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Emacs Lesson

I believe Emacs is the base environment of GNU's operating system , which has not however been realized yet due to their too much strict sense of free software.

XEmacs used to be a good competitor for its powerful image display and modern graphical user interface components, although Emacs 21 and the later version pushed them behind already.

$ emacs fileA &

===============================================================================

$ sudo dselect

$ fink list

;
; Key mappings
;

(define-key global-map "\C-x ^" 'enlarge-window)
(define-key global-map "\C-x -" 'shrink-window)

Emacs as a development tool

etags

Register all your Java source files with etags command :

$ etags src/sh/run/Runftp/*.java

After that, you can apply function search within all those files.

• M-. : Find the tag entered. (find-tag)

• M-* : Pop back to the previous tag. (pop-tag-mark)

• M-x tags-search : Apply full-text search in the files registered in the TAGS file. M-, finds the next match.

JDEE

Java Devolopment Environment for Emacs is a powerful environment where you can rely on templates, automatic abbreviation expansion, in-place compilation and debugging, an N80BASIC-like command interpreter called beanshell, source code browser, etc. Be sure to have Java Development Kit installed proper way :

• Java Concepts and Practices

$ sudo aptitude install jde

This takes time as elisps (for Emacs and XEmacs) like cedet and elib that jde depends on will also be installed, byte-compiled and configured.

To manually install JDEE and the packages required by it, set up your Mac so you can use a decent Emacsen like GNU Emacs or Aquamacs.

Download the recent versions of cedet which also comes with Eric Ludlam's speedbar, eieio, and semantic bovinator packages and install them on your system.

Always use the lately version, which is in my experience 1.0pre4 working fine at the time of writing, as I encountered problems with older versions with other packages.

Typically you just need to unarchive the tarball into Emacs site-lisp directory such as :

$ tar zxvf cedet-1.0pre4.tar.gz
$ sudo mv cedet-1.0pre4/* /usr/share/emacs/site-lisp

Sure you can byte-compile the elisps for faster operation, applying the Makefile with make command that can be download from Apple's Xcode page.

$ cd /usr/share/emacs/site-lisp
$ sudo make
$ sudo rm Makefile INSTALL

If you use different kinds of Emacs at the same time, you should specify the one you want to compile for :

$ sudo make EMACS=/Users/ryu/Desktop/Emacs.app/Contents/MacOS/Emacs

Also install the Emacs Lisp library package called elib using the Makefile that come with the package. Here is a typical modification of Makefile :

prefix = /usr/share
# datadir = $(prefix)
locallisppath = $(prefix)/emacs/site-lisp
ELIBDIR = $(locallisppath)/elib
infodir = $(prefix)/info

Usually ou just need to do make install in the package's directory and everything is copied into the specified lisp directory, but if you experience the error message :

install-info(elib.info): unable to determine description for `dir' entry - giving up

the compilation is failed.

If compilation failure happens in a special environment such as MacOSX, copy everything to the target elib directory and make every elc yourself :

$ sudo cp * /usr/share/emacs/site-lisp/elib/
$ cd /usr/share/emacs/site-lisp/elib
$ sudo make

Now, get the JDEE body and unarchive the tarball again under site-lisp directory.

$ sudo tar zxvf jde-2.3.5.1.tar.gz -C /usr/share/emacs/site-lisp
$ cd /usr/share/emacs/site-lisp
$ sudo chmod -R go+r jde  (in case strange permissions created especially
in Mac)
$ sudo ln -s jde-2.3.5.1 jde

In MacOSX, you might need to change the Classes/classes.jar in jde/lisp/jde.el/jde-get-tools.jar to /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/classes.jar like the following.

In MacOSX, you should edit /usr/share/emacs/site-lisp/jde/jde.el to change the tools variable definition in the defun block of jde-get-tools-jar.

(let ((tools
  (expand-file-name
    (if (eq system-type 'darwin)
      "/System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/classes.jar"
    )
    (jde-get-jdk-dir))))
    ....

Then you will want to byte-compile the elisps in JDEE using make. Some packages, in particular, cc-mode, run correctly only when compiled. Although many packages run fine without compiling, it is usually safest to compile.

Here's how to do it :

$ cd /usr/share/emacs/site-lisp/jde/lisp
$ sudo make CEDET=../..

After installation you must verify the permissions of particularly library files under /usr/share/emacs/site-lisp/jde/java/lib :

$ ls -l /usr/share/emacs/site-lisp/jde/java/lib
$ sudo chmod 644 /usr/share/emacs/site-lisp/jde/java/lib/*

In addition to the required packages, I highly recommend that you also install the Emacs Code Browser (ECB) to make it look like a true integrated development environment.

ECB greatly facilitates the JDEE's use in developing applications that comprise many classes.

$ sudo aptitude install ecb

Currently ECB 2.32 works best with working CEDET pre4. (2.40 did not go well.) In MacOSX, you will need to install ECB from the source (typically just copying, or byte-compiling) and you might sometimes need to modify the permissions under the ecb file structure correctly :

$ cd /usr/share/emacs/site-lisp/ecb/
$ sudo chmod -R 644 *
$ sudo find . -type d -exec chmod a+x {} \;

Anyway, you must tell Emacs where the JDEE and its required packages live and turn on cedet as well by editing the startup file '~/.emacs'.

(add-to-list 'load-path "/usr/share/emacs/site-lisp/jde/lisp")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/cedet-common")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/speedbar")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/eieio")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/ede")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/cogre")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/semantic")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/cedet-contrib")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/elib")
(add-to-list 'load-path "/usr/share/emacs/site-lisp/ecb")

(setq semantic-load-turn-useful-things-on t)
(load "cedet")

Tell JDEE where JDK resides and its version in ~/.emacs :

(setq jde-compiler '("javac server" ""))  ;; Use javac server
(setq jde-jdk '("Sun Java6 1.6.0.12"))
(setq jde-jdk-registry '(("Sun Java6 1.6.0.12" . "/usr/lib/jvm/java-6-sun/")))
(setq jde-debugger '("JDEbug"))  ;; Use JDEbug

In MacOSX, also set class path for Java :

(setq jde-global-classpath
  (list
    "."
    "/usr/share/java/*"
    "/System/Library/Frameworks/JavaVM.framework/Classes/classes.jar"
    "/usr/share/emacs/site-lisp/jde/java/lib/bsh.jar"
    "/usr/share/emacs/site-lisp/jde/java/lib/jde.jar"
  ))

You could invoke the environment with M-x jde-mode or require it at startup of Emacs, however I'd use autoload for loading on demand.

;; open jde-mode automatically for java source
(autoload 'jde-mode "jde" "Java Development Environment for Emacs." t)
(setq auto-mode-alist (cons '("\.java$" . jde-mode) auto-mode-alist))

;; ECB autoloads
(require 'ecb-autoloads)

Other useful settings are listed below :

;; Comment field setting
(setq user-full-name "Lewske Wada")
(setq user-mail-address "ryu@run.sh")

(setq compilation-window-height 10)

;; java document setting
(custom-set-variables
  '(jde-help-docsets (quote (
    ("JDK API" "/usr/share/doc/openjdk-6-jre/api/index.html" nil))))
  '(jde-jdk-doc-url "http://java.sun.com/javase/6/docs/"))
(custom-set-faces)

I think indentation is very important to make your coding smooth and without stumbling.

;; indentation
(add-hook 'jde-mode-hook
  '(lambda ()
    (c-set-offset 'inline-open 0)
    (c-set-offset 'statement-block-intro '+)
    (c-set-offset 'knr-argdecl-intro 5)
    (c-set-offset 'substatement-open '+)
    (c-set-offset 'label 0)
    (c-set-offset 'statement-case-open '+)
    (c-set-offset 'statement-cont '+)
    (c-set-offset 'access-label 0)
    (c-set-offset 'inher-cont 'c-lineup-java-inher)
    (c-set-offset 'func-decl-cont 'c-lineup-java-throws) 
    (c-set-offset 'arglist-intro '+)
    (c-set-offset 'arglist-close 0)
    (c-set-offset 'topmost-intro-cont 0)
    (setq c-basic-offset 4)
    (setq indent-tabs-mode nil)
  )
)
; Indent a new line like previous non-blank line.
(global-set-key "\C-m" 'newline-and-indent)
(setq indent-line-function 'indent-relative-maybe)

Set these variables as well in your .profile. bsh.jar implements beanshell which is the key component of JDEE.

Alternatively you can just copy the jar files into /usr/share/java.

$ sudo cp bsh.jar /usr/share/java  (alternatively)
$ sudo cp jde.jar /usr/share/java  (alternatively)

Set the class path accordingly anyways.

CLASSPATH=$CLASSPATH:/usr/share/emacs/site-lisp/jde/java/lib/bsh.jar
CLASSPATH=$CLASSPATH:/usr/share/emacs/site-lisp/jde/java/lib/jde.jar
export CLASSPATH
JAVA_HOME=/usr/lib/jvm/java-6-sun
export JAVA_HOME

Make sure M-x bsh-run works as it is the key for JDEE to run properly. If it says like Cannot find the BeanShell jar file at ...., check the permissions and the paths of the above jar files.

This is the path setting for use with Android SDK.

PATH=$PATH:$HOME/opt/android-sdk-linux_86/tools

You can travel through source codes with the top menu groups Buffers and Classes as well as utilizing M-x speedbar.

The easiest way to compile the files is to use the JDEE command jde-compile-jde.

The JDEE's lisp directory contains a makefile that compiles the JDE Lisp files. The makefile assumes that you are using GNU Emacs and that the packages required by the JDEE are installed in the same directory as the JDEE package itself, i.e., the makefile assumes a directory structure similar to the following:

  site
    jde
    speedbar
    semantic
    elib
    eieio

Autocompletion works in basically two ways.

• JDE Complete Function completes field or method names. Assigned to C-c C-v C-..
• Dynamic Keyword Completion attempts to find a candidate of completion within the buffer or in other buffers. Assigned to M-/.

The JDE → Code Generation → Import → All ( jde-import-all, C-c C-v z ) imports all the classes that need to be imported into the current buffer.

ECB presents analyzed views of classes, fields and methods that are focused synchronously with cursor movement. To activate the IDE, run it with M-x ecb-activate.

• C-c . l t : Toggle the layout
• C-c . l w : Toggle visibility of the ECB layout

Read the ECB manual, too : M-x ecb-show-help

To enable building projects with ant, you should also add these to your .emacs.

;; Ant
(setenv "ANT_HOME" "/usr/share/ant")
(setq jde-ant-enable-find t)
(setq jde-ant-program "/usr/bin/ant")
(setq jde-ant-read-target t)
(setq jde-build-function (quote (jde-ant-build)))

Type in emacs :

• C-c C-v C-b, and then specify build target such as debug

Android

With Android mode, you can also logcat and run GUI helpers like DDMS and the emulator from Emacs.

$ git clone git://github.com/remvee/android-mode.git
$ sudo cp -R android-mode /usr/share/emacs/site-lisp

;; android-mode
(add-to-list 'load-path "/usr/share/emacs/site-lisp/android-mode")
(require 'android-mode)
(setq android-mode-sdk-dir "/opt/android-sdk")

• M-x android-logcat
• M-x android-start-emulator
• M-x android-start-ddms

Garbages and Ideas

;; Auto indentation
(add-hook 'c-mode-common-hook
  '(lambda ()
    (c-set-style "gnu")
    (setq c-basic-offset 4)  ;; Change indentation offset to 4
    ;; Don't indent comment-only line
    (setq c-comment-only-line-offset . (0 . 0))
))

For the details, read these pages on:

• Emacs JDE User's Guide
• JDEE : Java Development Environment for Emacs
• JDEbug User's Guide
• Indentation for C/C++/Java modes
• A comfortable Java development environment with JDE
• Moinmoin JDEE - solutions for MacOSX and Meadow , Moinmoin HTML Helper Mode

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