QtWebChannelApiGenerator.cpp

#include "QMetaTypes.h"
#include "Api.h"

QString jsType(const QString& name);
void generateSignalClasses(QFile &out, const QMetaObject &apiMeta);
void generateParameterList(QFile &out, const QMetaMethod &methodMeta);
void generateApi(QFile &out, const QMetaObject &apiMeta);

int main(int argc, char *argv[]) {
  qRegisterMetaTypes();


  QFile out;
  out.open(stdout, QFile::WriteOnly);
  auto& apiMeta = Api::staticMetaObject;

  generateSignalClasses(out, apiMeta);
  out.write("\n");
  generateApi(out, apiMeta);

  return 0;
}

void generateSignalClasses(QFile &out, const QMetaObject &apiMeta) {
  for (int i = 0; i < apiMeta.methodCount(); ++i) {
    auto methodMeta = apiMeta.method(i);
    if (methodMeta.enclosingMetaObject()->className() == apiMeta.className()) {
      if (methodMeta.methodType() == QMetaMethod::Signal) {
        out.write("class ");
        out.write(methodMeta.name());
        out.write(" {\n  connect(callback: (");

        generateParameterList(out, methodMeta);

        out.write(") => void): void;\n}\n");
      }
    }
  }
}

void generateParameterList(QFile &out, const QMetaMethod &methodMeta) {
  auto parameterNames = methodMeta.parameterNames();
  auto parameterTypes = methodMeta.parameterTypes();
  for (int j = 0; j < methodMeta.parameterCount(); ++j) {
    if (j > 0) {
      out.write(", ");
    }
    out.write(parameterNames.at(j));
    out.write(": ");
    out.write(jsType(parameterTypes.at(j)).toUtf8());
  }
}

void generateApi(QFile &out, const QMetaObject &apiMeta) {
  out.write("class Api {\n");
  for (int i = 0; i < apiMeta.methodCount(); ++i) {
    auto methodMeta = apiMeta.method(i);
    if (methodMeta.enclosingMetaObject()->className() == apiMeta.className()) {
      if (methodMeta.methodType() == QMetaMethod::Slot) {
        out.write("  ");
        out.write(methodMeta.name());
        out.write("(");
        generateParameterList(out, methodMeta);
        if (strcmp(methodMeta.typeName(), "void") != 0) {
          if (methodMeta.parameterCount() > 0) {
            out.write(", ");
          }
          out.write("callback: (result: ");
          out.write(jsType(methodMeta.typeName()).toUtf8());
          out.write(") => void");
        }
        out.write("): void;\n");
      } else if (methodMeta.methodType() == QMetaMethod::Signal) {
        out.write("  ");
        out.write(methodMeta.name());
        out.write(": ");
        out.write(methodMeta.name());
        out.write(";\n");
      }
    }
  }

  out.write("}\n\n"
            "class WebChannelObjects {\n"
            "    api: Api;\n"
            "}\n"
            "\n"
            "class WebChannel {\n"
            "    objects: WebChannelObjects;\n"
            "}");
}

QString jsType(const QString& name) {
  if (name == "QVariantMap") {
    return "Object";
  }
  if (name == "QVariantList") {
    return "Array";
  }
  if (name == "QString") {
    return "string";
  }
  if (name == "bool") {
    return "boolean";
  }
  return name;
}