tag.go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tiff

import (
	"fmt"
)

type Tag interface {
	ID() uint16
	Name() string
	Interpreter() FieldInterpreter
	//ValidFieldTypes() []FieldType
}

func NewTag(id uint16, name string, fi FieldInterpreter) Tag {
	return &tag{id: id, name: name, fi: fi}
}

type tag struct {
	id   uint16
	name string
	fi   FieldInterpreter
}

func (t *tag) ID() uint16 {
	return t.id
}

func (t *tag) Name() string {
	if len(t.name) > 0 {
		return t.name
	}
	return fmt.Sprintf("UNNAMED_TAG_%d", t.id)
}

func (t *tag) Interpreter() FieldInterpreter {
	if t.fi == nil {
		return defaultFieldInterpreter
	}
	return t.fi
}

type FieldInterpreter func(Field) string

func defaultFieldInterpreter(f Field) string {
	return ""
}

/*
type FieldInterpreter interface {
	Interpret(Field) string
	Register(reg interface{}) bool
	// Reg, in this case, could be anything, but usually a struct or map with a key/value pair.
	// The idea is that the FieldInterpreter should know what to do with the thing or return false.
	//Register(key, val reflect.Value) bool
}
*/