如何使用 c++ QtScript 中的标准复数

Question

我尝试找出如何在 QtScript 中使用复数，以便可以从 QtScript 调用使用复数参数定义的插槽。用户还应该可以从脚本访问复数的基本代数（+、-、exp、...）。

只是为了说明，我想打电话的是：

#include<complex>
typedef complex<double> Complex;

class MyCppClass : public QObject
{
Q_OBJECT
public:
  ...
public slots:
void mySignal(Complex rCValue); !! <<== should be callable from QtScript
  ...
}

有什么想法吗？谢谢！

Answer 1

我认为你必须在 QtScript 中实现复杂的代数（类似于 http://examples. oreilly.com/9781565923928/text/8-6.txt），然后修改 mySignal 以接受这样的对象。

Answer 2

这不是最终的答案......因为如上所述，运算符 +、- 和 * 不能用于 javascript 端的复数。但对于那些感兴趣的人，我想分享以下代码片段，它们允许触发具有复杂参数的插槽。

测试.h:

#include <QtCore>
#include <QtScript>
#include <complex>
#include <iostream>
using namespace std;
typedef complex<double> Complex;
Q_DECLARE_METATYPE(Complex)

class TestClass : public QObject
{
Q_OBJECT    
public:
    TestClass() : QObject() {};
public slots:   
    void TestOutput(Complex rValue);
};

测试.cpp:

#include "test.h"
void TestClass::TestOutput(Complex rValue)
{
    cout << "received value "<< rValue << endl;
}

main.cpp:

#include "test.h"
QScriptValue toScriptValue(QScriptEngine *eng, const Complex& rValue)
{
    QScriptValue obj = eng->newObject();
    obj.setProperty("re",real(rValue));
    obj.setProperty("im",imag(rValue));
    return obj;
}

void fromScriptValue(const QScriptValue &obj, Complex& rValue)
{
    double re=obj.property("re").toNumber();
    double im=obj.property("im").toNumber();
    rValue=Complex(re,im);
}

QScriptValue constructComplex(QScriptContext *context, QScriptEngine *engine)
{
    Complex complex=Complex(2,1);
    return engine->toScriptValue(complex);
}

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);
    QScriptEngine eng;
    // register our custom type
    qScriptRegisterMetaType<Complex>(&eng, toScriptValue, fromScriptValue);

    TestClass *test=new TestClass;
    QObject *someObject = (QObject*)test;
    QScriptValue objectValue = eng.newQObject(someObject);
    eng.globalObject().setProperty("myObject", objectValue);

    QScriptValue val = eng.evaluate("function Complex(real, imaginary) { this.re = real; this.im = imaginary;}; cadd = function (a, b) {return new Complex(a.re + b.re, a.im + b.im);};");
    val = eng.evaluate("my_complex=new Complex(8,1); my_comp=new Complex(2,9);     my_c=cadd(my_comp,my_complex);");
    cout << "script"<< val.toString().toStdString() << endl;
    Complex cval = qscriptvalue_cast<Complex>(val);
    cout << "qscriptvalue_cast : "<< cval << endl;

    val = eng.evaluate("myObject.TestOutput(my_c)");

    return 0;
}