Golang C.DataValue類代碼示例

//export hookListPropertyAppend
func hookListPropertyAppend(foldp unsafe.Pointer, reflectIndex, setIndex C.intptr_t, objp unsafe.Pointer) {
	fold := (*valueFold)(foldp)
	slice := listSlice(fold, reflectIndex)
	var objdv C.DataValue
	objdv.dataType = C.DTObject
	*(*unsafe.Pointer)(unsafe.Pointer(&objdv.data)) = objp
	newslice := append(*slice, unpackDataValue(&objdv, fold.engine).(Object))
	if setIndex >= 0 {
		reflect.ValueOf(fold.gvalue).Method(int(setIndex)).Call([]reflect.Value{reflect.ValueOf(newslice)})
	} else {
		*slice = newslice
	}
}

//export hookListPropertyAppend
func hookListPropertyAppend(foldp unsafe.Pointer, reflectIndex, onChangedIndex C.intptr_t, objp unsafe.Pointer) {
	fold := (*valueFold)(foldp)
	field := fold.gfield(int(reflectIndex))
	slice := field.Addr().Interface().(*[]Object)
	var objdv C.DataValue
	objdv.dataType = C.DTObject
	*(*unsafe.Pointer)(unsafe.Pointer(&objdv.data)) = objp
	*slice = append(*slice, unpackDataValue(&objdv, fold.engine).(Object))
	if onChangedIndex != -1 {
		// TODO Must probably dereference the ptr here. Test it.
		reflect.ValueOf(fold.gvalue).Method(int(onChangedIndex)).Call(nil)
	}
}

//export hookGoValueCallMethod
func hookGoValueCallMethod(enginep, foldp unsafe.Pointer, reflectIndex C.int, args *C.DataValue) {
	fold := ensureEngine(enginep, foldp)
	v := reflect.ValueOf(fold.gvalue)

	// TODO Must assert that v is necessarily a pointer here, but we shouldn't have to manipulate
	//      gvalue here for that. This should happen in a sensible place in the wrapping functions
	//      that can still error out to the user in due time.

	method := v.Method(int(reflectIndex))
	methodt := method.Type()
	methodName := v.Type().Method(int(reflectIndex)).Name

	// TODO Ensure methods with more parameters than this are not registered.
	var params [C.MaxParams]reflect.Value
	var err error

	numIn := methodt.NumIn()
	for i := 0; i < numIn; i++ {
		paramdv := (*C.DataValue)(unsafe.Pointer(uintptr(unsafe.Pointer(args)) + (uintptr(i)+1)*dataValueSize))
		param := reflect.ValueOf(unpackDataValue(paramdv, fold.engine))
		if argt := methodt.In(i); param.Type() != argt {
			param, err = convertParam(methodName, i, param, argt)
			if err != nil {
				panic(err.Error())
			}
		}
		params[i] = param
	}

	result := method.Call(params[:numIn])

	if len(result) == 1 {
		packDataValue(result[0].Interface(), args, fold.engine, jsOwner)
	} else if len(result) > 1 {
		if len(result) > len(dataValueArray) {
			panic("function has too many results")
		}
		for i, v := range result {
			packDataValue(v.Interface(), &dataValueArray[i], fold.engine, jsOwner)
		}
		args.dataType = C.DTList
		*(*unsafe.Pointer)(unsafe.Pointer(&args.data)) = C.newVariantList(&dataValueArray[0], C.int(len(result)))
	}
}

//export hookGoValueReadField
func hookGoValueReadField(enginep, foldp unsafe.Pointer, reflectIndex, getIndex, setIndex C.int, resultdv *C.DataValue) {
	fold := ensureEngine(enginep, foldp)

	var field reflect.Value
	if getIndex >= 0 {
		field = reflect.ValueOf(fold.gvalue).Method(int(getIndex)).Call(nil)[0]
	} else {
		field = deref(reflect.ValueOf(fold.gvalue)).Field(int(reflectIndex))
	}
	field = deref(field)

	// Cannot compare Type directly as field may be invalid (nil).
	if field.Kind() == reflect.Slice && field.Type() == typeObjSlice {
		// TODO Handle getters that return []qml.Object.
		// TODO Handle other GoValue slices (!= []qml.Object).
		resultdv.dataType = C.DTListProperty
		*(*unsafe.Pointer)(unsafe.Pointer(&resultdv.data)) = C.newListProperty(foldp, C.intptr_t(reflectIndex), C.intptr_t(setIndex))
		return
	}

	fieldk := field.Kind()
	if fieldk == reflect.Slice || fieldk == reflect.Struct && field.Type() != typeRGBA {
		if field.CanAddr() {
			field = field.Addr()
		} else if !hashable(field.Interface()) {
			t := reflect.ValueOf(fold.gvalue).Type()
			for t.Kind() == reflect.Ptr {
				t = t.Elem()
			}
			panic(fmt.Sprintf("cannot access unaddressable and unhashable struct value on interface field %s.%s; value: %#v", t.Name(), t.Field(int(reflectIndex)).Name, field.Interface()))
		}
	}
	var gvalue interface{}
	if field.IsValid() {
		gvalue = field.Interface()
	}

	// TODO Strings are being passed in an unsafe manner here. There is a
	// small chance that the field is changed and the garbage collector is run
	// before C++ has a chance to look at the data. We can solve this problem
	// by queuing up values in a stack, and cleaning the stack when the
	// idle timer fires next.
	packDataValue(gvalue, resultdv, fold.engine, jsOwner)
}

//export hookGoValueCallMethod
func hookGoValueCallMethod(enginep, foldp unsafe.Pointer, reflectIndex C.int, args *C.DataValue) {
	fold := ensureEngine(enginep, foldp)
	v := reflect.ValueOf(fold.gvalue)

	// TODO Must assert that v is necessarily a pointer here, but we shouldn't have to manipulate
	//      gvalue here for that. This should happen in a sensible place in the wrapping functions
	//      that can still error out to the user in due time.

	method := v.Method(int(reflectIndex))

	// TODO Ensure methods with more parameters than this are not registered.
	var params [C.MaximumParamCount - 1]reflect.Value

	numIn := uintptr(method.Type().NumIn())
	for i := uintptr(0); i < numIn; i++ {
		// TODO Convert the arguments when possible (int32 => int, etc).
		// TODO Type checking to avoid explosions (or catch the explosion)
		paramdv := (*C.DataValue)(unsafe.Pointer(uintptr(unsafe.Pointer(args)) + (i+1)*dataValueSize))
		params[i] = reflect.ValueOf(unpackDataValue(paramdv, fold.engine))
	}

	result := method.Call(params[:numIn])

	if len(result) == 1 {
		packDataValue(result[0].Interface(), args, fold.engine, jsOwner)
	} else if len(result) > 1 {
		if len(result) > len(dataValueArray) {
			panic("function has too many results")
		}
		for i, v := range result {
			packDataValue(v.Interface(), &dataValueArray[i], fold.engine, jsOwner)
		}
		args.dataType = C.DTList
		*(*unsafe.Pointer)(unsafe.Pointer(&args.data)) = C.newVariantList(&dataValueArray[0], C.int(len(result)))
	}
}

// packDataValue packs the provided Go value into a C.DataValue for
// shiping into C++ land.
//
// For simple types (bool, int, etc) value is converted into a
// native C++ value. For anything else, including cases when value
// has a type that has an underlying simple type, the Go value itself
// is encapsulated into a C++ wrapper so that field access and method
// calls work.
//
// This must be run from the main GUI thread due to the cases where
// calling wrapGoValue is necessary.
func packDataValue(value interface{}, dvalue *C.DataValue, engine *Engine, owner valueOwner) {
	datap := unsafe.Pointer(&dvalue.data)
	if value == nil {
		dvalue.dataType = C.DTInvalid
		return
	}
	switch value := value.(type) {
	case string:
		dvalue.dataType = C.DTString
		cstr, cstrlen := unsafeStringData(value)
		*(**C.char)(datap) = cstr
		dvalue.len = cstrlen
	case bool:
		dvalue.dataType = C.DTBool
		*(*bool)(datap) = value
	case int:
		if value > 1<<31-1 {
			dvalue.dataType = C.DTInt64
			*(*int64)(datap) = int64(value)
		} else {
			dvalue.dataType = C.DTInt32
			*(*int32)(datap) = int32(value)
		}
	case int64:
		dvalue.dataType = C.DTInt64
		*(*int64)(datap) = value
	case int32:
		dvalue.dataType = C.DTInt32
		*(*int32)(datap) = value
	case float64:
		dvalue.dataType = C.DTFloat64
		*(*float64)(datap) = value
	case float32:
		dvalue.dataType = C.DTFloat32
		*(*float32)(datap) = value
	case *Common:
		dvalue.dataType = C.DTObject
		*(*unsafe.Pointer)(datap) = value.addr
	case color.RGBA:
		dvalue.dataType = C.DTColor
		*(*uint32)(datap) = uint32(value.A)<<24 | uint32(value.R)<<16 | uint32(value.G)<<8 | uint32(value.B)
	default:
		dvalue.dataType = C.DTObject
		if obj, ok := value.(Object); ok {
			*(*unsafe.Pointer)(datap) = obj.Common().addr
		} else {
			*(*unsafe.Pointer)(datap) = wrapGoValue(engine, value, owner)
		}
	}
}

// packDataValue packs the provided Go value into a C.DataValue for
// shiping into C++ land.
//
// For simple types (bool, int, etc) value is converted into a
// native C++ value. For anything else, including cases when value
// has a type that has an underlying simple type, the Go value itself
// is encapsulated into a C++ wrapper so that field access and method
// calls work.
//
// This must be run from the main GUI thread due to the cases where
// calling wrapGoValue is necessary.
func packDataValue(value interface{}, dvalue *C.DataValue, engine *Engine, owner valueOwner) {
	datap := unsafe.Pointer(&dvalue.data)
	if value == nil {
		dvalue.dataType = C.DTInvalid
		return
	}
	switch value := value.(type) {
	case string:
		dvalue.dataType = C.DTString
		cstr, cstrlen := unsafeStringData(value)
		*(**C.char)(datap) = cstr
		dvalue.len = cstrlen
	case bool:
		dvalue.dataType = C.DTBool
		*(*bool)(datap) = value
	case int:
		dvalue.dataType = intDT
		*(*int)(datap) = value
	case int64:
		dvalue.dataType = C.DTInt64
		*(*int64)(datap) = value
	case int32:
		dvalue.dataType = C.DTInt32
		*(*int32)(datap) = value
	case float64:
		dvalue.dataType = C.DTFloat64
		*(*float64)(datap) = value
	case float32:
		dvalue.dataType = C.DTFloat32
		*(*float32)(datap) = value
	case *Object:
		dvalue.dataType = C.DTObject
		*(*unsafe.Pointer)(datap) = value.addr
	default:
		dvalue.dataType = C.DTObject
		*(*unsafe.Pointer)(datap) = wrapGoValue(engine, value, owner)
	}
}

// packDataValue packs the provided Go value into a C.DataValue for
// shiping into C++ land.
//
// For simple types (bool, int, etc) value is converted into a
// native C++ value. For anything else, including cases when value
// has a type that has an underlying simple type, the Go value itself
// is encapsulated into a C++ wrapper so that field access and method
// calls work.
//
// This must be run from the main GUI thread due to the cases where
// calling wrapGoValue is necessary.
func packDataValue(value interface{}, dvalue *C.DataValue, engine *Engine, owner valueOwner) {
	datap := unsafe.Pointer(&dvalue.data)
	if value == nil {
		dvalue.dataType = C.DTInvalid
		return
	}
	switch value := value.(type) {
	case string:
		dvalue.dataType = C.DTString
		cstr, cstrlen := unsafeStringData(value)
		*(**C.char)(datap) = cstr
		dvalue.len = cstrlen
	case bool:
		dvalue.dataType = C.DTBool
		*(*bool)(datap) = value
	case int:
		if value > 1<<31-1 {
			dvalue.dataType = C.DTInt64
			*(*int64)(datap) = int64(value)
		} else {
			dvalue.dataType = C.DTInt32
			*(*int32)(datap) = int32(value)
		}
	case int64:
		dvalue.dataType = C.DTInt64
		*(*int64)(datap) = value
	case int32:
		dvalue.dataType = C.DTInt32
		*(*int32)(datap) = value
	case uint64:
		dvalue.dataType = C.DTUint64
		*(*uint64)(datap) = value
	case uint32:
		dvalue.dataType = C.DTUint32
		*(*uint32)(datap) = value
	case float64:
		dvalue.dataType = C.DTFloat64
		*(*float64)(datap) = value
	case float32:
		dvalue.dataType = C.DTFloat32
		*(*float32)(datap) = value
	case *Common:
		dvalue.dataType = C.DTObject
		*(*unsafe.Pointer)(datap) = value.addr
	case color.RGBA:
		dvalue.dataType = C.DTColor
		*(*uint32)(datap) = uint32(value.A)<<24 | uint32(value.R)<<16 | uint32(value.G)<<8 | uint32(value.B)
	default:
		rv := reflect.ValueOf(value)
		switch rv.Type().Kind() {
		case reflect.Ptr:
			rv = rv.Elem()
			if rv.Kind() != reflect.Array && rv.Kind() != reflect.Slice {
				break
			}
			fallthrough

		case reflect.Array, reflect.Slice:
			dvalue.dataType = C.DTVariantList
			dataValues := make([]C.DataValue, rv.Len())

			for i := range dataValues {
				packDataValue(rv.Index(i).Interface(), &dataValues[i], engine, owner)
			}

			switch len(dataValues) {
			case 0:
				*(*unsafe.Pointer)(unsafe.Pointer(&dvalue.data)) = C.newVariantList(nil, 0)

			default:
				*(*unsafe.Pointer)(unsafe.Pointer(&dvalue.data)) = C.newVariantList(&dataValues[0], C.int(len(dataValues)))
			}

			return
		}

		dvalue.dataType = C.DTObject
		if obj, ok := value.(Object); ok {
			*(*unsafe.Pointer)(datap) = obj.Common().addr
		} else {
			*(*unsafe.Pointer)(datap) = wrapGoValue(engine, value, owner)
		}
	}
}