INTRODUCTION TO XWINDOWS IN THE LAB

These notes were prepared for use on the xlab machines in the Math Department's Undergraduate Computer Lab.

DISAPPEARING WINDOWS: If you click on the title bar of your local window with the right mouse button it will disappear. Actually, it is still there in miniature form. Look at the top of the screen. Both on the left and right you will see little rectangles labelled local. Clicking on such a rectangle with the left (or right) mouse button causes the window to reappear. Practice making windows disappear and reappear.

TYPING: To type something, the cursor must be inside a window. Put it inside the local window and type whoami and press return. Put it outside the local window (on the screen background) and type the same thing. Did you notice a difference? In the first case you successfully gave a command to the computer, who (of course) obeyed. Practice typing commands.

MOVING WINDOWS: Click on the title bar with the left mouse button, drag to a new position, and release. Practice!

RESIZING WINDOWS Click on the square in the upper right corner of the window with the left mouse button, drag, and release. Note that you must enlarge the window before you can shrink it. In other words, to make a window more narrow, you must hold down the mouse and drag to make the window a bit wider than it was originally; then still holding down the mouse button, drag the mouse in the opposite direction until you have the desired width and then release the mouse button. Practice! You might also try what happens if you click the left mouse button on the other small square in the upper right corner of your window. Clicking on that box a second time should reverse this effect.

MULTIPLE WINDOWS: Your local window is used for Unix commands. Typically, you use the local window for two main purposes:

EXAMPLE: Move the cursor into the local window and type netscape & and press the Return key. Presently the ghost of a new window will appear in a kind of ``dotted outline form.'' Move the mouse to position this window and click with left mouse button when satisfied. (Try to place windows so that part of the title bar is visible for each window.) Netscape is a world wide web browser. Click on the House Icon (HOME) to go to the Math Department Home Page. Notice how the cursor changes when you move it over underlined, colored text. Use the scroll bar along the right edge of your netscape window to scroll down the Math Department Home page until you reach the "More Information" section. Click on the Computing Link there to get more information about what is available in the Undergraduate Computer Lab.

USING MENUS: Click on the background with each of the three mouse buttons to see some useful menus. The left menu contains the item Exit X-windows, used to end your session at the machine. (Don't do this yet!) The middle mouse button contains the menu item X Maple V4 which you can select to start a maple session. (Do this now!)

GOING FROM ONE WINDOW TO ANOTHER: You should have several windows on your screen now, overlapping each other unless you have done some careful resizing. In a typical session you may need to move back and forth between different windows. For example, you may be reading your assignment from a netscape window, doing problems using Maple, and chatting with your friends in e-mail about arranging that big study session. Practice moving the mouse among your three windows, the local window, the maple window and the netscape window. Observe the change in appearance of the title bar as you move the cursor from window to window. A dark title bar indicates the active window. Whatever typing you do will go into that window. The active window can be behind another window. You can bring it forward to the top layer by clicking with the middle mouse button on the title bar. Practice this now.