The GUI Burden

ATS 315

Stephenson, 118-125

Booting Your PC

• Starts off with some text with lots of cryptic messages.

• Next, the ugly windows logo…

Then the Beautiful GUI

Why start off in a text mode?

• Thousands of possible monitors

• Thousands of possible video cards

• = Millions of possible combinations

• All they have in command is “VGA” mode.

Drivers

• Translate the computers instructions into instructions for the specific brands of peripherals on your computer.

• The computer itself cannot care about the brand of hardware attached—it just talks to the drivers and the drivers sort it out.

Where are the drivers?

• Buried.• In binary.• You can set some of

the features of these drivers in the Display dialog box…

Macintosh

• Never see text at boot

• A lovely “welcome screen”• Why so different?

Unix

• At log in, you are on a glass teletype (tty)– Why?

– Server knows NOTHING about your computer’s hardware

– …or its own hardware!

Starting Xwindows

• Log in on wx-sun1 itself

XWindows

• A set of programs that reproduces the graphical metaphors in Unix

• XWindows itself is extremely ugly…

Window Managers

• A set of programs and settings that gives XWindows a coherent, modern “look and feel”.

• In cygwin, we are running XWin, which makes the windows look just like WindowsXP windows. (startxwin.sh)

CDE

• Common Desktop Environment

GNOME

KDE

Redmond98

Aqua

Transparent

Enlightenment

And Many More!

Developing Programs for a GUI

• A simple program: grep

– grep simply searches files for the requested string.

– grep fopen *.c

grep.c

• Is probably very simple and short:

• while(!feof(fin)) {– fscanf(fin, “%s”,&string2);– if (!strcmp(string1,string2)) printf (“%s”,string1);

• }

A grep XWindows Program

• Would have to open a window:

A grep XWindows Program

• Would have to prompt the user for the string to search for and the files to search in.

• Requires loading fonts, choosing colors for the fonts, etc. (i.e., the attributes of the text)

What text are you looking for?

In which file should I look?

A grep XWindows Program

• Would have to set up dialog boxes in which the user could enter text. What text are

you looking for?

In which file should I look?

A grep XWindows Program

• Would have to know how to work with the mouse, mousebuttons, etc. What text are

you looking for?

In which file should I look?

A grep XWindows Program

• Would need buttons for Search and probably for Cancel.

What text are you looking for?

In which file should I look?

Search Cancel

A grep XWindows Program

• All of this is BEFORE you write the part of the program that actually searches for the text!

What text are you looking for?

In which file should I look?

Search Cancel

A grep XWindows Program

• This program would be thousands of lines long!

• Hardly worth the work!

What text are you looking for?

In which file should I look?

Search Cancel

Omnibus Programs

• Microsoft Office

• Microsoft Windows Explorer

Microsoft Office

• File• Open• Tools• Search

Microsoft Office

Microsoft Windows Explorer

• Press Windows-F

Microsoft Windows Explorer

Microsoft Office

• Becomes full of “features”– = rand(5,4)

• dd

Microsoft Windows Explorer

• Becomes full of “features”

Big Programs

• have bugs that are hard to find!