Document Formatting Systems Survey Concepts and Issues RICHARD FURUTA JEFFREY SCOFIELD AND ALAN SHAW Department of Computer Scwnce Universityof Washmgton Seattle Washington 98195 Formatting systems are concerned with the physical layout of a document for hard and soft copy media This paper characterizes the formatting problem and its relation to other aspects of document processing describes and evaluates several representative and seminal systems and dtscusses some issues and problems relevant to future systems The emphasis is on topms related to the specification of document formats these include the underlying document and processing models functions performed by a formatter the formatting language and user interface variety of document objects the integration of formatters with other document processing tasks and implementation questions Categories and Subject Descriptors H 4 1 Information Systems Applications Office Automatmn wordprocessing 1 7 0 Text Processing General 1 7 1 Text Processing Text Editing 1 7 2 Text Processing Document Preparation K 2 Computing Milieux History of Computing software General Terms Algorithms Design Human Factors Languages Additional Key Words and Phrases Formatters editors text manipulation INTRODUCTION storage and the availability of high quality computer controlled printers typesetters Document preparation involves two prin and display devices it has become both cipal tasks defining the content and struc feasible and worthwhile to use computer ture of a document and generating the formatting systems for a wide variety of document from specifications of its appear technical business and literary documents ance The first task is typically called edit such as letters memos invoices brochures ing while the second the subject of this reports papers and books Many experipaper is known as formatting More pre mental and commercial systems have been cisely formatting is concerned with the lay developed for offices laboratories publishout of document objects on hard copy me ers and in fact virtually any enterprise dia usually paper and various soft copy that uses written documents devices such as video displays Our aims in this paper are to characterize While text processing especially editing the formatting problem and its relation to has long been a major application of com other aspects of document processing to puters it is only recently that particular describe and evaluate several representaattention has been given to formatting sys tive and seminal systems and to discuss tems The reason for this is a combination some issues and problems relevant to future of technology and economics Because of systems The emphasis is on topics related increasing costs of manually produced doc to the specification of document formats uments decreasing costs of computers and these include the underlying document and Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage the ACM copyright notme and the title of the publication and its date appear and notice is given that copying is by permission of the Association for Computing Machinery To copy otherwise or to republish requires a fee and or specific permission 1982 ACM 0010 4892 82 0900 0417 00 75 Computing Surveys VoI 14 No 3 September 1982 418 R Furuta J Scofield and A S h a w CONTENTS INTRODUCTION 1 THE FORMATTING PROBLEM 1 1 Object Model of Documents 1 2 E tmg Formatting and Viewing 1 3 Formatting Functions 2 REPRESENTATIVE AND SEMINAL SYSTEMS 2 1 The FLrst Generatmn Formatters 2 2 The First Structured Formatters 2 3 Structured Formatters with Many Objects 2 4 Integrated Editor Formatters 2 5 Other Systems 2 6 Some Current Developments 3 ISSUES AND CONCEPTS 3 1 Document and Processmg Models 3 2 Formattmg Functmns 3 3 Formatting Language 3 4 Integratmn of Objects 3 5 Integratmn of Document Processing Functmns 3 6 User Interface 3 7 Implementatmn 4 CONCLUDING REMARKS ACKNOWLEDGMENTS REFERENCES v processing models functions performed by a formatter the formatting language and user interface variety of document objects the integration of formatters with other document processing tasks and implementation questions A number of important related areas are not covered in any detail for example there is little discussion of font design the characteristics of typical output devices commercial typesetting programs or particular applications such as newspaper production 1 THE FORMATTING PROBLEM 1 1 Object Model of Documents In order to discuss formatters and their functions and to distinguish formatting from other aspects of document preparation it is convenient to use an object model of documents SHAw80a somewhat analogous to that in programming languages The model introduces a uniform terminology which is useful when comparing and evaluating various systems and ideas and it allows a more precise definition of terms such as editing formatting and viewing Computing Surveys Vol 14 No 3 September 1982 A document is an object composed of a hierarchy of more primitive objects Each object is an instance of a class that defines the possible constituents and representations of the instances Some typical document classes are business letters papers for a particular journal or conference theses and programs in a given language common lower level classes include such document components as sections paragraphs headings footnotes tables equations matrices figures polygons and character fonts Objects are further classified as either abstract or concrete To each abstract object there corresponds one or more concrete objects An abstract object is denoted by an identifier and the class to which the object belongs One example could be the identifier the in the class word indicating the abstract word object the Another abstract object may be the identifier plus in the class operator denoting the operator for addition We sometimes use the term logical object as an informal synonym for abstract object Concrete objects are defined over one or more two dimensionalpage spaces and represent the possible formatted images of abstract objects For example a particular paragraph of a document an abstract paragraph object may be represented concretely in many different ways depending on font hyphenation conventions line length and other concrete variables Example The extended abstract for this paper SHAw80b has the logical objects partially defined