func (self *Environment) setDoubleField(z interface{}, static bool, name string, val float64) (err error) { jval, field, err := self.getField(z, static, name, types.Basic(types.IntKind)) if err != nil { return } if static { C.envSetStaticDoubleField(self.env, C.valObject(jval), field.field, C.jdouble(val)) } else { C.envSetDoubleField(self.env, C.valObject(jval), field.field, C.jdouble(val)) } if self.ExceptionCheck() { err = self.ExceptionOccurred() } return }
// C callbacks actually start in the 'generifiedX' calls (see the .c files) // Next, goCallbackNArgs is used to determine the number of variadic paramers to expect ( // java doesn't inform us of this, and we can't force any of the callback parameters. // // Finally, goCallback looks up the 'fId' - our internal function reference ID (the X in generified), // un(re) marshalls all the parameters appropriately, calls our function, and returns // any underlying value back to generified who will return it to the JVM. // The initial jbool indicates success, and any failure should check for exceptions. // //export goCallback func goCallback(envp, obj uintptr, fId int, nargs int, argp uintptr) (ok C.jboolean, val interface{}) { args := C.ArgListPtr(unsafe.Pointer(argp)) env := AllEnvs.Find(envp) if env == nil { panic("Got a nil environment") } if env.jvm == nil { panic("Environment pointer has no JVM") } var cd callbackDescriptor var _ok bool if cd, _ok = env.jvm.registered[fId]; !_ok { print("Unknown callbackId: \t", fId, "\n") return } // TODO: pack argp somehow... if nargs != len(cd.Signature.Params) { panic("callback/signature length mismatch") } inCall := []reflect.Value{reflect.ValueOf(env), reflect.ValueOf(newObject(C.jobject(unsafe.Pointer(obj))))} var err error for i := 0; i < nargs; i++ { switch cd.Signature.Params[i].Kind() { case types.BoolKind: inCall = append(inCall, reflect.ValueOf(bool(0 != C.valBool(C.getArg(args, C.int(i)))))) case types.LongKind: inCall = append(inCall, reflect.ValueOf(int64(C.valLong(C.getArg(args, C.int(i)))))) case types.IntKind: inCall = append(inCall, reflect.ValueOf(int(C.valInt(C.getArg(args, C.int(i)))))) case types.ShortKind: inCall = append(inCall, reflect.ValueOf(int16(C.valShort(C.getArg(args, C.int(i)))))) case types.FloatKind: inCall = append(inCall, reflect.ValueOf(float32(C.valFloat(C.getArg(args, C.int(i)))))) case types.DoubleKind: inCall = append(inCall, reflect.ValueOf(float64(C.valDouble(C.getArg(args, C.int(i)))))) case types.ClassKind: inCall = append(inCall, reflect.ValueOf(newObject(C.valObject(C.getArg(args, C.int(i)))))) default: err = errors.New("Couldn't reflect kind " + cd.Signature.Params[i].Kind().TypeString()) } if err != nil { break } } if err != nil { return } outCall := reflect.ValueOf(cd.F).Call(inCall) switch cd.Signature.Return.Kind() { case types.VoidKind: return 1, nil } switch cd.Signature.Return.Kind() { case types.BoolKind: if outCall[0].Interface().(bool) { return 1, C.jboolean(C.JNI_TRUE) } else { return 1, C.jboolean(C.JNI_FALSE) } case types.ByteKind: return 1, C.jbyte(outCall[0].Interface().(byte)) case types.CharKind: return 1, C.jchar(outCall[0].Interface().(int)) case types.IntKind: return 1, C.jint(outCall[0].Interface().(int)) case types.ShortKind: return 1, C.jshort(outCall[0].Interface().(int16)) case types.LongKind: return 1, C.jint(outCall[0].Interface().(int64)) case types.FloatKind: return 1, C.jfloat(outCall[0].Interface().(float32)) case types.DoubleKind: return 1, C.jdouble(outCall[0].Interface().(float64)) case types.ClassKind: klass := cd.Signature.Return.(types.Class).Klass if klass.Cmp(types.JavaLangString) == 0 { var obj *Object str := outCall[0].Interface().(string) obj, err = env.NewStringObject(str) if err == nil { return 1, C.jstring(obj.object) } // else, exception occurred // not needed as callbacks will reap their own refs. // env.DeleteLocalRef(obj) print("String Error\t", err.Error()) return 0, nil } return 1, C.jobject(outCall[0].Interface().(*Object).object) default: panic("array return type not yet supported") } panic("not reached") }