Code Organization

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I've tried to split exmh into meaningful modules, separating display modules (fdisp, for instance) from those that maintain display-independent data structures (like flist). Features like the Find and Pick dialogs are in their own file, so you can easily replace those. I have not documented the interfaces between modules at all, so you'll have to read some code. It's easy to find definitions: the .tcl file names reflect the names of the procedures that they define. In addition, many modules use a global array to hold their state variables; this array variable has the same name as the module.

If you are really interested in the internals of exmh (that is, if something about it really bugs you!), you can look into the implementation to see what is wrong and how you might do things better. The following sections contain a list of the files that make up exmh and short explanations of the Tcl procedures in each.

Main Scripts

The sources are divided into two parts. The main scripts include exmh and some associated utility scripts. The files with the .MASTER suffix are patched with site-dependent information before they are installed. The remaining sources are kept in a script library. The library files are loaded on demand by the Tcl auto_load facility.
exmh.MASTER
This is the main script. It gets patched with site-dependent information, and the results are written to exmh, which gets installed. exmh.MASTER doesn't define much because it loads almost everything from the script library.
exmh-bg.MASTER
This is the main script for the background process. It redefines a few procedures and loads the rest of its implementation from the library. The initial rendezvous between the background process is implemented in this script and in some supporting routines in background.tcl.
install.tcl
These are supporting routines for the installation process. This should be generic enough for use with your own Tcl application. Feel free to borrow it.
exmh.install
This is the installation script for exmh.
exmh-async
This is the wrapper for external editors.

Library

The remainder of the files are kept in the script library.
aliases.tcl
A browser for the MH alias file.
background.tcl
The background processing module. This can run in a separate process or as part of the main process. The BgRPC routine is used to invoke a background operation, and it works in either case.
bindings.tcl
The default bindings and the implementation of the binding user interface.
busy.tcl
Three different ways to indicate that exmh is busy doing something.
buttons.tcl
The resource-based button and menu implementation.
cutbuffer.tcl
A stub for the C cutbuffer extension. If you have added the extension to your wish, you'll have slightly better cut-and-paste interoperability with older X programs.
editor.tcl
The interface to editors for message composition.
error.tcl
The error handler.
extrasInit.tcl
This has Init routines for optional modules. The idea is to avoid loading the modules until they are actually used.
exwin.tcl
The main window display is set up here. The code that remembers where top-level windows go is here.
faces.tcl
The interface to the faces database.
fcache.tcl
The folder cache display.
fdisp.tcl
The main folder display.
fdispColor.tcl
The color definitions for the folder display.
fdispPopup.tcl
The nested folder popup implementation.
fileselect.tcl
The file selection dialog.
find.tcl
The find dialog.
flag.tcl
Manages the appearance of the icon.
flist.tcl
Manages the set of unseen folders.
folder.tcl
Folder operations like Folder_Change and Folder_Commit.
folderNew.tcl
The folder-create and -delete dialogs.
ftoc.tcl
The folder table of contents (scan listing).
ftocColor.tcl
Color definitions for the highlights in the table of contents.
ftocFind.tcl
Routines that search over the table of contents.
help.tcl
Some very simple help text and a color key.
import.tcl
Routines to import folders from UCB mail.
inc.tcl
Several ways to incorporate mail.
labels.tcl
There are three labels in the display -- can you see them?
mailcap.tcl
Routines to parse the MIME mailcap files.
main.tcl
The main Exmh procedure, plus Exmh_Status and Exmh_Debug.
mh.tcl
A basic layer on top of the MH commands.
mime.tcl
The MIME display code.
msg.tcl
Message operations -- although these tend to be distributed partly among ftoc.tcl and mh.tcl as well.
msgShow.tcl
This used to be the main message display code, but it has become dwarfed by the MIME display.
pgp.tcl
An interface to the Pretty Good Privacy system.
pick.tcl
An interface to the MH pick program.
preferences.tcl
The Preferences user interface.
print.tcl
Routines to print messages.
rich2tk.tcl
This parses text/enriched MIME contents.
scan.tcl
This manages the scan caches.
sedit.tcl
The main routines for the built-in editor.
seditBind.tcl
The keybindings for the built-in editor.
seditCompose.tcl
The table of compose key sequences that insert 8-bit characters is defined here.
seditEnriched.tcl
Implements the composition of text/enriched.
seditExtras.tcl
More editor stuff, like Whom, Spell, Sign, Find, and the dialogs associated with Insert Part.
seditMime.tcl
Implements the MIME multipart structuring.
seditQP.tcl
Support for quoted-printable encoding of outgoing messages.
select.tcl
Implements the keyboard selection of folders and messages.
sound.tcl
Sound effects.
text.tcl
Some text tagging routines.
textButton.tcl
An implementation of a pseudo-button in a text widget. This used to be part of the MIME display code but is no longer used.
textSelect.tcl
The main guts of text bindings.
user.tcl
Stubs for User_Init and User_Layout.
widgetMenu.tcl
Support for the popup menus used in MIME messages.
widgetText.tcl
Handles constrained text scrolling and dragging a selection off the window.
widgets.tcl
A basic layer on top of the Tk widgets. These routines integrate the pack geometry manager. Even more important, they guard against errors that occur because of missing fonts. You should try to use these instead of the straight Tk widget commands.
xns.tcl
An interface to xnsgetmail for those folks with mail on an XNS mail server.

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Last change $Date: 1996/06/06 15:09:15 $

This file is from the third edition of the book MH & xmh: Email for Users & Programmers, ISBN 1-56592-093-7, by Jerry Peek. Copyright 1991, 1992, 1995 by O'Reilly & Associates, Inc. This file is freely-available; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation. For more information, see the file copying.htm.

Suggestions are welcome: <Brent.Welch@eng.sun.com>

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