view src/dragdrop.c @ 5566:4654c01af32b

Improve the implementation, documentation of #'labels, #'flet. lisp/ChangeLog addition: 2011-09-07 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el: * bytecomp.el (for-effect): Move this earlier in the file, it's referenced in byte-compile-initial-macro-environment. * bytecomp.el (byte-compile-initial-macro-environment): In the byte-compile-macro-environment definition for #'labels, put off the compiling the lambda bodies until the point where the rest of the form is being compiled, allowing the lambda bodies to access appropriate values for byte-compile-bound-variables, and reducing excessive warning about free variables. Add a byte-compile-macro-environment definition for #'flet. This modifies byte-compile-function-environment appropriately, and warns about bindings of functions that have macro definitions in the current environment, about functions that have byte codes, and about functions that have byte-compile methods (which may not do what the user wants at runtime). * bytecomp.el (byte-compile-funcall): If FUNCTION is constant, call #'byte-compile-callargs-warn if that's appropriate, giving warnings about problems with calling functions bound with #'labels. * cl-macs.el: * cl-macs.el (flet): Mention the main difference from Common Lisp, that the bindings are dynamic, not lexical. Counsel the use of #'labels, not #'flet, for this and other reasons. Explain the limited single use case for #'flet. Cross-reference to bytecomp.el in a comment. * cl-macs.el (labels): Go into detail on which functions may be called from where. Explain how to access the function definition of a label within FORM. Add a comment cross-referencing to bytecomp.el. man/ChangeLog addition: 2011-09-07 Aidan Kehoe <kehoea@parhasard.net> * cl.texi (Function Bindings): Move #'labels first, describe it in more detail, explaining that it is to be preferred over #'flet, and explaining why. Explain that dynamic bindings with #'flet will also not work when functions are accessed through their bytecodes.
author Aidan Kehoe <kehoea@parhasard.net>
date Wed, 07 Sep 2011 16:26:45 +0100
parents 308d34e9f07d
children
line wrap: on
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/* Drag'n'Drop definitions
   created 03-may-98 by Oliver Graf <ograf@fga.de>
   Copyright (C) 1998 Oliver Graf <ograf@fga.de>
   Copyright (C) 2004 Ben Wing.

This file is part of XEmacs.

XEmacs is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: Not in FSF. */

/* This file should be Mule-ized. */

/* A short introduction to the new Drag'n'Drop Model:

   A drop generates a extended misc-user-event, as defined in events.[ch].
   This event contains the same as a eval and a button event.
   The function of a drop is set to 'dragdrop-drop-dispatch' which will be
   defined in ../lisp/dragdrop.el.
   The object of the misc-user-event has the following format:
              ( TYPE . DATA )
   TYPE  is one of `dragdrop-MIME' and `dragdrop-URL'
   DATA  - if TYPE is `dragdrop-URL', DATA is a list of valid URL strings. It
	   is always a list, also if only one URL string is within it.
	 - if TYPE is `dragdrop-MIME', DATA is a list of MIME elements.
	   Each can be a string or a list.
	   if it is a string it is the pure MIME data complete with header
	   and body.
	   if it is a list it should look like
	      ( MIME-TYPE MIME-ENCODING MIME-DATA )
	   MIME-TYPE list of type and key.value conses. Same as in tm-view
	   MIME-ENC  the same (a string in this case)
	   MIME-DATA is a string
*/

#include <config.h>
#include "lisp.h"
#include "dragdrop.h"

/* The supported protocol list */
Lisp_Object Vdragdrop_protocols;

/* Drag'n'Drop data types known by XEmacs */
Lisp_Object Qdragdrop_MIME;
Lisp_Object Qdragdrop_URL;

/* External defined functions to handle Drag'n'Drop */
Lisp_Object Qdragdrop_drop_dispatch;

/* from wget -- thanxx Hrvoje */
/* A list of unsafe characters for encoding, as per RFC1738.  '@' and
   ':' (not listed in RFC) were added because of user/password
   encoding, and \033 for safe printing.  */

#define URL_UNSAFE " <>\"#%{}|\\^~[]`@:\033"

/* HEX digit -> ASCII char */
#define HEXD2ASC(x) (((x) < 10) ? ((x) + '0') : ((x) - 10 + 'A'))

/* Encodes the unsafe characters (listed in URL_UNSAFE) in a given
   string, returning a malloc-ed %XX encoded string.
   if method is != NULL it is prepended to the string. */
Ibyte *
dnd_url_hexify_string (const Ibyte *s, const Ibyte *m)
{
  const Ibyte *b;
  Ibyte *p, *res;
  Bytecount i;

  b = s;
  for (i = 0; *s; s++, i++)
    if (strchr (URL_UNSAFE, *s))
      i += 2; /* Two more characters (hex digits) */
  if (m)
    {
      res = xnew_ibytes (i + ITEXT_ZTERM_SIZE + qxestrlen (m));
      qxestrcpy (res, m);
      p = res + qxestrlen (m);
    }
  else
    {
      res = xnew_ibytes (i + ITEXT_ZTERM_SIZE);
      p = res;
    }
  for (s = b; *s; s++)
    if (strchr (URL_UNSAFE, *s))
      {
	const Ibyte c = *s;
	*p++ = '%';
	*p++ = HEXD2ASC (c >> 4);
	*p++ = HEXD2ASC (c & 0xf);
      }
    else
      *p++ = *s;
  *p = '\0';
  return res;
}

void
syms_of_dragdrop (void)
{
  DEFSYMBOL (Qdragdrop_MIME);
  DEFSYMBOL (Qdragdrop_URL);
  DEFSYMBOL (Qdragdrop_drop_dispatch);
}

void
vars_of_dragdrop (void)
{
  Fprovide (intern ("dragdrop-api"));

  DEFVAR_CONST_LISP ("dragdrop-protocols", &Vdragdrop_protocols /*
A list of supported Drag'n'drop protocols.
Each element is the feature symbol of the protocol.
*/ );
  
  Vdragdrop_protocols = Qnil;

#ifdef HAVE_MS_WINDOWS
  Vdragdrop_protocols = Fcons (Qmswindows, Vdragdrop_protocols);
#endif
#ifdef HAVE_CDE
  Vdragdrop_protocols = Fcons (intern ("cde"), Vdragdrop_protocols);
#endif
#ifdef HAVE_GTK
  Vdragdrop_protocols = Fcons (Qgtk, Vdragdrop_protocols);
#endif
}