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  if  (RL_ISSTATE (RL_STATE_ISEARCH))
129    {
130      eof = _rl_isearch_callback (_rl_iscxt);
131      if (eof == 0 && (RL_ISSTATE (RL_STATE_ISEARCH) == 0) && RL_ISSTATE (RL_STATE_INPUTPENDING))
132	rl_callback_read_char ();
133
134      return;
135    }
136  else if  (RL_ISSTATE (RL_STATE_NSEARCH))
137    {
138      eof = _rl_nsearch_callback (_rl_nscxt);
139      return;
140    }
141  else if (RL_ISSTATE (RL_STATE_NUMERICARG))
142    {
143      eof = _rl_arg_callback (_rl_argcxt);
144      if (eof == 0 && (RL_ISSTATE (RL_STATE_NUMERICARG) == 0) && RL_ISSTATE (RL_STATE_INPUTPENDING))
145	rl_callback_read_char ();
146      /* XXX - this should handle _rl_last_command_was_kill better */
147      else if (RL_ISSTATE (RL_STATE_NUMERICARG) == 0)
148	_rl_internal_char_cleanup ();
149
150      return;
151    }
152  else if (RL_ISSTATE (RL_STATE_MULTIKEY))
153    {
154      eof = _rl_dispatch_callback (_rl_kscxt);	/* For now */
155      while ((eof == -1 || eof == -2) && RL_ISSTATE (RL_STATE_MULTIKEY) && _rl_kscxt && (_rl_kscxt->flags & KSEQ_DISPATCHED))
156	eof = _rl_dispatch_callback (_rl_kscxt);
157      if (RL_ISSTATE (RL_STATE_MULTIKEY) == 0)
158	{
159	  _rl_internal_char_cleanup ();
160	  _rl_want_redisplay = 1;
161	}
162    }
163  else if (_rl_callback_func)
164    {
165      /* This allows functions that simply need to read an additional character
166	 (like quoted-insert) to register a function to be called when input is
167	 available.  _rl_callback_data is simply a pointer to a struct that has
168	 the argument count originally passed to the registering function and
169	 space for any additional parameters.  */
170      eof = (*_rl_callback_func) (_rl_callback_data);
171      /* If the function `deregisters' itself, make sure the data is cleaned
172	 up. */
173      if (_rl_callback_func == 0)
174	{
175	  if (_rl_callback_data)
176	    {
177	      _rl_callback_data_dispose (_rl_callback_data);
178	      _rl_callback_data = 0;
179	    }
180	  _rl_internal_char_cleanup ();
181	}
182    }
183  else
184    eof = readline_internal_char ();
185
186  if (rl_done == 0 && _rl_want_redisplay)
187    {
188      (*rl_redisplay_function) ();
189      _rl_want_redisplay = 0;
190    }
191
192  /* We loop in case some function has pushed input back with rl_execute_next. */
193  for (;;)
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      if (rl_pending_input || _rl_pushed_input_available () || RL_ISSTATE (RL_STATE_MACROINPUT))
217	eof = readline_internal_char ();
218      else
219	break;
220    }
221}
222
223/* Remove the handler, and make sure the terminal is in its normal state. */
224void
225rl_callback_handler_remove ()
226{
227  rl_linefunc = NULL;
228  RL_UNSETSTATE (RL_STATE_CALLBACK);
229  if (in_handler)
230    {
231      in_handler = 0;
232      if (rl_deprep_term_function)
233	(*rl_deprep_term_function) ();
234#if defined (HANDLE_SIGNALS)
235      rl_clear_signals ();
236#endif
237    }
238}
239
240_rl_callback_generic_arg *
241_rl_callback_data_alloc (count)
242     int count;
243{
244  _rl_callback_generic_arg *arg;
245
246  arg = (_rl_callback_generic_arg *)xmalloc (sizeof (_rl_callback_generic_arg));
247  arg->count = count;
248
249  arg->i1 = arg->i2 = 0;
250
251  return arg;
252}
253
254void _rl_callback_data_dispose (arg)
255     _rl_callback_generic_arg *arg;
256{
257  if (arg)
258    free (arg);
259}
260
261#endif
262