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#ifndef MOZC_UNIX_IBUS_CANDIDATE_WINDOW_HANDLER_H_
#define MOZC_UNIX_IBUS_CANDIDATE_WINDOW_HANDLER_H_

#include <memory>
#include <string>
#include <variant>

#include "base/port.h"
#include "protocol/commands.pb.h"
#include "protocol/renderer_command.pb.h"
#include "renderer/renderer_interface.h"
#include "unix/ibus/candidate_window_handler_interface.h"
#include "unix/ibus/ibus_wrapper.h"

namespace mozc {
namespace ibus {

class GsettingsObserver;

class CandidateWindowHandler : public CandidateWindowHandlerInterface {
 public:
  CandidateWindowHandler(const CandidateWindowHandler &) = delete;
  CandidateWindowHandler &operator=(const CandidateWindowHandler &) = delete;
  // CandidateWindowHandler takes ownership of renderer_ pointer.
  explicit CandidateWindowHandler(renderer::RendererInterface *renderer);
  virtual ~CandidateWindowHandler();

  virtual void Update(IbusEngineWrapper *engine,
                      const commands::Output &output);
  virtual void UpdateCursorRect(IbusEngineWrapper *engine);
  virtual void Hide(IbusEngineWrapper *engine);
  virtual void Show(IbusEngineWrapper *engine);

  virtual void OnIBusCustomFontDescriptionChanged(
      const std::string &custom_font_description);

  virtual void OnIBusUseCustomFontDescriptionChanged(
      bool use_custom_font_description);

  void RegisterGSettingsObserver();

  void OnSettingsUpdated(absl::string_view key,
                         const GsettingsWrapper::Variant &value);

 protected:
  bool SendUpdateCommand(IbusEngineWrapper *engine,
                         const commands::Output &output, bool visibility);

  std::unique_ptr<renderer::RendererInterface> renderer_;
  std::unique_ptr<commands::Output> last_update_output_;

 private:
  std::string GetFontDescription() const;
  std::string custom_font_description_;
  bool use_custom_font_description_;
  std::unique_ptr<GsettingsObserver> settings_observer_;
  commands::RendererCommand::Rectangle preedit_begin_;
};

}  // namespace ibus
}  // namespace mozc
#endif  // MOZC_UNIX_IBUS_CANDIDATE_WINDOW_HANDLER_H_
