abstract-gui-listener.hh

#pragma once

#include <string>
#include <variant>
#include <vector>
#include <functional>

#include <clap/clap.h>

namespace clap {
   using InvocationArgumentType = std::variant<bool, int64_t, double, std::string>;
   using InvocationArgumentsType = std::vector<InvocationArgumentType>;

   // Listener for events produced by the Gui, to the destination of the plugin.
   //
   // Beaware that the callbacks happen on the plugin's GUI thread, not the host's main thread.
   class AbstractGuiListener {
   public:
      virtual ~AbstractGuiListener();

      virtual void onGuiRunOnMainThread(std::function<void()> callback) = 0;

      // timer based polling of new parameter changes, transport value, ...
      // the plugin shall transmit them via
      virtual void onGuiPoll() = 0;

      virtual void onGuiParamBeginAdjust(clap_id paramId) = 0;
      virtual void onGuiParamAdjust(clap_id paramId, double value) = 0;
      virtual void onGuiParamEndAdjust(clap_id paramId) = 0;

      virtual void onGuiSetTransportIsSubscribed(bool isSubscribed) = 0;

      virtual void onGuiWindowClosed(bool wasDestroyed) = 0;

      virtual void onGuiUndo() = 0;
      virtual void onGuiRedo() = 0;

      virtual void onGuiInvoke(const std::string &method, const InvocationArgumentsType &args) = 0;
   };
} // namespace clap