#include <simgear/structure/subsystem_mgr.hxx>
#include <simgear/nasal/nasal.h>
+class FGNasalScript;
+
class FGNasalSys : public SGSubsystem
{
public:
virtual void init();
virtual void update(double dt) { /* noop */ }
- virtual bool handleCommand(const SGPropertyNode* arg);
+ // Simple hook to run arbitrary source code. Returns a bool to
+ // indicate successful execution. Does *not* return any Nasal
+ // values, because handling garbage-collected objects from C space
+ // is deep voodoo and violates the "simple hook" idea.
+ bool parseAndRun(const char* sourceCode);
+
+ // Slightly more complicated hook to get a handle to a precompiled
+ // Nasal script that can be invoked via a call() method. The
+ // caller is expected to delete the FGNasalScript returned from
+ // this function. The "name" argument specifies the "file name"
+ // for the source code that will be printed in Nasal stack traces
+ // on error.
+ FGNasalScript* parseScript(const char* src, const char* name=0);
// Implementation of the settimer extension function
void setTimer(naRef args);
+ // Returns a ghost wrapper for the current _cmdArg
+ naRef cmdArgGhost();
+
+ // Callbacks for command and timer bindings
+ virtual bool handleCommand(const SGPropertyNode* arg);
+
private:
+ friend class FGNasalScript;
+
//
// FGTimer subclass for handling Nasal timer callbacks.
// See the implementation of the settimer() extension function for
struct NasalTimer {
virtual void timerExpired();
naRef handler;
- int hashKey;
+ int gcKey;
FGNasalSys* nasal;
};
+ void loadPropertyScripts();
+ void initModule(const char* moduleName, const char* fileName,
+ const char* src, int len);
void readScriptFile(SGPath file, const char* lib);
void hashset(naRef hash, const char* key, naRef val);
void logError();
- naRef parse(const char* filename, const char* buf, int len);
+ naRef parse(const char* filename, const char* buf, int len=0);
+ naRef genPropsModule();
+ naRef propNodeGhost(SGPropertyNode* handle);
+
+ // This mechanism is here to allow naRefs to be passed to
+ // locations "outside" the interpreter. Normally, such a
+ // reference would be garbage collected unexpectedly. By passing
+ // it to gcSave and getting a key/handle, it can be cached in a
+ // globals.__gcsave hash. Be sure to release it with gcRelease
+ // when done.
+ int gcSave(naRef r);
+ void gcRelease(int key);
naContext _context;
naRef _globals;
- naRef _timerHash;
- int _nextTimerHashKey;
+ SGPropertyNode* _cmdArg;
+ int _nextGCKey;
+ naRef _gcHash;
+
+ public: void handleTimer(NasalTimer* t);
+};
+
+class FGNasalScript {
public:
- void handleTimer(NasalTimer* t);
+ ~FGNasalScript() { _nas->gcRelease(_gcKey); }
+
+ bool call() {
+ naCall(_nas->_context, _code, naNil(), naNil(), naNil());
+ return naGetError(_nas->_context) == 0;
+ }
+
+private:
+ friend class FGNasalSys;
+ naRef _code;
+ int _gcKey;
+ FGNasalSys* _nas;
};
#endif // __NASALSYS_HXX