1/* callback.c -- functions to use readline as an X `callback' mechanism. */
2
3/* Copyright (C) 1987-2005 Free Software Foundation, Inc.
4
5   This file is part of the GNU Readline Library, a library for
6   reading lines of text with interactive input and history editing.
7
8   The GNU Readline Library is free software; you can redistribute it
9   and/or modify it under the terms of the GNU General Public License
10   as published by the Free Software Foundation; either version 2, or
11   (at your option) any later version.
12
13   The GNU Readline Library is distributed in the hope that it will be
14   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
15   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   The GNU General Public License is often shipped with GNU software, and
19   is generally kept in a file called COPYING or LICENSE.  If you do not
20   have a copy of the license, write to the Free Software Foundation,
21   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
22#define READLINE_LIBRARY
23
24#if defined (HAVE_CONFIG_H)
25#  include <config.h>
26#endif
27
28#include "rlconf.h"
29
30#if defined (READLINE_CALLBACKS)
31
32#include <sys/types.h>
33
34#ifdef HAVE_STDLIB_H
35#  include <stdlib.h>
36#else
37#  include "ansi_stdlib.h"
38#endif
39
40#include <stdio.h>
41
42/* System-specific feature definitions and include files. */
43#include "rldefs.h"
44#include "readline.h"
45#include "rlprivate.h"
46#include "xmalloc.h"
47
48/* Private data for callback registration functions.  See comments in
49   rl_callback_read_char for more details. */
50_rl_callback_func_t *_rl_callback_func = 0;
51_rl_callback_generic_arg *_rl_callback_data = 0;
52
53/* **************************************************************** */
54/*								    */
55/*			Callback Readline Functions		 */
56/*								    */
57/* **************************************************************** */
58
59/* Allow using readline in situations where a program may have multiple
60   things to handle at once, and dispatches them via select().  Call
61   rl_callback_handler_install() with the prompt and a function to call
62   whenever a complete line of input is ready.  The user must then
63   call rl_callback_read_char() every time some input is available, and
64   rl_callback_read_char() will call the user's function with the complete
65   text read in at each end of line.  The terminal is kept prepped and
66   signals handled all the time, except during calls to the user's function. */
67
68rl_vcpfunc_t *rl_linefunc;		/* user callback function */
69static int in_handler;		/* terminal_prepped and signals set? */
70
71/* Make sure the terminal is set up, initialize readline, and prompt. */
72static void
73_rl_callback_newline ()
74{
75  rl_initialize ();
76
77  if (in_handler == 0)
78    {
79      in_handler = 1;
80
81      if (rl_prep_term_function)
82	(*rl_prep_term_function) (_rl_meta_flag);
83
84#if defined (HANDLE_SIGNALS)
85      rl_set_signals ();
86#endif
87    }
88
89  readline_internal_setup ();
90}
91
92/* Install a readline handler, set up the terminal, and issue the prompt. */
93void
94rl_callback_handler_install (prompt, linefunc)
95     const char *prompt;
96     rl_vcpfunc_t *linefunc;
97{
98  rl_set_prompt (prompt);
99  RL_SETSTATE (RL_STATE_CALLBACK);
100  rl_linefunc = linefunc;
101  _rl_callback_newline ();
102}
103
104/* Read one character, and dispatch to the handler if it ends the line. */
105void
106rl_callback_read_char ()
107{
108  char *line;
109  int eof, jcode;
110  static procenv_t olevel;
111
112  if (rl_linefunc == NULL)
113    {
114      fprintf (stderr, "readline: readline_callback_read_char() called with no handler!\r\n");
115      abort ();
116    }
117
118  memcpy ((void *)olevel, (void *)readline_top_level, sizeof (procenv_t));
119  jcode = setjmp (readline_top_level);
120  if (jcode)
121    {
122      (*rl_redisplay_function) ();
123      _rl_want_redisplay = 0;
124      memcpy ((void *)readline_top_level, (void *)olevel, sizeof (procenv_t));
125      return;
126    }
127
128  do
129    {
130      if  (RL_ISSTATE (RL_STATE_ISEARCH))
131	{
132	  eof = _rl_isearch_callback (_rl_iscxt);
133	  if (eof == 0 && (RL_ISSTATE (RL_STATE_ISEARCH) == 0) && RL_ISSTATE (RL_STATE_INPUTPENDING))
134	    rl_callback_read_char ();
135
136	  return;
137	}
138      else if  (RL_ISSTATE (RL_STATE_NSEARCH))
139	{
140	  eof = _rl_nsearch_callback (_rl_nscxt);
141	  return;
142	}
143      else if (RL_ISSTATE (RL_STATE_NUMERICARG))
144	{
145	  eof = _rl_arg_callback (_rl_argcxt);
146	  if (eof == 0 && (RL_ISSTATE (RL_STATE_NUMERICARG) == 0) && RL_ISSTATE (RL_STATE_INPUTPENDING))
147	    rl_callback_read_char ();
148	  /* XXX - this should handle _rl_last_command_was_kill better */
149	  else if (RL_ISSTATE (RL_STATE_NUMERICARG) == 0)
150	    _rl_internal_char_cleanup ();
151
152	  return;
153	}
154      else if (RL_ISSTATE (RL_STATE_MULTIKEY))
155	{
156	  eof = _rl_dispatch_callback (_rl_kscxt);	/* For now */
157	  while ((eof == -1 || eof == -2) && RL_ISSTATE (RL_STATE_MULTIKEY) && _rl_kscxt && (_rl_kscxt->flags & KSEQ_DISPATCHED))
158	    eof = _rl_dispatch_callback (_rl_kscxt);
159	  if (RL_ISSTATE (RL_STATE_MULTIKEY) == 0)
160	    {
161	      _rl_internal_char_cleanup ();
162	      _rl_want_redisplay = 1;
163	    }
164	}
165      else if (_rl_callback_func)
166	{
167	  /* This allows functions that simply need to read an additional
168	     character (like quoted-insert) to register a function to be
169	     called when input is available.  _rl_callback_data is simply a
170	     pointer to a struct that has the argument count originally
171	     passed to the registering function and space for any additional
172	     parameters.  */
173	  eof = (*_rl_callback_func) (_rl_callback_data);
174	  /* If the function `deregisters' itself, make sure the data is
175	     cleaned up. */
176	  if (_rl_callback_func == 0)
177	    {
178	      if (_rl_callback_data)
179		{
180		  _rl_callback_data_dispose (_rl_callback_data);
181		  _rl_callback_data = 0;
182		}
183	      _rl_internal_char_cleanup ();
184	    }
185	}
186      else
187	eof = readline_internal_char ();
188
189      if (rl_done == 0 && _rl_want_redisplay)
190	{
191	  (*rl_redisplay_function) ();
192	  _rl_want_redisplay = 0;
193	}
194
195      if (rl_done)
196	{
197	  line = readline_internal_teardown (eof);
198
199	  if (rl_deprep_term_function)
200	    (*rl_deprep_term_function) ();
201#if defined (HANDLE_SIGNALS)
202	  rl_clear_signals ();
203#endif
204	  in_handler = 0;
205	  (*rl_linefunc) (line);
206
207	  /* If the user did not clear out the line, do it for him. */
208	  if (rl_line_buffer[0])
209	    _rl_init_line_state ();
210
211	  /* Redisplay the prompt if readline_handler_{install,remove}
212	     not called. */
213	  if (in_handler == 0 && rl_linefunc)
214	    _rl_callback_newline ();
215	}
216    }
217  while (rl_pending_input || _rl_pushed_input_available () || RL_ISSTATE (RL_STATE_MACROINPUT));
218}
219
220/* Remove the handler, and make sure the terminal is in its normal state. */
221void
222rl_callback_handler_remove ()
223{
224  rl_linefunc = NULL;
225  RL_UNSETSTATE (RL_STATE_CALLBACK);
226  if (in_handler)
227    {
228      in_handler = 0;
229      if (rl_deprep_term_function)
230	(*rl_deprep_term_function) ();
231#if defined (HANDLE_SIGNALS)
232      rl_clear_signals ();
233#endif
234    }
235}
236
237_rl_callback_generic_arg *
238_rl_callback_data_alloc (count)
239     int count;
240{
241  _rl_callback_generic_arg *arg;
242
243  arg = (_rl_callback_generic_arg *)xmalloc (sizeof (_rl_callback_generic_arg));
244  arg->count = count;
245
246  arg->i1 = arg->i2 = 0;
247
248  return arg;
249}
250
251void _rl_callback_data_dispose (arg)
252     _rl_callback_generic_arg *arg;
253{
254  if (arg)
255    free (arg);
256}
257
258#endif
259