Next: X Window Principles Up: The X Window System Previous: What is X Windows?

Why Use GUIs?

Before we study X Windows in detail it is worth considering why we need GUI's.

GUIs provide an easy means of data entry and modification. They should provides an attractive and easy to use interface between human and machine. So easy in fact that a non-computer literate person could use the system.

GUI's provide a better means of communication than cumbersome text-based interfaces.

How do GUIs provide such facilities? By means of:

Although GUIs provide some very powerful advantages, there are a couple drawbacks to the GUI approach:

Efficiency
- As we will shortly see even the most basic windowing program can be quite large. (hello world prog will about 2 pages long!!.) This is because we will have to write or call upon many functions to control the windowing system - e.g. create, move, resize etc. windows; handle input via mouse and keyboard actions; control graphics.
Programming
- a different approach to programming is needed from the command-line approach. You have been used to top down structured programming approach. We will have to adopt a different strategy known as event-driven programming where the actions in our program will be triggered by mouse and keyboard actions.


Dave.Marshall@cm.cf.ac.uk
Tue May 24 16:52:56 BST 1994