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

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