3 #include "chimara-glk-private.h"
5 extern ChimaraGlkPrivate *glk_data;
9 * @win: A window, or %NULL.
10 * @rockptr: Return location for the next window's rock, or %NULL.
12 * This function can be used to iterate through the list of all open windows
13 * (including pair windows.) See <link
14 * linkend="chimara-Iterating-Through-Opaque-Objects">Iterating Through Opaque
17 * As that section describes, the order in which windows are returned is
18 * arbitrary. The root window is not necessarily first, nor is it necessarily
21 * Returns: the next window, or %NULL if there are no more.
24 glk_window_iterate(winid_t win, glui32 *rockptr)
26 VALID_WINDOW_OR_NULL(win, return NULL);
31 retnode = glk_data->root_window;
34 GNode *node = win->window_node;
35 if( G_NODE_IS_LEAF(node) )
37 while(node && node->next == NULL)
45 retnode = g_node_first_child(node);
47 winid_t retval = retnode? (winid_t)retnode->data : NULL;
49 /* Store the window's rock in rockptr */
51 *rockptr = glk_window_get_rock(retval);
57 * glk_window_get_rock:
60 * Returns @win's rock value. Pair windows always have rock 0; all other windows
61 * return whatever rock value you created them with.
63 * Returns: A rock value.
66 glk_window_get_rock(winid_t win)
68 VALID_WINDOW(win, return 0);
73 * glk_window_get_type:
76 * Returns @win's type, one of #wintype_Blank, #wintype_Pair,
77 * #wintype_TextBuffer, #wintype_TextGrid, or #wintype_Graphics.
79 * Returns: The window's type.
82 glk_window_get_type(winid_t win)
84 VALID_WINDOW(win, return 0);
89 * glk_window_get_parent:
92 * Returns the window which is the parent of @win. If @win is the root window,
93 * this returns %NULL, since the root window has no parent. Remember that the
94 * parent of every window is a pair window; other window types are always
97 * Returns: A window, or %NULL.
100 glk_window_get_parent(winid_t win)
102 VALID_WINDOW(win, return NULL);
103 /* Value will also be NULL if win is the root window */
104 return (winid_t)win->window_node->parent->data;
108 * glk_window_get_sibling:
111 * Returns the other child of @win's parent. If @win is the root window, this
114 * Returns: A window, or %NULL.
117 glk_window_get_sibling(winid_t win)
119 VALID_WINDOW(win, return NULL);
121 if(G_NODE_IS_ROOT(win->window_node))
123 if(win->window_node->next)
124 return (winid_t)win->window_node->next;
125 return (winid_t)win->window_node->prev;
129 * glk_window_get_root:
131 * Returns the root window. If there are no windows, this returns %NULL.
133 * Returns: A window, or %NULL.
136 glk_window_get_root()
138 if(glk_data->root_window == NULL)
140 return (winid_t)glk_data->root_window->data;
145 * @split: The window to split to create the new window. Must be 0 if there
146 * are no windows yet.
147 * @method: Position of the new window and method of size computation. One of
148 * #winmethod_Above, #winmethod_Below, #winmethod_Left, or #winmethod_Right
149 * OR'ed with #winmethod_Fixed or #winmethod_Proportional. If @wintype is
150 * #wintype_Blank, then #winmethod_Fixed is not allowed.
151 * @size: Size of the new window, in percentage points if @method is
152 * #winmethod_Proportional, otherwise in characters if @wintype is
153 * #wintype_TextBuffer or #wintype_TextGrid, or pixels if @wintype is
155 * @wintype: Type of the new window. One of #wintype_Blank, #wintype_TextGrid,
156 * #wintype_TextBuffer, or #wintype_Graphics.
157 * @rock: The new window's rock value.
159 * Creates a new window. If there are no windows, the first three arguments are
160 * meaningless. @split <emphasis>must</emphasis> be 0, and @method and @size
161 * are ignored. @wintype is the type of window you're creating, and @rock is
162 * the rock (see <link linkend="chimara-Rocks">Rocks</link>).
164 * If any windows exist, new windows must be created by splitting existing
165 * ones. @split is the window you want to split; this <emphasis>must
166 * not</emphasis> be zero. @method is a mask of constants to specify the
167 * direction and the split method (see below). @size is the size of the split.
168 * @wintype is the type of window you're creating, and @rock is the rock.
170 * Remember that it is possible that the library will be unable to create a new
171 * window, in which case glk_window_open() will return %NULL.
174 * It is acceptable to gracefully exit, if the window you are creating is an
175 * important one — such as your first window. But you should not try to
176 * perform any window operation on the id until you have tested to make sure
180 * The examples we've seen so far have the simplest kind of size control. (Yes,
181 * this is <quote>below</quote>.) Every pair is a percentage split, with
184 * <mathphrase>X</mathphrase>
186 * percent going to one side, and
189 * <mathphrase>(100 - X)</mathphrase>
191 * percent going to the other side. If the player resizes the window, the whole
192 * mess expands, contracts, or stretches in a uniform way.
194 * As I said above, you can also make fixed-size splits. This is a little more
195 * complicated, because you have to know how this fixed size is measured.
197 * Sizes are measured in a way which is different for each window type. For
198 * example, a text grid window is measured by the size of its fixed-width font.
199 * You can make a text grid window which is fixed at a height of four rows, or
200 * ten columns. A text buffer window is measured by the size of its font.
203 * Remember that different windows may use different size fonts. Even two
204 * text grid windows may use fixed-size fonts of different sizes.
207 * Graphics windows are measured in pixels, not characters. Blank windows
208 * aren't measured at all; there's no meaningful way to measure them, and
209 * therefore you can't create a blank window of a fixed size, only of a
210 * proportional (percentage) size.
212 * So to create a text buffer window which takes the top 40% of the original
213 * window's space, you would execute
214 * <informalexample><programlisting>
215 * newwin = #glk_window_open(win, #winmethod_Above | #winmethod_Proportional, 40, #wintype_TextBuffer, 0);
216 * </programlisting></informalexample>
218 * To create a text grid which is always five lines high, at the bottom of the
219 * original window, you would do
220 * <informalexample><programlisting>
221 * newwin = #glk_window_open(win, #winmethod_Below | #winmethod_Fixed, 5, #wintype_TextGrid, 0);
222 * </programlisting></informalexample>
224 * Note that the meaning of the @size argument depends on the @method argument.
225 * If the method is #winmethod_Fixed, it also depends on the @wintype argument.
226 * The new window is then called the <quote>key window</quote> of this split,
227 * because its window type determines how the split size is computed.
230 * For #winmethod_Proportional splits, you can still call the new window the
231 * <quote>key window</quote>. But the key window is not important for
232 * proportional splits, because the size will always be computed as a simple
233 * ratio of the available space, not a fixed size of one child window.
236 * This system is more or less peachy as long as all the constraints work out.
237 * What happens when there is a conflict? The rules are simple. Size control
238 * always flows down the tree, and the player is at the top. Let's bring out an
240 * <mediaobject><textobject><phrase>Screen shot 5</phrase></textobject>
243 * First we split A into A and B, with a 50% proportional split. Then we split
244 * A into A and C, with C above, C being a text grid window, and C gets a fixed
245 * size of two rows (as measured in its own font size). A gets whatever remains
246 * of the 50% it had before.
248 * Now the player stretches the window vertically.
249 * <mediaobject><textobject><phrase>Screen shot 6</phrase></textobject>
252 * The library figures: the topmost split, the original A/B split, is 50-50. So
253 * B gets half the screen space, and the pair window next to it (the lower
254 * <quote>O</quote>) gets the other half. Then it looks at the lower
255 * <quote>O</quote>. C gets two rows; A gets the rest. All done.
257 * Then the user maliciously starts squeezing the window down, in stages:
258 * <mediaobject id="chimara-Figure-Squeezing-Window"><textobject><phrase>
259 * Screen shot 7</phrase></textobject></mediaobject>
261 * The logic remains the same. B always gets half the space. At stage 3,
262 * there's no room left for A, so it winds up with zero height. Nothing
263 * displayed in A will be visible. At stage 4, there isn't even room in the
264 * upper 50% to give C its two rows; so it only gets one. Finally, C is
265 * squashed out of existence as well.
267 * When a window winds up undersized, it remembers what size it should be. In
268 * the example above, A remembers that it should be two rows; if the user
269 * expands the window to the original size, it would return to the original
272 * The downward flow of control is a bit harsh. After all, in stage 4, there's
273 * room for C to have its two rows if only B would give up some of its 50%. But
274 * this does not happen.
277 * This makes life much easier for the Glk library. To determine the
278 * configuration of a window, it only needs to look at the window's
279 * ancestors, never at its descendants. So window layout is a simple
280 * recursive algorithm, no backtracking.
283 * What happens when you split a fixed-size window? The resulting pair window
284 * — that is, the two new parts together — retain the same size
285 * constraint as the original window that was split. The key window for the
286 * original split is still the key window for that split, even though it's now
287 * a grandchild instead of a child.
289 * The easy, and correct, way to think about this is that the size constraint
290 * is stored by a window's parent, not the window itself; and a constraint
291 * consists of a pointer to a key window plus a size value.
293 * <mediaobject><textobject><phrase>Screen shot 8</phrase></textobject>
295 * After the first split, the new pair window (O1, which covers the whole
296 * screen) knows that its first child (A) is above the second, and gets 50% of
297 * its own area. (A is the key window for this split, but a proportional split
298 * doesn't care about key windows.)
300 * After the second split, all this remains true; O1 knows that its first child
301 * gets 50% of its space, and A is O1's key window. But now O1's first child is
302 * O2 instead of A. The newer pair window (O2) knows that its first child (C)
303 * is above the second, and gets a fixed size of two rows. (As measured in C's
304 * font, because C is O2's key window.)
306 * If we split C, now, the resulting pair will still be two C-font rows high
307 * — that is, tall enough for two lines of whatever font C displays. For
308 * the sake of example, we'll do this vertically.
309 * <mediaobject><textobject><phrase>Screen shot 9</phrase></textobject>
312 * O3 now knows that its children have a 50-50 left-right split. O2 is still
313 * committed to giving its upper child, O3, two C-font rows. Again, this is
314 * because C is O2's key window.
317 * This turns out to be a good idea, because it means that C, the text grid
318 * window, is still two rows high. If O3 had been a upper-lower split, things
319 * wouldn't work out so neatly. But the rules would still apply. If you don't
320 * like this, don't do it.
323 * Returns: the new window, or %NULL on error.
326 glk_window_open(winid_t split, glui32 method, glui32 size, glui32 wintype,
329 VALID_WINDOW_OR_NULL(split, return NULL);
331 if(split == NULL && glk_data->root_window != NULL)
333 ILLEGAL("Tried to open a new root window, but there is already a root window");
339 /* Create the new window */
340 winid_t win = g_new0(struct glk_window_struct, 1);
341 win->magic = MAGIC_WINDOW;
344 win->window_node = g_node_new(win);
350 /* A blank window will be a label without any text */
351 GtkWidget *label = gtk_label_new("");
352 gtk_widget_show(label);
356 /* A blank window has no size */
358 win->unit_height = 0;
359 /* You can print to a blank window's stream, but it does nothing */
360 win->window_stream = window_stream_new(win);
361 win->echo_stream = NULL;
365 case wintype_TextGrid:
367 GtkWidget *scrolledwindow = gtk_scrolled_window_new(NULL, NULL);
368 GtkWidget *textview = gtk_text_view_new();
370 gtk_scrolled_window_set_policy( GTK_SCROLLED_WINDOW(scrolledwindow), GTK_POLICY_NEVER, GTK_POLICY_NEVER );
372 gtk_text_view_set_wrap_mode( GTK_TEXT_VIEW(textview), GTK_WRAP_CHAR );
373 gtk_text_view_set_editable( GTK_TEXT_VIEW(textview), FALSE );
375 gtk_container_add( GTK_CONTAINER(scrolledwindow), textview );
376 gtk_widget_show_all(scrolledwindow);
378 /* Set the window's font */
379 gtk_widget_modify_font(textview, glk_data->monospace_font_desc);
381 win->widget = textview;
382 win->frame = scrolledwindow;
384 /* Determine the size of a "0" character in pixels */
385 PangoLayout *zero = gtk_widget_create_pango_layout(textview, "0");
386 pango_layout_set_font_description(zero, glk_data->monospace_font_desc);
387 pango_layout_get_pixel_size(zero, &(win->unit_width), &(win->unit_height));
388 g_object_unref(zero);
390 /* Set the other parameters (width and height are set later) */
391 win->window_stream = window_stream_new(win);
392 win->echo_stream = NULL;
393 win->input_request_type = INPUT_REQUEST_NONE;
394 win->line_input_buffer = NULL;
395 win->line_input_buffer_unicode = NULL;
397 /* Connect signal handlers */
398 win->keypress_handler = g_signal_connect( G_OBJECT(textview), "key-press-event", G_CALLBACK(on_window_key_press_event), win );
399 g_signal_handler_block( G_OBJECT(textview), win->keypress_handler );
403 case wintype_TextBuffer:
405 GtkWidget *scrolledwindow = gtk_scrolled_window_new(NULL, NULL);
406 GtkWidget *textview = gtk_text_view_new();
407 GtkTextBuffer *textbuffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(textview) );
409 gtk_scrolled_window_set_policy( GTK_SCROLLED_WINDOW(scrolledwindow), GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC );
411 gtk_text_view_set_wrap_mode( GTK_TEXT_VIEW(textview), GTK_WRAP_WORD_CHAR );
412 gtk_text_view_set_editable( GTK_TEXT_VIEW(textview), FALSE );
414 gtk_container_add( GTK_CONTAINER(scrolledwindow), textview );
415 gtk_widget_show_all(scrolledwindow);
417 /* Set the window's font */
418 gtk_widget_modify_font(textview, glk_data->default_font_desc);
420 win->widget = textview;
421 win->frame = scrolledwindow;
423 /* Determine the size of a "0" character in pixels */
424 PangoLayout *zero = gtk_widget_create_pango_layout(textview, "0");
425 pango_layout_set_font_description(zero, glk_data->default_font_desc);
426 pango_layout_get_pixel_size(zero, &(win->unit_width), &(win->unit_height));
427 g_object_unref(zero);
429 /* Set the other parameters */
430 win->window_stream = window_stream_new(win);
431 win->echo_stream = NULL;
432 win->input_request_type = INPUT_REQUEST_NONE;
433 win->line_input_buffer = NULL;
434 win->line_input_buffer_unicode = NULL;
436 /* Connect signal handlers */
437 win->keypress_handler = g_signal_connect( G_OBJECT(textview), "key-press-event", G_CALLBACK(on_window_key_press_event), win );
438 g_signal_handler_block( G_OBJECT(textview), win->keypress_handler );
440 win->insert_text_handler = g_signal_connect_after( G_OBJECT(textbuffer), "insert-text", G_CALLBACK(after_window_insert_text), win );
441 g_signal_handler_block( G_OBJECT(textbuffer), win->insert_text_handler );
443 /* Create an editable tag to indicate uneditable parts of the window
445 gtk_text_buffer_create_tag(textbuffer, "uneditable", "editable", FALSE, "editable-set", TRUE, NULL);
447 /* Mark the position where the user will input text */
449 gtk_text_buffer_get_end_iter(textbuffer, &end);
450 gtk_text_buffer_create_mark(textbuffer, "input_position", &end, TRUE);
456 ILLEGAL_PARAM("Unknown window type: %u", wintype);
458 g_node_destroy(glk_data->root_window);
459 glk_data->root_window = NULL;
465 /* When splitting, construct a new parent window
466 * copying most characteristics from the window that is being split */
467 winid_t pair = g_new0(struct glk_window_struct, 1);
468 pair->magic = MAGIC_WINDOW;
470 pair->type = wintype_Pair;
471 pair->window_node = g_node_new(pair);
472 pair->window_stream = NULL;
473 pair->echo_stream = NULL;
475 /* The pair window must know about its children's split method */
476 pair->key_window = win;
477 pair->split_method = method;
478 pair->constraint_size = size;
480 /* Insert the new window into the window tree */
481 if(split->window_node->parent == NULL)
483 glk_data->root_window = pair->window_node;
485 g_node_append(split->window_node->parent, pair->window_node);
486 g_node_unlink(split->window_node);
488 /* Place the windows in the correct order */
489 switch(method & winmethod_DirMask)
492 case winmethod_Above:
493 g_node_append(pair->window_node, win->window_node);
494 g_node_append(pair->window_node, split->window_node);
496 case winmethod_Right:
497 case winmethod_Below:
498 g_node_append(pair->window_node, split->window_node);
499 g_node_append(pair->window_node, win->window_node);
504 /* Set the window as root window */
505 glk_data->root_window = win->window_node;
508 /* Set the window as a child of the Glk widget */
509 gtk_widget_set_parent(win->frame, GTK_WIDGET(glk_data->self));
510 gtk_widget_queue_resize(GTK_WIDGET(glk_data->self));
512 /* For text grid windows, wait until GTK draws the window (see note in glk_window_get_size() ), calculate the size and fill the buffer with blanks. */
513 if(wintype == wintype_TextGrid)
515 while(win->widget->allocation.width == 1 && win->widget->allocation.height == 1)
517 /* Release the GDK lock momentarily */
520 while(gtk_events_pending())
521 gtk_main_iteration();
523 win->width = (glui32)(win->widget->allocation.width / win->unit_width);
524 win->height = (glui32)(win->widget->allocation.height / win->unit_height);
526 /* Mark the cursor position */
528 GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
529 gtk_text_buffer_get_start_iter(buffer, &begin);
530 gtk_text_buffer_create_mark(buffer, "cursor_position", &begin, TRUE);
532 /* Fill the buffer with blanks and move the cursor to the upper left */
534 glk_window_clear(win);
545 * @win: Window to close.
546 * @result: Pointer to a #stream_result_t in which to store the write count.
548 * Closes @win, which is pretty much exactly the opposite of opening a window.
549 * It is legal to close all your windows, or to close the root window (which is
552 * The @result argument is filled with the output character count of the window
553 * stream. See <link linkend="chimara-Streams">Streams</link> and <link
554 * linkend="chimara-Closing-Streams">Closing Streams</link>.
556 * When you close a window (and it is not the root window), the other window
557 * in its pair takes over all the freed-up area. Let's close D, in the current
559 * <mediaobject><textobject><phrase>Screen shot 10</phrase></textobject>
562 * Notice what has happened. D is gone. O3 is gone, and its 50-50 left-right
563 * split has gone with it. The other size constraints are unchanged; O2 is
564 * still committed to giving its upper child two rows, as measured in the font
565 * of O2's key window, which is C. Conveniently, O2's upper child is C, just as
566 * it was before we created D. In fact, now that D is gone, everything is back
567 * to the way it was before we created D.
569 * But what if we had closed C instead of D? We would have gotten this:
570 * <mediaobject><textobject><phrase>Screen shot 11</phrase></textobject>
573 * Again, O3 is gone. But D has collapsed to zero height. This is because its
574 * height is controlled by O2, and O2's key window was C, and C is now gone. O2
575 * no longer has a key window at all, so it cannot compute a height for its
576 * upper child, so it defaults to zero.
579 * This may seem to be an inconvenient choice. That is deliberate. You should
580 * not leave a pair window with no key, and the zero-height default reminds
581 * you not to. You can use glk_window_set_arrangement() to set a new split
582 * measurement and key window. See <link
583 * linkend="chimara-Changing-Window-Constraints">Changing Window
584 * Constraints</link>.
588 glk_window_close(winid_t win, stream_result_t *result)
590 VALID_WINDOW(win, return);
592 /* First close the window stream before trashing the window tree */
593 stream_close_common(win->window_stream, result);
599 gtk_widget_unparent(win->widget);
603 case wintype_TextGrid:
604 case wintype_TextBuffer:
606 gtk_widget_unparent(win->frame);
608 /* TODO: Cancel all input requests */
613 GNode *left = win->window_node->children;
614 GNode *right = win->window_node->children->next;
615 glk_window_close(left->data, NULL);
616 glk_window_close(right->data, NULL);
621 ILLEGAL_PARAM("Unknown window type: %u", win->type);
625 /* Parent window changes from a split window into the sibling window */
626 GNode *pair_node = win->window_node->parent;
627 g_node_destroy(win->window_node);
628 /* If win was not the root window, or was not unhooked from the tree: */
629 if(pair_node != NULL)
631 gboolean new_child_on_left = ( pair_node == g_node_first_sibling(pair_node) );
632 GNode *sibling_node = pair_node->children; /* only one child left */
633 GNode *new_parent_node = pair_node->parent;
634 g_node_unlink(pair_node);
635 g_node_unlink(sibling_node);
636 /* pair_node and sibling_node should now be totally unconnected to the tree */
638 if(new_parent_node == NULL)
640 glk_data->root_window = sibling_node;
644 if(new_child_on_left)
645 g_node_prepend(new_parent_node, sibling_node);
647 g_node_append(new_parent_node, sibling_node);
650 winid_t pair = (winid_t) pair_node->data;
651 g_node_destroy(pair_node);
653 pair->magic = MAGIC_FREE;
657 win->magic = MAGIC_FREE;
660 /* Schedule a redraw */
662 gtk_widget_queue_resize( GTK_WIDGET(glk_data->self) );
670 * Erases @win. The meaning of this depends on the window type.
673 * <term>Text buffer</term>
675 * This may do any number of things, such as delete all text in the window, or
676 * print enough blank lines to scroll all text beyond visibility, or insert a
677 * page-break marker which is treated specially by the display part of the
682 * <term>Text grid</term>
684 * This will clear the window, filling all positions with blanks. The window
685 * cursor is moved to the top left corner (position 0,0).
689 * <term>Graphics</term>
691 * Clears the entire window to its current background color. See <link
692 * linkend="chimara-Graphics-Windows">Graphics Windows</link>.
696 * <term>Other window types</term>
697 * <listitem><para>No effect.</para></listitem>
701 * It is illegal to erase a window which has line input pending.
704 glk_window_clear(winid_t win)
706 VALID_WINDOW(win, return);
707 g_return_if_fail(win->input_request_type != INPUT_REQUEST_LINE && win->input_request_type != INPUT_REQUEST_LINE_UNICODE);
716 case wintype_TextGrid:
717 /* fill the buffer with blanks */
721 /* Manually put newlines at the end of each row of characters in the buffer; manual newlines make resizing the window's grid easier. */
722 gchar *blanks = g_strnfill(win->width, ' ');
723 gchar **blanklines = g_new0(gchar *, win->height + 1);
725 for(count = 0; count < win->height; count++)
726 blanklines[count] = blanks;
727 blanklines[win->height] = NULL;
728 gchar *text = g_strjoinv("\n", blanklines);
729 g_free(blanklines); /* not g_strfreev() */
732 GtkTextBuffer *textbuffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
733 gtk_text_buffer_set_text(textbuffer, text, -1);
737 gtk_text_buffer_get_start_iter(textbuffer, &begin);
738 gtk_text_buffer_move_mark_by_name(textbuffer, "cursor_position", &begin);
744 case wintype_TextBuffer:
745 /* delete all text in the window */
749 GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
750 GtkTextIter start, end;
751 gtk_text_buffer_get_bounds(buffer, &start, &end);
752 gtk_text_buffer_delete(buffer, &start, &end);
759 ILLEGAL_PARAM("Unknown window type: %d", win->type);
767 * Sets the current stream to @win's window stream. It is exactly equivalent to
768 * <code>#glk_stream_set_current(#glk_window_get_stream(@win))</code>.
771 glk_set_window(winid_t win)
773 VALID_WINDOW_OR_NULL(win, return);
774 glk_stream_set_current( glk_window_get_stream(win) );
778 * glk_window_get_stream:
781 * Returns the stream which is associated with @win. (See <link
782 * linkend="chimara-Window-Streams">Window Streams</link>.) Every window has a
783 * stream which can be printed to, but this may not be useful, depending on the
787 * For example, printing to a blank window's stream has no effect.
790 * Returns: A window stream.
792 strid_t glk_window_get_stream(winid_t win)
794 VALID_WINDOW(win, return NULL);
795 return win->window_stream;
799 * glk_window_set_echo_stream:
801 * @str: A stream to attach to the window, or %NULL.
803 * Sets @win's echo stream to @str, which can be any valid output stream. You
804 * can reset a window to stop echoing by calling
805 * <code>#glk_window_set_echo_stream(@win, %NULL)</code>.
807 * It is illegal to set a window's echo stream to be its
808 * <emphasis>own</emphasis> window stream. That would create an infinite loop,
809 * and is nearly certain to crash the Glk library. It is similarly illegal to
810 * create a longer loop (two or more windows echoing to each other.)
813 glk_window_set_echo_stream(winid_t win, strid_t str)
815 VALID_WINDOW(win, return);
816 VALID_STREAM_OR_NULL(str, return);
818 /* Test for an infinite loop */
820 for(; next && next->type == STREAM_TYPE_WINDOW; next = next->window->echo_stream)
822 if(next == win->window_stream)
824 ILLEGAL("Infinite loop detected");
825 win->echo_stream = NULL;
830 win->echo_stream = str;
834 * glk_window_get_echo_stream:
837 * Returns the echo stream of window @win. Initially, a window has no echo
838 * stream, so <code>#glk_window_get_echo_stream(@win)</code> will return %NULL.
840 * Returns: A stream, or %NULL.
843 glk_window_get_echo_stream(winid_t win)
845 VALID_WINDOW(win, return NULL);
846 return win->echo_stream;
850 * glk_window_get_size:
852 * @widthptr: Pointer to a location to store the window's width, or %NULL.
853 * @heightptr: Pointer to a location to store the window's height, or %NULL.
855 * Simply returns the actual size of the window, in its measurement system.
856 * As described in <link linkend="chimara-Other-API-Conventions">Other API
857 * Conventions</link>, either @widthptr or @heightptr can be %NULL, if you
858 * only want one measurement.
860 * <note><para>Or, in fact, both, if you want to waste time.</para></note>
863 glk_window_get_size(winid_t win, glui32 *widthptr, glui32 *heightptr)
865 VALID_WINDOW(win, return);
873 if(heightptr != NULL)
877 case wintype_TextGrid:
878 /* The text grid caches its width and height */
880 *widthptr = win->width;
881 if(heightptr != NULL)
882 *heightptr = win->height;
885 case wintype_TextBuffer:
886 /* TODO: Glk wants to be able to get its windows' sizes as soon as they are created, but GTK doesn't decide on their sizes until they are drawn. The drawing happens somewhere in an idle function. A good method would be to make an educated guess of the window's size using the ChimaraGlk widget's size. */
888 /*if(win->widget->allocation.width == 1 && win->widget->allocation.height == 1)
890 g_warning("glk_window_get_size: The Glk program requested the size of a window before it was allocated screen space by GTK. The window size is just an educated guess.");
891 guess the size from the parent window;
895 /* Instead, we wait for GTK to draw the widget. This is probably very slow and should be fixed. */
896 while(win->widget->allocation.width == 1 && win->widget->allocation.height == 1)
898 /* Release the GDK lock momentarily */
901 while(gtk_events_pending())
902 gtk_main_iteration();
906 *widthptr = (glui32)(win->widget->allocation.width / win->unit_width);
907 if(heightptr != NULL)
908 *heightptr = (glui32)(win->widget->allocation.height / win->unit_height);
914 ILLEGAL_PARAM("Unknown window type: %u", win->type);
919 * glk_window_move_cursor:
920 * @win: A text grid window.
921 * @xpos: Horizontal cursor position.
922 * @ypos: Vertical cursor position.
924 * Sets the cursor position. If you move the cursor right past the end of a
925 * line, it wraps; the next character which is printed will appear at the
926 * beginning of the next line.
928 * If you move the cursor below the last line, or when the cursor reaches the
929 * end of the last line, it goes <quote>off the screen</quote> and further
930 * output has no effect. You must call glk_window_move_cursor() or
931 * glk_window_clear() to move the cursor back into the visible region.
934 * Note that the arguments of glk_window_move_cursor() are <type>unsigned
935 * int</type>s. This is okay, since there are no negative positions. If you try
936 * to pass a negative value, Glk will interpret it as a huge positive value,
937 * and it will wrap or go off the last line.
941 * Also note that the output cursor is not necessarily visible. In particular,
942 * when you are requesting line or character input in a grid window, you cannot
943 * rely on the cursor position to prompt the player where input is indicated.
944 * You should print some character prompt at that spot — a
945 * <quote>></quote> character, for example.
949 glk_window_move_cursor(winid_t win, glui32 xpos, glui32 ypos)
951 VALID_WINDOW(win, return);
952 g_return_if_fail(win->type == wintype_TextGrid);
954 /* Calculate actual position if cursor is moved past the right edge */
955 if(xpos >= win->width)
957 ypos += xpos / win->width;
960 /* Go to the end if the cursor is moved off the bottom edge */
961 if(ypos >= win->height)
963 xpos = win->width - 1;
964 ypos = win->height - 1;
969 GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
971 /* There must actually be a character at xpos, or the following function will choke */
972 gtk_text_buffer_get_iter_at_line_offset(buffer, &newpos, ypos, xpos);
973 gtk_text_buffer_move_mark_by_name(buffer, "cursor_position", &newpos);