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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 /* Length of echobuf field in each KBOARD.  */
  21
  22 #define ECHOBUFSIZE 300
  23
  24 /* Each KBOARD represents one logical input stream from which Emacs gets input.
  25    If we are using an ordinary terminal, it has one KBOARD object.
  26    Usually each X display screen has its own KBOARD,
  27    but when two of them are on the same X server,
  28    we assume they share a keyboard and give them one KBOARD in common.
  29
  30    Some Lisp variables are per-kboard; they are stored in the KBOARD structure
  31    and accessed indirectly via a Lisp_Misc_Kboard_Objfwd object.
  32
  33    So that definition of keyboard macros, and reading of prefix arguments,
  34    can happen in parallel on various KBOARDs at once,
  35    the state information for those activities is stored in the KBOARD.
  36
  37    Emacs has two states for reading input:
  38
  39    ** Any kboard.  Emacs can accept input from any KBOARD,
  40    and as soon as any of them provides a complete command, Emacs can run it.
  41
  42    ** Single kboard.  Then Emacs is running a command for one KBOARD
  43    and can only read input from that KBOARD.
  44
  45    All input, from all KBOARDs, goes together in a single event queue
  46    at interrupt level.  read_char sees the events sequentially,
  47    but deals with them in accord with the current input state.
  48
  49    In the any-kboard state, read_key_sequence processes input from any KBOARD
  50    immediately.  When a new event comes in from a particular KBOARD,
  51    read_key_sequence switches to that KBOARD.  As a result,
  52    as soon as a complete key arrives from some KBOARD or other,
  53    Emacs starts executing that key's binding.  It switches to the
  54    single-kboard state for the execution of that command,
  55    so that that command can get input only from its own KBOARD.
  56
  57    While in the single-kboard state, read_char can consider input only
  58    from the current KBOARD.  If events come from other KBOARDs, they
  59    are put aside for later in the KBOARDs' kbd_queue lists.
  60    The flag kbd_queue_has_data in a KBOARD is 1 if this has happened.
  61    When Emacs goes back to the any-kboard state, it looks at all the KBOARDS
  62    to find those; and it tries processing their input right away.  */
  63
  64 typedef struct kboard KBOARD;
  65 struct kboard
  66   {
  67     KBOARD *next_kboard;
  68
  69     /* If non-nil, a keymap that overrides all others but applies only to
  70        this KBOARD.  Lisp code that uses this instead of calling read-char
  71        can effectively wait for input in the any-kboard state, and hence
  72        avoid blocking out the other KBOARDs.  See universal-argument in
  73        lisp/simple.el for an example.  */
  74     Lisp_Object Voverriding_terminal_local_map;
  75
  76     /* Last command executed by the editor command loop, not counting
  77        commands that set the prefix argument.  */
  78     Lisp_Object Vlast_command;
  79
  80     /* The prefix argument for the next command, in raw form.  */
  81     Lisp_Object Vprefix_arg;
  82
  83     /* Unread events specific to this kboard.  */
  84     Lisp_Object kbd_queue;
  85
  86     /* Non-nil while a kbd macro is being defined.  */
  87     Lisp_Object defining_kbd_macro;
  88
  89     /* The start of storage for the current keyboard macro.  */
  90     Lisp_Object *kbd_macro_buffer;
  91
  92     /* Where to store the next keystroke of the macro.  */
  93     Lisp_Object *kbd_macro_ptr;
  94
  95     /* The finalized section of the macro starts at kbd_macro_buffer and
  96        ends before this.  This is not the same as kbd_macro_ptr, because
  97        we advance this to kbd_macro_ptr when a key's command is complete.
  98        This way, the keystrokes for "end-kbd-macro" are not included in the
  99        macro.  */
 100     Lisp_Object *kbd_macro_end;
 101
 102     /* Allocated size of kbd_macro_buffer.  */
 103     int kbd_macro_bufsize;
 104
 105     /* Last anonymous kbd macro defined.  */
 106     Lisp_Object Vlast_kbd_macro;
 107
 108     /* Alist of system-specific X windows key symbols.  */
 109     Lisp_Object Vsystem_key_alist;
 110
 111     /* Cache for modify_event_symbol.  */
 112     Lisp_Object system_key_syms;
 113
 114     /* Minibufferless frames on this display use this frame's minibuffer.  */
 115     Lisp_Object Vdefault_minibuffer_frame;
 116
 117     /* Number of displays using this KBOARD.  Normally 1, but can be
 118        larger when you have multiple screens on a single X display.  */
 119     int reference_count;
 120
 121     /* Where to append more text to echobuf if we want to.  */
 122     char *echoptr;
 123
 124     /* The text we're echoing in the modeline - partial key sequences,
 125        usually.  '\0'-terminated.  This really shouldn't have a fixed size.  */
 126     char echobuf[ECHOBUFSIZE];
 127
 128     /* This flag indicates that events were put into kbd_queue
 129        while Emacs was running for some other KBOARD.
 130        The flag means that, when Emacs goes into the any-kboard state again,
 131        it should check this KBOARD to see if there is a complete command
 132        waiting.
 133
 134        Note that the kbd_queue field can be non-nil even when
 135        kbd_queue_has_data is 0.  When we push back an incomplete
 136        command, then this flag is 0, meaning we don't want to try
 137        reading from this KBOARD again until more input arrives.  */
 138     char kbd_queue_has_data;
 139
 140     /* Nonzero means echo each character as typed.  */
 141     char immediate_echo;
 142
 143     /* If we have echoed a prompt string specified by the user,
 144        this is its length.  Otherwise this is -1.  */
 145     char echo_after_prompt;
 146   };
 147
 148 #ifdef MULTI_KBOARD
 149 /* Temporarily used before a frame has been opened, and for termcap frames */
 150 extern KBOARD *initial_kboard;
 151
 152 /* In the single-kboard state, this is the kboard
 153    from which input is accepted.
 154
 155    In the any-kboard state, this is the kboard from which we are
 156    right now considering input.  We can consider input from another
 157    kboard, but doing so requires throwing to wrong_kboard_jmpbuf.  */
 158 extern KBOARD *current_kboard;
 159
 160 /* A list of all kboard objects, linked through next_kboard.  */
 161 extern KBOARD *all_kboards;
 162
 163 /* Nonzero in the single-kboard state, 0 in the any-kboard state.  */
 164 extern int single_kboard;
 165 #else
 166 extern KBOARD the_only_kboard;
 167 #define current_kboard (&the_only_kboard)
 168 #define all_kboards (&the_only_kboard)
 169 #define single_kboard 1
 170 #endif
 171 \f
 172 extern Lisp_Object Vlucid_menu_bar_dirty_flag;
 173 extern Lisp_Object Qrecompute_lucid_menubar, Qactivate_menubar_hook;
 174
 175 /* Total number of times read_char has returned.  */
 176 extern int num_input_chars;
 177
 178 /* Total number of times read_char has returned, outside of macros.  */
 179 extern int num_nonmacro_input_chars;
 180
 181 /* Nonzero means polling for input is temporarily suppressed.  */
 182 extern int poll_suppress_count;
 183
 184 /* Nonzero if polling_for_input is actually being used.  */
 185 extern int polling_for_input;
 186
 187 /* Keymap mapping ASCII function key sequences onto their preferred forms.
 188    Initialized by the terminal-specific lisp files.  */
 189 extern Lisp_Object Vfunction_key_map;
 190
 191 /* Vector holding the key sequence that invoked the current command.
 192    It is reused for each command, and it may be longer than the current
 193    sequence; this_command_key_count indicates how many elements
 194    actually mean something.  */
 195 extern Lisp_Object this_command_keys;
 196 extern int this_command_key_count;
 197
 198 #ifdef MULTI_FRAME
 199 /* The frame in which the last input event occurred, or Qmacro if the
 200    last event came from a macro.  We use this to determine when to
 201    generate switch-frame events.  This may be cleared by functions
 202    like Fselect_frame, to make sure that a switch-frame event is
 203    generated by the next character.  */
 204 extern Lisp_Object internal_last_event_frame;
 205 #endif
 206
 207 \f
 208 /* Macros for dealing with lispy events.  */
 209
 210 /* True iff EVENT has data fields describing it (i.e. a mouse click).  */
 211 #define EVENT_HAS_PARAMETERS(event) (CONSP (event))
 212
 213 /* Extract the head from an event.
 214    This works on composite and simple events.  */
 215 #define EVENT_HEAD(event) \
 216   (EVENT_HAS_PARAMETERS (event) ? XCONS (event)->car : (event))
 217
 218 /* Extract the starting and ending positions from a composite event.  */
 219 #define EVENT_START(event) (XCONS (XCONS (event)->cdr)->car)
 220 #define EVENT_END(event) (XCONS (XCONS (XCONS (event)->cdr)->cdr)->car)
 221
 222 /* Extract the click count from a multi-click event.  */
 223 #define EVENT_CLICK_COUNT(event) (Fnth ((event), make_number (2)))
 224
 225 /* Extract the fields of a position.  */
 226 #define POSN_WINDOW(posn) (XCONS (posn)->car)
 227 #define POSN_BUFFER_POSN(posn) (XCONS (XCONS (posn)->cdr)->car)
 228 #define POSN_WINDOW_POSN(posn) (XCONS (XCONS (XCONS (posn)->cdr)->cdr)->car)
 229 #define POSN_TIMESTAMP(posn) \
 230   (XCONS (XCONS (XCONS (XCONS (posn)->cdr)->cdr)->cdr)->car)
 231 #define POSN_SCROLLBAR_PART(posn)       (Fnth ((posn), make_number (4)))
 232
 233 /* Some of the event heads.  */
 234 extern Lisp_Object Qswitch_frame;
 235
 236 /* Properties on event heads.  */
 237 extern Lisp_Object Qevent_kind, Qevent_symbol_elements;
 238
 239 /* Getting an unmodified version of an event head.  */
 240 #define EVENT_HEAD_UNMODIFIED(event_head) \
 241   (Fcar (Fget ((event_head), Qevent_symbol_elements)))
 242
 243 /* The values of Qevent_kind properties.  */
 244 extern Lisp_Object Qfunction_key, Qmouse_click, Qmouse_movement;
 245 extern Lisp_Object Qscroll_bar_movement;
 246
 247 /* Getting the kind of an event head.  */
 248 #define EVENT_HEAD_KIND(event_head) \
 249   (Fget ((event_head), Qevent_kind))
 250
 251 /* Symbols to use for non-text mouse positions.  */
 252 extern Lisp_Object Qmode_line, Qvertical_line;
 253
 254 extern Lisp_Object get_keymap_1 ();
 255 extern Lisp_Object Fkeymapp ();
 256 extern Lisp_Object reorder_modifiers ();
 257 extern Lisp_Object read_char ();
 258 /* User-supplied string to translate input characters through.  */
 259 extern Lisp_Object Vkeyboard_translate_table;
 260
 261 extern Lisp_Object map_prompt ();