...

2 files changed, 13 insertions, 0 deletions

diff --git a/include/cru/win/native/window.hpp b/include/cru/win/native/window.hpp
index a137463b..a27a3384 100644
--- a/include/cru/win/native/window.hpp
+++ b/include/cru/win/native/window.hpp
@@ -156,6 +156,11 @@ class WinNativeWindow : public WinNativeResource, public virtual INativeWindow {
   Event<std::string> char_event_;
 
   Event<WindowNativeMessageEventArgs&> native_message_event_;
+
+  // WM_CHAR may be sent twice successively with two utf-16 code units of
+  // surrogate pair when character is from supplementary planes. This field is
+  // used to save the previous one.
+  wchar_t last_wm_char_event_wparam_;
 };
 
 class WinNativeWindowResolver : public WinNativeResource,
diff --git a/include/cru/win/string.hpp b/include/cru/win/string.hpp
index 3fdadbf8..b2bfd245 100644
--- a/include/cru/win/string.hpp
+++ b/include/cru/win/string.hpp
@@ -27,6 +27,14 @@ namespace cru::platform::win {
 std::string ToUtf8String(const std::wstring_view& string);
 std::wstring ToUtf16String(const std::string_view& string);
 
+inline bool IsSurrogatePairLeading(wchar_t c) {
+  return c >= 0xD800 && c <= 0xDBFF;
+}
+
+inline bool IsSurrogatePairTrailing(wchar_t c) {
+  return c >= 0xDC00 && c <= 0xDFFF;
+}
+
 using CodePoint = std::int32_t;
 constexpr CodePoint k_code_point_end = -1;