Graphical user interfaces have become an increasingly common feature of computers, and in particular of personal computers. Such interfaces are provided either as built-in portions of the computer operating system, as in the case of the Macintosh computer available from Apple Computer Corporation, or as add-on software products that can be purchased separately from the underlying operating system, as in the case of the Windows 3.0 system available from Microsoft Corporation.
One of the many useful features provided by graphical user interfaces is the ability to initiate execution of other programs, usually referred to as "application programs," or simply as "applications." Examples of application programs are spreadsheets, word processing programs, database programs, etc. The process of initiating execution of an application program is typically handled through the use of small graphical symbols known as icons. The graphical user interface displays the icons on the computer screen, one icon for each application program that can be run. The user initiates execution of an application program by selecting the corresponding icon, most often using a pointing device such as a mouse.
Most graphical user interfaces permit the user to create an association between an application program and a selected application file. For example, in a word processing system, an application file might be a particular document created through use of the word processing system. In general, the terms "application file" and "document" are synonymous for purposes of the present description. When an association has been created, initiation of execution of the application program automatically causes the application program to load the associated document. This association may also work in reverse, such that selection by the user of a particular document causes the associated application program to be loaded and run with that document.
The conventional graphical user interfaces described above significantly reduce the amount of information that a user must recall in order to effectively use the computer. For example, instead of remembering the name of an application program, and the location of the program on a particular disk and within a given folder or directory, the user need only remember that a particular icon is associated with the application program. However, this simplification generally does not extend, to the same extent, to documents created by application programs. That is, a user must in general remember the file name assigned to a given document to cause that document to be loaded, either from the graphical user interface or from the application itself.
To address this problem, a number of software products have recently become available that permit designated graphical symbols (similar to icons) to be associated with particular documents. However, existing products of this type have a number of significant limitations. For example, some such systems require the user to create an icon for each document, a potentially time consuming task. Other systems provide for automatic icon creation based upon the contents of the document itself. However, these products work only for particular types of documents, i.e., for documents created by particular applications. There is a need for a technique for permitting visual cataloging of documents that can be used for all documents, regardless of their internal format.