1 files changed, 80 insertions, 0 deletions
diff --git a/include/cru/platform/gui/InputMethod.hpp b/include/cru/platform/gui/InputMethod.hpp
new file mode 100644
index 00000000..53a8d671
--- /dev/null
+++ b/include/cru/platform/gui/InputMethod.hpp
@@ -0,0 +1,80 @@
+#pragma once
+#include "Base.hpp"
+
+#include "cru/common/Event.hpp"
+
+#include <fmt/format.h>
+#include <memory>
+#include <vector>
+
+namespace cru::platform::gui {
+struct CompositionClause {
+  int start;
+  int end;
+  bool target;
+};
+
+using CompositionClauses = std::vector<CompositionClause>;
+
+struct CompositionText {
+  std::u16string text;
+  CompositionClauses clauses;
+  TextRange selection;
+};
+
+struct IInputMethodContext : virtual INativeResource {
+  // Return true if you should draw composition text manually. Return false if
+  // system will take care of that for you.
+  virtual bool ShouldManuallyDrawCompositionText() = 0;
+
+  virtual void EnableIME() = 0;
+
+  virtual void DisableIME() = 0;
+
+  virtual void CompleteComposition() = 0;
+
+  virtual void CancelComposition() = 0;
+
+  virtual CompositionText GetCompositionText() = 0;
+
+  // Set the candidate window lefttop. Use this method to prepare typing.
+  virtual void SetCandidateWindowPosition(const Point& point) = 0;
+
+  // Triggered when user starts composition.
+  virtual IEvent<std::nullptr_t>* CompositionStartEvent() = 0;
+
+  // Triggered when user stops composition.
+  virtual IEvent<std::nullptr_t>* CompositionEndEvent() = 0;
+
+  // Triggered every time composition text changes.
+  virtual IEvent<std::nullptr_t>* CompositionEvent() = 0;
+
+  virtual IEvent<std::u16string_view>* TextEvent() = 0;
+};
+}  // namespace cru::platform::gui
+
+template <>
+struct fmt::formatter<cru::platform::gui::CompositionText, char16_t>
+    : fmt::formatter<std::u16string_view, char16_t> {
+  auto parse(fmt::basic_format_parse_context<char16_t>& ctx) {
+    return fmt::formatter<std::u16string_view, char16_t>::parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(const cru::platform::gui::CompositionText& ct,
+              FormatContext& ctx) {
+    auto output = ctx.out();
+    output = format_to(output, u"text: {}\n", ct.text);
+    output = format_to(output, u"clauses:\n");
+    for (gsl::index i = 0; i < static_cast<gsl::index>(ct.clauses.size());
+         i++) {
+      const auto& clause = ct.clauses[i];
+      output =
+          format_to(output, u"\t{}. start: {} end: {}{}\n", i, clause.start,
+                    clause.end, clause.target ? u" target" : u"");
+    }
+    output = format_to(output, u"selection: position: {} count: {}",
+                       ct.selection.position, ct.selection.count);
+    return output;
+  }
+};