...

9 files changed, 166 insertions, 5 deletions

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 1de11236..9b38e418 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -66,6 +66,9 @@
     "xloctime": "cpp",
     "string_view": "cpp",
     "cassert": "cpp",
-    "gsl_util": "cpp"
+    "gsl_util": "cpp",
+    "multi_span": "cpp",
+    "span": "cpp",
+    "string_span": "cpp"
   }
 }
diff --git a/include/cru/platform/native/base.hpp b/include/cru/platform/native/base.hpp
index 5ebd98d6..883a9450 100644
--- a/include/cru/platform/native/base.hpp
+++ b/include/cru/platform/native/base.hpp
@@ -10,6 +10,7 @@ struct ICursorManager;
 struct IUiApplication;
 struct INativeWindow;
 struct INativeWindowResolver;
+struct IInputMethodManager;
 
 struct Dpi {
   float x;
diff --git a/include/cru/platform/native/input_method.hpp b/include/cru/platform/native/input_method.hpp
new file mode 100644
index 00000000..ecc47fd8
--- /dev/null
+++ b/include/cru/platform/native/input_method.hpp
@@ -0,0 +1,30 @@
+#pragma once
+#include "../resource.hpp"
+#include "base.hpp"
+#include "cru/common/event.hpp"
+
+#include <memory>
+
+namespace cru::platform::native {
+// It is a reference, so there is a ref count, remember to destroy it to release
+// the ref after use.
+struct IInputMethodContextRef : INativeResource {
+  // Reset composition string. Use this method to prepare typing.
+  virtual void Reset() = 0;
+  // Get the composition string.
+  virtual std::string GetCompositionString() = 0;
+  // Set the candidate window lefttop. Use this method to prepare typing.
+  virtual void SetCandidateWindowPosition(const Point& point);
+  // Triggered every time composition text changes, evet args is the new
+  // composition text.
+  virtual IEvent<std::string>* CompositionTextChangeEvent() = 0;
+  // User comfirmed compostition. Use this method to get the final input text.
+  virtual IEvent<std::string>* CharEvent() = 0;
+};
+
+struct IInputMethodManager : INativeResource {
+  // Get a reference of context of a window.
+  virtual std::unique_ptr<IInputMethodContextRef> GetContext(
+      INativeWindow* window) = 0;
+};
+}  // namespace cru::platform::native
diff --git a/include/cru/win/native/input_method.hpp b/include/cru/win/native/input_method.hpp
new file mode 100644
index 00000000..3ea16709
--- /dev/null
+++ b/include/cru/win/native/input_method.hpp
@@ -0,0 +1,42 @@
+#pragma once
+#include "resource.hpp"
+
+#include "cru/platform/native/input_method.hpp"
+
+#include <imm.h>
+
+namespace cru::platform::native::win {
+class WinNativeWindow;
+
+class WinInputMethodContextRef : public WinNativeResource,
+                                 public IInputMethodContextRef {
+ public:
+  WinInputMethodContextRef(WinNativeWindow* window);
+
+  CRU_DELETE_COPY(WinInputMethodContextRef)
+  CRU_DELETE_MOVE(WinInputMethodContextRef)
+
+  ~WinInputMethodContextRef() override;
+
+  ::HIMC GetHandle() const { return handle_; }
+
+  void Reset() override;
+
+  std::string GetCompositionString() override;
+
+  void SetCandidateWindowPosition(const Point& point) override;
+
+  IEvent<std::string>* CompositionTextChangeEvent() override;
+
+  IEvent<std::string>* CharEvent() override;
+
+ private:
+  WinNativeWindow* window_;
+
+  ::HWND window_handle_;
+  ::HIMC handle_;
+
+  Event<std::string> composition_text_change_event_;
+  Event<std::string> char_event_;
+};
+}  // namespace cru::platform::native::win
diff --git a/src/platform/native/CMakeLists.txt b/src/platform/native/CMakeLists.txt
index c280ddd0..688f2890 100644
--- a/src/platform/native/CMakeLists.txt
+++ b/src/platform/native/CMakeLists.txt
@@ -5,6 +5,7 @@ add_library(cru_platform_native STATIC
 target_sources(cru_platform_native PUBLIC
 	${CRU_PLATFORM_NATIVE_INCLUDE_DIR}/base.hpp
 	${CRU_PLATFORM_NATIVE_INCLUDE_DIR}/cursor.hpp
+	${CRU_PLATFORM_NATIVE_INCLUDE_DIR}/input_method.hpp
 	${CRU_PLATFORM_NATIVE_INCLUDE_DIR}/keyboard.hpp
 	${CRU_PLATFORM_NATIVE_INCLUDE_DIR}/window.hpp
 	${CRU_PLATFORM_NATIVE_INCLUDE_DIR}/ui_application.hpp
diff --git a/src/win/native/CMakeLists.txt b/src/win/native/CMakeLists.txt
index 82994d67..521b32cf 100644
--- a/src/win/native/CMakeLists.txt
+++ b/src/win/native/CMakeLists.txt
@@ -9,6 +9,7 @@ add_library(cru_win_native STATIC
 
 	cursor.cpp
 	god_window.cpp
+	input_method.cpp
 	keyboard.cpp
 	timer.cpp
 	ui_application.cpp
@@ -22,6 +23,7 @@ target_sources(cru_win_native PUBLIC
 	${CRU_WIN_NATIVE_INCLUDE_DIR}/cursor.hpp
 	${CRU_WIN_NATIVE_INCLUDE_DIR}/exception.hpp
 	${CRU_WIN_NATIVE_INCLUDE_DIR}/god_window.hpp
+	${CRU_WIN_NATIVE_INCLUDE_DIR}/input_method.hpp
 	${CRU_WIN_NATIVE_INCLUDE_DIR}/keyboard.hpp
 	${CRU_WIN_NATIVE_INCLUDE_DIR}/resource.hpp
 	${CRU_WIN_NATIVE_INCLUDE_DIR}/ui_application.hpp
diff --git a/src/win/native/dpi_util.hpp b/src/win/native/dpi_util.hpp
index d8c5610c..07b89a95 100644
--- a/src/win/native/dpi_util.hpp
+++ b/src/win/native/dpi_util.hpp
@@ -32,4 +32,15 @@ inline float PixelToDipX(const int pixel_x) {
 inline float PixelToDipY(const int pixel_y) {
   return DipToPixelInternal(pixel_y, GetDpi().y);
 }
+
+inline Point PiToDip(const POINT& pi_point) {
+  return Point(PixelToDipX(pi_point.x), PixelToDipY(pi_point.y));
+}
+
+inline POINT DipToPi(const Point& dip_point) {
+  POINT result;
+  result.x = DipToPixelX(dip_point.x);
+  result.y = DipToPixelY(dip_point.y);
+  return result;
+}
 }  // namespace cru::platform::native::win
diff --git a/src/win/native/input_method.cpp b/src/win/native/input_method.cpp
new file mode 100644
index 00000000..4edfdc5f
--- /dev/null
+++ b/src/win/native/input_method.cpp
@@ -0,0 +1,75 @@
+#include "cru/win/native/input_method.hpp"
+
+#include "cru/common/logger.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/native/window.hpp"
+#include "cru/win/string.hpp"
+#include "dpi_util.hpp"
+
+#include <vector>
+
+namespace cru::platform::native::win {
+WinInputMethodContextRef::WinInputMethodContextRef(WinNativeWindow* window)
+    : window_(window) {
+  Expects(window);
+
+  window_handle_ = window->GetWindowHandle();
+  handle_ = ::ImmGetContext(window_handle_);
+
+  // TODO: Events
+}
+
+WinInputMethodContextRef::~WinInputMethodContextRef() {
+  ::ImmReleaseContext(window_handle_, handle_);
+}
+
+void WinInputMethodContextRef::Reset() {
+  wchar_t s[1] = {L'\0'};
+
+  if (!::ImmSetCompositionStringW(handle_, SCS_SETSTR, static_cast<LPVOID>(s),
+                                  sizeof(s), static_cast<LPVOID>(s),
+                                  sizeof(s))) {
+    log::Warn(
+        "WinInputMethodContextRef: Failed to reset input method context.");
+  }
+}
+
+std::string WinInputMethodContextRef::GetCompositionString() {
+  const auto length =
+      ::ImmGetCompositionStringW(handle_, GCS_RESULTREADSTR, NULL, 0) +
+      sizeof(wchar_t);
+  std::vector<std::byte> data(length);
+  const auto result = ::ImmGetCompositionStringW(
+      handle_, GCS_RESULTREADSTR, static_cast<LPVOID>(data.data()), length);
+
+  if (result == IMM_ERROR_NODATA) {
+    return std::string{};
+  } else if (result == IMM_ERROR_GENERAL) {
+    throw new platform::win::Win32Error(::GetLastError(),
+                                        "Failed to get composition string.");
+  }
+
+  return platform::win::ToUtf8String(
+      std::wstring_view(reinterpret_cast<wchar_t*>(data.data())));
+}
+
+void WinInputMethodContextRef::SetCandidateWindowPosition(const Point& point) {
+  ::CANDIDATEFORM form;
+  form.dwIndex = 1;
+  form.dwStyle = CFS_CANDIDATEPOS;
+  form.ptCurrentPos = DipToPi(point);
+
+  if (!::ImmSetCandidateWindow(handle_, &form))
+    log::Debug(
+        "WinInputMethodContextRef: Failed to set input method candidate window "
+        "position.");
+}
+
+IEvent<std::string>* WinInputMethodContextRef::CompositionTextChangeEvent() {
+  return &composition_text_change_event_;
+}
+
+IEvent<std::string>* WinInputMethodContextRef::CharEvent() {
+  return &char_event_;
+}
+}  // namespace cru::platform::native::win
diff --git a/src/win/native/window.cpp b/src/win/native/window.cpp
index 1b590026..6f66cb57 100644
--- a/src/win/native/window.cpp
+++ b/src/win/native/window.cpp
@@ -17,10 +17,6 @@
 #include <windowsx.h>
 
 namespace cru::platform::native::win {
-inline Point PiToDip(const POINT& pi_point) {
-  return Point(PixelToDipX(pi_point.x), PixelToDipY(pi_point.y));
-}
-
 WinNativeWindow::WinNativeWindow(WinUiApplication* application,
                                  WindowClass* window_class, DWORD window_style,
                                  WinNativeWindow* parent)