src/w32inevt.c

   1 /* Input event support for Emacs on the Microsoft Windows API.
   2    Copyright (C) 1992-1993, 1995, 2001-2013 Free Software Foundation,
   3    Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 /*
  21    Drew Bliss                   01-Oct-93
  22      Adapted from ntkbd.c by Tim Fleehart
  23 */
  24
  25
  26 #include <config.h>
  27 #include <stdio.h>
  28 #include <windows.h>
  29
  30 #ifndef MOUSE_MOVED
  31 #define MOUSE_MOVED   1
  32 #endif
  33
  34 #include "lisp.h"
  35 #include "keyboard.h"
  36 #include "frame.h"
  37 #include "dispextern.h"
  38 #include "window.h"
  39 #include "blockinput.h"
  40 #include "termhooks.h"
  41 #include "termchar.h"
  42 #include "w32heap.h"
  43 #include "w32term.h"
  44 #include "w32inevt.h"
  45
  46 /* stdin, from w32console.c */
  47 extern HANDLE keyboard_handle;
  48
  49 /* Info for last mouse motion */
  50 static COORD movement_pos;
  51 static Time movement_time;
  52
  53 /* from w32fns.c */
  54 extern unsigned int map_keypad_keys (unsigned int, unsigned int);
  55 extern unsigned int w32_key_to_modifier (int key);
  56
  57 /* Event queue */
  58 #define EVENT_QUEUE_SIZE 50
  59 static INPUT_RECORD event_queue[EVENT_QUEUE_SIZE];
  60 static INPUT_RECORD *queue_ptr = event_queue, *queue_end = event_queue;
  61
  62 /* Temporarily store lead byte of DBCS input sequences.  */
  63 static char dbcs_lead = 0;
  64
  65 static inline BOOL
  66 w32_read_console_input (HANDLE h, INPUT_RECORD *rec, DWORD recsize,
  67                         DWORD *waiting)
  68 {
  69   return (w32_console_unicode_input
  70           ? ReadConsoleInputW (h, rec, recsize, waiting)
  71           : ReadConsoleInputA (h, rec, recsize, waiting));
  72 }
  73
  74 /* Set by w32_console_toggle_lock_key.  */
  75 int faked_key;
  76
  77 static int
  78 fill_queue (BOOL block)
  79 {
  80   BOOL rc;
  81   DWORD events_waiting;
  82
  83   if (queue_ptr < queue_end)
  84     return queue_end-queue_ptr;
  85
  86   if (!block)
  87     {
  88       /* Check to see if there are some events to read before we try
  89          because we can't block.  */
  90       if (!GetNumberOfConsoleInputEvents (keyboard_handle, &events_waiting))
  91         return -1;
  92       if (events_waiting == 0)
  93         return 0;
  94     }
  95
  96   rc = w32_read_console_input (keyboard_handle, event_queue, EVENT_QUEUE_SIZE,
  97                                &events_waiting);
  98   if (!rc)
  99     return -1;
 100   queue_ptr = event_queue;
 101   queue_end = event_queue + events_waiting;
 102   return (int) events_waiting;
 103 }
 104
 105 /* In a generic, multi-frame world this should take a console handle
 106    and return the frame for it
 107
 108    Right now, there's only one frame so return it.  */
 109 static FRAME_PTR
 110 get_frame (void)
 111 {
 112   return SELECTED_FRAME ();
 113 }
 114
 115 /* Translate console modifiers to emacs modifiers.
 116    German keyboard support (Kai Morgan Zeise 2/18/95).  */
 117
 118
 119 #if 0
 120 /* Return nonzero if the virtual key is a dead key.  */
 121 static int
 122 is_dead_key (int wparam)
 123 {
 124   unsigned int code = MapVirtualKey (wparam, 2);
 125
 126   /* Windows 95 returns 0x8000, NT returns 0x80000000.  */
 127   return (code & 0x80008000) ? 1 : 0;
 128 }
 129 #endif
 130
 131 /* The return code indicates key code size.  cpID is the codepage to
 132    use for translation to Unicode; -1 means use the current console
 133    input codepage.  */
 134
 135
 136 /* return code -1 means that event_queue_ptr won't be incremented.
 137    In other word, this event makes two key codes.   (by himi)       */
 138 static int
 139 key_event (KEY_EVENT_RECORD *event, struct input_event *emacs_ev, int *isdead)
 140 {
 141   static int mod_key_state = 0;
 142   int wParam;
 143
 144   *isdead = 0;
 145
 146   /* Skip key-up events.  */
 147   if (!event->bKeyDown)
 148     {
 149       switch (event->wVirtualKeyCode)
 150         {
 151         case VK_LWIN:
 152           mod_key_state &= ~LEFT_WIN_PRESSED;
 153           break;
 154         case VK_RWIN:
 155           mod_key_state &= ~RIGHT_WIN_PRESSED;
 156           break;
 157         case VK_APPS:
 158           mod_key_state &= ~APPS_PRESSED;
 159           break;
 160         }
 161       return 0;
 162     }
 163
 164   /* Ignore keystrokes we fake ourself; see below.  */
 165   if (faked_key == event->wVirtualKeyCode)
 166     {
 167       faked_key = 0;
 168       return 0;
 169     }
 170
 171   /* To make it easier to debug this code, ignore modifier keys!  */
 172   switch (event->wVirtualKeyCode)
 173     {
 174     case VK_LWIN:
 175       if (NILP (Vw32_pass_lwindow_to_system))
 176         {
 177           /* Prevent system from acting on keyup (which opens the Start
 178              menu if no other key was pressed) by simulating a press of
 179              Space which we will ignore.  */
 180           if ((mod_key_state & LEFT_WIN_PRESSED) == 0)
 181             {
 182               if (NUMBERP (Vw32_phantom_key_code))
 183                 faked_key = XUINT (Vw32_phantom_key_code) & 255;
 184               else
 185                 faked_key = VK_SPACE;
 186               keybd_event (faked_key, (BYTE) MapVirtualKey (faked_key, 0), 0, 0);
 187             }
 188         }
 189       mod_key_state |= LEFT_WIN_PRESSED;
 190       if (!NILP (Vw32_lwindow_modifier))
 191         return 0;
 192       break;
 193     case VK_RWIN:
 194       if (NILP (Vw32_pass_rwindow_to_system))
 195         {
 196           if ((mod_key_state & RIGHT_WIN_PRESSED) == 0)
 197             {
 198               if (NUMBERP (Vw32_phantom_key_code))
 199                 faked_key = XUINT (Vw32_phantom_key_code) & 255;
 200               else
 201                 faked_key = VK_SPACE;
 202               keybd_event (faked_key, (BYTE) MapVirtualKey (faked_key, 0), 0, 0);
 203             }
 204         }
 205       mod_key_state |= RIGHT_WIN_PRESSED;
 206       if (!NILP (Vw32_rwindow_modifier))
 207         return 0;
 208       break;
 209     case VK_APPS:
 210       mod_key_state |= APPS_PRESSED;
 211       if (!NILP (Vw32_apps_modifier))
 212         return 0;
 213       break;
 214     case VK_CAPITAL:
 215       /* Decide whether to treat as modifier or function key.  */
 216       if (NILP (Vw32_enable_caps_lock))
 217         goto disable_lock_key;
 218       return 0;
 219     case VK_NUMLOCK:
 220       /* Decide whether to treat as modifier or function key.  */
 221       if (NILP (Vw32_enable_num_lock))
 222         goto disable_lock_key;
 223       return 0;
 224     case VK_SCROLL:
 225       /* Decide whether to treat as modifier or function key.  */
 226       if (NILP (Vw32_scroll_lock_modifier))
 227         goto disable_lock_key;
 228       return 0;
 229     disable_lock_key:
 230       /* Ensure the appropriate lock key state is off (and the
 231          indicator light as well).  */
 232       wParam = event->wVirtualKeyCode;
 233       if (GetAsyncKeyState (wParam) & 0x8000)
 234         {
 235           /* Fake another press of the relevant key.  Apparently, this
 236              really is the only way to turn off the indicator.  */
 237           faked_key = wParam;
 238           keybd_event ((BYTE) wParam, (BYTE) MapVirtualKey (wParam, 0),
 239                        KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
 240           keybd_event ((BYTE) wParam, (BYTE) MapVirtualKey (wParam, 0),
 241                        KEYEVENTF_EXTENDEDKEY | 0, 0);
 242           keybd_event ((BYTE) wParam, (BYTE) MapVirtualKey (wParam, 0),
 243                        KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
 244         }
 245       break;
 246     case VK_MENU:
 247     case VK_CONTROL:
 248     case VK_SHIFT:
 249       return 0;
 250     case VK_CANCEL:
 251       /* Windows maps Ctrl-Pause (aka Ctrl-Break) into VK_CANCEL,
 252          which is confusing for purposes of key binding; convert
 253          VK_CANCEL events into VK_PAUSE events.  */
 254       event->wVirtualKeyCode = VK_PAUSE;
 255       break;
 256     case VK_PAUSE:
 257       /* Windows maps Ctrl-NumLock into VK_PAUSE, which is confusing
 258          for purposes of key binding; convert these back into
 259          VK_NUMLOCK events, at least when we want to see NumLock key
 260          presses.  (Note that there is never any possibility that
 261          VK_PAUSE with Ctrl really is C-Pause as per above.)  */
 262       if (NILP (Vw32_enable_num_lock)
 263           && (event->dwControlKeyState
 264               & (LEFT_CTRL_PRESSED | RIGHT_CTRL_PRESSED)) != 0)
 265         event->wVirtualKeyCode = VK_NUMLOCK;
 266       break;
 267     }
 268
 269   /* Recognize state of Windows and Apps keys.  */
 270   event->dwControlKeyState |= mod_key_state;
 271
 272   /* Distinguish numeric keypad keys from extended keys.  */
 273   event->wVirtualKeyCode =
 274     map_keypad_keys (event->wVirtualKeyCode,
 275                      (event->dwControlKeyState & ENHANCED_KEY));
 276
 277   if (lispy_function_keys[event->wVirtualKeyCode] == 0)
 278     {
 279       if (!NILP (Vw32_recognize_altgr)
 280           && (event->dwControlKeyState & LEFT_CTRL_PRESSED)
 281           && (event->dwControlKeyState & RIGHT_ALT_PRESSED))
 282         {
 283           /* Don't try to interpret AltGr key chords; ToAscii seems not
 284              to process them correctly.  */
 285         }
 286       /* Handle key chords including any modifiers other than shift
 287          directly, in order to preserve as much modifier information as
 288          possible.  */
 289       else if (event->dwControlKeyState
 290                & (  RIGHT_CTRL_PRESSED | LEFT_CTRL_PRESSED
 291                   | RIGHT_ALT_PRESSED | LEFT_ALT_PRESSED
 292                   | (!NILP (Vw32_lwindow_modifier) ? LEFT_WIN_PRESSED : 0)
 293                   | (!NILP (Vw32_rwindow_modifier) ? RIGHT_WIN_PRESSED : 0)
 294                   | (!NILP (Vw32_apps_modifier) ? APPS_PRESSED : 0)
 295                   | (!NILP (Vw32_scroll_lock_modifier) ? SCROLLLOCK_ON : 0)))
 296         {
 297           /* Don't translate modified alphabetic keystrokes, so the user
 298              doesn't need to constantly switch layout to type control or
 299              meta keystrokes when the normal layout translates
 300              alphabetic characters to non-ascii characters.  */
 301           if ('A' <= event->wVirtualKeyCode && event->wVirtualKeyCode <= 'Z')
 302             {
 303               event->uChar.AsciiChar = event->wVirtualKeyCode;
 304               if ((event->dwControlKeyState & SHIFT_PRESSED) == 0)
 305                 event->uChar.AsciiChar += ('a' - 'A');
 306             }
 307           /* Try to handle unrecognized keystrokes by determining the
 308              base character (ie. translating the base key plus shift
 309              modifier).  */
 310           else if (event->uChar.AsciiChar == 0)
 311             w32_kbd_patch_key (event, -1);
 312         }
 313
 314       if (event->uChar.AsciiChar == 0)
 315         {
 316           emacs_ev->kind = NO_EVENT;
 317           return 0;
 318         }
 319       else if (event->uChar.AsciiChar > 0)
 320         {
 321           /* Pure ASCII characters < 128.  */
 322           emacs_ev->kind = ASCII_KEYSTROKE_EVENT;
 323           emacs_ev->code = event->uChar.AsciiChar;
 324         }
 325       else if (event->uChar.UnicodeChar > 0
 326                && w32_console_unicode_input)
 327         {
 328           /* Unicode codepoint; only valid if we are using Unicode
 329              console input mode.  */
 330           emacs_ev->kind = MULTIBYTE_CHAR_KEYSTROKE_EVENT;
 331           emacs_ev->code = event->uChar.UnicodeChar;
 332         }
 333       else
 334         {
 335           /* Fallback handling of non-ASCII characters for non-Unicode
 336              versions of Windows, and for non-Unicode input on NT
 337              family of Windows.  Only characters in the current
 338              console codepage are supported by this fallback.  */
 339           wchar_t code;
 340           char dbcs[2];
 341           int cpId;
 342
 343           /* Get the current console input codepage to interpret this
 344              key with.  Note that the system defaults for the OEM
 345              codepage could have been changed by calling SetConsoleCP
 346              or w32-set-console-codepage, so using GetLocaleInfo to
 347              get LOCALE_IDEFAULTCODEPAGE is not TRT here.  */
 348           cpId = GetConsoleCP ();
 349
 350           dbcs[0] = dbcs_lead;
 351           dbcs[1] = event->uChar.AsciiChar;
 352           if (dbcs_lead)
 353             {
 354               dbcs_lead = 0;
 355               if (!MultiByteToWideChar (cpId, 0, dbcs, 2, &code, 1))
 356                 {
 357                   /* Garbage  */
 358                   DebPrint (("Invalid DBCS sequence: %d %d\n",
 359                              dbcs[0], dbcs[1]));
 360                   emacs_ev->kind = NO_EVENT;
 361                 }
 362             }
 363           else if (IsDBCSLeadByteEx (cpId, dbcs[1]))
 364             {
 365               dbcs_lead = dbcs[1];
 366               emacs_ev->kind = NO_EVENT;
 367             }
 368           else
 369             {
 370               if (!MultiByteToWideChar (cpId, 0, &dbcs[1], 1, &code, 1))
 371                 {
 372                   /* Garbage  */
 373                   DebPrint (("Invalid character: %d\n", dbcs[1]));
 374                   emacs_ev->kind = NO_EVENT;
 375                 }
 376             }
 377           emacs_ev->kind = MULTIBYTE_CHAR_KEYSTROKE_EVENT;
 378           emacs_ev->code = code;
 379         }
 380     }
 381   else
 382     {
 383       /* Function keys and other non-character keys.  */
 384       emacs_ev->kind = NON_ASCII_KEYSTROKE_EVENT;
 385       emacs_ev->code = event->wVirtualKeyCode;
 386     }
 387
 388   XSETFRAME (emacs_ev->frame_or_window, get_frame ());
 389   emacs_ev->modifiers = w32_kbd_mods_to_emacs (event->dwControlKeyState,
 390                                                event->wVirtualKeyCode);
 391   emacs_ev->timestamp = GetTickCount ();
 392   return 1;
 393 }
 394
 395 /* Mouse position hook.  */
 396 void
 397 w32_console_mouse_position (FRAME_PTR *f,
 398                             int insist,
 399                             Lisp_Object *bar_window,
 400                             enum scroll_bar_part *part,
 401                             Lisp_Object *x,
 402                             Lisp_Object *y,
 403                             Time *time)
 404 {
 405   block_input ();
 406
 407   insist = insist;
 408
 409   *f = get_frame ();
 410   *bar_window = Qnil;
 411   *part = 0;
 412   SELECTED_FRAME ()->mouse_moved = 0;
 413
 414   XSETINT (*x, movement_pos.X);
 415   XSETINT (*y, movement_pos.Y);
 416   *time = movement_time;
 417
 418   unblock_input ();
 419 }
 420
 421 /* Remember mouse motion and notify emacs.  */
 422 static void
 423 mouse_moved_to (int x, int y)
 424 {
 425   /* If we're in the same place, ignore it.  */
 426   if (x != movement_pos.X || y != movement_pos.Y)
 427     {
 428       SELECTED_FRAME ()->mouse_moved = 1;
 429       movement_pos.X = x;
 430       movement_pos.Y = y;
 431       movement_time = GetTickCount ();
 432     }
 433 }
 434
 435 /* Consoles return button bits in a strange order:
 436      least significant - Leftmost button
 437      next - Rightmost button
 438      next - Leftmost+1
 439      next - Leftmost+2...
 440
 441    Assume emacs likes three button mice, so
 442      Left == 0
 443      Middle == 1
 444      Right == 2
 445    Others increase from there.  */
 446
 447 #define NUM_TRANSLATED_MOUSE_BUTTONS 3
 448 static int emacs_button_translation[NUM_TRANSLATED_MOUSE_BUTTONS] =
 449 {
 450   0, 2, 1
 451 };
 452
 453 static int
 454 do_mouse_event (MOUSE_EVENT_RECORD *event,
 455                 struct input_event *emacs_ev)
 456 {
 457   static DWORD button_state = 0;
 458   static Lisp_Object last_mouse_window;
 459   DWORD but_change, mask;
 460   int i;
 461
 462   if (event->dwEventFlags == MOUSE_MOVED)
 463     {
 464       FRAME_PTR f = SELECTED_FRAME ();
 465       Mouse_HLInfo *hlinfo = MOUSE_HL_INFO (f);
 466       int mx = event->dwMousePosition.X, my = event->dwMousePosition.Y;
 467
 468       mouse_moved_to (mx, my);
 469
 470       if (f->mouse_moved)
 471         {
 472           if (hlinfo->mouse_face_hidden)
 473             {
 474               hlinfo->mouse_face_hidden = 0;
 475               clear_mouse_face (hlinfo);
 476             }
 477
 478           /* Generate SELECT_WINDOW_EVENTs when needed.  */
 479           if (!NILP (Vmouse_autoselect_window))
 480             {
 481               Lisp_Object mouse_window = window_from_coordinates (f, mx, my,
 482                                                                   0, 0);
 483               /* A window will be selected only when it is not
 484                  selected now, and the last mouse movement event was
 485                  not in it.  A minibuffer window will be selected iff
 486                  it is active.  */
 487               if (WINDOWP (mouse_window)
 488                   && !EQ (mouse_window, last_mouse_window)
 489                   && !EQ (mouse_window, selected_window))
 490                 {
 491                   struct input_event event;
 492
 493                   EVENT_INIT (event);
 494                   event.kind = SELECT_WINDOW_EVENT;
 495                   event.frame_or_window = mouse_window;
 496                   event.arg = Qnil;
 497                   event.timestamp = movement_time;
 498                   kbd_buffer_store_event (&event);
 499                 }
 500               last_mouse_window = mouse_window;
 501             }
 502           else
 503             last_mouse_window = Qnil;
 504
 505           previous_help_echo_string = help_echo_string;
 506           help_echo_string = help_echo_object = help_echo_window = Qnil;
 507           help_echo_pos = -1;
 508           note_mouse_highlight (f, mx, my);
 509           /* If the contents of the global variable help_echo has
 510              changed (inside note_mouse_highlight), generate a HELP_EVENT.  */
 511           if (!NILP (help_echo_string) || !NILP (previous_help_echo_string))
 512             gen_help_event (help_echo_string, selected_frame, help_echo_window,
 513                             help_echo_object, help_echo_pos);
 514         }
 515       return 0;
 516     }
 517
 518   /* It looks like the console code sends us a mouse event with
 519      dwButtonState == 0 when a window is activated.  Ignore this case.  */
 520   if (event->dwButtonState == button_state)
 521     return 0;
 522
 523   emacs_ev->kind = MOUSE_CLICK_EVENT;
 524
 525   /* Find out what button has changed state since the last button event.  */
 526   but_change = button_state ^ event->dwButtonState;
 527   mask = 1;
 528   for (i = 0; mask; i++, mask <<= 1)
 529     if (but_change & mask)
 530       {
 531         if (i < NUM_TRANSLATED_MOUSE_BUTTONS)
 532           emacs_ev->code = emacs_button_translation[i];
 533         else
 534           emacs_ev->code = i;
 535         break;
 536       }
 537
 538   button_state = event->dwButtonState;
 539   emacs_ev->timestamp = GetTickCount ();
 540   emacs_ev->modifiers = w32_kbd_mods_to_emacs (event->dwControlKeyState, 0) |
 541     ((event->dwButtonState & mask) ? down_modifier : up_modifier);
 542
 543   XSETFASTINT (emacs_ev->x, event->dwMousePosition.X);
 544   XSETFASTINT (emacs_ev->y, event->dwMousePosition.Y);
 545 /* for Mule 2.2 (Based on Emacs 19.28 */
 546 #ifdef MULE
 547   XSET (emacs_ev->frame_or_window, Lisp_Frame, get_frame ());
 548 #else
 549   XSETFRAME (emacs_ev->frame_or_window, get_frame ());
 550 #endif
 551
 552   return 1;
 553 }
 554
 555 static void
 556 resize_event (WINDOW_BUFFER_SIZE_RECORD *event)
 557 {
 558   FRAME_PTR f = get_frame ();
 559
 560   change_frame_size (f, event->dwSize.Y, event->dwSize.X, 0, 1, 0);
 561   SET_FRAME_GARBAGED (f);
 562 }
 563
 564 static void
 565 maybe_generate_resize_event (void)
 566 {
 567   CONSOLE_SCREEN_BUFFER_INFO info;
 568   FRAME_PTR f = get_frame ();
 569
 570   GetConsoleScreenBufferInfo (GetStdHandle (STD_OUTPUT_HANDLE), &info);
 571
 572   /* It is okay to call this unconditionally, since it will do nothing
 573      if the size hasn't actually changed.  */
 574   change_frame_size (f,
 575                      1 + info.srWindow.Bottom - info.srWindow.Top,
 576                      1 + info.srWindow.Right - info.srWindow.Left,
 577                      0, 0, 0);
 578 }
 579
 580 static int
 581 handle_file_notifications (struct input_event *hold_quit)
 582 {
 583   BYTE *p = file_notifications;
 584   FILE_NOTIFY_INFORMATION *fni = (PFILE_NOTIFY_INFORMATION)p;
 585   const DWORD min_size
 586     = offsetof (FILE_NOTIFY_INFORMATION, FileName) + sizeof(wchar_t);
 587   struct input_event inev;
 588   int nevents = 0;
 589
 590   /* We cannot process notification before Emacs is fully initialized,
 591      since we need the UTF-16LE coding-system to be set up.  */
 592   if (!initialized)
 593     {
 594       notification_buffer_in_use = 0;
 595       return nevents;
 596     }
 597
 598   enter_crit ();
 599   if (notification_buffer_in_use)
 600     {
 601       DWORD info_size = notifications_size;
 602       Lisp_Object cs = intern ("utf-16le");
 603       Lisp_Object obj = w32_get_watch_object (notifications_desc);
 604
 605       /* notifications_size could be zero when the buffer of
 606          notifications overflowed on the OS level, or when the
 607          directory being watched was itself deleted.  Do nothing in
 608          that case.  */
 609       if (info_size
 610           && !NILP (obj) && CONSP (obj))
 611         {
 612           Lisp_Object callback = XCDR (obj);
 613
 614           EVENT_INIT (inev);
 615
 616           while (info_size >= min_size)
 617             {
 618               Lisp_Object utf_16_fn
 619                 = make_unibyte_string ((char *)fni->FileName,
 620                                        fni->FileNameLength);
 621               /* Note: mule-conf is preloaded, so utf-16le must
 622                  already be defined at this point.  */
 623               Lisp_Object fname
 624                 = code_convert_string_norecord (utf_16_fn, cs, 0);
 625               Lisp_Object action = lispy_file_action (fni->Action);
 626
 627               inev.kind = FILE_NOTIFY_EVENT;
 628               inev.code = (ptrdiff_t)XINT (XIL ((EMACS_INT)notifications_desc));
 629               inev.timestamp = GetTickCount ();
 630               inev.modifiers = 0;
 631               inev.frame_or_window = callback;
 632               inev.arg = Fcons (action, fname);
 633               kbd_buffer_store_event_hold (&inev, hold_quit);
 634
 635               if (!fni->NextEntryOffset)
 636                 break;
 637               p += fni->NextEntryOffset;
 638               fni = (PFILE_NOTIFY_INFORMATION)p;
 639               info_size -= fni->NextEntryOffset;
 640             }
 641         }
 642       notification_buffer_in_use = 0;
 643     }
 644   leave_crit ();
 645   return nevents;
 646 }
 647
 648 /* Here's an overview of how Emacs input works in non-GUI sessions on
 649    MS-Windows.  (For description of the GUI input, see the commentary
 650    before w32_msg_pump in w32fns.c.)
 651
 652    When Emacs is idle, it loops inside wait_reading_process_output,
 653    calling pselect periodically to check whether any input is
 654    available.  On Windows, pselect is redirected to sys_select, which
 655    uses MsgWaitForMultipleObjects to wait for input, either from the
 656    keyboard or from any of the Emacs subprocesses.  In addition,
 657    MsgWaitForMultipleObjects wakes up when some Windows message is
 658    posted to the input queue of the Emacs's main thread (which is the
 659    thread in which sys_select runs).
 660
 661    When the Emacs's console window has focus, Windows sends input
 662    events that originate from the keyboard or the mouse; these events
 663    wake up MsgWaitForMultipleObjects, which reports that input is
 664    available.  Emacs then calls w32_console_read_socket, below, to
 665    read the input.  w32_console_read_socket uses
 666    GetNumberOfConsoleInputEvents and ReadConsoleInput to peek at and
 667    read the console input events.
 668
 669    One type of non-keyboard input event that gets reported as input
 670    available is due to the Emacs's console window receiving focus.
 671    When that happens, Emacs gets the FOCUS_EVENT event and sys_select
 672    reports some input; however, w32_console_read_socket ignores such
 673    events when called to read them.
 674
 675    Note that any other Windows message sent to the main thread will
 676    also wake up MsgWaitForMultipleObjects.  These messages get
 677    immediately dispatched to their destinations by calling
 678    drain_message_queue.  */
 679
 680 int
 681 w32_console_read_socket (struct terminal *terminal,
 682                          struct input_event *hold_quit)
 683 {
 684   int nev, add;
 685   int isdead;
 686
 687   block_input ();
 688
 689   for (;;)
 690     {
 691       int nfnotify = handle_file_notifications (hold_quit);
 692
 693       nev = fill_queue (0);
 694       if (nev <= 0)
 695         {
 696           /* If nev == -1, there was some kind of error
 697              If nev == 0 then no events were available
 698              so return.  */
 699           if (nfnotify)
 700             nev = 0;
 701           break;
 702         }
 703
 704       while (nev > 0)
 705         {
 706           struct input_event inev;
 707
 708           EVENT_INIT (inev);
 709           inev.kind = NO_EVENT;
 710           inev.arg = Qnil;
 711
 712           switch (queue_ptr->EventType)
 713             {
 714             case KEY_EVENT:
 715               add = key_event (&queue_ptr->Event.KeyEvent, &inev, &isdead);
 716               if (add == -1) /* 95.7.25 by himi */
 717                 {
 718                   queue_ptr--;
 719                   add = 1;
 720                 }
 721               if (add)
 722                 kbd_buffer_store_event_hold (&inev, hold_quit);
 723               break;
 724
 725             case MOUSE_EVENT:
 726               add = do_mouse_event (&queue_ptr->Event.MouseEvent, &inev);
 727               if (add)
 728                 kbd_buffer_store_event_hold (&inev, hold_quit);
 729               break;
 730
 731             case WINDOW_BUFFER_SIZE_EVENT:
 732               if (w32_use_full_screen_buffer)
 733                 resize_event (&queue_ptr->Event.WindowBufferSizeEvent);
 734               break;
 735
 736             case MENU_EVENT:
 737             case FOCUS_EVENT:
 738               /* Internal event types, ignored. */
 739               break;
 740             }
 741
 742           queue_ptr++;
 743           nev--;
 744         }
 745     }
 746
 747   /* We don't get told about changes in the window size (only the buffer
 748      size, which we no longer care about), so we have to check it
 749      periodically.  */
 750   if (!w32_use_full_screen_buffer)
 751     maybe_generate_resize_event ();
 752
 753   unblock_input ();
 754   return nev;
 755 }