js_define.h

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// Copyright 2014 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
#ifndef FXJS_JS_DEFINE_H_
#define FXJS_JS_DEFINE_H_
 
#include <memory>
 
#include "core/fxcrt/span.h"
#include "core/fxcrt/unowned_ptr.h"
#include "fxjs/cfxjs_engine.h"
#include "fxjs/cjs_result.h"
#include "fxjs/cjs_runtime.h"
#include "fxjs/js_resources.h"
#include "v8/include/v8-local-handle.h"
 
class CJS_Object;
 
double JS_DateParse(v8::Isolate* pIsolate, const WideString& str);
 
// Some JS methods have the bizarre convention that they may also be called
// with a single argument which is an object containing the actual arguments
// as its properties. The varying arguments to this method are the property
// names as wchar_t string literals corresponding to each positional argument.
// The result will always contain |nKeywords| value, check for the unspecified
// ones in the result using IsExpandedParamKnown() below.
v8::LocalVector<v8::Value> ExpandKeywordParams(
    CJS_Runtime* pRuntime,
    pdfium::span<v8::Local<v8::Value>> originals,
    size_t nKeywords,
    ...);
 
bool IsExpandedParamKnown(v8::Local<v8::Value> value);
 
// All JS classes have a name, an object defintion ID, and the ability to
// register themselves with FXJS_V8. We never make a BASE class on its own
// because it can't really do anything.
 
// Rich JS classes provide constants, methods, properties, and the ability
// to construct native object state.
 
template <class T>
static void JSConstructor(CFXJS_Engine* pEngine,
                          v8::Local<v8::Object> obj,
                          v8::Local<v8::Object> proxy) {
  pEngine->SetBinding(
      obj, std::make_unique<T>(proxy, static_cast<CJS_Runtime*>(pEngine)));
}
 
// CJS_Object has virtual dtor, template not required.
void JSDestructor(v8::Local<v8::Object> obj);
 
template <class C>
UnownedPtr<C> JSGetObject(v8::Isolate* isolate, v8::Local<v8::Object> obj) {
  CFXJS_PerObjectData* pData = CFXJS_PerObjectData::GetFromObject(obj);
  if (!pData) {
    return nullptr;
  }
  if (pData->GetObjDefnID() != C::GetObjDefnID()) {
    return nullptr;
  }
  CFXJS_PerObjectData::Binding* pBinding = pData->GetBinding();
  if (!pBinding) {
    return nullptr;
  }
  return UnownedPtr<C>(static_cast<C*>(pBinding));
}
 
template <class C, CJS_Result (C::*M)(CJS_Runtime*)>
void JSPropGetter(const char* prop_name_string,
                  const char* class_name_string,
                  v8::Local<v8::Name> property,
                  const v8::PropertyCallbackInfo<v8::Value>& info) {
  auto pObj = JSGetObject<C>(info.GetIsolate(), info.Holder());
  if (!pObj)
    return;
 
  CJS_Runtime* pRuntime = pObj->GetRuntime();
  if (!pRuntime)
    return;
 
  CJS_Result result = (pObj.get()->*M)(pRuntime);
  if (result.HasError()) {
    pRuntime->Error(JSFormatErrorString(class_name_string, prop_name_string,
                                        result.Error()));
    return;
  }
 
  if (result.HasReturn())
    info.GetReturnValue().Set(result.Return());
}
 
template <class C, CJS_Result (C::*M)(CJS_Runtime*, v8::Local<v8::Value>)>
void JSPropSetter(const char* prop_name_string,
                  const char* class_name_string,
                  v8::Local<v8::Name> property,
                  v8::Local<v8::Value> value,
                  const v8::PropertyCallbackInfo<void>& info) {
  auto pObj = JSGetObject<C>(info.GetIsolate(), info.Holder());
  if (!pObj)
    return;
 
  CJS_Runtime* pRuntime = pObj->GetRuntime();
  if (!pRuntime)
    return;
 
  CJS_Result result = (pObj.get()->*M)(pRuntime, value);
  if (result.HasError()) {
    pRuntime->Error(JSFormatErrorString(class_name_string, prop_name_string,
                                        result.Error()));
  }
}
 
template <class C,
          CJS_Result (C::*M)(CJS_Runtime*, pdfium::span<v8::Local<v8::Value>>)>
void JSMethod(const char* method_name_string,
              const char* class_name_string,
              const v8::FunctionCallbackInfo<v8::Value>& info) {
  auto pObj = JSGetObject<C>(info.GetIsolate(), info.This());
  if (!pObj)
    return;
 
  CJS_Runtime* pRuntime = pObj->GetRuntime();
  if (!pRuntime)
    return;
 
  v8::LocalVector<v8::Value> parameters(info.GetIsolate());
  for (unsigned int i = 0; i < (unsigned int)info.Length(); i++)
    parameters.push_back(info[i]);
 
  CJS_Result result = (pObj.get()->*M)(pRuntime, parameters);
  if (result.HasError()) {
    pRuntime->Error(JSFormatErrorString(class_name_string, method_name_string,
                                        result.Error()));
    return;
  }
 
  if (result.HasReturn())
    info.GetReturnValue().Set(result.Return());
}
 
#define JS_STATIC_PROP(err_name, prop_name, class_name)
  static void get_##prop_name##_static(
      v8::Local<v8::Name> property,
      const v8::PropertyCallbackInfo<v8::Value>& info) {
    JSPropGetter<class_name, &class_name::get_##prop_name>(
        #err_name, class_name::kName, property, info);
  }
  static void set_##prop_name##_static(
      v8::Local<v8::Name> property, v8::Local<v8::Value> value,
      const v8::PropertyCallbackInfo<void>& info) {
    JSPropSetter<class_name, &class_name::set_##prop_name>(
        #err_name, class_name::kName, property, value, info);
  }
 
#define JS_STATIC_METHOD(method_name, class_name)
  static void method_name##_static(
      const v8::FunctionCallbackInfo<v8::Value>& info) {
    JSMethod<class_name, &class_name::method_name>(#method_name,
                                                   class_name::kName, info);
  }
 
#endif  // FXJS_JS_DEFINE_H_