code.delx.au - gnu-emacs/blob - nextstep/README

   1   NS -- the Cocoa interface for OS X and compatible systems
   2   ---------------------------------------------------------
   3
   4 This directory contains files needed to build Emacs on system based on
   5 NextStep (NS), including OS X (Mac) and GNUstep, using the Cocoa API.
   6
   7
   8   HISTORY
   9
  10
  11 The Nextstep (NS) interface of GNU Emacs was originally written in
  12 1994 for NeXTSTEP systems running Emacs 19 and subsequently ported to
  13 OpenStep and then Rhapsody, which became Mac OS X.  In 2004 it was
  14 adapted to GNUstep, a free OpenStep implementation, and in 2008 it was
  15 merged to the GNU Emacs trunk and released with Emacs 23.  Around the
  16 same time a separate Mac-only port using the Carbon APIs and
  17 descending from a 2001 MacOS 8/9 port of Emacs 21 was removed. (It
  18 remains available externally under the name "mac".)
  19
  20
  21   OVERVIEW OF COCOA AND OBJECTIVE-C
  22
  23 Cocoa is an API for the Objective-C language, an objective oriented
  24 superset of C.  Anybody with experience with iOS or modern OS X
  25 application development should feel at home.
  26
  27 A method call in Objective-C differs from most other languages in the
  28 fact that it doesn't have a normal name.  Instead, the method name is
  29 made up of the name of each parameter.  An exception to this rule are
  30 methods without parameters.
  31
  32 The following calls a method in the object 'anObject'.
  33
  34     [anObject alpha:1 beta:2 gamma:3];
  35
  36 Classes are declared like the following:
  37
  38     @interface AClassName
  39     {
  40       // A class method.
  41       + (TYPE)name1:(TYPE)param1
  42
  43       // An object method.
  44       - (TYPE)name1:(TYPE)param1 name2:(TYPE)param2;
  45     }
  46     @end
  47
  48
  49   GUIDELINES
  50
  51 * Adhere the to the FSF philosophy that a feature in GNU software
  52   should not only be available on non-free systems.
  53
  54 * People with varying Cocoa and Objective-C skills will read and
  55   modify the NS code over a long period of time.  Keep the code simple
  56   and avoid language constructs that makes the code hard to maintain.
  57
  58 * Don't use macros and types intended for the XCode Interface Builder,
  59   like 'IBAction'.
  60
  61 * The NS interface should work on all version of OS X from 10.6.8
  62   (Snow Leopard) to the latest official release.
  63
  64 * Under OS X, it is possible to build Emacs using NS, X11, or console
  65   only.  A new OS X feature should work in all appropriate builds.
  66
  67
  68   TRACING SUPPORT
  69
  70 The NS interface features a printf-based trace package that prints the
  71 call tree of selected functions in the Cocoa interface, plus various
  72 extra information.  It can be enabled by uncommenting the line
  73 defining 'NSTRACE_ENABLED' in "nsterm.h".  To enable more output,
  74 uncomment the lines defining symbols starting with 'NSTRACE_GROUP'.
  75
  76
  77   GNUSTEP AND OTHER COMPATIBLE SYSTEMS
  78
  79 The NS interface works on system compatible with OS X, for example
  80 GNUstep.  Even though they are less frequently used, this is important
  81 for a number of reasons:
  82
  83 * It supports the GNUstep project and provides an Emacs with the same
  84   look-and-feel as the rest of the system.
  85
  86 * This allows other Emacs developers to test their changes on the NS
  87   interface without having access to an OS X machine.
  88
  89 * If a feature in the NS interface work on free systems like GNUstep,
  90   this meets the FSF requirement that features in GNU software should
  91   not only be available on non-free systems.
  92
  93
  94   SEE ALSO
  95
  96 The src/ns... files contains the C and Objective-C parts.
  97
  98 The lisp/term/ns-win.el file contains the lisp part of the NS
  99 interface.
 100
 101 The INSTALL file in this directory for compilation instructions.
 102
 103 The Nextstep section in the etc/TODO file for a list of ideas for
 104 future development.
 105
 106 \f
 107 ----------------------------------------------------------------------
 108 Copyright 2008-2016 Free Software Foundation, Inc.
 109
 110 This file is part of GNU Emacs.
 111
 112 GNU Emacs is free software: you can redistribute it and/or modify
 113 it under the terms of the GNU General Public License as published by
 114 the Free Software Foundation, either version 3 of the License, or
 115 (at your option) any later version.
 116
 117 GNU Emacs is distributed in the hope that it will be useful,
 118 but WITHOUT ANY WARRANTY; without even the implied warranty of
 119 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 120 GNU General Public License for more details.
 121
 122 You should have received a copy of the GNU General Public License
 123 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.