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