THE FRONT PANEL

When you log in on a MathLAN workstation, you see a gray front panel across the bottom of the screen, decorated with various intriguing but cryptic icons. Here's a guide to its contents.

GNOME footprint logo  Main menu

The GNOME footprint logo appears on the Main Menu button. If you move the mouse pointer onto this logo and click the left mouse button, a long menu of software categories and application programs appears; you can select any of them by moving the mouse pointer onto the menu item and clicking with the left mouse button.

GNOME help browser logo  Help browser

A speech balloon containing a question mark is the logo of the GNOME Help Browser, a simple document browser for reading the on-line GNOME manual and related documents. Moving the mouse pointer onto this logo and clicking the left mouse button launches the Help Browser, which appears on the desktop as a new window.

When the Help Browser starts up, it displays a table of contents containing links to several other documents (such as the GNOME user's guide). To follow a link, move the mouse pointer onto it and click with the left mouse button. The table of contents disappears and is replaced by the document at the other end of the link. You can follow links in the new document in the same way.

To back up through the most recent link, move the mouse pointer onto the word Back near the top left corner of the Help Browser and click the left mouse button. To return to the table of contents, move the mouse pointer onto the word Index near the top center of the Help Browser and click the left mouse button.

To exit from the Help Browser, move the mouse pointer onto the word File in the top left corner and click the left mouse button. A menu appears. Move the mouse pointer onto the word Exit at the bottom of this menu and click the left mouse button.

Nautilus logo  File manager

This shell is the logo of the Nautilus, the GNOME file manager. Moving the mouse pointer onto this logo and clicking the left mouse button launches Nautilus, which appears (after several seconds) on the desktop as a new window, with a panel of controls at the top and a main panel with sidebar below. The sidebar, at the left, contains a description of your home directory and its contents and (at the bottom) several tabs for assistance with Nautilus. The main panel, at the right, shows the files and subdirectories that are contained in your home directory. They are displayed individually as icons -- subdirectories as heavy-looking folder-of-folders and text files as sheets of paper. (Sometimes, when Nautilus can determine that a file was created by or for a particular application program---a Web document or an Excel spreadsheet, for instance---it uses a special icon that indicates the nature of the application.)

If you move the mouse pointer onto a file icon and click twice with the left mouse button, Nautilus displays the contents of the file for you, or tries to. Typically the display is read-only, but if Nautilus knows of some editor or application program that is capable of interacting with the file, you'll be offered the opportunity to start that program by clicking on a button in the left subwindow.

You can use Nautilus to perform all kinds of common operations on files -- renaming them, moving them from one subdirectory to another, sharing and unsharing them, deleting them, and so on -- by pointing, clicking, and dragging with the mouse rather than by typing command lines. For details, consult the Nautilus User Manual.

To exit from Nautilus, move the mouse pointer onto the word File in the top left corner and click the left mouse button. A menu appears. Move the mouse pointer onto the phrase Close window on this menu and click the left mouse button.

GNOME terminal logo  Terminal emulator

This monitor icon is the logo for the GNOME terminal emulator, which is the tool through which long-term computer users (survivors from the era before graphical user interfaces) interact with the shell -- the command-language interpreter that reads and executes typed instructions, line by line. Clicking on the icon for the GNOME terminal emulator causes a new window to appear, with a shell running in it, ready to receive instructions.

You may find that some of the characteristics of the terminal emulator, such as the font and the color scheme, are not to your liking. The handout ``Preferences for the GNOME terminal emulator'' describes how to change them.

To exit from the shell, type the word exit or press <Ctrl/D> at the shell prompt. The terminal-emulator window disappears when the shell exits.

Mozilla logo Mozilla

This red saurian head is the logo of the Mozilla Web browser. Moving the mouse pointer onto this logo and clicking the left mouse buttons launches the browser, with the department's origin page loaded initially.

To exit from Mozilla, move the mouse pointer onto the word File in the top left corner and click the left mouse button. A menu appears. Move the mouse pointer onto the word Quit at the bottom of this menu and click the left mouse button.

XEmacs logo  XEmacs

The head of a gnu is the logo of the XEmacs text editor. Moving the mouse pointer onto this icon and clicking the left mouse button launches XEmacs in a new window. If you're new to XEmacs, you might want to look over the handout ``XEmacs: the basics.''

To exit from XEmacs, start by saving any files that you have edited. One good way to do this is to move the mouse pointer onto the word File in the top left corner of the XEmacs window, click the left mouse button, move the mouse pointer onto the phrase Save Some Buffers on the menu that appears, and click the left mouse button. XEmacs pops up a confirmation box for each file that has been changed, one at a time. In each confirmation box, move the mouse pointer into the small rectangle marked Yes and click the left mouse button to save the file.

Once all the edited files have been saved, exit from XEmacs by moving the mouse pointer onto the word File again, clicking the left mouse button, moving the mouse pointer onto the phrase Exit XEmacs at the bottom of the menu, and clicking the left mouse button.

Maple logo  Maple

The panel button labelled with the red maple leaf launches the Maple symbolic-algebra program.

To exit from Maple, move the mouse pointer onto the word File in the top left corner and click the left mouse button. A menu appears. Move the mouse pointer onto the word Exit at the bottom of this menu and click the left mouse button.

If you start to exit without saving your work, a confirmation box appears. If you want to save your work as a Maple worksheet, move the mouse pointer onto the button labelled Yes and click the left mouse button; if not, similarly click on the button labelled No

If you choose Yes and have not yet chosen a file name for the worksheet, Maple will pop up yet another window. Move the mouse pointer into the text field labelled Filename, click the left mouse button, and edit the text field until it contains the name you want to use. Then move the mouse pointer onto the button labelled OK and click the left mouse button.

MATLAB logo  MATLAB

The icon bearing the two-by-two identity matrix launches the MATLAB program.

For classroom demonstrations, you may want the window in which you interact with MATLAB to use an unusually large font. Since MATLAB actually runs inside a GNOME terminal emulator, you can use the method described in the handout ``Preferences for the GNOME terminal emulator'' to achieve this result.

To exit from MATLAB, type quit at the MATLAB prompt (two greater-than signs and a space). The window disappears when MATLAB exits.

logo of the Programming Languages Team, developers of DrScheme  DrScheme

The lower-case Greek letter lambda inscribed on a red-and-blue disk is the logo of the Programming Languages Team, the creators of the DrScheme programming environment. Moving the mouse pointer onto this logo and clicking the left mouse button starts DrScheme.

To exit from DrScheme, move the mouse pointer onto the word File in the top left corner and click the left mouse button. A menu appears. Move the mouse pointer onto the word Quit at the bottom of this menu and click the left mouse button. DrScheme puts up a confirmation box, asking ``Are you sure you want to quit?'' Move the mouse pointer onto the word Quit and click the left mouse button.

If you have unsaved work in one or more of DrScheme's definition windows, DrScheme pops up another warning box. To discard unsaved work, move the mouse pointer onto the phrase Close Anyway and click the left mouse button; to save your work before exiting, similarly click on the word Save. In the latter case, if you have not yet chosen a name for the file that is to contain your work, DrScheme puts up yet another window. Move the mouse pointer into the text field labelled Full pathname, click the left mouse button, and edit the text field until it contains the name of the file in which you want to save your work. Then move the mouse pointer onto the button labelled OK and click the left mouse button.

icon for mail agent  Mail agent

In some MathLAN accounts, the front panel contains this icon, showing an envelope sailing towards a silver-and-gold triangle. Moving the mouse pointer onto this icon and clicking the left mouse button launches the exmh mail agent, a program for reading, sorting, filing, composing, and sending e-mail messages and attachments. (If you don't have this icon, you can also start exmh from a terminal window by typing exmh & at the shell prompt.) For a quick introduction to exmh, see the handout ``Exmh: the basics.''

To exit from exmh, move the mouse pointer onto the button labelled Quit in the top right corner of the exmh window and click the left mouse button. If you have refiled messages or marked some for deletion, but have not yet ``committed'' these changes, exmh pops up a confirmation box. Move the mouse pointer onto the words Commit and exit and click the left mouse button.

icon for the GNOME desk guide  Desk Guide and Tasklist

This configuration is the GNOME Desk Guide and Tasklist, which provide you with an overview of all of the windows that you have opened and their contents. This can be quite helpful when you have opened a lot of windows and some of them are hidden behind others or ``minimized.''

To minimize a window is to shrink it temporarily without exiting from the program that is running in the window, in such a way that you can later un-minimize it and continue work. To minimize a window under GNOME, move the mouse pointer onto the underscore at the left of the group of three small symbols in the top right corner of the frame and click the left mouse button.

A minimized window is placed just to the right of the Desk Guide and looks like a rectangular subpanel, labelled with part of the window's title. Moving the mouse pointer onto the rectangle and clicking the left mouse button un-minimizes the window, restoring it to the desktop.

The area that is visible above the front panel when you log in is actually only the top left quarter of the notional surface that GNOME allows you to spread your work out on. The quartered rectangle at the left of the desk guide is a miniature representation of the entire desktop, with the windows that are currently open (and not minimized) by small rectangles. You can make a different part of the desktop visible by moving the mouse pointer into the desired quadrant of the quartered rectangle and clicking the left mouse button.

It is also possible to move from one quadrant to another -- even without meaning to! -- by moving the mouse pointer over the edge of the visible quadrant. Unfortunately, there is no scrolling effect -- the quadrant that used to be visible is replaced, all at once, by the quadrant to which the mouse pointer has now been dragged, in a way that can be disorienting. (The effect is delayed for a fraction of a second, so that it doesn't occur if the mouse pointer strays over the quadrant for just a moment.) If you windows seem to have vanished abruptly from your desktop, check the Desk Guide -- the explanation is probably that your mouse pointer has wandered into an unaccustomed quadrant, and you can click in the upper left quadrant of the Desk Guide to get back.

If you move the mouse pointer onto the upwards-pointing triangle at the left of the quartered rectangle and click on the left mouse button, a panel appears, containing a menu of all the windows that you have opened, including those that are minimized, hidden by other windows, or located in other quadrants. If you move the mouse pointer onto one of the menu items and click the left mouse button, the selected window is made visible by whatever means are necessary. (If minimized, it is un-minimized; if hidden behind other windows, it is brought to the top; if in a different quadrant, that quadrant is made visible.)

icon for the clock applet  Clock

Near the right end of the panel, you'll find the clock applet, which displays the current time, date, and day of the week.

padlock icon (`lock screen')  Lock screen

The padlock icon stands for the screen-lock utility. If you move the mouse pointer onto this icon and click the left mouse button, a screen saver program starts up and obscures the screen. When you then press any key or move the mouse, a pop-up box appears in which you are asked for your password; if you type it in accurately and press Enter, the screen saver vanishes, and your desktop reappears unchanged. Otherwise, the screen saver continues to run.

Locking the screen makes it possible to leave the workstation for a few minutes without either logging out or leaving your desktop accessible to passers-by -- you click on the padlock icon when you're about to leave, and type in your password when you return.

It is antisocial and rude to leave a workstation in a public lab with its screen locked if you're going to be away for more than a few minutes. Bear in mind, too, that anyone can force a logout even when the screen is locked by pressing the Ctrl, Alt, and Backspace keys simultaneously.

moon-and-stars icon (`log out')  Log out

At the right end of the panel is an icon of a monitor displaying a crescent moon and stars. If you move the mouse pointer onto this icon and click the left mouse button, GNOME starts to log you out. A confirmation box appears, asking ``Really log out?'' Move the mouse pointer onto the button labelled Yes at the lower left of the panel and click the left mouse button.

(laurel leaf logo)

Validated as XHTML
1.1 by the World Wide Web Consortium Style information validated as
CSS2 by the World Wide Web Consortium

created July 28, 2000
last revised July 19, 2002

John David Stone (stone@cs.grinnell.edu)