libchimara/input.c

   1 #include "charset.h"
   2 #include "magic.h"
   3 #include "input.h"
   4 #include "pager.h"
   5 #include "chimara-glk-private.h"
   6 #include "garglk.h"
   7
   8 extern GPrivate *glk_data_key;
   9
  10 /* Forward declarations */
  11 static int finish_text_buffer_line_input(winid_t win, gboolean emit_signal);
  12 static int finish_text_grid_line_input(winid_t win, gboolean emit_signal);
  13 static void cancel_old_input_request(winid_t win);
  14
  15 /* Internal function: code common to both flavors of char event request */
  16 void
  17 request_char_event_common(winid_t win, gboolean unicode)
  18 {
  19         VALID_WINDOW(win, return);
  20         g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
  21
  22         cancel_old_input_request(win);
  23
  24         flush_window_buffer(win);
  25
  26         if(win->type == wintype_TextBuffer) {
  27                 /* Move the input_position mark to the end of the window_buffer */
  28                 GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
  29                 GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
  30                 GtkTextIter end_iter;
  31                 gtk_text_buffer_get_end_iter(buffer, &end_iter);
  32                 gtk_text_buffer_move_mark(buffer, input_position, &end_iter);
  33         }
  34
  35
  36         win->input_request_type = unicode? INPUT_REQUEST_CHARACTER_UNICODE : INPUT_REQUEST_CHARACTER;
  37         g_signal_handler_unblock( win->widget, win->char_input_keypress_handler );
  38
  39         gdk_threads_enter();
  40         gtk_widget_grab_focus( GTK_WIDGET(win->widget) );
  41         gdk_threads_leave();
  42
  43         /* Emit the "waiting" signal to let listeners know we are ready for input */
  44         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
  45         g_signal_emit_by_name(glk_data->self, "waiting");
  46 }
  47
  48 /**
  49  * glk_request_char_event:
  50  * @win: A window to request char events from.
  51  *
  52  * Request input of a Latin-1 character or special key. A window cannot have
  53  * requests for both character and line input at the same time. Nor can it have
  54  * requests for character input of both types (Latin-1 and Unicode). It is
  55  * illegal to call glk_request_char_event() if the window already has a pending
  56  * request for either character or line input.
  57  */
  58 void
  59 glk_request_char_event(winid_t win)
  60 {
  61         request_char_event_common(win, FALSE);
  62 }
  63
  64 /**
  65  * glk_request_char_event_uni:
  66  * @win: A window to request char events from.
  67  *
  68  * Request input of a Unicode character or special key. See
  69  * glk_request_char_event().
  70  */
  71 void
  72 glk_request_char_event_uni(winid_t win)
  73 {
  74         request_char_event_common(win, TRUE);
  75 }
  76
  77 /**
  78  * glk_cancel_char_event:
  79  * @win: A window to cancel the latest char event request on.
  80  *
  81  * This cancels a pending request for character input. (Either Latin-1 or
  82  * Unicode.) For convenience, it is legal to call glk_cancel_char_event() even
  83  * if there is no charcter input request on that window. Glk will ignore the
  84  * call in this case.
  85  */
  86 void
  87 glk_cancel_char_event(winid_t win)
  88 {
  89         VALID_WINDOW(win, return);
  90         g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
  91
  92         if(win->input_request_type == INPUT_REQUEST_CHARACTER || win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE)
  93         {
  94                 win->input_request_type = INPUT_REQUEST_NONE;
  95                 g_signal_handler_block( win->widget, win->char_input_keypress_handler );
  96         }
  97 }
  98
  99 /* Internal function: Request either latin-1 or unicode line input, in a text grid window. */
 100 static void
 101 text_grid_request_line_event_common(winid_t win, glui32 maxlen, gboolean insert, gchar *inserttext)
 102 {
 103         /* All outstanding printing _must_ be finished before putting an input entry
 104          into the buffer */
 105         flush_window_buffer(win);
 106
 107         gdk_threads_enter();
 108
 109         GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 110
 111     GtkTextMark *cursor = gtk_text_buffer_get_mark(buffer, "cursor_position");
 112     GtkTextIter start_iter, end_iter;
 113     gtk_text_buffer_get_iter_at_mark(buffer, &start_iter, cursor);
 114
 115     /* Determine the maximum length of the line input */
 116     gint cursorpos = gtk_text_iter_get_line_offset(&start_iter);
 117     /* Odd; the Glk spec says the maximum input length is
 118     windowwidth - 1 - cursorposition. I say no, because if cursorposition is
 119     zero, then the input should fill the whole line. FIXME??? */
 120     win->input_length = MIN(win->width - cursorpos, win->line_input_buffer_max_len);
 121     end_iter = start_iter;
 122     gtk_text_iter_set_line_offset(&end_iter, cursorpos + win->input_length);
 123
 124         /* If the buffer currently has a selection with one bound in the middle of
 125         the input field, then deselect it. Otherwise the input field gets trashed */
 126         GtkTextIter start_sel, end_sel;
 127         if( gtk_text_buffer_get_selection_bounds(buffer, &start_sel, &end_sel) )
 128         {
 129                 if( gtk_text_iter_in_range(&start_sel, &start_iter, &end_iter) )
 130                         gtk_text_buffer_place_cursor(buffer, &end_sel);
 131                 if( gtk_text_iter_in_range(&end_sel, &start_iter, &end_iter) )
 132                         gtk_text_buffer_place_cursor(buffer, &start_sel);
 133         }
 134
 135     /* Erase the text currently in the input field and replace it with a GtkEntry */
 136     gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
 137     win->input_anchor = gtk_text_buffer_create_child_anchor(buffer, &start_iter);
 138     win->input_entry = gtk_entry_new();
 139         /* Set the entry's font to match that of the window */
 140     GtkRcStyle *style = gtk_widget_get_modifier_style(win->widget);     /* Don't free */
 141         gtk_widget_modify_font(win->input_entry, style->font_desc);
 142         /* Make the entry as small as possible to fit with the text */
 143         gtk_entry_set_has_frame(GTK_ENTRY(win->input_entry), FALSE);
 144         GtkBorder border = { 0, 0, 0, 0 };
 145
 146         gtk_entry_set_inner_border(GTK_ENTRY(win->input_entry), &border);
 147     gtk_entry_set_max_length(GTK_ENTRY(win->input_entry), win->input_length);
 148     gtk_entry_set_width_chars(GTK_ENTRY(win->input_entry), win->input_length);
 149
 150     /* Insert pre-entered text if needed */
 151     if(insert)
 152         gtk_entry_set_text(GTK_ENTRY(win->input_entry), inserttext);
 153
 154     /* Set background color of entry (TODO: implement as property) */
 155     GdkColor background;
 156         gdk_color_parse("grey", &background);
 157     gtk_widget_modify_base(win->input_entry, GTK_STATE_NORMAL, &background);
 158
 159     g_signal_connect(win->input_entry, "activate", G_CALLBACK(on_input_entry_activate), win);
 160     g_signal_connect(win->input_entry, "key-press-event", G_CALLBACK(on_input_entry_key_press_event), win);
 161     win->line_input_entry_changed = g_signal_connect(win->input_entry, "changed", G_CALLBACK(on_input_entry_changed), win);
 162
 163     gtk_widget_show(win->input_entry);
 164     gtk_text_view_add_child_at_anchor(GTK_TEXT_VIEW(win->widget), win->input_entry, win->input_anchor);
 165
 166         gtk_widget_grab_focus(win->input_entry);
 167
 168         gdk_threads_leave();
 169 }
 170
 171 /* Internal function: Request either latin-1 or unicode line input, in a text buffer window. */
 172 static void
 173 text_buffer_request_line_event_common(winid_t win, glui32 maxlen, gboolean insert, gchar *inserttext)
 174 {
 175         flush_window_buffer(win);
 176
 177         gdk_threads_enter();
 178
 179         GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 180
 181     /* Move the input_position mark to the end of the window_buffer */
 182     GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
 183     GtkTextIter end_iter;
 184     gtk_text_buffer_get_end_iter(buffer, &end_iter);
 185     gtk_text_buffer_move_mark(buffer, input_position, &end_iter);
 186
 187     /* Set the entire contents of the window_buffer as uneditable
 188      * (so input can only be entered at the end) */
 189     GtkTextIter start_iter;
 190     gtk_text_buffer_get_start_iter(buffer, &start_iter);
 191     gtk_text_buffer_remove_tag_by_name(buffer, "uneditable", &start_iter, &end_iter);
 192     gtk_text_buffer_apply_tag_by_name(buffer, "uneditable", &start_iter, &end_iter);
 193
 194     /* Insert pre-entered text if needed */
 195     if(insert) {
 196         gtk_text_buffer_insert(buffer, &end_iter, inserttext, -1);
 197                 gtk_text_buffer_get_end_iter(buffer, &end_iter); /* update after text insertion */
 198         }
 199
 200         /* Apply the correct style to the input prompt */
 201         GtkTextIter input_iter;
 202     gtk_text_buffer_get_iter_at_mark(buffer, &input_iter, input_position);
 203     gtk_text_buffer_apply_tag_by_name(buffer, "default", &input_iter, &end_iter);
 204     gtk_text_buffer_apply_tag_by_name(buffer, "input", &input_iter, &end_iter);
 205     gtk_text_buffer_apply_tag_by_name(buffer, "glk-input", &input_iter, &end_iter);
 206
 207     gtk_text_view_set_editable(GTK_TEXT_VIEW(win->widget), TRUE);
 208
 209         g_signal_handler_unblock(buffer, win->insert_text_handler);
 210         gtk_widget_grab_focus(win->widget);
 211
 212         gdk_threads_leave();
 213 }
 214
 215 /**
 216  * glk_request_line_event:
 217  * @win: A text buffer or text grid window to request line input on.
 218  * @buf: A buffer of at least @maxlen bytes.
 219  * @maxlen: Length of the buffer.
 220  * @initlen: The number of characters in @buf to pre-enter.
 221  *
 222  * Requests input of a line of Latin-1 characters. A window cannot have requests
 223  * for both character and line input at the same time. Nor can it have requests
 224  * for line input of both types (Latin-1 and Unicode). It is illegal to call
 225  * glk_request_line_event() if the window already has a pending request for
 226  * either character or line input.
 227  *
 228  * The @buf argument is a pointer to space where the line input will be stored.
 229  * (This may not be %NULL.) @maxlen is the length of this space, in bytes; the
 230  * library will not accept more characters than this. If @initlen is nonzero,
 231  * then the first @initlen bytes of @buf will be entered as pre-existing input
 232  * &mdash; just as if the player had typed them himself. (The player can continue
 233  * composing after this pre-entered input, or delete it or edit as usual.)
 234  *
 235  * The contents of the buffer are undefined until the input is completed (either
 236  * by a line input event, or glk_cancel_line_event(). The library may or may not
 237  * fill in the buffer as the player composes, while the input is still pending;
 238  * it is illegal to change the contents of the buffer yourself.
 239  */
 240 void
 241 glk_request_line_event(winid_t win, char *buf, glui32 maxlen, glui32 initlen)
 242 {
 243         VALID_WINDOW(win, return);
 244         g_return_if_fail(buf);
 245         g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
 246         g_return_if_fail(initlen <= maxlen);
 247
 248         cancel_old_input_request(win);
 249
 250         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
 251
 252         /* Register the buffer */
 253         if(glk_data->register_arr)
 254         win->buffer_rock = (*glk_data->register_arr)(buf, maxlen, "&+#!Cn");
 255
 256         win->input_request_type = INPUT_REQUEST_LINE;
 257         win->line_input_buffer = buf;
 258         win->line_input_buffer_max_len = maxlen;
 259         win->echo_current_line_input = win->echo_line_input;
 260         win->current_extra_line_terminators = g_slist_copy(win->extra_line_terminators);
 261
 262         gchar *inserttext = (initlen > 0)? g_strndup(buf, initlen) : g_strdup("");
 263         switch(win->type)
 264         {
 265             case wintype_TextBuffer:
 266                 text_buffer_request_line_event_common(win, maxlen, (initlen > 0), inserttext);
 267                 break;
 268             case wintype_TextGrid:
 269                 text_grid_request_line_event_common(win, maxlen, (initlen > 0), inserttext);
 270                 break;
 271     }
 272         g_free(inserttext);
 273         g_signal_handler_unblock(win->widget, win->line_input_keypress_handler);
 274
 275         /* Emit the "waiting" signal to let listeners know we are ready for input */
 276         g_signal_emit_by_name(glk_data->self, "waiting");
 277 }
 278
 279 /**
 280  * glk_request_line_event_uni:
 281  * @win: A text buffer or text grid window to request line input on.
 282  * @buf: A buffer of at least @maxlen characters.
 283  * @maxlen: Length of the buffer.
 284  * @initlen: The number of characters in @buf to pre-enter.
 285  *
 286  * Request input of a line of Unicode characters. This works the same as
 287  * glk_request_line_event(), except the result is stored in an array of
 288  * <type>glui32</type> values instead of an array of characters, and the values
 289  * may be any valid Unicode code points.
 290  *
 291  * If possible, the library should return fully composed Unicode characters,
 292  * rather than strings of base and composition characters.
 293  *
 294  * <note><para>
 295  *   Fully-composed characters are the norm for Unicode text, so an
 296  *   implementation that ignores this issue will probably produce the right
 297  *   result. However, the game may not want to rely on that. Another factor is
 298  *   that case-folding can (occasionally) produce non-normalized text.
 299  *   Therefore, to cover all its bases, a game should call
 300  *   glk_buffer_to_lower_case_uni(), followed by
 301  *   glk_buffer_canon_normalize_uni(), before parsing.
 302  * </para></note>
 303  *
 304  * <note><para>
 305  *   Earlier versions of this spec said that line input must always be in
 306  *   Unicode Normalization Form C. However, this has not been universally
 307  *   implemented. It is also somewhat redundant, for the results noted above.
 308  *   Therefore, we now merely recommend that line input be fully composed. The
 309  *   game is ultimately responsible for all case-folding and normalization. See
 310  *   <link linkend="chimara-Unicode-String-Normalization">Unicode String
 311  *   Normalization</link>.
 312  * </para></note>
 313  */
 314 void
 315 glk_request_line_event_uni(winid_t win, glui32 *buf, glui32 maxlen, glui32 initlen)
 316 {
 317         VALID_WINDOW(win, return);
 318         g_return_if_fail(buf);
 319         g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
 320         g_return_if_fail(initlen <= maxlen);
 321
 322         cancel_old_input_request(win);
 323         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
 324
 325         /* Register the buffer */
 326         if(glk_data->register_arr)
 327         win->buffer_rock = (*glk_data->register_arr)(buf, maxlen, "&+#!Iu");
 328
 329         win->input_request_type = INPUT_REQUEST_LINE_UNICODE;
 330         win->line_input_buffer_unicode = buf;
 331         win->line_input_buffer_max_len = maxlen;
 332         win->echo_current_line_input = win->echo_line_input;
 333         win->current_extra_line_terminators = g_slist_copy(win->extra_line_terminators);
 334
 335         gchar *utf8;
 336         if(initlen > 0) {
 337                 utf8 = convert_ucs4_to_utf8(buf, initlen);
 338                 if(utf8 == NULL)
 339                         return;
 340         }
 341         else
 342                 utf8 = g_strdup("");
 343
 344     switch(win->type)
 345         {
 346             case wintype_TextBuffer:
 347                 text_buffer_request_line_event_common(win, maxlen, (initlen > 0), utf8);
 348                 break;
 349             case wintype_TextGrid:
 350                 text_grid_request_line_event_common(win, maxlen, (initlen > 0), utf8);
 351                 break;
 352     }
 353     g_signal_handler_unblock(win->widget, win->line_input_keypress_handler);
 354         g_free(utf8);
 355
 356         /* Emit the "waiting" signal to let listeners know we are ready for input */
 357         g_signal_emit_by_name(glk_data->self, "waiting");
 358 }
 359
 360 /**
 361  * glk_cancel_line_event:
 362  * @win: A text buffer or text grid window to cancel line input on.
 363  * @event: Will be filled in if the user had already input something.
 364  *
 365  * This cancels a pending request for line input. (Either Latin-1 or Unicode.)
 366  *
 367  * The event pointed to by the event argument will be filled in as if the
 368  * player had hit <keycap>enter</keycap>, and the input composed so far will be
 369  * stored in the buffer; see below. If you do not care about this information,
 370  * pass %NULL as the @event argument. (The buffer will still be filled.)
 371  *
 372  * For convenience, it is legal to call glk_cancel_line_event() even if there
 373  * is no line input request on that window. The event type will be set to
 374  * %evtype_None in this case.
 375  */
 376 void
 377 glk_cancel_line_event(winid_t win, event_t *event)
 378 {
 379         VALID_WINDOW(win, return);
 380         g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
 381
 382         if(event != NULL) {
 383                 event->type = evtype_None;
 384                 event->win = win;
 385                 event->val1 = 0;
 386                 event->val2 = 0;
 387         }
 388
 389         if(win->input_request_type != INPUT_REQUEST_LINE && win->input_request_type != INPUT_REQUEST_LINE_UNICODE)
 390                 return;
 391
 392         g_signal_handler_block( win->widget, win->line_input_keypress_handler );
 393
 394         int chars_written = 0;
 395
 396         gdk_threads_enter();
 397         if(win->type == wintype_TextGrid) {
 398                 chars_written = finish_text_grid_line_input(win, FALSE);
 399         } else if(win->type == wintype_TextBuffer) {
 400                 gtk_text_view_set_editable( GTK_TEXT_VIEW(win->widget), FALSE );
 401                 GtkTextBuffer *window_buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 402                 g_signal_handler_block(window_buffer, win->insert_text_handler);
 403                 chars_written = finish_text_buffer_line_input(win, FALSE);
 404         }
 405         gdk_threads_leave();
 406
 407         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
 408         if(glk_data->unregister_arr)
 409         {
 410                 if(win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
 411                         (*glk_data->unregister_arr)(win->line_input_buffer_unicode, win->line_input_buffer_max_len, "&+#!Iu", win->buffer_rock);
 412                 else
 413                 (*glk_data->unregister_arr)(win->line_input_buffer, win->line_input_buffer_max_len, "&+#!Cn", win->buffer_rock);
 414     }
 415
 416         if(event != NULL && chars_written > 0) {
 417                 event->type = evtype_LineInput;
 418                 event->val1 = chars_written;
 419         }
 420 }
 421
 422 /* Helper function: Turn off shutdown key-press-event signal handler */
 423 static gboolean
 424 turn_off_handler(GNode *node)
 425 {
 426         winid_t win = node->data;
 427         g_signal_handler_block(win->widget, win->shutdown_keypress_handler);
 428         return FALSE; /* don't stop */
 429 }
 430
 431 /* Internal function: Callback for signal key-press-event while waiting for shutdown. */
 432 gboolean
 433 on_shutdown_key_press_event(GtkWidget *widget, GdkEventKey *event, winid_t win)
 434 {
 435         ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(widget, CHIMARA_TYPE_GLK));
 436         g_assert(glk);
 437         CHIMARA_GLK_USE_PRIVATE(glk, priv);
 438
 439         /* Turn off all the signal handlers */
 440         if(priv->root_window)
 441                 g_node_traverse(priv->root_window, G_IN_ORDER, G_TRAVERSE_LEAVES, -1, (GNodeTraverseFunc)turn_off_handler, NULL);
 442
 443         /* Signal the Glk library that it can shut everything down now */
 444         g_mutex_lock(&priv->shutdown_lock);
 445         g_cond_signal(&priv->shutdown_key_pressed);
 446         g_mutex_unlock(&priv->shutdown_lock);
 447
 448         return TRUE; /* block the event */
 449 }
 450
 451 /* Internal function: General callback for signal key-press-event on a text buffer or text grid window. Used in character input on both text buffers and grids. Blocked when not in use. */
 452 gboolean
 453 on_char_input_key_press_event(GtkWidget *widget, GdkEventKey *event, winid_t win)
 454 {
 455         /* Ignore modifier keys, otherwise the char input will already trigger on
 456         the shift key when the user tries to type a capital letter */
 457         if(event->is_modifier)
 458                 return FALSE; /* don't stop the event */
 459
 460         /* All text up to the input position is now regarded as being read by the user */
 461         if(win->type == wintype_TextBuffer)
 462                 pager_update(win);
 463
 464         glui32 keycode = keyval_to_glk_keycode(event->keyval, win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE);
 465
 466         ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(widget, CHIMARA_TYPE_GLK));
 467         g_assert(glk);
 468         event_throw(glk, evtype_CharInput, win, keycode, 0);
 469         g_signal_emit_by_name(glk, "char-input", win->rock, event->keyval);
 470
 471         /* Only one keypress will be handled */
 472         win->input_request_type = INPUT_REQUEST_NONE;
 473         g_signal_handler_block(win->widget, win->char_input_keypress_handler);
 474
 475         return TRUE;
 476 }
 477
 478 gboolean
 479 on_line_input_key_press_event(GtkWidget *widget, GdkEventKey *event, winid_t win)
 480 {
 481         switch(win->type)
 482         {
 483                 case wintype_TextBuffer:
 484                 {
 485                         GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(win->widget));
 486                         GtkTextMark *input_position_mark = gtk_text_buffer_get_mark(buffer, "input_position");
 487                         GtkTextIter input_position_iter;
 488                         gtk_text_buffer_get_iter_at_mark(buffer, &input_position_iter, input_position_mark);
 489                         GtkTextIter end_iter;
 490                         gtk_text_buffer_get_end_iter(buffer, &end_iter);
 491
 492                         /* Check whether the cursor is at the prompt or somewhere else in the text */
 493                         GtkTextIter selection_start, selection_end;
 494                         gtk_text_buffer_get_selection_bounds(buffer, &selection_start, &selection_end);
 495                         if(gtk_text_iter_compare(&selection_start, &input_position_iter) < 0) {
 496                                 // Cursor is somewhere else in the text, place it at the end if the user starts typing
 497                                 if(event->keyval >= GDK_KEY_space && event->keyval <= GDK_KEY_asciitilde) {
 498                                         gtk_text_buffer_place_cursor(buffer, &end_iter);
 499                                 } else {
 500                                         // User is walking around, let him be.
 501                                         return FALSE;
 502                                 }
 503                         }
 504
 505                         /* All text up to the input position is now regarded as being read by the user */
 506                         pager_update(win);
 507
 508                         /* History up/down */
 509                         if(event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up
 510                                 || event->keyval == GDK_KEY_Down || event->keyval == GDK_KEY_KP_Down)
 511                         {
 512                                 /* Prevent falling off the end of the history list */
 513                                 if(win->history == NULL)
 514                                         return TRUE;
 515                                 if( (event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up)
 516                                         && win->history_pos && win->history_pos->next == NULL)
 517                                         return TRUE;
 518                                 if( (event->keyval == GDK_KEY_Down || event->keyval == GDK_KEY_KP_Down)
 519                                         && (win->history_pos == NULL || win->history_pos->prev == NULL) )
 520                                         return TRUE;
 521
 522                                 /* Erase any text that was already typed */
 523                                 if(win->history_pos == NULL) {
 524                                         gchar *current_input = gtk_text_buffer_get_text(buffer, &input_position_iter, &end_iter, FALSE);
 525                                         win->history = g_list_prepend(win->history, current_input);
 526                                         win->history_pos = win->history;
 527                                 }
 528
 529                                 gtk_text_buffer_delete(buffer, &input_position_iter, &end_iter);
 530
 531                                 if(event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up)
 532                                 {
 533                                         if(win->history_pos)
 534                                                 win->history_pos = g_list_next(win->history_pos);
 535                                         else
 536                                                 win->history_pos = win->history;
 537                                 }
 538                                 else /* down */
 539                                         win->history_pos = g_list_previous(win->history_pos);
 540
 541                                 /* Insert the history item into the window */
 542                                 gtk_text_buffer_get_end_iter(buffer, &end_iter);
 543
 544                                 g_signal_handler_block(buffer, win->insert_text_handler);
 545                                 gtk_text_buffer_insert_with_tags_by_name(buffer, &end_iter, win->history_pos->data, -1, "default", "input", "glk-input", NULL);
 546                                 g_signal_handler_unblock(buffer, win->insert_text_handler);
 547
 548                                 return TRUE;
 549                         }
 550
 551                         /* Move to beginning/end of input field */
 552                         else if(event->keyval == GDK_KEY_Home) {
 553                                 GtkTextIter input_iter;
 554                                 GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
 555                                 gtk_text_buffer_get_iter_at_mark(buffer, &input_iter, input_position);
 556                                 gtk_text_buffer_place_cursor(buffer, &input_iter);
 557                                 return TRUE;
 558                         }
 559                         else if(event->keyval == GDK_KEY_End) {
 560                                 gtk_text_buffer_place_cursor(buffer, &end_iter);
 561                                 return TRUE;
 562                         }
 563
 564                         /* Handle the line terminators */
 565                         else if(event->keyval == GDK_KEY_Return || event->keyval == GDK_KEY_KP_Enter
 566                            || g_slist_find(win->current_extra_line_terminators, GUINT_TO_POINTER(event->keyval)))
 567                         {
 568                                 /* Remove signal handlers */
 569                                 g_signal_handler_block(buffer, win->insert_text_handler);
 570                                 g_signal_handler_block(win->widget, win->line_input_keypress_handler);
 571
 572                                 /* Insert a newline (even if line input was terminated with a different key */
 573                                 gtk_text_buffer_get_end_iter(buffer, &end_iter);
 574                                 gtk_text_buffer_insert(buffer, &end_iter, "\n", 1);
 575                                 gtk_text_buffer_place_cursor(buffer, &end_iter);
 576
 577                                 /* Make the window uneditable again and retrieve the text that was input */
 578                                 gtk_text_view_set_editable(GTK_TEXT_VIEW(win->widget), FALSE);
 579
 580                                 int chars_written = finish_text_buffer_line_input(win, TRUE);
 581                                 ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
 582                                 event_throw(glk, evtype_LineInput, win, chars_written, 0);
 583                                 return TRUE;
 584                         }
 585                 }
 586                         return FALSE;
 587
 588                 /* If this is a text grid window, then redirect the key press to the line input GtkEntry */
 589                 case wintype_TextGrid:
 590                 {
 591                         if(event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up
 592                                 || event->keyval == GDK_KEY_Down || event->keyval == GDK_KEY_KP_Down
 593                                 || event->keyval == GDK_KEY_Left || event->keyval == GDK_KEY_KP_Left
 594                                 || event->keyval == GDK_KEY_Right || event->keyval == GDK_KEY_KP_Right
 595                                 || event->keyval == GDK_KEY_Tab || event->keyval == GDK_KEY_KP_Tab
 596                                 || event->keyval == GDK_KEY_Page_Up || event->keyval == GDK_KEY_KP_Page_Up
 597                                 || event->keyval == GDK_KEY_Page_Down || event->keyval == GDK_KEY_KP_Page_Down
 598                                 || event->keyval == GDK_KEY_Home || event->keyval == GDK_KEY_KP_Home
 599                                 || event->keyval == GDK_KEY_End || event->keyval == GDK_KEY_KP_End)
 600                                 return FALSE; /* Don't redirect these keys */
 601                         gtk_widget_grab_focus(win->input_entry);
 602                         gtk_editable_set_position(GTK_EDITABLE(win->input_entry), -1);
 603                         gboolean retval = TRUE;
 604                         g_signal_emit_by_name(win->input_entry, "key-press-event", event, &retval);
 605                         return retval; /* Block this key event if the entry handled it */
 606                 }
 607         }
 608         return FALSE;
 609 }
 610
 611 /* Internal function: finish handling a line input request, for both text grid and text buffer windows. */
 612 static int
 613 write_to_window_buffer(winid_t win, const gchar *inserted_text)
 614 {
 615         int copycount = 0;
 616
 617     /* Convert the string from UTF-8 to Latin-1 or Unicode */
 618     if(win->input_request_type == INPUT_REQUEST_LINE)
 619     {
 620         gsize bytes_written;
 621         gchar *latin1 = convert_utf8_to_latin1(inserted_text, &bytes_written);
 622
 623         if(latin1 == NULL)
 624             return 0;
 625
 626         /* Place input in the echo stream */
 627         if(win->echo_stream != NULL)
 628             glk_put_string_stream(win->echo_stream, latin1);
 629
 630         /* Copy the string (bytes_written does not include the NULL at the end) */
 631         copycount = MIN(win->line_input_buffer_max_len, bytes_written);
 632         memcpy(win->line_input_buffer, latin1, copycount);
 633         g_free(latin1);
 634     }
 635     else if(win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
 636     {
 637         glong items_written;
 638         gunichar *unicode = convert_utf8_to_ucs4(inserted_text, &items_written);
 639
 640         if(unicode == NULL)
 641             return 0;
 642
 643         /* Place input in the echo stream */
 644         if(win->echo_stream != NULL)
 645             glk_put_string_stream_uni(win->echo_stream, unicode);
 646
 647         /* Copy the string (but not the NULL at the end) */
 648         copycount = MIN(win->line_input_buffer_max_len, items_written);
 649         memcpy(win->line_input_buffer_unicode, unicode, copycount * sizeof(gunichar));
 650         g_free(unicode);
 651     }
 652     else
 653         WARNING("Wrong input request type");
 654
 655     win->input_request_type = INPUT_REQUEST_NONE;
 656         return copycount;
 657 }
 658
 659 /* Internal function: Retrieves the input of a TextBuffer window and stores it in the window buffer.
 660  * Returns the number of characters written, suitable for inclusion in a line input event. */
 661 static int
 662 finish_text_buffer_line_input(winid_t win, gboolean emit_signal)
 663 {
 664         VALID_WINDOW(win, return 0);
 665         g_return_val_if_fail(win->type == wintype_TextBuffer, 0);
 666
 667         GtkTextIter start_iter, end_iter;
 668
 669         GtkTextBuffer *window_buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 670         GtkTextMark *input_position = gtk_text_buffer_get_mark(window_buffer, "input_position");
 671         gtk_text_buffer_get_iter_at_mark(window_buffer, &start_iter, input_position);
 672         gtk_text_buffer_get_end_iter(window_buffer, &end_iter);
 673
 674         gchar *inserted_text = gtk_text_buffer_get_text(window_buffer, &start_iter, &end_iter, FALSE);
 675
 676         /* If echoing is turned off, remove the text from the window */
 677         if(!win->echo_current_line_input)
 678                 gtk_text_buffer_delete(window_buffer, &start_iter, &end_iter);
 679
 680         /* Don't include the newline in the input */
 681         char *last_char = inserted_text + strlen(inserted_text) - 1;
 682         if(*last_char == '\n')
 683                 *last_char = '\0';
 684
 685         int chars_written = write_to_window_buffer(win, inserted_text);
 686         if(emit_signal)
 687         {
 688                 ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
 689                 g_assert(glk);
 690                 g_signal_emit_by_name(glk, "line-input", win->rock, inserted_text);
 691         }
 692
 693         /* Add the text to the window input history */
 694         if(win->history_pos != NULL)
 695         {
 696                 g_free(win->history->data);
 697                 win->history = g_list_delete_link(win->history, win->history);
 698         }
 699         if(*inserted_text != 0)
 700                 win->history = g_list_prepend(win->history, g_strdup(inserted_text));
 701
 702         win->history_pos = NULL;
 703
 704         g_free(inserted_text);
 705
 706         return chars_written;
 707 }
 708
 709 /* Internal function: Retrieves the input of a TextGrid window and stores it in the window buffer.
 710  * Returns the number of characters written, suitable for inclusion in a line input event. */
 711 static int
 712 finish_text_grid_line_input(winid_t win, gboolean emit_signal)
 713 {
 714         VALID_WINDOW(win, return 0);
 715         g_return_val_if_fail(win->type == wintype_TextGrid, 0);
 716
 717         GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 718
 719         gchar *text = g_strdup( gtk_entry_get_text(GTK_ENTRY(win->input_entry)) );
 720         /* Move the focus back into the text view */
 721         gtk_widget_grab_focus(win->widget);
 722         /* Remove entry widget from text view */
 723         /* Should be ok even though this is the widget's own signal handler */
 724         gtk_container_remove( GTK_CONTAINER(win->widget), GTK_WIDGET(win->input_entry) );
 725         win->input_entry = NULL;
 726         /* Delete the child anchor */
 727         GtkTextIter start, end;
 728         gtk_text_buffer_get_iter_at_child_anchor(buffer, &start, win->input_anchor);
 729         end = start;
 730         gtk_text_iter_forward_char(&end); /* Point after the child anchor */
 731         gtk_text_buffer_delete(buffer, &start, &end);
 732         win->input_anchor = NULL;
 733
 734     gchar *spaces = g_strnfill(win->input_length - g_utf8_strlen(text, -1), ' ');
 735     gchar *text_to_insert = g_strconcat(text, spaces, NULL);
 736         g_free(spaces);
 737     gtk_text_buffer_insert(buffer, &start, text_to_insert, -1);
 738     g_free(text_to_insert);
 739
 740     int chars_written = write_to_window_buffer(win, text);
 741     if(emit_signal)
 742     {
 743                 ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
 744                 g_assert(glk);
 745                 g_signal_emit_by_name(glk, "line-input", win->rock, text);
 746     }
 747
 748         /* Add the text to the window input history */
 749         if(win->history_pos != NULL)
 750         {
 751                 g_free(win->history->data);
 752                 win->history = g_list_delete_link(win->history, win->history);
 753         }
 754         if(*text != 0)
 755                 win->history = g_list_prepend(win->history, g_strdup(text));
 756         win->history_pos = NULL;
 757
 758         g_free(text);
 759         return chars_written;
 760 }
 761
 762 /* Internal function: Callback for signal insert-text on a text buffer window.
 763 Runs after the default handler has already inserted the text. */
 764 void
 765 after_window_insert_text(GtkTextBuffer *textbuffer, GtkTextIter *location, gchar *text, gint len, winid_t win)
 766 {
 767         GtkTextBuffer *window_buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 768
 769         /* Set the history position to NULL and erase the text we were already editing */
 770         if(win->history_pos != NULL)
 771         {
 772                 g_free(win->history->data);
 773                 win->history = g_list_delete_link(win->history, win->history);
 774                 win->history_pos = NULL;
 775         }
 776
 777         /* Apply the 'input' style to the text that was entered */
 778         GtkTextIter end_iter;
 779         gtk_text_buffer_get_end_iter(window_buffer, &end_iter);
 780         GtkTextIter input_iter;
 781         GtkTextMark *input_position = gtk_text_buffer_get_mark(window_buffer, "input_position");
 782         gtk_text_buffer_get_iter_at_mark(window_buffer, &input_iter, input_position);
 783         gtk_text_buffer_apply_tag_by_name(window_buffer, "default", &input_iter, &end_iter);
 784         gtk_text_buffer_apply_tag_by_name(window_buffer, "input", &input_iter, &end_iter);
 785         gtk_text_buffer_apply_tag_by_name(window_buffer, "glk-input", &input_iter, &end_iter);
 786 }
 787
 788 /* Internal function: Callback for signal activate on the line input GtkEntry
 789 in a text grid window. */
 790 void
 791 on_input_entry_activate(GtkEntry *input_entry, winid_t win)
 792 {
 793         g_signal_handler_block(win->widget, win->line_input_keypress_handler);
 794
 795         int chars_written = finish_text_grid_line_input(win, TRUE);
 796         ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
 797         event_throw(glk, evtype_LineInput, win, chars_written, 0);
 798 }
 799
 800 /* Internal function: Callback for signal key-press-event on the line input
 801 GtkEntry in a text grid window. */
 802 gboolean
 803 on_input_entry_key_press_event(GtkEntry *input_entry, GdkEventKey *event, winid_t win)
 804 {
 805         if(event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up
 806                 || event->keyval == GDK_KEY_Down || event->keyval == GDK_KEY_KP_Down)
 807         {
 808                 /* Prevent falling off the end of the history list */
 809                 if( (event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up)
 810                         && win->history_pos && win->history_pos->next == NULL)
 811                         return TRUE;
 812                 if( (event->keyval == GDK_KEY_Down || event->keyval == GDK_KEY_KP_Down)
 813                         && (win->history_pos == NULL || win->history_pos->prev == NULL) )
 814                         return TRUE;
 815
 816                 if(win->history_pos == NULL)
 817                 {
 818                         const gchar *current_input = gtk_entry_get_text(input_entry);
 819                         win->history = g_list_prepend(win->history, g_strdup(current_input));
 820                         win->history_pos = win->history;
 821                 }
 822
 823                 if(event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_KP_Up)
 824                 {
 825                         if(win->history_pos)
 826                                 win->history_pos = g_list_next(win->history_pos);
 827                         else
 828                                 win->history_pos = win->history;
 829                 }
 830                 else /* down */
 831                         win->history_pos = g_list_previous(win->history_pos);
 832
 833                 /* Insert the history item into the window */
 834                 g_signal_handler_block(input_entry, win->line_input_entry_changed);
 835                 gtk_entry_set_text(input_entry, win->history_pos->data);
 836                 g_signal_handler_unblock(input_entry, win->line_input_entry_changed);
 837                 return TRUE;
 838         }
 839         else if(g_slist_find(win->current_extra_line_terminators, GUINT_TO_POINTER(event->keyval)))
 840         {
 841                 /* If this key was a line terminator, pretend we pressed enter */
 842                 on_input_entry_activate(input_entry, win);
 843         }
 844         return FALSE;
 845 }
 846
 847 void
 848 on_input_entry_changed(GtkEditable *editable, winid_t win)
 849 {
 850         /* Set the history position to NULL and erase the text we were already editing */
 851         if(win->history_pos != NULL)
 852         {
 853                 g_free(win->history->data);
 854                 win->history = g_list_delete_link(win->history, win->history);
 855                 win->history_pos = NULL;
 856         }
 857 }
 858
 859 glui32
 860 keyval_to_glk_keycode(guint keyval, gboolean unicode)
 861 {
 862         glui32 keycode;
 863         switch(keyval) {
 864                 case GDK_KEY_Up:
 865                 case GDK_KEY_KP_Up: return keycode_Up;
 866                 case GDK_KEY_Down:
 867                 case GDK_KEY_KP_Down: return keycode_Down;
 868                 case GDK_KEY_Left:
 869                 case GDK_KEY_KP_Left: return keycode_Left;
 870                 case GDK_KEY_Right:
 871                 case GDK_KEY_KP_Right: return keycode_Right;
 872                 case GDK_KEY_Linefeed:
 873                 case GDK_KEY_Return:
 874                 case GDK_KEY_KP_Enter: return keycode_Return;
 875                 case GDK_KEY_Delete:
 876                 case GDK_KEY_BackSpace:
 877                 case GDK_KEY_KP_Delete: return keycode_Delete;
 878                 case GDK_KEY_Escape: return keycode_Escape;
 879                 case GDK_KEY_Tab:
 880                 case GDK_KEY_KP_Tab: return keycode_Tab;
 881                 case GDK_KEY_Page_Up:
 882                 case GDK_KEY_KP_Page_Up: return keycode_PageUp;
 883                 case GDK_KEY_Page_Down:
 884                 case GDK_KEY_KP_Page_Down: return keycode_PageDown;
 885                 case GDK_KEY_Home:
 886                 case GDK_KEY_KP_Home: return keycode_Home;
 887                 case GDK_KEY_End:
 888                 case GDK_KEY_KP_End: return keycode_End;
 889                 case GDK_KEY_F1:
 890                 case GDK_KEY_KP_F1: return keycode_Func1;
 891                 case GDK_KEY_F2:
 892                 case GDK_KEY_KP_F2: return keycode_Func2;
 893                 case GDK_KEY_F3:
 894                 case GDK_KEY_KP_F3: return keycode_Func3;
 895                 case GDK_KEY_F4:
 896                 case GDK_KEY_KP_F4: return keycode_Func4;
 897                 case GDK_KEY_F5: return keycode_Func5;
 898                 case GDK_KEY_F6: return keycode_Func6;
 899                 case GDK_KEY_F7: return keycode_Func7;
 900                 case GDK_KEY_F8: return keycode_Func8;
 901                 case GDK_KEY_F9: return keycode_Func9;
 902                 case GDK_KEY_F10: return keycode_Func10;
 903                 case GDK_KEY_F11: return keycode_Func11;
 904                 case GDK_KEY_F12: return keycode_Func12;
 905                 default:
 906                         keycode = gdk_keyval_to_unicode(keyval);
 907                         /* If keycode is 0, then keyval was not recognized; also return
 908                         unknown if Latin-1 input was requested and the character is not in
 909                         Latin-1 */
 910                         if(keycode == 0 || (!unicode && keycode > 255))
 911                                 return keycode_Unknown;
 912                         return keycode;
 913         }
 914 }
 915
 916 void
 917 force_char_input_from_queue(winid_t win, event_t *event)
 918 {
 919         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
 920         guint keyval = GPOINTER_TO_UINT(g_async_queue_pop(glk_data->char_input_queue));
 921
 922         glk_cancel_char_event(win);
 923
 924         gdk_threads_enter();
 925         ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
 926         g_assert(glk);
 927         g_signal_emit_by_name(glk, "char-input", win->rock, keyval);
 928         gdk_threads_leave();
 929
 930         event->type = evtype_CharInput;
 931         event->win = win;
 932         event->val1 = keyval_to_glk_keycode(keyval, win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE);
 933         event->val2 = 0;
 934 }
 935
 936 void
 937 force_line_input_from_queue(winid_t win, event_t *event)
 938 {
 939         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
 940         const gchar *text = g_async_queue_pop(glk_data->line_input_queue);
 941         glui32 chars_written = 0;
 942
 943         gdk_threads_enter();
 944         if(win->type == wintype_TextBuffer)
 945         {
 946                 GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
 947                 GtkTextIter start, end;
 948
 949                 /* Remove signal handlers so the line input doesn't get picked up again */
 950                 g_signal_handler_block(buffer, win->insert_text_handler);
 951                 g_signal_handler_block(win->widget, win->line_input_keypress_handler);
 952
 953                 /* Erase any text that was already typed */
 954                 GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
 955                 gtk_text_buffer_get_iter_at_mark(buffer, &start, input_position);
 956                 gtk_text_buffer_get_end_iter(buffer, &end);
 957                 gtk_text_buffer_delete(buffer, &start, &end);
 958
 959                 /* Make the window uneditable again */
 960                 gtk_text_view_set_editable(GTK_TEXT_VIEW(win->widget), FALSE);
 961
 962                 /* Insert the forced input into the window */
 963                 if(win->echo_current_line_input)
 964                 {
 965                         gtk_text_buffer_get_end_iter(buffer, &end);
 966                         gchar *text_to_insert = g_strconcat(text, "\n", NULL);
 967                         gtk_text_buffer_insert_with_tags_by_name(buffer, &end, text_to_insert, -1, "default", "input", "glk-input", NULL);
 968                 }
 969
 970                 chars_written = finish_text_buffer_line_input(win, TRUE);
 971         }
 972         else if(win->type == wintype_TextGrid)
 973         {
 974                 /* Remove signal handlers so the line input doesn't get picked up again */
 975                 g_signal_handler_block(win->widget, win->char_input_keypress_handler);
 976
 977                 /* Insert the forced input into the window */
 978                 gtk_entry_set_text(GTK_ENTRY(win->input_entry), text);
 979                 chars_written = finish_text_grid_line_input(win, TRUE);
 980         }
 981         gdk_threads_leave();
 982
 983         event->type = evtype_LineInput;
 984         event->win = win;
 985         event->val1 = chars_written;
 986         event->val2 = 0;
 987 }
 988
 989 /*** Internal function: cancels any pending input requests on the window and presents a warning if not INPUT_REQUEST_NONE ***/
 990 void
 991 cancel_old_input_request(winid_t win)
 992 {
 993         switch(win->input_request_type) {
 994         case INPUT_REQUEST_NONE:
 995                 break; /* All is well */
 996         case INPUT_REQUEST_CHARACTER:
 997         case INPUT_REQUEST_CHARACTER_UNICODE:
 998                 glk_cancel_char_event(win);
 999                 WARNING("Cancelling pending char event");
1000                 break;
1001         case INPUT_REQUEST_LINE:
1002         case INPUT_REQUEST_LINE_UNICODE:
1003                 glk_cancel_line_event(win, NULL);
1004                 WARNING("Cancelling pending line event");
1005                 break;
1006         default:
1007                 WARNING("Could not cancel pending input request: unknown input request");
1008         }
1009 }
1010
1011 /**
1012  * glk_set_echo_line_event:
1013  * @win: The window in which to change the echoing behavior.
1014  * @val: Zero to turn off echoing, nonzero for normal echoing.
1015  *
1016  * Normally, after line input is completed or cancelled in a buffer window, the
1017  * library ensures that the complete input line (or its latest state, after
1018  * cancelling) is displayed at the end of the buffer, followed by a newline.
1019  * This call allows you to suppress this behavior. If the @val argument is zero,
1020  * all <emphasis>subsequent</emphasis> line input requests in the given window
1021  * will leave the buffer unchanged after the input is completed or cancelled;
1022  * the player's input will not be printed. If @val is nonzero, subsequent input
1023  * requests will have the normal printing behavior.
1024  *
1025  * <note><para>
1026  *   Note that this feature is unrelated to the window's echo stream.
1027  * </para></note>
1028  *
1029  * If you turn off line input echoing, you can reproduce the standard input
1030  * behavior by following each line input event (or line input cancellation) by
1031  * printing the input line, in the Input style, followed by a newline in the
1032  * original style.
1033  *
1034  * The glk_set_echo_line_event() does not affect a pending line input request.
1035  * It also has no effect in non-buffer windows.
1036  * <note><para>
1037  *   In a grid window, the game can overwrite the input area at will, so there
1038  *   is no need for this distinction.
1039  * </para></note>
1040  *
1041  * Not all libraries support this feature. You can test for it with
1042  * %gestalt_LineInputEcho.
1043  */
1044 void
1045 glk_set_echo_line_event(winid_t win, glui32 val)
1046 {
1047         VALID_WINDOW(win, return);
1048
1049         if(win->type != wintype_TextBuffer)
1050                 return; /* Quietly do nothing */
1051
1052         win->echo_line_input = val? TRUE : FALSE;
1053 }
1054
1055 /* Internal function to convert from a Glk keycode to a GDK keyval. */
1056 static unsigned
1057 keycode_to_gdk_keyval(glui32 keycode)
1058 {
1059         switch (keycode)
1060         {
1061                 case keycode_Left:
1062                         return GDK_KEY_Left;
1063                 case keycode_Right:
1064                         return GDK_KEY_Right;
1065                 case keycode_Up:
1066                         return GDK_KEY_Up;
1067                 case keycode_Down:
1068                         return GDK_KEY_Down;
1069                 case keycode_Return:
1070                         return GDK_KEY_Return;
1071                 case keycode_Delete:
1072                         return GDK_KEY_Delete;
1073                 case keycode_Escape:
1074                         return GDK_KEY_Escape;
1075                 case keycode_Tab:
1076                         return GDK_KEY_Tab;
1077                 case keycode_PageUp:
1078                         return GDK_KEY_Page_Up;
1079                 case keycode_PageDown:
1080                         return GDK_KEY_Page_Down;
1081                 case keycode_Home:
1082                         return GDK_KEY_Home;
1083                 case keycode_End:
1084                         return GDK_KEY_End;
1085                 case keycode_Func1:
1086                         return GDK_KEY_F1;
1087                 case keycode_Func2:
1088                         return GDK_KEY_F2;
1089                 case keycode_Func3:
1090                         return GDK_KEY_F3;
1091                 case keycode_Func4:
1092                         return GDK_KEY_F4;
1093                 case keycode_Func5:
1094                         return GDK_KEY_F5;
1095                 case keycode_Func6:
1096                         return GDK_KEY_F6;
1097                 case keycode_Func7:
1098                         return GDK_KEY_F7;
1099                 case keycode_Func8:
1100                         return GDK_KEY_F8;
1101                 case keycode_Func9:
1102                         return GDK_KEY_F9;
1103                 case keycode_Func10:
1104                         return GDK_KEY_F10;
1105                 case keycode_Func11:
1106                         return GDK_KEY_F11;
1107                 case keycode_Func12:
1108                         return GDK_KEY_F12;
1109                 case keycode_Erase:
1110                         return GDK_KEY_BackSpace;
1111         }
1112         unsigned keyval = gdk_unicode_to_keyval(keycode);
1113         if(keyval < 0x01000000) /* magic number meaning illegal unicode point */
1114                 return keyval;
1115         return 0;
1116 }
1117
1118 /* Internal function to decide whether @keycode is a valid line terminator. */
1119 gboolean
1120 is_valid_line_terminator(glui32 keycode)
1121 {
1122         switch(keycode) {
1123                 case keycode_Escape:
1124                 case keycode_Func1:
1125                 case keycode_Func2:
1126                 case keycode_Func3:
1127                 case keycode_Func4:
1128                 case keycode_Func5:
1129                 case keycode_Func6:
1130                 case keycode_Func7:
1131                 case keycode_Func8:
1132                 case keycode_Func9:
1133                 case keycode_Func10:
1134                 case keycode_Func11:
1135                 case keycode_Func12:
1136                         return TRUE;
1137         }
1138         return FALSE;
1139 }
1140
1141 /**
1142  * glk_set_terminators_line_event:
1143  * @win: The window for which to set the line input terminator keys.
1144  * @keycodes: An array of <code>keycode_</code> constants, of length @count.
1145  * @count: The array length of @keycodes.
1146  *
1147  * It is possible to request that other keystrokes complete line input as well.
1148  * (This allows a game to intercept function keys or other special keys during
1149  * line input.) To do this, call glk_set_terminators_line_event(), and pass an
1150  * array of @count keycodes. These must all be special keycodes (see <link
1151  * linkend="chimara-Character-Input">Character Input</link>). Do not include
1152  * regular printable characters in the array, nor %keycode_Return (which
1153  * represents the default <keycap>enter</keycap> key and will always be
1154  * recognized). To return to the default behavior, pass a %NULL or empty array.
1155  *
1156  * The glk_set_terminators_line_event() affects <emphasis>subsequent</emphasis>
1157  * line input requests in the given window. It does not affect a pending line
1158  * input request.
1159  *
1160  * <note><para>
1161  *   This distinction makes life easier for interpreters that set up UI
1162  *   callbacks only at the start of input.
1163  * </para></note>
1164  *
1165  * A library may not support this feature; if it does, it may not support all
1166  * special keys as terminators. (Some keystrokes are reserved for OS or
1167  * interpreter control.) You can test for this with %gestalt_LineTerminators and
1168  * %gestalt_LineTerminatorKey.
1169  */
1170 void
1171 glk_set_terminators_line_event(winid_t win, glui32 *keycodes, glui32 count)
1172 {
1173         VALID_WINDOW(win, return);
1174
1175         g_slist_free(win->extra_line_terminators);
1176         win->extra_line_terminators = NULL;
1177
1178         if(keycodes == NULL || count == 0)
1179                 return;
1180
1181         int i;
1182         for(i = 0; i < count; i++)
1183         {
1184                 unsigned key = keycode_to_gdk_keyval(keycodes[i]);
1185                 if(is_valid_line_terminator(keycodes[i]))
1186                         win->extra_line_terminators = g_slist_prepend(win->extra_line_terminators, GUINT_TO_POINTER(key));
1187                 else
1188                    WARNING_S("Ignoring invalid line terminator", gdk_keyval_name(key));
1189         }
1190 }