CST(16)-Client Anatomy

Client/server applications are client centric. All client applications have one thing in common that is, they request the services of a server. What makes client applications different is what triggers the request and what GUI is needed. Based on these we classify clients into three categories : Non GUI clients, GUI clients and OOUI clients.

Non-GUI Clients:

Non-GUI client applications generate server request with a minimal amount of human interaction. Non-GUI clients fall into two sub categories:

Non-GUI clients that do not need multitasking:

Examples include automatic teller machines (ATMs), barcode readers, cellular phones, fax machines, smart gas pumps and intelligent clipboards. These clients may provide a simple human interface in the request generation loop.

Non-GUI clients that do need multitasking:

Examples include robots, testers and daemon programs. These clients often require very real-time, event-driven multitasking services.

GUI Clients:

Simple GUI clients are applications where occasional requests to the server result from a human interacting with a GUI. The simple GUI interface is a good fit for mainstream, OLTP type applications with repetitive tasks and high volumes. They also make good front-end clients to database servers. GUI replace the ‘green-screen uglies’ with graphic dialogs, menu bars, scroll boxes and pop-up windows. Simple GUI dialogs uses the object/action model where users can select objects and the select the action to be performed on the chosen objects. This model of interaction is used in windows 3.x. It is also known as CUA 89 graphical model.

OOUI Clients:

This is a highly iconic, object-oriented user interfaces that provide3s seamless access to information in very visual formats. Information workers doing multiple, variable tasks whose sequence cannot be predicted use oOUIs. Examples include executive and decision-support applications and multimedia-based training systems. OOUI desktop objects need to communicate among themselves and with external servers. The communications are by necessity, real time, interactive and highly concurrent.

Examples of OOUI are OS/2 workspace shell, Mac OS and to some extent windows 95. The desktop can contain multiple workspaces running concurrently. Each workplace may be running parallel dialogs, also called modeless dialogs over parallel sessions with the server. OOUI focus on the objects required to complete a task. In an OOUI the application is transparent to the user. The desktop is a collection of objects and windows as opposed to GUI where the desktop is a collection of windows or icons representing the windows associated with those applications. In OOUI the user interacts with the objects rather than with the operating system. The OOUI is the simulation of how the user interacts with the objects of real world. It is a computer visual of real-life simulation. 
CST(16)-Client Anatomy Reviewed by 1000sourcecodes on 21:47 Rating: 5
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