Code Organization

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

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

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.

[Table of Contents] [Index] [Previous: Programming exmh] [Next: Where Can You Go from Here?]

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.