reaper-keyboard-intercept.cpp

// Demo REAPER extension to intercept keyboard input
// https://i.imgur.com/xMSrqRr.gif

#include <cstdio>
#include <reaper_plugin.h>

static int (*plugin_register)(const char *name, void *infostruct);
static int HandleKey(MSG *, accelerator_register_t *);

static accelerator_register_t g_accel{HandleKey, true};

extern "C" REAPER_PLUGIN_DLL_EXPORT int REAPER_PLUGIN_ENTRYPOINT(
  REAPER_PLUGIN_HINSTANCE instance, reaper_plugin_info_t *rec)
{
  if(!rec) {
    plugin_register("-accelerator", &g_accel);
    return 0;
  }

  if(rec->caller_version != REAPER_PLUGIN_VERSION)
    return 0;

  (plugin_register = rec->Register)("accelerator", &g_accel);

  return 1;
}

int HandleKey(MSG *event, accelerator_register_t *)
{
  const char *name;

  switch(event->message) {
  case WM_KEYUP:
    name = "keyup";
    break;
  case WM_KEYDOWN:
    name = "keydown";
    break;
  default:
    name = "???";
    break;
  };

  printf("%s: %lu\n", name, event->wParam);

  return 0; // "not our window" (makes REAPER continue processing the event normally)
}