Shelf (computing)
Encyclopedia
The Shelf is an interface feature in NeXTSTEP
and OPENSTEP
, and is used as a repository to store links to commonly used files, directories and programs, and as a temporary "holding" place to move/copy files and directories around in the file system hierarchy. In Mac OS X
, items may be dragged onto the sidebar area of the Finder while holding the Apple key, but these do not behave as placeholders and cannot be manipulated in the below manner.
The dynamics of the Shelf in file system operations can be illustrated by comparison with the metaphor used in the Microsoft Windows
operating systems. In order to move a file the following steps may be taken:
With the NeXT
operating systems, in addition to moving files by dragging them from window to window, the following method can be used:
Note that the file, when dragged to the Shelf, has not moved anywhere and is not changed in any way. The Shelf icon is merely a placeholder for the file. In moving the placeholder off the shelf, the actual action occurs.
The NeXT functionality builds upon this concept by allowing the destination directory to be put on the Shelf as well, and the file can be merely dragged to the destination directory icon.
The process is similar to the Microsoft Windows functionality of copying or cutting
file system objects (a file or files, a folder or folders, or a combination of both) to the clipboard; the objects are not copied or removed from their original location until the paste operation to the new location is completed. The Shelf concept, though older, is more powerful in that the file system objects, their sources and destinations are persistent and available as long as they are on the Shelf (in the Windows cut, copy, and paste metaphor the objects and locations persist until one copy/move operation is complete or until something else is placed in the clipboard).
Since Shelf icons are 'placeholders' of sorts, icons can be put on the Shelf representing commonly used directories, and commonly used programs can be put on the Shelf as well.
The NeXTSTEP and OPENSTEP file management application (called FileViewer and run by the Workspace Manager) also allowed users to have different shelves associated with particular directories. Users simply opened a new browser rooted in a particular subdirectory, and that browser window would show the corresponding shelf, allowing users to have many different shelves based on whatever folder hierarchy they happened to be using to organize their files.
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
and OPENSTEP
OpenStep
OpenStep was an object-oriented application programming interface specification for an object-oriented operating system that used a non-NeXTSTEP operating system as its core, principally developed by NeXT with Sun Microsystems. OPENSTEP was a specific implementation of the OpenStep API developed...
, and is used as a repository to store links to commonly used files, directories and programs, and as a temporary "holding" place to move/copy files and directories around in the file system hierarchy. In Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
, items may be dragged onto the sidebar area of the Finder while holding the Apple key, but these do not behave as placeholders and cannot be manipulated in the below manner.
The dynamics of the Shelf in file system operations can be illustrated by comparison with the metaphor used in the Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating systems. In order to move a file the following steps may be taken:
- the window containing the source folder is opened
- the window containing the destination folder is opened
- the desired file in the source directory is dragged to the destination folder
With the NeXT
NeXT
Next, Inc. was an American computer company headquartered in Redwood City, California, that developed and manufactured a series of computer workstations intended for the higher education and business markets...
operating systems, in addition to moving files by dragging them from window to window, the following method can be used:
- the user navigates to the source directory
- the file is dragged to the Shelf
- the user navigates to the destination directory
- the file is dragged from the Shelf to the destination directory
Note that the file, when dragged to the Shelf, has not moved anywhere and is not changed in any way. The Shelf icon is merely a placeholder for the file. In moving the placeholder off the shelf, the actual action occurs.
The NeXT functionality builds upon this concept by allowing the destination directory to be put on the Shelf as well, and the file can be merely dragged to the destination directory icon.
The process is similar to the Microsoft Windows functionality of copying or cutting
Clipboard (software)
The clipboard is a software facility that can be used for short-term data storage and/or data transfer between documents or applications, via copy and paste operations...
file system objects (a file or files, a folder or folders, or a combination of both) to the clipboard; the objects are not copied or removed from their original location until the paste operation to the new location is completed. The Shelf concept, though older, is more powerful in that the file system objects, their sources and destinations are persistent and available as long as they are on the Shelf (in the Windows cut, copy, and paste metaphor the objects and locations persist until one copy/move operation is complete or until something else is placed in the clipboard).
Since Shelf icons are 'placeholders' of sorts, icons can be put on the Shelf representing commonly used directories, and commonly used programs can be put on the Shelf as well.
The NeXTSTEP and OPENSTEP file management application (called FileViewer and run by the Workspace Manager) also allowed users to have different shelves associated with particular directories. Users simply opened a new browser rooted in a particular subdirectory, and that browser window would show the corresponding shelf, allowing users to have many different shelves based on whatever folder hierarchy they happened to be using to organize their files.