User Interface

User interface

ž  A user interface, or ‘ human-computer interface’ (HCI), consists of all the hardware and software through which a user provides input to a computer or receives information from it. We study the

›      Command line interface

›      Graphical user interface

Command line interface

For several decades, a command line interface (CLI) was the only type of user interface available.

Screen output was restricted хязгаарлагдсан  to text without graphics or graphics without text.

 It was quite difficult to user a computer because a CLI has no permanently тасралтгүй available menus.

It relies найдах on the user accurately яг нарийн remembering and entering commands, using only the key board for input

The user has to

ž  Remember what commands are available and the rules дүрэм( or ‘syntax’) for constructing all of a user`s software and data

ž  Type commands нарийн accurately-some errors can have  эрс drastic unintended санаандгүй effects, such as reformatting a hard disk containing багтаамж  all of a user`s software and data.

However, a CLI can be very useful for an expert шинжээч , such as a network administrator, because it enables them to work rapidly түргэн and access a very wide range of commands.

Graphical user interface

A graphical user interface(GUI) is the type of interface that most modern computers offer. It is called ‘graphical’ because it displays graphics as well us text.

ž  Graphical user interface`s advantages are:

ž  As well as helping the presentation of information

ž  To use software easier for users

ž  Easier for understanding

ž  To make computers more ‘ user-friendly’

We briefly mentioned some commonly occurring features of a GUI when studying application programs. They are summarised by the acronym “ WIMP”.

ž  Windows

ž  Icons

ž  Menus

ž  Pointing devices

Windows

ž  A multi-tasking OS with GUI usually displays each task in separate window

ž  Each window is rectangular region of the screen through which we can view a running program, a document or a dialogue box

ž   clicking a mouse or other pointing device`s button on a application program window is an intuitive way to switch to working on different task, automatically bringing its window in front of other windows

Icons

ž  A small, pictorial symbol, sometimes with text, that represents a command, a file or a shortcut to a program, file or web resource

ž  An icon can be selected or ‘clicked’ by operating a button on mouse or other pointing device

ž  An icon may be available on a permanently visible menu called a ‘toolbar’ or on a drop-down list

ž  Dragging a file icon onto a suitable application program icon or window often opens the file in that application

ž  Icons

Pointing devices

ž  A mouse or other pointing device positions a graphical cursor on the display screen

ž  The appearance of the cursor depends on its position relative to selected text or objects

ž  Clicking the pointing device`s button provides an intuitive means of selecting a window, an icon or a menu command

ž  The device can selected text or objects within an application window by clicking-and-dragging and  move them by drag-and-drop.