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 *request,
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 (request), 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 (request), request,
151 method, previous_method,
155 g_object_set_qdata (G_OBJECT (request), recursion_check_quark, (char*) method);
156 #endif /* G_DISABLE_CHECKS */
160 pop_recursion_check (GtkWidget *request,
161 GtkSizeGroupMode orientation)
163 #ifndef G_DISABLE_CHECKS
164 g_object_set_qdata (G_OBJECT (request), recursion_check_quark, NULL);
169 compute_size_for_orientation (GtkWidget *request,
170 GtkSizeGroupMode orientation,
175 SizeRequestCache *cache;
176 SizeRequest *cached_size;
178 gboolean found_in_cache = FALSE;
179 int adjusted_min, adjusted_natural;
181 g_return_if_fail (GTK_IS_WIDGET (request));
182 g_return_if_fail (minimum_size != NULL || natural_size != NULL);
184 widget = GTK_WIDGET (request);
185 cache = _gtk_widget_peek_request_cache (widget);
187 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
189 cached_size = &cache->widths[0];
191 if (!_gtk_widget_get_width_request_needed (widget))
192 found_in_cache = get_cached_size (cache, orientation, for_size, &cached_size);
195 memset (cache->widths, 0, GTK_SIZE_REQUEST_CACHED_SIZES * sizeof (SizeRequest));
196 cache->cached_widths = 1;
197 cache->last_cached_width = 0;
202 cached_size = &cache->heights[0];
204 if (!_gtk_widget_get_height_request_needed (widget))
205 found_in_cache = get_cached_size (cache, orientation, for_size, &cached_size);
208 memset (cache->heights, 0, GTK_SIZE_REQUEST_CACHED_SIZES * sizeof (SizeRequest));
209 cache->cached_heights = 1;
210 cache->last_cached_height = 0;
216 GtkRequisition requisition = { 0, 0 };
217 gint min_size = 0, nat_size = 0;
218 gint requisition_size;
220 /* Unconditional size request runs but is often unhandled. */
221 do_size_request (widget, &requisition);
223 push_recursion_check (request, orientation, for_size);
224 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
226 requisition_size = requisition.width;
230 GTK_WIDGET_GET_CLASS (request)->get_preferred_width (request, &min_size, &nat_size);
234 int ignored_position = 0;
237 /* Pull the base natural height from the cache as it's needed to adjust
238 * the proposed 'for_size' */
239 gtk_widget_get_preferred_height (widget, NULL, &natural_height);
241 /* convert for_size to unadjusted height (for_size is a proposed allocation) */
242 GTK_WIDGET_GET_CLASS (request)->adjust_size_allocation (widget,
243 GTK_ORIENTATION_VERTICAL,
248 GTK_WIDGET_GET_CLASS (request)->get_preferred_width_for_height (request, for_size,
249 &min_size, &nat_size);
254 requisition_size = requisition.height;
258 GTK_WIDGET_GET_CLASS (request)->get_preferred_height (request, &min_size, &nat_size);
262 int ignored_position = 0;
265 /* Pull the base natural width from the cache as it's needed to adjust
266 * the proposed 'for_size' */
267 gtk_widget_get_preferred_width (widget, NULL, &natural_width);
269 /* convert for_size to unadjusted width (for_size is a proposed allocation) */
270 GTK_WIDGET_GET_CLASS (request)->adjust_size_allocation (widget,
271 GTK_ORIENTATION_HORIZONTAL,
276 GTK_WIDGET_GET_CLASS (request)->get_preferred_height_for_width (request, for_size,
277 &min_size, &nat_size);
280 pop_recursion_check (request, orientation);
282 if (min_size > nat_size)
284 g_warning ("%s %p reported min size %d and natural size %d; natural size must be >= min size",
285 G_OBJECT_TYPE_NAME (request), request, min_size, nat_size);
288 /* Support for dangling "size-request" signal implementations on
291 min_size = MAX (min_size, requisition_size);
292 nat_size = MAX (nat_size, requisition_size);
294 cached_size->minimum_size = min_size;
295 cached_size->natural_size = nat_size;
296 cached_size->for_size = for_size;
298 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
299 _gtk_widget_set_width_request_needed (widget, FALSE);
301 _gtk_widget_set_height_request_needed (widget, FALSE);
303 adjusted_min = cached_size->minimum_size;
304 adjusted_natural = cached_size->natural_size;
305 GTK_WIDGET_GET_CLASS (request)->adjust_size_request (GTK_WIDGET (request),
306 orientation == GTK_SIZE_GROUP_HORIZONTAL ?
307 GTK_ORIENTATION_HORIZONTAL :
308 GTK_ORIENTATION_VERTICAL,
312 if (adjusted_min < cached_size->minimum_size ||
313 adjusted_natural < cached_size->natural_size)
315 g_warning ("%s %p adjusted size %s min %d natural %d must not decrease below min %d natural %d",
316 G_OBJECT_TYPE_NAME (request), request,
317 orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
318 adjusted_min, adjusted_natural,
319 cached_size->minimum_size, cached_size->natural_size);
320 /* don't use the adjustment */
322 else if (adjusted_min > adjusted_natural)
324 g_warning ("%s %p adjusted size %s min %d natural %d original min %d natural %d has min greater than natural",
325 G_OBJECT_TYPE_NAME (request), request,
326 orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
327 adjusted_min, adjusted_natural,
328 cached_size->minimum_size, cached_size->natural_size);
329 /* don't use the adjustment */
333 /* adjustment looks good */
334 cached_size->minimum_size = adjusted_min;
335 cached_size->natural_size = adjusted_natural;
338 /* Update size-groups with our request and update our cached requests
339 * with the size-group values in a single pass.
341 _gtk_size_group_bump_requisition (GTK_WIDGET (request),
343 &cached_size->minimum_size,
344 &cached_size->natural_size);
348 *minimum_size = cached_size->minimum_size;
351 *natural_size = cached_size->natural_size;
353 g_assert (cached_size->minimum_size <= cached_size->natural_size);
355 GTK_NOTE (SIZE_REQUEST,
356 g_print ("[%p] %s\t%s: %d is minimum %d and natural: %d (hit cache: %s)\n",
357 request, G_OBJECT_TYPE_NAME (request),
358 orientation == GTK_SIZE_GROUP_HORIZONTAL ?
359 "width for height" : "height for width" ,
361 cached_size->minimum_size,
362 cached_size->natural_size,
363 found_in_cache ? "yes" : "no"));
368 * gtk_widget_get_request_mode:
369 * @widget: a #GtkWidget instance
371 * Gets whether the widget prefers a height-for-width layout
372 * or a width-for-height layout.
374 * <note><para>#GtkBin widgets generally propagate the preference of
375 * their child, container widgets need to request something either in
376 * context of their children or in context of their allocation
377 * capabilities.</para></note>
379 * Returns: The #GtkSizeRequestMode preferred by @widget.
384 gtk_widget_get_request_mode (GtkWidget *widget)
386 GtkWidgetClass *klass;
388 g_return_val_if_fail (GTK_IS_WIDGET (widget), GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH);
390 klass = GTK_WIDGET_GET_CLASS (widget);
391 if (klass->get_request_mode)
392 return klass->get_request_mode (widget);
394 /* By default widgets are height-for-width. */
395 return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
399 * gtk_widget_get_preferred_width:
400 * @widget: a #GtkWidget instance
401 * @minimum_width: (out) (allow-none): location to store the minimum width, or %NULL
402 * @natural_width: (out) (allow-none): location to store the natural width, or %NULL
404 * Retrieves a widget's initial minimum and natural width.
406 * <note><para>This call is specific to height-for-width
407 * requests.</para></note>
409 * The returned request will be modified by the
410 * GtkWidgetClass::adjust_size_request virtual method and by any
411 * #GtkSizeGroup that have been applied. That is, the returned request
412 * is the one that should be used for layout, not necessarily the one
413 * returned by the widget itself.
418 gtk_widget_get_preferred_width (GtkWidget *widget,
422 compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
423 -1, minimum_width, natural_width);
428 * gtk_widget_get_preferred_height:
429 * @widget: a #GtkWidget instance
430 * @minimum_height: (out) (allow-none): location to store the minimum height, or %NULL
431 * @natural_height: (out) (allow-none): location to store the natural height, or %NULL
433 * Retrieves a widget's initial minimum and natural height.
435 * <note><para>This call is specific to width-for-height requests.</para></note>
437 * The returned request will be modified by the
438 * GtkWidgetClass::adjust_size_request virtual method and by any
439 * #GtkSizeGroup that have been applied. That is, the returned request
440 * is the one that should be used for layout, not necessarily the one
441 * returned by the widget itself.
446 gtk_widget_get_preferred_height (GtkWidget *widget,
447 gint *minimum_height,
448 gint *natural_height)
450 compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
451 -1, minimum_height, natural_height);
457 * gtk_widget_get_preferred_width_for_height:
458 * @widget: a #GtkWidget instance
459 * @height: the height which is available for allocation
460 * @minimum_width: (out) (allow-none): location for storing the minimum width, or %NULL
461 * @natural_width: (out) (allow-none): location for storing the natural width, or %NULL
463 * Retrieves a widget's minimum and natural width if it would be given
464 * the specified @height.
466 * The returned request will be modified by the
467 * GtkWidgetClass::adjust_size_request virtual method and by any
468 * #GtkSizeGroup that have been applied. That is, the returned request
469 * is the one that should be used for layout, not necessarily the one
470 * returned by the widget itself.
475 gtk_widget_get_preferred_width_for_height (GtkWidget *widget,
480 compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
481 height, minimum_width, natural_width);
485 * gtk_widget_get_preferred_height_for_width:
486 * @widget: a #GtkWidget instance
487 * @width: the width which is available for allocation
488 * @minimum_height: (out) (allow-none): location for storing the minimum height, or %NULL
489 * @natural_height: (out) (allow-none): location for storing the natural height, or %NULL
491 * Retrieves a widget's minimum and natural height if it would be given
492 * the specified @width.
494 * The returned request will be modified by the
495 * GtkWidgetClass::adjust_size_request virtual method and by any
496 * #GtkSizeGroup that have been applied. That is, the returned request
497 * is the one that should be used for layout, not necessarily the one
498 * returned by the widget itself.
503 gtk_widget_get_preferred_height_for_width (GtkWidget *widget,
505 gint *minimum_height,
506 gint *natural_height)
508 compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
509 width, minimum_height, natural_height);
513 * gtk_widget_get_preferred_size:
514 * @widget: a #GtkWidget instance
515 * @minimum_size: (out) (allow-none): location for storing the minimum size, or %NULL
516 * @natural_size: (out) (allow-none): location for storing the natural size, or %NULL
518 * Retrieves the minimum and natural size of a widget taking
519 * into account the widget's preference for height-for-width management.
521 * This is used to retrieve a suitable size by container widgets which do
522 * not impose any restrictions on the child placement. It can be used
523 * to deduce toplevel window and menu sizes as well as child widgets in
524 * free form containers such as GtkLayout.
526 * <note><para>Handle with care, note that the natural height of a height-for-width
527 * widget will generally be a smaller size than the minimum height, since the required
528 * height for the natural width is generally smaller than the required height for
529 * the minimum width.</para></note>
534 gtk_widget_get_preferred_size (GtkWidget *widget,
535 GtkRequisition *minimum_size,
536 GtkRequisition *natural_size)
538 gint min_width, nat_width;
539 gint min_height, nat_height;
541 g_return_if_fail (GTK_IS_WIDGET (widget));
543 if (gtk_widget_get_request_mode (widget) == GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH)
545 gtk_widget_get_preferred_width (widget, &min_width, &nat_width);
549 minimum_size->width = min_width;
550 gtk_widget_get_preferred_height_for_width (widget, min_width,
551 &minimum_size->height, NULL);
556 natural_size->width = nat_width;
557 gtk_widget_get_preferred_height_for_width (widget, nat_width,
558 NULL, &natural_size->height);
561 else /* GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT */
563 gtk_widget_get_preferred_height (widget, &min_height, &nat_height);
567 minimum_size->height = min_height;
568 gtk_widget_get_preferred_width_for_height (widget, min_height,
569 &minimum_size->width, NULL);
574 natural_size->height = nat_height;
575 gtk_widget_get_preferred_width_for_height (widget, nat_height,
576 NULL, &natural_size->width);
583 compare_gap (gconstpointer p1,
587 GtkRequestedSize *sizes = data;
588 const guint *c1 = p1;
589 const guint *c2 = p2;
591 const gint d1 = MAX (sizes[*c1].natural_size -
592 sizes[*c1].minimum_size,
594 const gint d2 = MAX (sizes[*c2].natural_size -
595 sizes[*c2].minimum_size,
598 gint delta = (d2 - d1);
607 * gtk_distribute_natural_allocation:
608 * @extra_space: Extra space to redistribute among children after subtracting
609 * minimum sizes and any child padding from the overall allocation
610 * @n_requested_sizes: Number of requests to fit into the allocation
611 * @sizes: An array of structs with a client pointer and a minimum/natural size
612 * in the orientation of the allocation.
614 * Distributes @extra_space to child @sizes by bringing up smaller
615 * children up to natural size first.
617 * The remaining space will be added to the @minimum_size member of the
618 * GtkRequestedSize struct. If all sizes reach their natural size then
619 * the remaining space is returned.
621 * Returns: The remainder of @extra_space after redistributing space
625 gtk_distribute_natural_allocation (gint extra_space,
626 guint n_requested_sizes,
627 GtkRequestedSize *sizes)
632 g_return_val_if_fail (extra_space >= 0, 0);
634 spreading = g_newa (guint, n_requested_sizes);
636 for (i = 0; i < n_requested_sizes; i++)
639 /* Distribute the container's extra space c_gap. We want to assign
640 * this space such that the sum of extra space assigned to children
641 * (c^i_gap) is equal to c_cap. The case that there's not enough
642 * space for all children to take their natural size needs some
643 * attention. The goals we want to achieve are:
645 * a) Maximize number of children taking their natural size.
646 * b) The allocated size of children should be a continuous
647 * function of c_gap. That is, increasing the container size by
648 * one pixel should never make drastic changes in the distribution.
649 * c) If child i takes its natural size and child j doesn't,
650 * child j should have received at least as much gap as child i.
652 * The following code distributes the additional space by following
656 /* Sort descending by gap and position. */
657 g_qsort_with_data (spreading,
658 n_requested_sizes, sizeof (guint),
661 /* Distribute available space.
662 * This master piece of a loop was conceived by Behdad Esfahbod.
664 for (i = n_requested_sizes - 1; extra_space > 0 && i >= 0; --i)
666 /* Divide remaining space by number of remaining children.
667 * Sort order and reducing remaining space by assigned space
668 * ensures that space is distributed equally.
670 gint glue = (extra_space + i) / (i + 1);
671 gint gap = sizes[(spreading[i])].natural_size
672 - sizes[(spreading[i])].minimum_size;
674 gint extra = MIN (glue, gap);
676 sizes[spreading[i]].minimum_size += extra;
678 extra_space -= extra;