the current one, change_color() returns, as there is no point in reloading an identical pixmap. For additional
information about loading and using colors, see Volume One, Xlib Programming Manual, and Volume Two, Xlib
Reference Manual.
The help_cb() function is the callback routine for the Help menu item on the Help menu. It simply displays an
InformationDialog that contains a message describing how to use the program. See Chapter 5, Introduction to
Dialogs, and Chapter 21, Advanced Dialog Programming, for a complete description of these dialogs and
suggestions on implementing a functional help system.
5.3 The Command and Message Areas
We have already covered most of what you need to know about the MainWindow of an application in this chapter and
Chapter 3, Overview of the Motif Toolkit. The material in the rest of the chapter is considered somewhat advanced, so
you could skip the remaining sections and be relatively secure in moving on to the next chapter. The remaining
material provides details about the MainWindow widget that need to be discussed in order to make this chapter
complete.
The greatest difficulty with the command and message areas of the MainWindow is that these objects are better
defined in the Motif specification than in the Motif toolkit. The command area is intended to support a tty−style
command−line interface to an application. The command area is not supposed to act like xterm or any sort of terminal
emulator; it is just a single−line text area for entering individually ...