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POCall object instance from C++ function called via script
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  1. POCall object instance from C++ function called via script
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    copied!<p>I have a class named Jellyfish who use the singleton design pattern :</p> <p>jellyfish.h</p> <pre><code>#ifndef JELLYFISH_H #define JELLYFISH_H #include &lt;QHash&gt; #include &lt;QScriptEngine&gt; class QScriptValue; class Jellyfish : public QObject { public: static Jellyfish * getInstance(); static Jellyfish * instance; private: Jellyfish(); }; #ifndef </code></pre> <p>jellyfish.cpp</p> <pre><code>Jellyfish * Jellyfish::instance = NULL; Jellyfish * Jellyfish::getInstance() { if ( !Jellyfish::instance ) { Jellyfish::instance = new Jellyfish(); } return Jellyfish::instance; } </code></pre> <p>When I am in main.cpp and make tests, I have no errors:</p> <p>main.cpp</p> <pre><code>#include &lt;QApplication&gt; #include "jellyfish.h" class Jellyfish; int main( int argc, char *argv[] ) { QApplication app( argc, argv ); Jellyfish *toto = Jellyfish::getInstance(); Jellyfish *toto2 = Jellyfish::getInstance(); Jellyfish *toto3 = Jellyfish::getInstance(); return app.exec(); } </code></pre> <p>But I want to use some static methods in <code>Jellyfish</code> in external QScript files :</p> <p>jellyfish.h</p> <pre><code>private: static QScriptValue set( QScriptContext *context, QScriptEngine *engine ); QScriptEngine *script_engine; </code></pre> <p>jellyfish.cpp</p> <pre><code>Jellyfish::Jellyfish() { script_engine = new QScriptEngine; /* ... */ initScriptEngine(); } void Jellyfish::initScriptEngine() { QScriptValue object = script_engine-&gt;newQObject( this ); object.setProperty( "set", script_engine-&gt;newFunction( set ) ); script_engine-&gt;globalObject().setProperty( "jellyfish", object ); } QScriptValue Jellyfish::set( QScriptContext *context, QScriptEngine *engine ) { // I have to load instance because I am in a static method. // But this is where the application loop endlessly. Jellyfish *jellyfish = Jellyfish::getInstance(); return true; } </code></pre> <p>And finaly the parsed script:</p> <pre><code>jellyfish.set( "line_numbers", true ); </code></pre> <p><strong>Problem</strong></p> <p>When I run the application, <code>getInstance()</code> always creates a new Jellyfish instance. But the real problem is that on the output with debug (<code>qDebug() &lt;&lt; "test";</code>) I can see that the application loop on <code>Jellyfish::getInstance();</code> until I get a <code>sgmentation fault</code>.</p> <p>Could someone help me to understand this ?</p>
 

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