Win32: Support Korean input

shell/platform/windows/flutter_window_win32.cc

@@ -176,6 +176,10 @@ void FlutterWindowWin32::OnComposeBegin() {
   binding_handler_delegate_->OnComposeBegin();
 }
 
+void FlutterWindowWin32::OnComposeCommit() {
+  binding_handler_delegate_->OnComposeCommit();
+}
+
 void FlutterWindowWin32::OnComposeEnd() {
   binding_handler_delegate_->OnComposeEnd();
 }

shell/platform/windows/flutter_window_win32.h

@@ -65,6 +65,9 @@ class FlutterWindowWin32 : public WindowWin32, public WindowBindingHandler {
   // |WindowWin32|
   void OnComposeBegin() override;
 
+  // |WindowWin32|
+  void OnComposeCommit() override;
+
   // |WindowWin32|
   void OnComposeEnd() override;
 

shell/platform/windows/flutter_window_win32_unittests.cc

@@ -78,6 +78,7 @@ class SpyKeyboardKeyHandler : public KeyboardHandlerBase {
   MOCK_METHOD2(TextHook,
                void(FlutterWindowsView* window, const std::u16string& text));
   MOCK_METHOD0(ComposeBeginHook, void());
+  MOCK_METHOD0(ComposeCommitHook, void());
   MOCK_METHOD0(ComposeEndHook, void());
   MOCK_METHOD2(ComposeChangeHook,
                void(const std::u16string& text, int cursor_pos));
@@ -112,6 +113,7 @@ class SpyTextInputPlugin : public KeyboardHandlerBase,
   MOCK_METHOD2(TextHook,
                void(FlutterWindowsView* window, const std::u16string& text));
   MOCK_METHOD0(ComposeBeginHook, void());
+  MOCK_METHOD0(ComposeCommitHook, void());
   MOCK_METHOD0(ComposeEndHook, void());
   MOCK_METHOD2(ComposeChangeHook,
                void(const std::u16string& text, int cursor_pos));

shell/platform/windows/flutter_windows_view.cc

@@ -210,6 +210,10 @@ void FlutterWindowsView::OnComposeBegin() {
   SendComposeBegin();
 }
 
+void FlutterWindowsView::OnComposeCommit() {
+  SendComposeCommit();
+}
+
 void FlutterWindowsView::OnComposeEnd() {
   SendComposeEnd();
 }
@@ -329,6 +333,12 @@ void FlutterWindowsView::SendComposeBegin() {
   }
 }
 
+void FlutterWindowsView::SendComposeCommit() {
+  for (const auto& handler : keyboard_handlers_) {
+    handler->ComposeCommitHook();
+  }
+}
+
 void FlutterWindowsView::SendComposeEnd() {
   for (const auto& handler : keyboard_handlers_) {
     handler->ComposeEndHook();

shell/platform/windows/flutter_windows_view.h

@@ -111,6 +111,9 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate,
   // |WindowBindingHandlerDelegate|
   void OnComposeBegin() override;
 
+  // |WindowBindingHandlerDelegate|
+  void OnComposeCommit() override;
+
   // |WindowBindingHandlerDelegate|
   void OnComposeEnd() override;
 
@@ -202,6 +205,13 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate,
   // input method such as in CJK text input.
   void SendComposeBegin();
 
+  // Reports an IME compose commit event.
+  //
+  // Triggered when the user commits the current composing text while using a
+  // multi-step input method such as in CJK text input. Composing continues with
+  // the next keypress.
+  void SendComposeCommit();
+
   // Reports an IME compose end event.
   //
   // Triggered when the user commits the composing text while using a multi-step

shell/platform/windows/keyboard_handler_base.h

@@ -45,10 +45,17 @@ class KeyboardHandlerBase {
   // input method such as in CJK text input.
   virtual void ComposeBeginHook() = 0;
 
+  // Handler for IME compose commit events.
+  //
+  // Triggered when the user commits the current composing text while using a
+  // multi-step input method such as in CJK text input. Composing continues with
+  // the next keypress.
+  virtual void ComposeCommitHook() = 0;
+
   // Handler for IME compose end events.
   //
-  // Triggered when the user commits the composing text while using a multi-step
-  // input method such as in CJK text input.
+  // Triggered when the user ends editing composing text while using a
+  // multi-step input method such as in CJK text input.
   virtual void ComposeEndHook() = 0;
 
   // Handler for IME compose change events.

shell/platform/windows/keyboard_key_handler.cc

@@ -181,6 +181,10 @@ void KeyboardKeyHandler::ComposeBeginHook() {
   // Ignore.
 }
 
+void KeyboardKeyHandler::ComposeCommitHook() {
+  // Ignore.
+}
+
 void KeyboardKeyHandler::ComposeEndHook() {
   // Ignore.
 }

shell/platform/windows/keyboard_key_handler.h

@@ -107,6 +107,9 @@ class KeyboardKeyHandler : public KeyboardHandlerBase {
   // |KeyboardHandlerBase|
   void ComposeBeginHook() override;
 
+  // |KeyboardHandlerBase|
+  void ComposeCommitHook() override;
+
   // |KeyboardHandlerBase|
   void ComposeEndHook() override;
 

shell/platform/windows/testing/mock_window_win32.h

@@ -42,6 +42,7 @@ class MockWin32Window : public WindowWin32 {
   MOCK_METHOD6(OnKey, bool(int, int, int, char32_t, bool, bool));
   MOCK_METHOD2(OnScroll, void(double, double));
   MOCK_METHOD0(OnComposeBegin, void());
+  MOCK_METHOD0(OnComposeCommit, void());
   MOCK_METHOD0(OnComposeEnd, void());
   MOCK_METHOD2(OnComposeChange, void(const std::u16string&, int));
   MOCK_METHOD4(DefaultWindowProc, LRESULT(HWND, UINT, WPARAM, LPARAM));

shell/platform/windows/text_input_plugin.cc

@@ -111,6 +111,14 @@ void TextInputPlugin::ComposeBeginHook() {
   SendStateUpdate(*active_model_);
 }
 
+void TextInputPlugin::ComposeCommitHook() {
+  if (active_model_ == nullptr) {
+    return;
+  }
+  active_model_->CommitComposing();
+  SendStateUpdate(*active_model_);
+}
+
 void TextInputPlugin::ComposeEndHook() {
   if (active_model_ == nullptr) {
     return;

shell/platform/windows/text_input_plugin.h

@@ -47,6 +47,9 @@ class TextInputPlugin : public KeyboardHandlerBase {
   // |KeyboardHandlerBase|
   void ComposeBeginHook() override;
 
+  // |KeyboardHandlerBase|
+  void ComposeCommitHook() override;
+
   // |KeyboardHandlerBase|
   void ComposeEndHook() override;
 

shell/platform/windows/window_binding_handler_delegate.h

@@ -59,6 +59,13 @@ class WindowBindingHandlerDelegate {
   // input method such as in CJK text input.
   virtual void OnComposeBegin() = 0;
 
+  // Notifies the delegate that IME composing region have been committed.
+  //
+  // Triggered when the user commits the current composing text while using a
+  // multi-step input method such as in CJK text input. Composing continues with
+  // the next keypress.
+  virtual void OnComposeCommit() = 0;
+
   // Notifies the delegate that IME composing mode has ended.
   //
   // Triggered when the user commits the composing text while using a multi-step

shell/platform/windows/window_win32.cc

@@ -142,18 +142,13 @@ void WindowWin32::OnImeComposition(UINT const message,
       OnComposeChange(text.value(), pos);
     }
   } else if (lparam & GCS_RESULTSTR) {
+    // Commit but don't end composing.
     // Read the committed composing string.
     long pos = text_input_manager_.GetComposingCursorPosition();
     std::optional<std::u16string> text = text_input_manager_.GetResultString();
     if (text) {
       OnComposeChange(text.value(), pos);
-    }
-    // Next, try reading the composing string. Some Japanese IMEs send a message
-    // containing both a GCS_RESULTSTR and a GCS_COMPSTR when one composition is
-    // committed and another immediately started.
-    text = text_input_manager_.GetResultString();
-    if (text) {
-      OnComposeChange(text.value(), pos);
+      OnComposeCommit();
     }
   }
 }

shell/platform/windows/window_win32.h

@@ -107,6 +107,9 @@ class WindowWin32 {
   // Called when IME composing begins.
   virtual void OnComposeBegin() = 0;
 
+  // Called when IME composing text is committed.
+  virtual void OnComposeCommit() = 0;
+
   // Called when IME composing ends.
   virtual void OnComposeEnd() = 0;