Desktop publishing systems using a screen, inputting means for inputting document information and commands, and a processing unit are well known.
Various methods for editing data stored in word processing systems are known, e.g., U.S. Pat. No. 4,506,343. These systems also include methods for editing compound documents, e.g., U.S. Pat. No. 4,723,209 and for creating a special document from a master document, e.g., European Patent Application No. 0185904.
It is also known to couple the processing unit to a screen and to an inputting means to interactively makeup and manage documents according to a model. The model comprises a document made up of one or more kinds of components characterized by contents, name and properties. This model represents a number of text columns for reproducing at least part of the contents of the document, said processing unit being adapted to set up a separate component column for each text column, in order to identify, in case of presentation of a component column on the screen, the start of the contents of the component by an indication at the level of the component contained in the text column concerned.
A commercially available system of this kind is sold in the form of a computer and a software package known as the "Workstation Publishing System" by Interleaf, Inc., Cambridge, Mass., U.S.A. It is described, for example, in its reference Manual "Workstation Publishing Software," Vol. 1, SUN/Release C. In this particular system, the inputting means comprise a keyboard and a mouse. The mouse can be used by the operator to select a position on the screen, whereupon he can input commands or text at that place on the screen by using the keyboard. This system also uses menus which appear on the screen locally after a button on the mouse has been pressed and which comprise a set of commands from which the operator, again using the mouse, can select and execute one.
The known system enables the operator to prepare a document consisting of different parts, named components. Kinds of components are: headings, text blocks, graphics, diagrams, pages etc. This document is displayed on the screen in a text window provided with a margin. A label with the name of that component is provided in that margin at the start of each component.
The external characteristics of each component, such as type face and size, margin positions, typographical functions, and so on, are fixed in the properties which may have a different setting or value for each component. The set of properties of a component may be displayed on the screen in a separate window by bringing it up via a menu with the mouse at the label of that component. This window also displays the values of the properties. These can be changed by the operator. If he does not change them, then the values pre-programmed by the supplier (default values) apply.
To increase legibility, the operator will often wish to make the appearance of certain components different, e.g., by printing the heading in bold and centered on the line. He can achieve this by giving the properties of that component a corresponding value.
The known system enables the contents of a document to be displayed in the text window in the form of a number of columns. A column of this kind, which will hereinafter be referred to as the text column, is to be distinguished from a component column, in which an indication of the name of a component contained in the text column currently being worked upon is given at the level of the start of the associated component in front of any margin line. It should be noted that graphic representations or tables may also occur in a text column in addition to the text.
By means of a mouse, for example, the operator is able to move a pointer element or cursor and move from one text column to the other in order to supplement and adapt the document as desired. On moving from one text column to the other, only the component column corresponding to the other text column is displayed in the known system. Thus the component column corresponding to the "active" text column is always visible.
The disadvantage of this system is that with such a representation and display of the component structure of the document it is necessary for the operator always to move from one text column to the other in order to have an idea of the position and kind of all the components present in the different text columns.
Another disadvantage of the known system is that if one or more components are selected from a component column displayed at a specific moment, and, after the changeover to another text column, components from the component column corresponding to this other text column are also selected, whereafter the values of the properties of the components thus selected are changed, the operator, particularly in the case of displaying of a number of text columns, has a considerable risk of losing the overview of his previous selections, because it is not clear what components have been selected in which component columns. The risk of errors is thus considerable. Accordingly, it is an object of the present invention to provide a system and method which overcomes these disadvantages.