed to set cursor because failed to set class long. Last "
                  u"error code: {}.",
                  ::GetLastError());
@@ -244,8 +244,8 @@ void WinNativeWindow::SetCursor(std::shared_ptr<ICursor> cursor) {
   if (GetVisibility() != WindowVisibilityType::Show) return;
 
   auto lg = [](StringView reason) {
-    log::TagWarn(
-        log_tag,
+    CRU_LOG_WARN(
+        
         u"Failed to set cursor because {} when window is visible. (We need to "
         u"update cursor if it is inside the window.) Last error code: {}.",
         reason, ::GetLastError());
@@ -507,7 +507,7 @@ void WinNativeWindow::OnPaintInternal() {
   paint_event_.Raise(nullptr);
   ValidateRect(hwnd_, nullptr);
   if constexpr (DebugFlags::paint) {
-    log::TagDebug(log_tag, u"A repaint is finished.");
+    CRU_LOG_DEBUG(u"A repaint is finished.");
   }
 }