January 28th, 2000

[Editorial] Reflections of Aqua: NEXTSTEP Moves Mac Desktop Aside by Tuan Truong It has been said that Aqua was a secret undertaking at Apple for 18 months. And it is true in the pragmatic sense, implementing a new Steve Jobs auteured graphical user interface for the Macintosh could not have begun until after the iCEO became the iCEO. But in a more spiritual sense, Aqua was a seed germinating in Jobs' and the NeXT dominated Mac OS X design teams' minds for a very long time dating back to their NEXTSTEP days in 1995 and perhaps before. The clues are all there in the Aqua UI and in various versions of the NEXTSTEP UI, and it gives me the feeling that they are trying to set the users free of the limitations of the Mac OS UI. All of us consumers who are not privy to the Aqua design team or Mac OS X developer releases can't say much about the feel of Aqua, and with only a few screenshots, we can't say that much about it's look either. The look is an exercise left to art design discussions, and in many ways is subjective as has been seen by many comments on the Internet. I will speculate on its feel or the way it operates which seems to be primarily based on Steve Jobs' NEXTSTEP developments. Three of NEXTSTEP's many key elements were the concept of the Shelf, its miniwindow application and document window management scheme, and elegant and pervasive drag-n-drop conventions amongst them. From the keynote demonstration, all of these elements seem to be refined and reborn for Mac OS X: the desktop looks to be a Shelf-based system, the Dock is an encapsulation of the NEXTSTEP's miniwindow based window and application management scheme, NEXTSTEP's application dock and NEXTSTEP's Shelf, and pervasive drag-n-drop between Dock tiles, desktop icons, Finder windows, and application windows would be a natural process for Shelf and Dock systems. During the demonstration, icons from the desktop were double clicked and the objects they represented opened up. Icons from the desktop were dragged into the Dock, and they disappeared from the desktop. Icons were dragged from the Dock onto the desktop, and they disappeared from the Dock. This behavior seen on the desktop is classic Shelf type behavior. The Dock tiles, more appropriately, miniwindows, followed some of the NEXTSTEP miniwindow conventions. Application miniwindows popped into the dock when started. The Finder application miniwindow was on the left of the Dock as indication it was running. When Quicktime was started, the Quicktime app miniwindow was docked to the right of the Finder miniwindow. When a Quicktime movie window was minimized, it's miniwindow genie-ed to the last Dock position before the trash can miniwindow. Double clicking on the minimized windows genie-ed them open and the miniwindow disappeared. This is essentially the NEXTSTEP miniwindow behavior but with flash and a dock. Furthermore, files, folders, applications, system objects like DVDs, essentially any persistent object in Mac OS X could be dragged or placed on the Dock which is another UI idea NeXT was exploring before the buyout. What does this mean? The Mac OS Desktop metaphor has been superseded. The desktop has been turned into a Shelf, and the Dock has been added to help the user manage and work with the system and to takeover much of the MenuBar functionality. Many would say the Mac OS "Desktop" has been eliminated and that may be true, but in regards to the usage of the desktop, it will be similar to it with a few, but significant, differences. What Aqua seems to have done is virtualized the process of working directly with the file system as seen in Mac OS Classic, and moved it one abstraction layer up. The Dock takes over much of the MenuBar functionality of task switching and quick access to the system while expanding on it by having more screen space and more programmability. This is what will give Aqua the feel of freer and more fluid movement, like water. This abstraction is embodied in the concept of the proxy and a Shelf. An example of a proxy is the little document icon to the left of window title bar names as seen in Mac OS X Server and modern versions of Mac OS Classic. This proxy could be dragged to Finder windows and other application windows and will open, paste or copy whatever document it represented. It is seemingly similar to an alias, but it is not. The key difference is that a proxy is an entity of the Mac OS X Server Finder application or Mac OS 9.x Finder application, and not a file system object like an alias is. Working with a proxy is working directly with a file or folder itself, except that it is not constrain by being part of the file system. A Shelf, as the name implies, is a place to hold things much like in concept to the Mac OS Classic desktop. The difference is the Mac OS Classic desktop is a hidden folder, a file system object, albeit a special one. Actions done on the Mac OS Classic desktop is mostly limited to what can be done within a filesystem folder. Files and folders from the Finder are moved or copied to the Desktop folder. A desktop that is a Shelf is not a folder. It is a virtual place that holds proxies. It gives immediate access on the desktop to any filesystem object no matter how deep it is in the filesystem. The drag-n-drop and mouse click conventions will be nearly identical. Double clicking a Shelf item or icon opens it up. Dragging a file on top of folder proxy, moves or copies it to the folder. This virtual place, this desktop-as-Shelf is the one abstraction layer up. It is not a part of the filesystem, but is a shelf above it in which files, folders, applications, aliases-essentially any filesystem object of the filesystem including removable media-can be placed and where all the actions are done by proxy. The Dock, again as the name implies, is a place to anchor things to. It is the centerpiece of the management of the system, not simply a place to hold minimized windows or running application icons. It is also a Shelf. Like the Shelf-like desktop, applications, files and folders can be dragged to it for quick access. Files can be dragged on top of docked items and they will open up in the docked application or are copied or moved into a docked folder. Removable media can be dragged there or automatically shown there after it is mounted. The most significant thing about the Dock, however, is the concept of the miniwindow. The miniwindow is not an icon with a tile underneath, it is a small window. Since it is a window, it's contents are programmable. The clock application seen on the desktop of the MWSF demo can be dragged onto the Dock or it can be just started and its application miniwindow will appear on the dock and while it's running, its miniwindow will have a clock inside it with the hour, minute and second hands all moving to indicate the time. A mail application can have a number in its miniwindow and it'll tell the user how much new mail there is. A CD player application can have controls in its miniwindow, and the user can change songs or stop playing it without switching to the CD player application. And of course, the previews of documents in the miniwindows are amply seen in the screenshots. What does this mean? Apple has broken the limitations inherent in having the desktop being a folder and has broken the limitations of the MenuBar being a small and relatively inactive management system. The Dock, desktop-as-Shelf, proxies and miniwindows all hold tremendously flexibility because they are programmatic entities of the UI application. For instance, a disparate collection of files can be grouped together and placed on the desktop or Dock, and it could be represented by one proxy or miniwindow. Double clicking on the proxy would open them up all at the same time. Dragging the proxy to another folder will copy or move all of them. Both the Dock and desktop could be improved so they can accept clipboard datatypes and any persistant objects. Objects such as swatches of colors, font types or swatches of transparency could conceivably be dragged to the desktop or Dock for later use. A Shelf application can be developed where users can have a Shelf in a window or Shelves in windows and work as if there are multiple desktops. Since it is in a window, the user doesn't have to worry about hiding or minimizing windows to look at the desktop, all they need to do is bring it to the front. The Dock in of itself has limitless possibilities. Gone are the days of using extensions or control panels to add functionality to the MenuBar. They can now exist as applications designed exclusively for Dock usage. An app can have its miniwindow popup a column of miniwindows containing recent applications and documents used. Applications which monitor system usage could show system statisics in their miniwindows. An MP3 or audio CD player can have their controls in the miniwindow so the user can skip to the next song or increase the volume without changing the key window. An app miniwindow could have a pop-up list of recently used websites. Feeds of streaming media (radio, stock tickers, sports news, general news, video) could be playing in a miniwindow of you own. Double clicking on one of them would expand it to a full window with more details. The system can truly be an interface to fulfill the needs of computing today, from novice users to power users. It is designed with preemptive multitasking in mind where users can seemlessly run dozens of applications and documents at the same time and easily manage and interact with those applications and documents at the same time. It is designed with a simplicity in UI interaction in mind. Drag-n-drop is pervasive between Finder windows, applications, the Dock, and the desktop. The novice user is given an easy starting point with the initial Finder window where they have quick access to the rudiments of the system. They can branch out by either spawning more Finder windows, using one Finder window, or using all the UI elements: desktop, Dock and Finder in tandom. The power user is given power mechanisms to maintain and manage their system through the Dock's miniwindow programmability and app and document window management. It is a system that will grow with the user. It is a system that is dynamic, it will flow like water, aqua. At least that's what I'm speculating. Tuan Truong