src/keyboard.h

   1 /* Declarations useful when processing input.
   2    Copyright (C) 1985, 1986, 1987, 1993 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Length of echobuf field in each KBOARD.  */
  22
  23 #define ECHOBUFSIZE 300
  24
  25 /* Each KBOARD represents one logical input stream from which Emacs gets input.
  26    If we are using an ordinary terminal, it has one KBOARD object.
  27    Usually each X display screen has its own KBOARD,
  28    but when two of them are on the same X server,
  29    we assume they share a keyboard and give them one KBOARD in common.
  30
  31    Some Lisp variables are per-kboard; they are stored in the KBOARD structure
  32    and accessed indirectly via a Lisp_Misc_Kboard_Objfwd object.
  33
  34    So that definition of keyboard macros, and reading of prefix arguments,
  35    can happen in parallel on various KBOARDs at once,
  36    the state information for those activities is stored in the KBOARD.
  37
  38    Emacs has two states for reading input:
  39
  40    ** Any kboard.  Emacs can accept input from any KBOARD,
  41    and as soon as any of them provides a complete command, Emacs can run it.
  42
  43    ** Single kboard.  Then Emacs is running a command for one KBOARD
  44    and can only read input from that KBOARD.
  45
  46    All input, from all KBOARDs, goes together in a single event queue
  47    at interrupt level.  read_char sees the events sequentially,
  48    but deals with them in accord with the current input state.
  49
  50    In the any-kboard state, read_key_sequence processes input from any KBOARD
  51    immediately.  When a new event comes in from a particular KBOARD,
  52    read_key_sequence switches to that KBOARD.  As a result,
  53    as soon as a complete key arrives from some KBOARD or other,
  54    Emacs starts executing that key's binding.  It switches to the
  55    single-kboard state for the execution of that command,
  56    so that that command can get input only from its own KBOARD.
  57
  58    While in the single-kboard state, read_char can consider input only
  59    from the current KBOARD.  If events come from other KBOARDs, they
  60    are put aside for later in the KBOARDs' kbd_queue lists.
  61    The flag kbd_queue_has_data in a KBOARD is 1 if this has happened.
  62    When Emacs goes back to the any-kboard state, it looks at all the KBOARDS
  63    to find those; and it tries processing their input right away.  */
  64
  65 typedef struct kboard KBOARD;
  66 struct kboard
  67   {
  68     KBOARD *next_kboard;
  69
  70     /* If non-nil, a keymap that overrides all others but applies only to
  71        this KBOARD.  Lisp code that uses this instead of calling read-char
  72        can effectively wait for input in the any-kboard state, and hence
  73        avoid blocking out the other KBOARDs.  See universal-argument in
  74        lisp/simple.el for an example.  */
  75     Lisp_Object Voverriding_terminal_local_map;
  76
  77     /* Last command executed by the editor command loop, not counting
  78        commands that set the prefix argument.  */
  79     Lisp_Object Vlast_command;
  80
  81     /* The prefix argument for the next command, in raw form.  */
  82     Lisp_Object Vprefix_arg;
  83
  84     /* Unread events specific to this kboard.  */
  85     Lisp_Object kbd_queue;
  86
  87     /* Non-nil while a kbd macro is being defined.  */
  88     Lisp_Object defining_kbd_macro;
  89
  90     /* The start of storage for the current keyboard macro.  */
  91     Lisp_Object *kbd_macro_buffer;
  92
  93     /* Where to store the next keystroke of the macro.  */
  94     Lisp_Object *kbd_macro_ptr;
  95
  96     /* The finalized section of the macro starts at kbd_macro_buffer and
  97        ends before this.  This is not the same as kbd_macro_ptr, because
  98        we advance this to kbd_macro_ptr when a key's command is complete.
  99        This way, the keystrokes for "end-kbd-macro" are not included in the
 100        macro.  */
 101     Lisp_Object *kbd_macro_end;
 102
 103     /* Allocated size of kbd_macro_buffer.  */
 104     int kbd_macro_bufsize;
 105
 106     /* Last anonymous kbd macro defined.  */
 107     Lisp_Object Vlast_kbd_macro;
 108
 109     /* Alist of system-specific X windows key symbols.  */
 110     Lisp_Object Vsystem_key_alist;
 111
 112     /* Cache for modify_event_symbol.  */
 113     Lisp_Object system_key_syms;
 114
 115     /* Minibufferless frames on this display use this frame's minibuffer.  */
 116     Lisp_Object Vdefault_minibuffer_frame;
 117
 118     /* Number of displays using this KBOARD.  Normally 1, but can be
 119        larger when you have multiple screens on a single X display.  */
 120     int reference_count;
 121
 122     /* Where to append more text to echobuf if we want to.  */
 123     char *echoptr;
 124
 125     /* The text we're echoing in the modeline - partial key sequences,
 126        usually.  '\0'-terminated.  This really shouldn't have a fixed size.  */
 127     char echobuf[ECHOBUFSIZE];
 128
 129     /* This flag indicates that events were put into kbd_queue
 130        while Emacs was running for some other KBOARD.
 131        The flag means that, when Emacs goes into the any-kboard state again,
 132        it should check this KBOARD to see if there is a complete command
 133        waiting.
 134
 135        Note that the kbd_queue field can be non-nil even when
 136        kbd_queue_has_data is 0.  When we push back an incomplete
 137        command, then this flag is 0, meaning we don't want to try
 138        reading from this KBOARD again until more input arrives.  */
 139     char kbd_queue_has_data;
 140
 141     /* Nonzero means echo each character as typed.  */
 142     char immediate_echo;
 143
 144     /* If we have echoed a prompt string specified by the user,
 145        this is its length.  Otherwise this is -1.  */
 146     char echo_after_prompt;
 147   };
 148
 149 #ifdef MULTI_KBOARD
 150 /* Temporarily used before a frame has been opened, and for termcap frames */
 151 extern KBOARD *initial_kboard;
 152
 153 /* In the single-kboard state, this is the kboard
 154    from which input is accepted.
 155
 156    In the any-kboard state, this is the kboard from which we are
 157    right now considering input.  We can consider input from another
 158    kboard, but doing so requires throwing to wrong_kboard_jmpbuf.  */
 159 extern KBOARD *current_kboard;
 160
 161 /* A list of all kboard objects, linked through next_kboard.  */
 162 extern KBOARD *all_kboards;
 163
 164 /* Nonzero in the single-kboard state, 0 in the any-kboard state.  */
 165 extern int single_kboard;
 166 #else
 167 extern KBOARD the_only_kboard;
 168 #define current_kboard (&the_only_kboard)
 169 #define all_kboards (&the_only_kboard)
 170 #define single_kboard 1
 171 #endif
 172 \f
 173 extern Lisp_Object Vlucid_menu_bar_dirty_flag;
 174 extern Lisp_Object Qrecompute_lucid_menubar, Qactivate_menubar_hook;
 175
 176 /* Total number of times read_char has returned.  */
 177 extern int num_input_chars;
 178
 179 /* Total number of times read_char has returned, outside of macros.  */
 180 extern int num_nonmacro_input_chars;
 181
 182 /* Nonzero means polling for input is temporarily suppressed.  */
 183 extern int poll_suppress_count;
 184
 185 /* Nonzero if polling_for_input is actually being used.  */
 186 extern int polling_for_input;
 187
 188 /* Keymap mapping ASCII function key sequences onto their preferred forms.
 189    Initialized by the terminal-specific lisp files.  */
 190 extern Lisp_Object Vfunction_key_map;
 191
 192 /* Vector holding the key sequence that invoked the current command.
 193    It is reused for each command, and it may be longer than the current
 194    sequence; this_command_key_count indicates how many elements
 195    actually mean something.  */
 196 extern Lisp_Object this_command_keys;
 197 extern int this_command_key_count;
 198
 199 #ifdef MULTI_FRAME
 200 /* The frame in which the last input event occurred, or Qmacro if the
 201    last event came from a macro.  We use this to determine when to
 202    generate switch-frame events.  This may be cleared by functions
 203    like Fselect_frame, to make sure that a switch-frame event is
 204    generated by the next character.  */
 205 extern Lisp_Object internal_last_event_frame;
 206 #endif
 207
 208 \f
 209 /* Macros for dealing with lispy events.  */
 210
 211 /* True iff EVENT has data fields describing it (i.e. a mouse click).  */
 212 #define EVENT_HAS_PARAMETERS(event) (CONSP (event))
 213
 214 /* Extract the head from an event.
 215    This works on composite and simple events.  */
 216 #define EVENT_HEAD(event) \
 217   (EVENT_HAS_PARAMETERS (event) ? XCONS (event)->car : (event))
 218
 219 /* Extract the starting and ending positions from a composite event.  */
 220 #define EVENT_START(event) (XCONS (XCONS (event)->cdr)->car)
 221 #define EVENT_END(event) (XCONS (XCONS (XCONS (event)->cdr)->cdr)->car)
 222
 223 /* Extract the click count from a multi-click event.  */
 224 #define EVENT_CLICK_COUNT(event) (Fnth ((event), make_number (2)))
 225
 226 /* Extract the fields of a position.  */
 227 #define POSN_WINDOW(posn) (XCONS (posn)->car)
 228 #define POSN_BUFFER_POSN(posn) (XCONS (XCONS (posn)->cdr)->car)
 229 #define POSN_WINDOW_POSN(posn) (XCONS (XCONS (XCONS (posn)->cdr)->cdr)->car)
 230 #define POSN_TIMESTAMP(posn) \
 231   (XCONS (XCONS (XCONS (XCONS (posn)->cdr)->cdr)->cdr)->car)
 232 #define POSN_SCROLLBAR_PART(posn)       (Fnth ((posn), make_number (4)))
 233
 234 /* Some of the event heads.  */
 235 extern Lisp_Object Qswitch_frame;
 236
 237 /* Properties on event heads.  */
 238 extern Lisp_Object Qevent_kind, Qevent_symbol_elements;
 239
 240 /* Getting an unmodified version of an event head.  */
 241 #define EVENT_HEAD_UNMODIFIED(event_head) \
 242   (Fcar (Fget ((event_head), Qevent_symbol_elements)))
 243
 244 /* The values of Qevent_kind properties.  */
 245 extern Lisp_Object Qfunction_key, Qmouse_click, Qmouse_movement;
 246 extern Lisp_Object Qscroll_bar_movement;
 247
 248 /* Getting the kind of an event head.  */
 249 #define EVENT_HEAD_KIND(event_head) \
 250   (Fget ((event_head), Qevent_kind))
 251
 252 /* Symbols to use for non-text mouse positions.  */
 253 extern Lisp_Object Qmode_line, Qvertical_line;
 254
 255 extern Lisp_Object get_keymap_1 ();
 256 extern Lisp_Object Fkeymapp ();
 257 extern Lisp_Object reorder_modifiers ();
 258 extern Lisp_Object read_char ();
 259 /* User-supplied string to translate input characters through.  */
 260 extern Lisp_Object Vkeyboard_translate_table;
 261
 262 extern Lisp_Object map_prompt ();