What is UI ( User Interface )

The user interface (UI) , in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of this interaction is effective operation and control of the machine on the user’s end, and feedback from the machine, which aids the operator in making operational decisions. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls, and process controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology.

A user interface is the system by which people (users) interact with a machine. The user interface includes hardware (physical) and software (logical) components. User interfaces exist for various systems, and provide a means of:

Input, allowing the users to manipulate a system Output, allowing the system to indicate the effects of the users’ manipulation

Generally, the goal of human-machine interaction engineering is to produce a user interface which makes it easy (self exploratory), efficient, and enjoyable (user friendly) to operate a machine in the way which produces the desired result. This generally means that the operator needs to provide minimal input to achieve the desired output, and also that the machine minimizes undesired outputs to the human.

With the increased use of personal computers and the relative decline in societal awareness of heavy machinery, the term user interface is generally assumed to mean the graphical user interface, while industrial control panel and machinery control design discussions more commonly refer to human-machine interfaces.

Other terms for user interface include human–computer interface (HCI) and man–machine interface (MMI).

Human-MachineInterface

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CLI (command-line interface)

A command-line interface (CLI), also known as command-line user interface, console user interface, and character user interface (CUI), is a means of interacting with a computer program where the user (or client) issues commands to the program in the form of successive lines of text (command lines).

The CLI was the primary means of interaction with most popular operating systems in the 1970s and 1980s, including MS-DOS, CP/M, Unix, and Apple DOS. The interface is usually implemented with a command line shell, which is a program that accepts commands as text input and converts commands to appropriate operating system functions.

Command-line interfaces to computer operating systems are less widely used by casual computer users, who favor graphical user interfaces. Command-line interfaces are often preferred by more advanced computer users, as they often provide a more concise and powerful means to control a program or operating system.

Programs with command-line interfaces are generally easier to automate via scripting.

Alternatives to the command line include, but are not limited to menus, keyboard shortcuts, and various other desktop metaphors centered on the pointer (usually controlled with a mouse).

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commandLine

TUI (Text-based user interface)

Text-based user interface (TUI), also called textual user interface or terminal user interface, is a retronym that was coined sometime after the invention of graphical user interfaces, to distinguish them from user interfaces that were text-based. The concept of TUI refers primarily to the way of output and does not coincide with command-line interfaces which is a certain user input mode. An advanced TUI may, like GUIs, use the entire screen area and does not necessarily provide line-by-line output, although TUIs only use text, symbols and colors available on a given text environment.

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QB45TUInterface

GUI ( graphical user interface )

In computing, graphical user interface (GUI, is a type of user interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLI), which require commands to be typed on the keyboard.

The actions in GUI are usually performed through direct manipulation of the graphical elements. Besides in computers, GUIs can be found in hand-held devices such as MP3 players, portable media players, gaming devices, household appliances, office, and industry equipment. The term GUI is usually not applied to other low-resolution types of interfaces with display resolutions, such as video games (where HUD is preferred), or not restricted to flat screens, like volumetric displays because the term is restricted to the scope of two-dimensional display screens able to describe generic information.

FedoraGUInterface

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Mere Clipper

An article by Roger Donnay, March, 1998
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We often do not realize the importance of people and events until many years later when the dust has settled and we can put them into perspective. Three years ago I was asked to write an article for the CDGN Magazine. It was titled “Back to the Future” and it dealt with the the role of Clipper in 1995 and into the future. I recently broke out my old copy of CDGN magazine and reread the article to see if my predictions match the current landscape.
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I predicted that I would be writing my final article about Clipper in the year 2035. Many of you assumed that either I was much younger than I really am, that this was a typographical error, or that I had already lost it and was living on a ranch somewhere in California with Ronald Reagan. None of the above are true. I am now fifty-four years old. In the year 2035, I will be 91 years old but I will still be programming because in the year 2007 we will discover a new drug that restores dead brain cells. The year 2035 will mark the year that we finally arise from the ashes of the “great computer meltdown” of 2010. The meltdown will occur because of the Year 2000 debacle which will create a world-wide depression and create a political climate of hatred towards programmers that will build to a frenzy leading to “The Night of Broken Disks”. Computer programmers will be fleeing to Russia, Iran and Iraq – the only safe havens in the world that will not be affected by the “Great-Satan Virus” due to their refusal to connect to the Information SuperHighway.
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This great oppression of computer programmers will force those who are not killed outright, or sent to “de-programming camps” made their escape to third-world countries to hide for years in attics, befriended by a few, brave souls who know it is not their fault they were born “computer-literate”. During this 20-year war on computers, an arsenal of “giant magnets” are created by the new war machine and the industrialized cities of the world are bombed with the largest “de-gaussing” campaign in history. No piece of software or database will be safe from annilation. Finally, the great war machine is defeated because it will fail to realize that it cannot maintain such a war when it destroys the very machines and software that allow it to wage war.When it is all over, a discovery is made in a little house on the Prinsengracht in Amsterdam. A old notebook computer is found in the attic and sent to a museum. While restoring the computer, a small disk is found, still fused in the disk drive. Because of its condition, it appears that the notebook had been there for many years. Much work goes into the restoration of the disk and its data and finally, it is discovered that the disk contains the diary of a young, computer-literate girl who had lived in hiding for many years. By this time, the only computer-literate people left in the world only speak Russian or Farsi, so it takes much effort to figure out how to decipher the data on the disk. Finally, a compelling and sad story emerges about a young girl who struggles to maintain her innocence, her sanity, her computer-proficiency, and her faith in God while hiding from the great de-gaussing and de-programming regime.
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It is a sad story, and it takes time for the world to really understand her story, especially her references to “The Book of Clipper”. What was Clipper? Was this what helped her maintain her sanity and her faith in God? What happened to the young girl? Her story spreads around the world, and a never-ending search continues for a copy of “The Book of Clipper”. Finally, the search ends in a little Russian town. Not a single person realizes that “The Book of Clipper” is a reference to the manual for the computer language that every single Russian speaks fluently, until someone finds a copy of the manual that Larry Heimendinger had left at the only Russian Clipper conference ever held – in 1992. It is dusty and worn, but it is the only book left that tells the true story of Clipper. Even though every programmer in Russia can speak Clipper, not a single one of them has seen a copy of “The Book of Clipper” because none had ever been sold. The software had been pirated, and then spread from disk to disk throughout the country while the story of Clipper passed from mouth to mouth. The Russians are the only civilized society that still has a programming language, so they offer it as a gift to the world, and the world becomes whole again, and the people rejoyce, and I come out of hiding – to write my final article about Clipper.

It’s a Wonderful Life

I like to imagine that I am the angel in the story “It’s a Wonderful Life” and that I have been called on by God to rescue a person who feels that his life has been lived in vain. In my rendition of the story, the desperate soul is not George Bailey but instead is Tom Rettig. Tom passed away about a year ago and I find myself haunted by him because I feel that I have never given back to him what he gave to me and the rest of the world. I often think back at what my life was like in the mid 80’s. After many successful years as an Electronics Engineer my life was just not working anymore. Thieves broke into my business office and stole my computers and my software (including the backups). I was struggling with a failing computer-accessories manufacturing business that had pushed me deep into debt, and then my wife decided to just leave one day and head for greener pastures. I thought she had been kidnapped because she disappeared without a trace.

Arlo Guthrie once wrote a song about “The Last Man”. He said “You think you’ve got it bad? Look at that guy?.” I WAS that guy.

Then, one day, in early 1986 I was struggling with a problem trying to get dBase-III to work properly on my new peer-to-peer network. I recall making a tech support call to the network developer and the person on the phone asked “Are you compiling with Clipper?”

This simple question, in retrospect, was equivalent to someone posting a huge sign “Except a man be born again, he cannot see the kingdom of God”. Clipper was my salvation. It allowed me to layeth down in green pastures and it restoreth my soul. So how did it come about that a person could be saved from the depths of depravity by a mere software product? We all have our stories of salvation, and they all take us down different paths but they all lead to the same place. My story in not unlike C.S. Lewis’ story in “Mere Christianity”, except the players are different. The Book of Clipper is not one story, but hundreds of stories all evolving from the “Platitudes of Vulcan”.

Tom Rettig entered the scene around 1986 and offered an add-on product to Clipper titled “Tom Rettig’s Library”. Tom was a well-liked, generous person who eventually offered his library into the public-domain. Some of us are old enough to remember him as Jeff, the small boy in the original “Lassie” series on television in the 50’s. I first met him at a user group in Southern California. After the meeting we went to a bar for a few beers and he sat and talked to us like we had all known him for years. He inspired us to do what he did, because he was just like us. The next day, I thought “If Tom Rettig can make a successful add-on product to Clipper, so can I”. I wasn’t the only person who had seen the light that night. Tom had broken new ground, had planted the first seeds, and from these seeds, an entire community of user-groups, programmers, applications, add-on products, books, magazines, et al, grew into maturity.

Two Steps Back

Have you ever heard anyone say “He’s so far behind he’s ahead”? By now, most of you have decided that you must move on to Windows and that there is no place for Clipper in your strategy. Many of you have already done so and are experimenting with products like VO, Delphi, VB, and Power-Builder or have created applications with these development environments. I am not writing this article to suggest that in any way, this was a bad choice. I have spent sufficient time with these products to come to the realization that Windows applications can be developed by travelling many different paths. What I am offering, however, is another perspective; one that frees us to open our minds to look at the future from a different view. Many of us have been so busy and so worried about constantly moving forward that we have forgotten how we got here in the first place, by the use of an enduring and powerful language – Clipper.

So you may be thinking “What is he talking about? Clipper is Dead!”. In the sense of a product, this may be true, but in the sense of a language, it is far from true. Let’s imagine that Chinese is packaged into a product named “Visual-Chinese” and this product includes a set of design-tools for creating quick-Chinese documents that can be easily integrated into our marketing documents. Soon we would find our business opened up to a new market of 1 billion people. The product becomes instantly successful and everyone love its and uses it – until, years later, when we find that our marketing documents are not delivering any sales. Why? Because the language had to be cut and trimmed to fit into the limitations of the software environment. It becomes ambiguous, arrogant and unwanted by the very people who inspired its development, so it dies and Visual-Chinese gets thrown away like every other Visual tool. Does this mean that the Chinese language dies with the product? No. Chinese is a language that will endure. It has lots of users; it is robust, and it is mature.

The key word is “language“. Development strategies should be built around the choice of a proper language, not just a product. Clipper is a language that endures. It cannot die. It has widespread use around the world and there are hundreds of thousands of Clipper legacy applications still doing mission- critical work. Unfortunately, because the word “Clipper” is owned by CA, and because CA has essentially abandoned Clipper, it cannot endure under the name Clipper, so it must endure under another name: that name is “Xbase”. Software developers try to treat languages like they own them, but they are only temporary custodians. This leads us to a discussion of the current state of the Xbase language. Xbase currently ( 1998 ) exists in 5 dialects:

      1. dBase – A Windows-based Interpreter.
      2. FoxPro – A Windows-based Interpreter.
      3. CA-Clipper – A DOS-based Xbase compiler.
      4. CA-VO – A 32-bit Windows-based Xbase compiler.
      5. Xbase++ – A 32-bit Multi-Platform Compiler.

Xbase as dBase

dBase was the custodian of the Xbase language from around 1983 until about 1987. Unfortunately, it was an interpretive language so it never gained respectability as a true, robust language, however, it had much to offer the developer in ease-of-use and database design. dBase continues to be supported by Borland, simply because there is still money to be made in upgrades and conferences, but Borland has made it clear that they intend to make dBase programmers learn how to speak Pascal and eventually will phase Xbase out of their products.

Xbase as FoxPro

FoxPro took over as a co-custodian of the Xbase language in about 1987 and emerged around the same time as Clipper. FoxPro defeated dBase nearly overnight simply because it was faster, not because it delivered any new language concepts. FoxPro continues to be supported by Microsoft, simply because there is still money to be made in upgrades and conferences, but Microsoft has made it clear that they intend to make FoxPro programmers learn how to speak Visual Basic and eventually will phase Xbase out of their products.

Xbase as Clipper

Clipper was undoubtely the best custodian of the Xbase language from 1987 to 1996. Clipper introduced the Xbase compiler, the open-architecture concept of the extend system, code blocks, locals, statics, multi-dimensional arrays, the RDD layer, the preprocessor, and language extensions. Clipper was the first Xbase custodian to give Xbase respectability as a true programming language. Clipper maintained this respectability until around 1996 when CA released CA-Clipper 5.3. CA chose to treat Clipper as a “package” rather than a “language” and alienated nearly the entire Clipper community when they bundled a Windows-IDE and several third-party products into the package. This was when Clipper died.

Xbase as VO

Computer Associates planned for VO to take over as the custodian of the Xbase language by forcing the death of Clipper and dragging CA customers into a new kind of development environment that kind of looks like Clipper, in that it inherited much of the new Clipper extensions. Unfortunately, migration to VO became cumbersome due to too many incompatabilities, poor performance, poor reliability and a third-party community who could not get their products to work with VO. VO promised it would be easy to migrate existing Clipper applications to Windows but could not deliver on the promise. Working in VO is in no way similar to working in Clipper. Many Clipper developers find that using a third-party Windows library (like Five-Win or Clip-4-Win) with Clipper is a much easier migration path than VO.

Why Xbase?

Many of us wonder why Xbase has not been given more respectability as a “mainstream” language. If Xbase is so good, why are Borland and Microsoft phasing it out of their future products? I was watching a television program the other day about an analysis of automobile technology over the years. We often assume that the best technology is what endures over time and that it eventually rises to the top. This may be true in an ideal world, but in a capitalist society, it is usually market dog-fights that determine dominance. In this analysis, it was determined that steam technology could have produced cars just as good as internal combustion technology, but Henry Ford chose the latter. Bill Gates has chosen Basic, not because it is better, but because he owns it. He doesn’t own Xbase, and Bill cannot embrace something that he cannot control. Borland chose Pascal. Not because it is better, but becaused they own it.

Over the past 10 years, the success of the Xbase products has been due to the high degree of abstraction of the Xbase language, which makes it vastly simpler to acces and use operating system functions and resources. In addition, Xbase is more than just a specialized programming language, a database navigation language, or a user interface language – instead, it combines all of these roles, harmoniously integrating them with one another.

Xbase offers dynamic data types and is generally described as being highly “tolerant“. Taken together, these benefits have persuaded a steadily growing community of users and developers to rely upon it as a choice for implementing mission-critical and commercial PC-desktop applications. In fact, world-wide, more than one-third of all DOS-based commercial applications now in use were written in Xbase, with Clipper accounting for the major share.

Square Pegs and Round Holes

Most Windows programmers will tell you that you cannot take a standard Clipper application with @SAY..GETS, Menu Prompts, etc, and convert it to a Windows GUI program without a major change in the architecture and the functionality of the program. They claim that a text-based, modal design has too little in common with GUI-based, event-driven, non-modal design. They will tell you that it like trying to fit a square peg into a round hole. For years, I believed this because it made sense. I, like everyone else, wrote my Windows applications with a different structure than my Clipper applications. They were built around an event model rather than a procedural model and the code was tightly-bound rather than loosely-bound to the functional model. This always leaves me with an uneasy feeling because it forces me to write applications that are less modular and are platform specific. Microsoft, Borland, and CA each wants us to build applications their way. They want us to learn their programming tools, their methods, their plug-ins, their workshops, and their studios – not their language. Why? Because applications built around their environment will be harder to migrate to competitor’s products than applications built around a language.

So they make sure that the language is difficult and inaccessible, and that the application cannot be maintained or migrated to any other platform, other than platforms that they support. Programmers, however, have to survive in the real world and this requires platform flexibility. The reason why so many mission- critical DOS applications are still surviving in the real world is because each development platform supports DOS as a subset, so DOS has been, out of necessity, elevated to the status “platform independent”. I can run my Clipper applications under MS-DOS, PC-DOS, DR-DOS, OS/2, Windows 3.1, Windows 95, Citrix- Winframe, MULTI-DOS, Windows NT and Novell-DOS. I can run my Delphi applications only under 32-bit Windows. Is this a step forward?

Cocoon

In my dream, the “Ghost of Xbase Future” led me through the Land of Clipper and how it might look like up through the year 2035. I couldn’t hold back my emotions as I witnessed the data meltdown and the termination of millions of programmers. I asked him “Spirit – is this a vision of how things MUST be or how things COULD be?” He never answered me. I woke up from my dream and ran to the mirror. I was relieved to see that I wasn’t 91 years old but was still a young man. I exclaimed “There’s still time!” I bolted to the window, looked out, and saw that The Land of Clipper looks different than it did yesterday. The paths are 32-bits wide and they lead everywhere, yet they look familiar and something tells me that there is nothing to fear at the end of these paths. Then I realized that I had not been dreaming and that Clipper had not really died at all but had been in a cocoon, waiting to metomorphose into a butterfly, one with big X’s on it’s wings. The butterfly is beautiful and it attracts the attention of people like Dirk Lesko (author of Funcky), of Jud Cole (author of Blinker), of Dave Kuechler (author of Comix), and others who once frolicked in the land of Clipper.

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Note: This article is a summary  ( by courtesy of author) original is here.