2 * Copyright (C) 2007-2010 Openismus GmbH
5 * Mathias Hasselmann <mathias@openismus.com>
6 * Tristan Van Berkom <tristan.van.berkom@gmail.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
26 #include "gtksizerequest.h"
30 #include "gtkprivate.h"
31 #include "gtksizegroup-private.h"
32 #include "gtkwidgetprivate.h"
34 /* looks for a cached size request for this for_size. If not
35 * found, returns the oldest entry so it can be overwritten
37 * Note that this caching code was directly derived from
38 * the Clutter toolkit.
41 get_cached_size (SizeRequestCache *cache,
42 GtkSizeGroupMode orientation,
47 SizeRequest *cached_sizes;
49 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
51 cached_sizes = cache->widths;
52 n_sizes = cache->cached_widths;
56 cached_sizes = cache->heights;
57 n_sizes = cache->cached_widths;
60 /* Search for an already cached size */
61 for (i = 0; i < n_sizes; i++)
63 if (cached_sizes[i].for_size == for_size)
65 *result = &cached_sizes[i];
70 /* If not found, pull a new size from the cache, the returned size cache
71 * will immediately be used to cache the new computed size so we go ahead
72 * and increment the last_cached_width/height right away */
73 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
75 if (cache->cached_widths < GTK_SIZE_REQUEST_CACHED_SIZES)
77 cache->cached_widths++;
78 cache->last_cached_width = cache->cached_widths - 1;
82 if (++cache->last_cached_width == GTK_SIZE_REQUEST_CACHED_SIZES)
83 cache->last_cached_width = 0;
86 *result = &cache->widths[cache->last_cached_width];
88 else /* GTK_SIZE_GROUP_VERTICAL */
90 if (cache->cached_heights < GTK_SIZE_REQUEST_CACHED_SIZES)
92 cache->cached_heights++;
93 cache->last_cached_height = cache->cached_heights - 1;
97 if (++cache->last_cached_height == GTK_SIZE_REQUEST_CACHED_SIZES)
98 cache->last_cached_height = 0;
101 *result = &cache->heights[cache->last_cached_height];
108 do_size_request (GtkWidget *widget,
109 GtkRequisition *requisition)
111 /* Now we dont bother caching the deprecated "size-request" returns,
112 * just unconditionally invoke here just in case we run into legacy stuff */
113 gtk_widget_ensure_style (widget);
114 g_signal_emit_by_name (widget, "size-request", requisition);
117 #ifndef G_DISABLE_CHECKS
118 static GQuark recursion_check_quark = 0;
119 #endif /* G_DISABLE_CHECKS */
122 push_recursion_check (GtkWidget *widget,
123 GtkSizeGroupMode orientation,
126 #ifndef G_DISABLE_CHECKS
127 const char *previous_method;
130 if (recursion_check_quark == 0)
131 recursion_check_quark = g_quark_from_static_string ("gtk-size-request-in-progress");
133 previous_method = g_object_get_qdata (G_OBJECT (widget), recursion_check_quark);
135 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
137 method = for_size < 0 ? "get_width" : "get_width_for_height";
141 method = for_size < 0 ? "get_height" : "get_height_for_width";
144 if (previous_method != NULL)
146 g_warning ("%s %p: widget tried to gtk_widget_%s inside "
147 " GtkWidget ::%s implementation. "
148 "Should just invoke GTK_WIDGET_GET_CLASS(widget)->%s "
149 "directly rather than using gtk_widget_%s",
150 G_OBJECT_TYPE_NAME (widget), widget,
151 method, previous_method,
155 g_object_set_qdata (G_OBJECT (widget), recursion_check_quark, (char*) method);
156 #endif /* G_DISABLE_CHECKS */
160 pop_recursion_check (GtkWidget *widget,
161 GtkSizeGroupMode orientation)
163 #ifndef G_DISABLE_CHECKS
164 g_object_set_qdata (G_OBJECT (widget), recursion_check_quark, NULL);
169 compute_size_for_orientation (GtkWidget *widget,
170 GtkSizeGroupMode orientation,
175 SizeRequestCache *cache;
176 SizeRequest *cached_size;
177 gboolean found_in_cache = FALSE;
178 int adjusted_min, adjusted_natural;
180 g_return_if_fail (GTK_IS_WIDGET (widget));
181 g_return_if_fail (minimum_size != NULL || natural_size != NULL);
183 cache = _gtk_widget_peek_request_cache (widget);
185 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
187 cached_size = &cache->widths[0];
189 if (!_gtk_widget_get_width_request_needed (widget))
190 found_in_cache = get_cached_size (cache, orientation, for_size, &cached_size);
193 memset (cache->widths, 0, GTK_SIZE_REQUEST_CACHED_SIZES * sizeof (SizeRequest));
194 cache->cached_widths = 1;
195 cache->last_cached_width = 0;
200 cached_size = &cache->heights[0];
202 if (!_gtk_widget_get_height_request_needed (widget))
203 found_in_cache = get_cached_size (cache, orientation, for_size, &cached_size);
206 memset (cache->heights, 0, GTK_SIZE_REQUEST_CACHED_SIZES * sizeof (SizeRequest));
207 cache->cached_heights = 1;
208 cache->last_cached_height = 0;
214 GtkRequisition requisition = { 0, 0 };
215 gint min_size = 0, nat_size = 0;
216 gint requisition_size;
218 /* Unconditional size request runs but is often unhandled. */
219 do_size_request (widget, &requisition);
221 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
223 requisition_size = requisition.width;
227 push_recursion_check (widget, orientation, for_size);
228 GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, &min_size, &nat_size);
229 pop_recursion_check (widget, orientation);
233 int ignored_position = 0;
236 /* Pull the base natural height from the cache as it's needed to adjust
237 * the proposed 'for_size' */
238 gtk_widget_get_preferred_height (widget, NULL, &natural_height);
240 /* convert for_size to unadjusted height (for_size is a proposed allocation) */
241 GTK_WIDGET_GET_CLASS (widget)->adjust_size_allocation (widget,
242 GTK_ORIENTATION_VERTICAL,
247 push_recursion_check (widget, orientation, for_size);
248 GTK_WIDGET_GET_CLASS (widget)->get_preferred_width_for_height (widget, for_size,
249 &min_size, &nat_size);
250 pop_recursion_check (widget, orientation);
255 requisition_size = requisition.height;
259 push_recursion_check (widget, orientation, for_size);
260 GTK_WIDGET_GET_CLASS (widget)->get_preferred_height (widget, &min_size, &nat_size);
261 pop_recursion_check (widget, orientation);
265 int ignored_position = 0;
268 /* Pull the base natural width from the cache as it's needed to adjust
269 * the proposed 'for_size' */
270 gtk_widget_get_preferred_width (widget, NULL, &natural_width);
272 /* convert for_size to unadjusted width (for_size is a proposed allocation) */
273 GTK_WIDGET_GET_CLASS (widget)->adjust_size_allocation (widget,
274 GTK_ORIENTATION_HORIZONTAL,
279 push_recursion_check (widget, orientation, for_size);
280 GTK_WIDGET_GET_CLASS (widget)->get_preferred_height_for_width (widget, for_size,
281 &min_size, &nat_size);
282 pop_recursion_check (widget, orientation);
286 if (min_size > nat_size)
288 g_warning ("%s %p reported min size %d and natural size %d; natural size must be >= min size",
289 G_OBJECT_TYPE_NAME (widget), widget, min_size, nat_size);
292 /* Support for dangling "size-request" signal implementations on
295 min_size = MAX (min_size, requisition_size);
296 nat_size = MAX (nat_size, requisition_size);
298 cached_size->minimum_size = min_size;
299 cached_size->natural_size = nat_size;
300 cached_size->for_size = for_size;
302 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
303 _gtk_widget_set_width_request_needed (widget, FALSE);
305 _gtk_widget_set_height_request_needed (widget, FALSE);
307 adjusted_min = cached_size->minimum_size;
308 adjusted_natural = cached_size->natural_size;
309 GTK_WIDGET_GET_CLASS (widget)->adjust_size_request (widget,
310 orientation == GTK_SIZE_GROUP_HORIZONTAL ?
311 GTK_ORIENTATION_HORIZONTAL :
312 GTK_ORIENTATION_VERTICAL,
316 if (adjusted_min < cached_size->minimum_size ||
317 adjusted_natural < cached_size->natural_size)
319 g_warning ("%s %p adjusted size %s min %d natural %d must not decrease below min %d natural %d",
320 G_OBJECT_TYPE_NAME (widget), widget,
321 orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
322 adjusted_min, adjusted_natural,
323 cached_size->minimum_size, cached_size->natural_size);
324 /* don't use the adjustment */
326 else if (adjusted_min > adjusted_natural)
328 g_warning ("%s %p adjusted size %s min %d natural %d original min %d natural %d has min greater than natural",
329 G_OBJECT_TYPE_NAME (widget), widget,
330 orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
331 adjusted_min, adjusted_natural,
332 cached_size->minimum_size, cached_size->natural_size);
333 /* don't use the adjustment */
337 /* adjustment looks good */
338 cached_size->minimum_size = adjusted_min;
339 cached_size->natural_size = adjusted_natural;
342 /* Update size-groups with our request and update our cached requests
343 * with the size-group values in a single pass.
345 _gtk_size_group_bump_requisition (widget,
347 &cached_size->minimum_size,
348 &cached_size->natural_size);
352 *minimum_size = cached_size->minimum_size;
355 *natural_size = cached_size->natural_size;
357 g_assert (cached_size->minimum_size <= cached_size->natural_size);
359 GTK_NOTE (SIZE_REQUEST,
360 g_print ("[%p] %s\t%s: %d is minimum %d and natural: %d (hit cache: %s)\n",
361 widget, G_OBJECT_TYPE_NAME (widget),
362 orientation == GTK_SIZE_GROUP_HORIZONTAL ?
363 "width for height" : "height for width" ,
365 cached_size->minimum_size,
366 cached_size->natural_size,
367 found_in_cache ? "yes" : "no"));
372 * gtk_widget_get_request_mode:
373 * @widget: a #GtkWidget instance
375 * Gets whether the widget prefers a height-for-width layout
376 * or a width-for-height layout.
378 * <note><para>#GtkBin widgets generally propagate the preference of
379 * their child, container widgets need to request something either in
380 * context of their children or in context of their allocation
381 * capabilities.</para></note>
383 * Returns: The #GtkSizeRequestMode preferred by @widget.
388 gtk_widget_get_request_mode (GtkWidget *widget)
390 GtkWidgetClass *klass;
392 g_return_val_if_fail (GTK_IS_WIDGET (widget), GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH);
394 klass = GTK_WIDGET_GET_CLASS (widget);
395 if (klass->get_request_mode)
396 return klass->get_request_mode (widget);
398 /* By default widgets are height-for-width. */
399 return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
403 * gtk_widget_get_preferred_width:
404 * @widget: a #GtkWidget instance
405 * @minimum_width: (out) (allow-none): location to store the minimum width, or %NULL
406 * @natural_width: (out) (allow-none): location to store the natural width, or %NULL
408 * Retrieves a widget's initial minimum and natural width.
410 * <note><para>This call is specific to height-for-width
411 * requests.</para></note>
413 * The returned request will be modified by the
414 * GtkWidgetClass::adjust_size_request virtual method and by any
415 * #GtkSizeGroup that have been applied. That is, the returned request
416 * is the one that should be used for layout, not necessarily the one
417 * returned by the widget itself.
422 gtk_widget_get_preferred_width (GtkWidget *widget,
426 compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
427 -1, minimum_width, natural_width);
432 * gtk_widget_get_preferred_height:
433 * @widget: a #GtkWidget instance
434 * @minimum_height: (out) (allow-none): location to store the minimum height, or %NULL
435 * @natural_height: (out) (allow-none): location to store the natural height, or %NULL
437 * Retrieves a widget's initial minimum and natural height.
439 * <note><para>This call is specific to width-for-height requests.</para></note>
441 * The returned request will be modified by the
442 * GtkWidgetClass::adjust_size_request virtual method and by any
443 * #GtkSizeGroup that have been applied. That is, the returned request
444 * is the one that should be used for layout, not necessarily the one
445 * returned by the widget itself.
450 gtk_widget_get_preferred_height (GtkWidget *widget,
451 gint *minimum_height,
452 gint *natural_height)
454 compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
455 -1, minimum_height, natural_height);
461 * gtk_widget_get_preferred_width_for_height:
462 * @widget: a #GtkWidget instance
463 * @height: the height which is available for allocation
464 * @minimum_width: (out) (allow-none): location for storing the minimum width, or %NULL
465 * @natural_width: (out) (allow-none): location for storing the natural width, or %NULL
467 * Retrieves a widget's minimum and natural width if it would be given
468 * the specified @height.
470 * The returned request will be modified by the
471 * GtkWidgetClass::adjust_size_request virtual method and by any
472 * #GtkSizeGroup that have been applied. That is, the returned request
473 * is the one that should be used for layout, not necessarily the one
474 * returned by the widget itself.
479 gtk_widget_get_preferred_width_for_height (GtkWidget *widget,
484 compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
485 height, minimum_width, natural_width);
489 * gtk_widget_get_preferred_height_for_width:
490 * @widget: a #GtkWidget instance
491 * @width: the width which is available for allocation
492 * @minimum_height: (out) (allow-none): location for storing the minimum height, or %NULL
493 * @natural_height: (out) (allow-none): location for storing the natural height, or %NULL
495 * Retrieves a widget's minimum and natural height if it would be given
496 * the specified @width.
498 * The returned request will be modified by the
499 * GtkWidgetClass::adjust_size_request virtual method and by any
500 * #GtkSizeGroup that have been applied. That is, the returned request
501 * is the one that should be used for layout, not necessarily the one
502 * returned by the widget itself.
507 gtk_widget_get_preferred_height_for_width (GtkWidget *widget,
509 gint *minimum_height,
510 gint *natural_height)
512 compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
513 width, minimum_height, natural_height);
517 * gtk_widget_get_preferred_size:
518 * @widget: a #GtkWidget instance
519 * @minimum_size: (out) (allow-none): location for storing the minimum size, or %NULL
520 * @natural_size: (out) (allow-none): location for storing the natural size, or %NULL
522 * Retrieves the minimum and natural size of a widget taking
523 * into account the widget's preference for height-for-width management.
525 * This is used to retrieve a suitable size by container widgets which do
526 * not impose any restrictions on the child placement. It can be used
527 * to deduce toplevel window and menu sizes as well as child widgets in
528 * free form containers such as GtkLayout.
530 * <note><para>Handle with care, note that the natural height of a height-for-width
531 * widget will generally be a smaller size than the minimum height, since the required
532 * height for the natural width is generally smaller than the required height for
533 * the minimum width.</para></note>
538 gtk_widget_get_preferred_size (GtkWidget *widget,
539 GtkRequisition *minimum_size,
540 GtkRequisition *natural_size)
542 gint min_width, nat_width;
543 gint min_height, nat_height;
545 g_return_if_fail (GTK_IS_WIDGET (widget));
547 if (gtk_widget_get_request_mode (widget) == GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH)
549 gtk_widget_get_preferred_width (widget, &min_width, &nat_width);
553 minimum_size->width = min_width;
554 gtk_widget_get_preferred_height_for_width (widget, min_width,
555 &minimum_size->height, NULL);
560 natural_size->width = nat_width;
561 gtk_widget_get_preferred_height_for_width (widget, nat_width,
562 NULL, &natural_size->height);
565 else /* GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT */
567 gtk_widget_get_preferred_height (widget, &min_height, &nat_height);
571 minimum_size->height = min_height;
572 gtk_widget_get_preferred_width_for_height (widget, min_height,
573 &minimum_size->width, NULL);
578 natural_size->height = nat_height;
579 gtk_widget_get_preferred_width_for_height (widget, nat_height,
580 NULL, &natural_size->width);
587 compare_gap (gconstpointer p1,
591 GtkRequestedSize *sizes = data;
592 const guint *c1 = p1;
593 const guint *c2 = p2;
595 const gint d1 = MAX (sizes[*c1].natural_size -
596 sizes[*c1].minimum_size,
598 const gint d2 = MAX (sizes[*c2].natural_size -
599 sizes[*c2].minimum_size,
602 gint delta = (d2 - d1);
611 * gtk_distribute_natural_allocation:
612 * @extra_space: Extra space to redistribute among children after subtracting
613 * minimum sizes and any child padding from the overall allocation
614 * @n_requested_sizes: Number of requests to fit into the allocation
615 * @sizes: An array of structs with a client pointer and a minimum/natural size
616 * in the orientation of the allocation.
618 * Distributes @extra_space to child @sizes by bringing up smaller
619 * children up to natural size first.
621 * The remaining space will be added to the @minimum_size member of the
622 * GtkRequestedSize struct. If all sizes reach their natural size then
623 * the remaining space is returned.
625 * Returns: The remainder of @extra_space after redistributing space
629 gtk_distribute_natural_allocation (gint extra_space,
630 guint n_requested_sizes,
631 GtkRequestedSize *sizes)
636 g_return_val_if_fail (extra_space >= 0, 0);
638 spreading = g_newa (guint, n_requested_sizes);
640 for (i = 0; i < n_requested_sizes; i++)
643 /* Distribute the container's extra space c_gap. We want to assign
644 * this space such that the sum of extra space assigned to children
645 * (c^i_gap) is equal to c_cap. The case that there's not enough
646 * space for all children to take their natural size needs some
647 * attention. The goals we want to achieve are:
649 * a) Maximize number of children taking their natural size.
650 * b) The allocated size of children should be a continuous
651 * function of c_gap. That is, increasing the container size by
652 * one pixel should never make drastic changes in the distribution.
653 * c) If child i takes its natural size and child j doesn't,
654 * child j should have received at least as much gap as child i.
656 * The following code distributes the additional space by following
660 /* Sort descending by gap and position. */
661 g_qsort_with_data (spreading,
662 n_requested_sizes, sizeof (guint),
665 /* Distribute available space.
666 * This master piece of a loop was conceived by Behdad Esfahbod.
668 for (i = n_requested_sizes - 1; extra_space > 0 && i >= 0; --i)
670 /* Divide remaining space by number of remaining children.
671 * Sort order and reducing remaining space by assigned space
672 * ensures that space is distributed equally.
674 gint glue = (extra_space + i) / (i + 1);
675 gint gap = sizes[(spreading[i])].natural_size
676 - sizes[(spreading[i])].minimum_size;
678 gint extra = MIN (glue, gap);
680 sizes[spreading[i]].minimum_size += extra;
682 extra_space -= extra;