Chapter 11 - Windowing Systems

Quiz

1. Which command is used to change access permissions on an X server?
The command used to change access permission on an X server is xhost.
2. Which Motif widget would you use in a window wherein you want to give users a choice among several options, but they can choose only one?
Radio buttons are used to specify one and only one of a list of mutually exclusive choices.
3. What is the X application argument used to cause the applicationís window to show up on a different computerís screen?
The -display argument allows you to specify a remote display where the application should create its windows.
4. What attribute about an X server allows you to change the appearance of an X application without having to modify the program?
X servers maintain an application resource database where individual application resources that the application recognizes can be loaded or modified to affect the behavior or look of the application when it runs.

Exercises

11.1 Explain why a window manager is an X client. [level: easy]
Just like any other X client, the window manager runs as an application and communicates with the X server to display widgets. The window manager does perform some unique functions that give it the impression of having more power than a regular X application, but any X application could do the things the window manager does.
11.2 Suppose that your window manager has exited and you cannot get focus in a window to type a command to bring up a new window manager. (Suppose also that you have no root menu button that starts a new window manager.) Explain how you might still be able to use copy-and-paste with your existing windows to execute a command. [level: hard]
If your window manager is mwm, and if you have other windows open that have an ìmî and a ìwî in selectable text areas, then you can copy those letters and paste them into a shell window. Then copy and paste a carriage return (the space at the end of a line to the next line) and mwm will execute in that window.

Project

Use the xrdb command to print the resource database of a running X server.  Study the output to learn what types of applications use which types of resources.  [level: medium]
The activity is the lesson.