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;
229 GTK_WIDGET_GET_CLASS (request)->get_preferred_width (request, &min_size, &nat_size);
231 GTK_WIDGET_GET_CLASS (request)->get_preferred_width_for_height (request, for_size,
232 &min_size, &nat_size);
236 requisition_size = requisition.height;
239 GTK_WIDGET_GET_CLASS (request)->get_preferred_height (request, &min_size, &nat_size);
241 GTK_WIDGET_GET_CLASS (request)->get_preferred_height_for_width (request, for_size,
242 &min_size, &nat_size);
244 pop_recursion_check (request, orientation);
246 if (min_size > nat_size)
248 g_warning ("%s %p reported min size %d and natural size %d; natural size must be >= min size",
249 G_OBJECT_TYPE_NAME (request), request, min_size, nat_size);
252 /* Support for dangling "size-request" signal implementations on
255 min_size = MAX (min_size, requisition_size);
256 nat_size = MAX (nat_size, requisition_size);
258 cached_size->minimum_size = min_size;
259 cached_size->natural_size = nat_size;
260 cached_size->for_size = for_size;
262 if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
263 _gtk_widget_set_width_request_needed (widget, FALSE);
265 _gtk_widget_set_height_request_needed (widget, FALSE);
267 adjusted_min = cached_size->minimum_size;
268 adjusted_natural = cached_size->natural_size;
269 GTK_WIDGET_GET_CLASS (request)->adjust_size_request (GTK_WIDGET (request),
270 orientation == GTK_SIZE_GROUP_HORIZONTAL ?
271 GTK_ORIENTATION_HORIZONTAL :
272 GTK_ORIENTATION_VERTICAL,
273 cached_size->for_size,
277 if (adjusted_min < cached_size->minimum_size ||
278 adjusted_natural < cached_size->natural_size)
280 g_warning ("%s %p adjusted size %s min %d natural %d must not decrease below min %d natural %d",
281 G_OBJECT_TYPE_NAME (request), request,
282 orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
283 adjusted_min, adjusted_natural,
284 cached_size->minimum_size, cached_size->natural_size);
285 /* don't use the adjustment */
287 else if (adjusted_min > adjusted_natural)
289 g_warning ("%s %p adjusted size %s min %d natural %d original min %d natural %d has min greater than natural",
290 G_OBJECT_TYPE_NAME (request), request,
291 orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
292 adjusted_min, adjusted_natural,
293 cached_size->minimum_size, cached_size->natural_size);
294 /* don't use the adjustment */
298 /* adjustment looks good */
299 cached_size->minimum_size = adjusted_min;
300 cached_size->natural_size = adjusted_natural;
303 /* Update size-groups with our request and update our cached requests
304 * with the size-group values in a single pass.
306 _gtk_size_group_bump_requisition (GTK_WIDGET (request),
308 &cached_size->minimum_size,
309 &cached_size->natural_size);
313 *minimum_size = cached_size->minimum_size;
316 *natural_size = cached_size->natural_size;
318 g_assert (cached_size->minimum_size <= cached_size->natural_size);
320 GTK_NOTE (SIZE_REQUEST,
321 g_print ("[%p] %s\t%s: %d is minimum %d and natural: %d (hit cache: %s)\n",
322 request, G_OBJECT_TYPE_NAME (request),
323 orientation == GTK_SIZE_GROUP_HORIZONTAL ?
324 "width for height" : "height for width" ,
326 cached_size->minimum_size,
327 cached_size->natural_size,
328 found_in_cache ? "yes" : "no"));
333 * gtk_widget_get_request_mode:
334 * @widget: a #GtkWidget instance
336 * Gets whether the widget prefers a height-for-width layout
337 * or a width-for-height layout.
339 * <note><para>#GtkBin widgets generally propagate the preference of
340 * their child, container widgets need to request something either in
341 * context of their children or in context of their allocation
342 * capabilities.</para></note>
344 * Returns: The #GtkSizeRequestMode preferred by @widget.
349 gtk_widget_get_request_mode (GtkWidget *widget)
351 GtkWidgetClass *klass;
353 g_return_val_if_fail (GTK_IS_WIDGET (widget), GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH);
355 klass = GTK_WIDGET_GET_CLASS (widget);
356 if (klass->get_request_mode)
357 return klass->get_request_mode (widget);
359 /* By default widgets are height-for-width. */
360 return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
364 * gtk_widget_get_preferred_width:
365 * @widget: a #GtkWidget instance
366 * @minimum_width: (out) (allow-none): location to store the minimum width, or %NULL
367 * @natural_width: (out) (allow-none): location to store the natural width, or %NULL
369 * Retrieves a widget's initial minimum and natural width.
371 * <note><para>This call is specific to height-for-width
372 * requests.</para></note>
374 * The returned request will be modified by the
375 * GtkWidgetClass::adjust_size_request virtual method and by any
376 * #GtkSizeGroup that have been applied. That is, the returned request
377 * is the one that should be used for layout, not necessarily the one
378 * returned by the widget itself.
383 gtk_widget_get_preferred_width (GtkWidget *widget,
387 compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
388 -1, minimum_width, natural_width);
393 * gtk_widget_get_preferred_height:
394 * @widget: a #GtkWidget instance
395 * @minimum_height: (out) (allow-none): location to store the minimum height, or %NULL
396 * @natural_height: (out) (allow-none): location to store the natural height, or %NULL
398 * Retrieves a widget's initial minimum and natural height.
400 * <note><para>This call is specific to width-for-height requests.</para></note>
402 * The returned request will be modified by the
403 * GtkWidgetClass::adjust_size_request virtual method and by any
404 * #GtkSizeGroup that have been applied. That is, the returned request
405 * is the one that should be used for layout, not necessarily the one
406 * returned by the widget itself.
411 gtk_widget_get_preferred_height (GtkWidget *widget,
412 gint *minimum_height,
413 gint *natural_height)
415 compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
416 -1, minimum_height, natural_height);
422 * gtk_widget_get_preferred_width_for_height:
423 * @widget: a #GtkWidget instance
424 * @height: the height which is available for allocation
425 * @minimum_width: (out) (allow-none): location for storing the minimum width, or %NULL
426 * @natural_width: (out) (allow-none): location for storing the natural width, or %NULL
428 * Retrieves a widget's minimum and natural width if it would be given
429 * the specified @height.
431 * The returned request will be modified by the
432 * GtkWidgetClass::adjust_size_request virtual method and by any
433 * #GtkSizeGroup that have been applied. That is, the returned request
434 * is the one that should be used for layout, not necessarily the one
435 * returned by the widget itself.
440 gtk_widget_get_preferred_width_for_height (GtkWidget *widget,
445 compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
446 height, minimum_width, natural_width);
450 * gtk_widget_get_preferred_height_for_width:
451 * @widget: a #GtkWidget instance
452 * @width: the width which is available for allocation
453 * @minimum_height: (out) (allow-none): location for storing the minimum height, or %NULL
454 * @natural_height: (out) (allow-none): location for storing the natural height, or %NULL
456 * Retrieves a widget's minimum and natural height if it would be given
457 * the specified @width.
459 * The returned request will be modified by the
460 * GtkWidgetClass::adjust_size_request virtual method and by any
461 * #GtkSizeGroup that have been applied. That is, the returned request
462 * is the one that should be used for layout, not necessarily the one
463 * returned by the widget itself.
468 gtk_widget_get_preferred_height_for_width (GtkWidget *widget,
470 gint *minimum_height,
471 gint *natural_height)
473 compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
474 width, minimum_height, natural_height);
478 * gtk_widget_get_preferred_size:
479 * @widget: a #GtkWidget instance
480 * @minimum_size: (out) (allow-none): location for storing the minimum size, or %NULL
481 * @natural_size: (out) (allow-none): location for storing the natural size, or %NULL
483 * Retrieves the minimum and natural size of a widget taking
484 * into account the widget's preference for height-for-width management.
486 * This is used to retrieve a suitable size by container widgets which do
487 * not impose any restrictions on the child placement. It can be used
488 * to deduce toplevel window and menu sizes as well as child widgets in
489 * free form containers such as GtkLayout.
491 * <note><para>Handle with care, note that the natural height of a height-for-width
492 * widget will generally be a smaller size than the minimum height, since the required
493 * height for the natural width is generally smaller than the required height for
494 * the minimum width.</para></note>
499 gtk_widget_get_preferred_size (GtkWidget *widget,
500 GtkRequisition *minimum_size,
501 GtkRequisition *natural_size)
503 gint min_width, nat_width;
504 gint min_height, nat_height;
506 g_return_if_fail (GTK_IS_WIDGET (widget));
508 if (gtk_widget_get_request_mode (widget) == GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH)
510 gtk_widget_get_preferred_width (widget, &min_width, &nat_width);
514 minimum_size->width = min_width;
515 gtk_widget_get_preferred_height_for_width (widget, min_width,
516 &minimum_size->height, NULL);
521 natural_size->width = nat_width;
522 gtk_widget_get_preferred_height_for_width (widget, nat_width,
523 NULL, &natural_size->height);
526 else /* GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT */
528 gtk_widget_get_preferred_height (widget, &min_height, &nat_height);
532 minimum_size->height = min_height;
533 gtk_widget_get_preferred_width_for_height (widget, min_height,
534 &minimum_size->width, NULL);
539 natural_size->height = nat_height;
540 gtk_widget_get_preferred_width_for_height (widget, nat_height,
541 NULL, &natural_size->width);
548 compare_gap (gconstpointer p1,
552 GtkRequestedSize *sizes = data;
553 const guint *c1 = p1;
554 const guint *c2 = p2;
556 const gint d1 = MAX (sizes[*c1].natural_size -
557 sizes[*c1].minimum_size,
559 const gint d2 = MAX (sizes[*c2].natural_size -
560 sizes[*c2].minimum_size,
563 gint delta = (d2 - d1);
572 * gtk_distribute_natural_allocation:
573 * @extra_space: Extra space to redistribute among children after subtracting
574 * minimum sizes and any child padding from the overall allocation
575 * @n_requested_sizes: Number of requests to fit into the allocation
576 * @sizes: An array of structs with a client pointer and a minimum/natural size
577 * in the orientation of the allocation.
579 * Distributes @extra_space to child @sizes by bringing up smaller
580 * children up to natural size first.
582 * The remaining space will be added to the @minimum_size member of the
583 * GtkRequestedSize struct. If all sizes reach their natural size then
584 * the remaining space is returned.
586 * Returns: The remainder of @extra_space after redistributing space
590 gtk_distribute_natural_allocation (gint extra_space,
591 guint n_requested_sizes,
592 GtkRequestedSize *sizes)
597 g_return_val_if_fail (extra_space >= 0, 0);
599 spreading = g_newa (guint, n_requested_sizes);
601 for (i = 0; i < n_requested_sizes; i++)
604 /* Distribute the container's extra space c_gap. We want to assign
605 * this space such that the sum of extra space assigned to children
606 * (c^i_gap) is equal to c_cap. The case that there's not enough
607 * space for all children to take their natural size needs some
608 * attention. The goals we want to achieve are:
610 * a) Maximize number of children taking their natural size.
611 * b) The allocated size of children should be a continuous
612 * function of c_gap. That is, increasing the container size by
613 * one pixel should never make drastic changes in the distribution.
614 * c) If child i takes its natural size and child j doesn't,
615 * child j should have received at least as much gap as child i.
617 * The following code distributes the additional space by following
621 /* Sort descending by gap and position. */
622 g_qsort_with_data (spreading,
623 n_requested_sizes, sizeof (guint),
626 /* Distribute available space.
627 * This master piece of a loop was conceived by Behdad Esfahbod.
629 for (i = n_requested_sizes - 1; extra_space > 0 && i >= 0; --i)
631 /* Divide remaining space by number of remaining children.
632 * Sort order and reducing remaining space by assigned space
633 * ensures that space is distributed equally.
635 gint glue = (extra_space + i) / (i + 1);
636 gint gap = sizes[(spreading[i])].natural_size
637 - sizes[(spreading[i])].minimum_size;
639 gint extra = MIN (glue, gap);
641 sizes[spreading[i]].minimum_size += extra;
643 extra_space -= extra;