unipdf/pdf/model/utils.go

/*
 * This file is subject to the terms and conditions defined in
 * file 'LICENSE.md', which is part of this source code package.
 */

package model

import (
	"errors"

	"github.com/unidoc/unidoc/common"
	. "github.com/unidoc/unidoc/pdf/core"
)

func getUniDocVersion() string {
	return common.Version
}

func getNumberAsFloat(obj PdfObject) (float64, error) {
	if fObj, ok := obj.(*PdfObjectFloat); ok {
		return float64(*fObj), nil
	}

	if iObj, ok := obj.(*PdfObjectInteger); ok {
		return float64(*iObj), nil
	}

	return 0, errors.New("Not a number")
}

func isNullObject(obj PdfObject) bool {
	if _, isNull := obj.(*PdfObjectNull); isNull {
		return true
	} else {
		return false
	}
}

// Convert a list of pdf objects representing floats or integers to a slice of float64 values.
func getNumbersAsFloat(objects []PdfObject) ([]float64, error) {
	floats := []float64{}
	for _, obj := range objects {
		val, err := getNumberAsFloat(obj)
		if err != nil {
			return nil, err
		}
		floats = append(floats, val)

	}
	return floats, nil
}

// Cases where expecting an integer, but some implementations actually
// store the number in a floating point format.
func getNumberAsInt64(obj PdfObject) (int64, error) {
	if iObj, ok := obj.(*PdfObjectInteger); ok {
		return int64(*iObj), nil
	}

	if fObj, ok := obj.(*PdfObjectFloat); ok {
		common.Log.Debug("Number expected as integer was stored as float (type casting used)")
		return int64(*fObj), nil
	}

	return 0, errors.New("Not a number")
}

func getNumberAsFloatOrNull(obj PdfObject) (*float64, error) {
	if fObj, ok := obj.(*PdfObjectFloat); ok {
		num := float64(*fObj)
		return &num, nil
	}

	if iObj, ok := obj.(*PdfObjectInteger); ok {
		num := float64(*iObj)
		return &num, nil
	}
	if _, ok := obj.(*PdfObjectNull); ok {
		return nil, nil
	}

	return nil, errors.New("Not a number")
}

// Handy function for debugging in development.
func debugObject(obj PdfObject) {
	common.Log.Debug("obj: %T %s", obj, obj.String())

	if stream, is := obj.(*PdfObjectStream); is {
		decoded, err := DecodeStream(stream)
		if err != nil {
			common.Log.Debug("Error: %v", err)
			return
		}
		common.Log.Debug("Decoded: %s", decoded)
	} else if indObj, is := obj.(*PdfIndirectObject); is {
		common.Log.Debug("%T %v", indObj.PdfObject, indObj.PdfObject)
		common.Log.Debug("%s", indObj.PdfObject.String())
	}
}