forked from AuroraMiddleware/gtk
737 lines
26 KiB
C
737 lines
26 KiB
C
/* gtksizerequest.c
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* Copyright (C) 2007-2010 Openismus GmbH
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*
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* Authors:
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* Mathias Hasselmann <mathias@openismus.com>
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* Tristan Van Berkom <tristan.van.berkom@gmail.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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/**
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* SECTION:gtksizerequest
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* @Short_Description: Height-for-width geometry management
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* @Title: GtkWidget
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*
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* The GtkWidget interface is GTK+'s height-for-width (and width-for-height)
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* geometry management system. Height-for-width means that a widget can
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* change how much vertical space it needs, depending on the amount
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* of horizontal space that it is given (and similar for width-for-height).
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* The most common example is a label that reflows to fill up the available
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* width, wraps to fewer lines, and therefore needs less height.
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*
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* GTK+'s traditional two-pass <link linkend="size-allocation">size-allocation</link>
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* algorithm does not allow this flexibility. #GtkWidget provides a default
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* implementation of the #GtkWidget interface for existing widgets,
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* which always requests the same height, regardless of the available width.
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*
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* <refsect2>
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* <title>Implementing GtkWidget </title>
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* <para>
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* Some important things to keep in mind when implementing
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* the GtkWidget interface and when using it in container
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* implementations.
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*
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* The geometry management system will query a logical hierarchy in
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* only one orientation at a time. When widgets are initially queried
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* for their minimum sizes it is generally done in a dual pass
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* in the direction chosen by the toplevel.
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*
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* For instance when queried in the normal height-for-width mode:
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* First the default minimum and natural width for each widget
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* in the interface will computed and collectively returned to
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* the toplevel by way of gtk_widget_get_preferred_width().
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* Next, the toplevel will use the minimum width to query for the
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* minimum height contextual to that width using
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* gtk_widget_get_preferred_height_for_width(), which will also
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* be a highly recursive operation. This minimum-for-minimum size can
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* be used to set the minimum size constraint on the toplevel.
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*
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* When allocating, each container can use the minimum and natural
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* sizes reported by their children to allocate natural sizes and
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* expose as much content as possible with the given allocation.
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*
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* That means that the request operation at allocation time will
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* usually fire again in contexts of different allocated sizes than
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* the ones originally queried for. #GtkWidget caches a
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* small number of results to avoid re-querying for the same
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* allocated size in one allocation cycle.
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*
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* A widget that does not actually do height-for-width
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* or width-for-height size negotiations only has to implement
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* get_width() and get_height().
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*
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* If a widget does move content around to smartly use up the
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* allocated size, then it must support the request properly in
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* both orientations; even if the request only makes sense in
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* one orientation.
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*
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* For instance, a GtkLabel that does height-for-width word wrapping
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* will not expect to have get_height() called because that
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* call is specific to a width-for-height request, in this case the
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* label must return the heights contextual to its minimum possible
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* width. By following this rule any widget that handles height-for-width
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* or width-for-height requests will always be allocated at least
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* enough space to fit its own content.
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*
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* Often a widget needs to get its own request during size request or
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* allocation, for example when computing height it may need to also
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* compute width, or when deciding how to use an allocation the widget may
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* need to know its natural size. In these cases, the widget should be
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* careful to call its virtual methods directly, like this:
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* <example>
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* <title>Widget calling its own size request method.</title>
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* <programlisting>
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* GTK_SIZE_REQUEST_GET_IFACE(widget)->get_width(GTK_SIZE_REQUEST(widget), &min, &natural);
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* </programlisting>
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* </example>
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*
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* It will not work to use the wrapper functions, such as
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* gtk_size_request_get_width(), inside your own size request
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* implementation. These return a request adjusted by #GtkSizeGroup
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* and by the GtkWidgetClass::adjust_size_request virtual method. If a
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* widget used the wrappers inside its virtual method implementations,
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* then the adjustments (such as widget margins) would be applied
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* twice. GTK+ therefore does not allow this and will warn if you try
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* to do it.
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*
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* Of course if you are getting the size request for
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* <emphasis>another</emphasis> widget, such as a child of a
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* container, you <emphasis>must</emphasis> use the wrapper APIs;
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* otherwise, you would not properly consider widget margins,
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* #GtkSizeGroup, and so forth.
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* </para>
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* </refsect2>
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*/
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#include <config.h>
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#include "gtksizerequest.h"
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#include "gtksizegroup.h"
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#include "gtkdebug.h"
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#include "gtkprivate.h"
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#include "gtkintl.h"
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/* looks for a cached size request for this for_size. If not
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* found, returns the oldest entry so it can be overwritten
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*
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* Note that this caching code was directly derived from
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* the Clutter toolkit.
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*/
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static gboolean
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get_cached_size (SizeRequestCache *cache,
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GtkSizeGroupMode orientation,
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gint for_size,
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SizeRequest **result)
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{
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guint i, n_sizes;
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SizeRequest *cached_sizes;
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if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
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{
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cached_sizes = cache->widths;
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n_sizes = cache->cached_widths;
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}
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else
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{
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cached_sizes = cache->heights;
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n_sizes = cache->cached_widths;
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}
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/* Search for an already cached size */
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for (i = 0; i < n_sizes; i++)
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{
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if (cached_sizes[i].for_size == for_size)
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{
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*result = &cached_sizes[i];
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return TRUE;
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}
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}
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/* If not found, pull a new size from the cache, the returned size cache
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* will immediately be used to cache the new computed size so we go ahead
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* and increment the last_cached_width/height right away */
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if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
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{
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if (cache->cached_widths < GTK_SIZE_REQUEST_CACHED_SIZES)
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{
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cache->cached_widths++;
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cache->last_cached_width = cache->cached_widths - 1;
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}
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else
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{
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if (++cache->last_cached_width == GTK_SIZE_REQUEST_CACHED_SIZES)
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cache->last_cached_width = 0;
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}
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*result = &cache->widths[cache->last_cached_width];
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}
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else /* GTK_SIZE_GROUP_VERTICAL */
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{
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if (cache->cached_heights < GTK_SIZE_REQUEST_CACHED_SIZES)
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{
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cache->cached_heights++;
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cache->last_cached_height = cache->cached_heights - 1;
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}
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else
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{
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if (++cache->last_cached_height == GTK_SIZE_REQUEST_CACHED_SIZES)
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cache->last_cached_height = 0;
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}
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*result = &cache->heights[cache->last_cached_height];
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}
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return FALSE;
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}
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static void
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do_size_request (GtkWidget *widget,
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GtkRequisition *requisition)
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{
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/* Now we dont bother caching the deprecated "size-request" returns,
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* just unconditionally invoke here just in case we run into legacy stuff */
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gtk_widget_ensure_style (widget);
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g_signal_emit_by_name (widget, "size-request", requisition);
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}
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#ifndef G_DISABLE_CHECKS
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static GQuark recursion_check_quark = 0;
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#endif /* G_DISABLE_CHECKS */
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static void
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push_recursion_check (GtkWidget *request,
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GtkSizeGroupMode orientation,
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gint for_size)
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{
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#ifndef G_DISABLE_CHECKS
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const char *previous_method;
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const char *method;
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if (recursion_check_quark == 0)
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recursion_check_quark = g_quark_from_static_string ("gtk-size-request-in-progress");
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previous_method = g_object_get_qdata (G_OBJECT (request), recursion_check_quark);
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if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
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{
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method = for_size < 0 ? "get_width" : "get_width_for_height";
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}
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else
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{
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method = for_size < 0 ? "get_height" : "get_height_for_width";
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}
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if (previous_method != NULL)
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{
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g_warning ("%s %p: widget tried to gtk_widget_%s inside "
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" GtkWidget ::%s implementation. "
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"Should just invoke GTK_WIDGET_GET_CLASS(widget)->%s "
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"directly rather than using gtk_widget_%s",
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G_OBJECT_TYPE_NAME (request), request,
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method, previous_method,
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method, method);
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}
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g_object_set_qdata (G_OBJECT (request), recursion_check_quark, (char*) method);
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#endif /* G_DISABLE_CHECKS */
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}
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static void
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pop_recursion_check (GtkWidget *request,
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GtkSizeGroupMode orientation)
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{
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#ifndef G_DISABLE_CHECKS
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g_object_set_qdata (G_OBJECT (request), recursion_check_quark, NULL);
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#endif
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}
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static void
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compute_size_for_orientation (GtkWidget *request,
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GtkSizeGroupMode orientation,
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gint for_size,
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gint *minimum_size,
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gint *natural_size)
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{
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SizeRequestCache *cache;
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SizeRequest *cached_size;
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GtkWidget *widget;
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gboolean found_in_cache = FALSE;
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int adjusted_min, adjusted_natural;
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g_return_if_fail (GTK_IS_WIDGET (request));
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g_return_if_fail (minimum_size != NULL || natural_size != NULL);
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widget = GTK_WIDGET (request);
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cache = _gtk_widget_peek_request_cache (widget);
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if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
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{
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cached_size = &cache->widths[0];
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if (!_gtk_widget_get_width_request_needed (widget))
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found_in_cache = get_cached_size (cache, orientation, for_size, &cached_size);
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else
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{
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memset (cache->widths, 0, GTK_SIZE_REQUEST_CACHED_SIZES * sizeof (SizeRequest));
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cache->cached_widths = 1;
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cache->last_cached_width = 0;
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}
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}
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else
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{
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cached_size = &cache->heights[0];
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if (!_gtk_widget_get_height_request_needed (widget))
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found_in_cache = get_cached_size (cache, orientation, for_size, &cached_size);
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else
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{
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memset (cache->heights, 0, GTK_SIZE_REQUEST_CACHED_SIZES * sizeof (SizeRequest));
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cache->cached_heights = 1;
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cache->last_cached_height = 0;
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}
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}
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if (!found_in_cache)
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{
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GtkRequisition requisition = { 0, 0 };
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gint min_size = 0, nat_size = 0;
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gint requisition_size;
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/* Unconditional size request runs but is often unhandled. */
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do_size_request (widget, &requisition);
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push_recursion_check (request, orientation, for_size);
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if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
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{
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requisition_size = requisition.width;
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if (for_size < 0)
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GTK_WIDGET_GET_CLASS (request)->get_preferred_width (request, &min_size, &nat_size);
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else
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GTK_WIDGET_GET_CLASS (request)->get_preferred_width_for_height (request, for_size,
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&min_size, &nat_size);
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}
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else
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{
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requisition_size = requisition.height;
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if (for_size < 0)
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GTK_WIDGET_GET_CLASS (request)->get_preferred_height (request, &min_size, &nat_size);
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else
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GTK_WIDGET_GET_CLASS (request)->get_preferred_height_for_width (request, for_size,
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&min_size, &nat_size);
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}
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pop_recursion_check (request, orientation);
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if (min_size > nat_size)
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{
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g_warning ("%s %p reported min size %d and natural size %d; natural size must be >= min size",
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G_OBJECT_TYPE_NAME (request), request, min_size, nat_size);
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}
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/* Support for dangling "size-request" signal implementations on
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* legacy widgets
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*/
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min_size = MAX (min_size, requisition_size);
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nat_size = MAX (nat_size, requisition_size);
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cached_size->minimum_size = min_size;
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cached_size->natural_size = nat_size;
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cached_size->for_size = for_size;
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if (orientation == GTK_SIZE_GROUP_HORIZONTAL)
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_gtk_widget_set_width_request_needed (widget, FALSE);
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else
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_gtk_widget_set_height_request_needed (widget, FALSE);
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adjusted_min = cached_size->minimum_size;
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adjusted_natural = cached_size->natural_size;
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GTK_WIDGET_GET_CLASS (request)->adjust_size_request (GTK_WIDGET (request),
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orientation == GTK_SIZE_GROUP_HORIZONTAL ?
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GTK_ORIENTATION_HORIZONTAL :
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GTK_ORIENTATION_VERTICAL,
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cached_size->for_size,
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&adjusted_min,
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&adjusted_natural);
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if (adjusted_min < cached_size->minimum_size ||
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adjusted_natural < cached_size->natural_size)
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{
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g_warning ("%s %p adjusted size %s min %d natural %d must not decrease below min %d natural %d",
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G_OBJECT_TYPE_NAME (request), request,
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orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
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adjusted_min, adjusted_natural,
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cached_size->minimum_size, cached_size->natural_size);
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/* don't use the adjustment */
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}
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else if (adjusted_min > adjusted_natural)
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{
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g_warning ("%s %p adjusted size %s min %d natural %d original min %d natural %d has min greater than natural",
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G_OBJECT_TYPE_NAME (request), request,
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orientation == GTK_SIZE_GROUP_VERTICAL ? "vertical" : "horizontal",
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adjusted_min, adjusted_natural,
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cached_size->minimum_size, cached_size->natural_size);
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/* don't use the adjustment */
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}
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else
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{
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/* adjustment looks good */
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cached_size->minimum_size = adjusted_min;
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cached_size->natural_size = adjusted_natural;
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}
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/* Update size-groups with our request and update our cached requests
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* with the size-group values in a single pass.
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*/
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_gtk_size_group_bump_requisition (GTK_WIDGET (request),
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orientation,
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&cached_size->minimum_size,
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&cached_size->natural_size);
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}
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if (minimum_size)
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*minimum_size = cached_size->minimum_size;
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if (natural_size)
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*natural_size = cached_size->natural_size;
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g_assert (cached_size->minimum_size <= cached_size->natural_size);
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GTK_NOTE (SIZE_REQUEST,
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g_print ("[%p] %s\t%s: %d is minimum %d and natural: %d (hit cache: %s)\n",
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request, G_OBJECT_TYPE_NAME (request),
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orientation == GTK_SIZE_GROUP_HORIZONTAL ?
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"width for height" : "height for width" ,
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for_size,
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cached_size->minimum_size,
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cached_size->natural_size,
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found_in_cache ? "yes" : "no"));
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}
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/**
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* gtk_widget_get_request_mode:
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* @widget: a #GtkWidget instance
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*
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* Gets whether the widget prefers a height-for-width layout
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* or a width-for-height layout.
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*
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* <note><para>#GtkBin widgets generally propagate the preference of
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* their child, container widgets need to request something either in
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* context of their children or in context of their allocation
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* capabilities.</para></note>
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*
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* Returns: The #GtkSizeRequestMode preferred by @widget.
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*
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* Since: 3.0
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*/
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GtkSizeRequestMode
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gtk_widget_get_request_mode (GtkWidget *widget)
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{
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GtkWidgetClass *klass;
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g_return_val_if_fail (GTK_IS_WIDGET (widget), GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH);
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klass = GTK_WIDGET_GET_CLASS (widget);
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if (klass->get_request_mode)
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return klass->get_request_mode (widget);
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/* By default widgets are height-for-width. */
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return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
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}
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/**
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* gtk_widget_get_preferred_width:
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* @widget: a #GtkWidget instance
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* @minimum_width: (out) (allow-none): location to store the minimum width, or %NULL
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* @natural_width: (out) (allow-none): location to store the natural width, or %NULL
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*
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* Retrieves a widget's initial minimum and natural width.
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*
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* <note><para>This call is specific to height-for-width
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* requests.</para></note>
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*
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* The returned request will be modified by the
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* GtkWidgetClass::adjust_size_request virtual method and by any
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* #GtkSizeGroup that have been applied. That is, the returned request
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* is the one that should be used for layout, not necessarily the one
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* returned by the widget itself.
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*
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* Since: 3.0
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*/
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void
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gtk_widget_get_preferred_width (GtkWidget *widget,
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gint *minimum_width,
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gint *natural_width)
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{
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compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
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-1, minimum_width, natural_width);
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}
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/**
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* gtk_widget_get_preferred_height:
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* @widget: a #GtkWidget instance
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* @minimum_height: (out) (allow-none): location to store the minimum height, or %NULL
|
|
* @natural_height: (out) (allow-none): location to store the natural height, or %NULL
|
|
*
|
|
* Retrieves a widget's initial minimum and natural height.
|
|
*
|
|
* <note><para>This call is specific to width-for-height requests.</para></note>
|
|
*
|
|
* The returned request will be modified by the
|
|
* GtkWidgetClass::adjust_size_request virtual method and by any
|
|
* #GtkSizeGroup that have been applied. That is, the returned request
|
|
* is the one that should be used for layout, not necessarily the one
|
|
* returned by the widget itself.
|
|
*
|
|
* Since: 3.0
|
|
*/
|
|
void
|
|
gtk_widget_get_preferred_height (GtkWidget *widget,
|
|
gint *minimum_height,
|
|
gint *natural_height)
|
|
{
|
|
compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
|
|
-1, minimum_height, natural_height);
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* gtk_widget_get_preferred_width_for_height:
|
|
* @widget: a #GtkWidget instance
|
|
* @height: the height which is available for allocation
|
|
* @minimum_width: (out) (allow-none): location for storing the minimum width, or %NULL
|
|
* @natural_width: (out) (allow-none): location for storing the natural width, or %NULL
|
|
*
|
|
* Retrieves a widget's minimum and natural width if it would be given
|
|
* the specified @height.
|
|
*
|
|
* The returned request will be modified by the
|
|
* GtkWidgetClass::adjust_size_request virtual method and by any
|
|
* #GtkSizeGroup that have been applied. That is, the returned request
|
|
* is the one that should be used for layout, not necessarily the one
|
|
* returned by the widget itself.
|
|
*
|
|
* Since: 3.0
|
|
*/
|
|
void
|
|
gtk_widget_get_preferred_width_for_height (GtkWidget *widget,
|
|
gint height,
|
|
gint *minimum_width,
|
|
gint *natural_width)
|
|
{
|
|
compute_size_for_orientation (widget, GTK_SIZE_GROUP_HORIZONTAL,
|
|
height, minimum_width, natural_width);
|
|
}
|
|
|
|
/**
|
|
* gtk_widget_get_preferred_height_for_width:
|
|
* @widget: a #GtkWidget instance
|
|
* @width: the width which is available for allocation
|
|
* @minimum_height: (out) (allow-none): location for storing the minimum height, or %NULL
|
|
* @natural_height: (out) (allow-none): location for storing the natural height, or %NULL
|
|
*
|
|
* Retrieves a widget's minimum and natural height if it would be given
|
|
* the specified @width.
|
|
*
|
|
* The returned request will be modified by the
|
|
* GtkWidgetClass::adjust_size_request virtual method and by any
|
|
* #GtkSizeGroup that have been applied. That is, the returned request
|
|
* is the one that should be used for layout, not necessarily the one
|
|
* returned by the widget itself.
|
|
*
|
|
* Since: 3.0
|
|
*/
|
|
void
|
|
gtk_widget_get_preferred_height_for_width (GtkWidget *widget,
|
|
gint width,
|
|
gint *minimum_height,
|
|
gint *natural_height)
|
|
{
|
|
compute_size_for_orientation (widget, GTK_SIZE_GROUP_VERTICAL,
|
|
width, minimum_height, natural_height);
|
|
}
|
|
|
|
/**
|
|
* gtk_widget_get_preferred_size:
|
|
* @widget: a #GtkWidget instance
|
|
* @minimum_size: (out) (allow-none): location for storing the minimum size, or %NULL
|
|
* @natural_size: (out) (allow-none): location for storing the natural size, or %NULL
|
|
*
|
|
* Retrieves the minimum and natural size of a widget taking
|
|
* into account the widget's preference for height-for-width management.
|
|
*
|
|
* This is used to retrieve a suitable size by container widgets which do
|
|
* not impose any restrictions on the child placement.
|
|
*
|
|
* Since: 3.0
|
|
*/
|
|
void
|
|
gtk_widget_get_preferred_size (GtkWidget *widget,
|
|
GtkRequisition *minimum_size,
|
|
GtkRequisition *natural_size)
|
|
{
|
|
gint min_width, nat_width;
|
|
gint min_height, nat_height;
|
|
|
|
g_return_if_fail (GTK_IS_WIDGET (widget));
|
|
|
|
if (gtk_widget_get_request_mode (widget) == GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH)
|
|
{
|
|
gtk_widget_get_preferred_width (widget, &min_width, &nat_width);
|
|
|
|
if (minimum_size)
|
|
{
|
|
minimum_size->width = min_width;
|
|
gtk_widget_get_preferred_height_for_width (widget, min_width,
|
|
&minimum_size->height, NULL);
|
|
}
|
|
|
|
if (natural_size)
|
|
{
|
|
natural_size->width = nat_width;
|
|
gtk_widget_get_preferred_height_for_width (widget, nat_width,
|
|
NULL, &natural_size->height);
|
|
}
|
|
}
|
|
else /* GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT */
|
|
{
|
|
gtk_widget_get_preferred_height (widget, &min_height, &nat_height);
|
|
|
|
if (minimum_size)
|
|
{
|
|
minimum_size->height = min_height;
|
|
gtk_widget_get_preferred_width_for_height (widget, min_height,
|
|
&minimum_size->width, NULL);
|
|
}
|
|
|
|
if (natural_size)
|
|
{
|
|
natural_size->height = nat_height;
|
|
gtk_widget_get_preferred_width_for_height (widget, nat_height,
|
|
NULL, &natural_size->width);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static gint
|
|
compare_gap (gconstpointer p1,
|
|
gconstpointer p2,
|
|
gpointer data)
|
|
{
|
|
GtkRequestedSize *sizes = data;
|
|
const guint *c1 = p1;
|
|
const guint *c2 = p2;
|
|
|
|
const gint d1 = MAX (sizes[*c1].natural_size -
|
|
sizes[*c1].minimum_size,
|
|
0);
|
|
const gint d2 = MAX (sizes[*c2].natural_size -
|
|
sizes[*c2].minimum_size,
|
|
0);
|
|
|
|
gint delta = (d2 - d1);
|
|
|
|
if (0 == delta)
|
|
delta = (*c2 - *c1);
|
|
|
|
return delta;
|
|
}
|
|
|
|
/**
|
|
* gtk_distribute_natural_allocation:
|
|
* @extra_space: Extra space to redistribute among children after subtracting
|
|
* minimum sizes and any child padding from the overall allocation
|
|
* @n_requested_sizes: Number of requests to fit into the allocation
|
|
* @sizes: An array of structs with a client pointer and a minimum/natural size
|
|
* in the orientation of the allocation.
|
|
*
|
|
* Distributes @extra_space to child @sizes by bringing up smaller
|
|
* children up to natural size first.
|
|
*
|
|
* The remaining space will be added to the @minimum_size member of the
|
|
* GtkRequestedSize struct. If all sizes reach their natural size then
|
|
* the remaining space is returned.
|
|
*
|
|
* Returns: The remainder of @extra_space after redistributing space
|
|
* to @sizes.
|
|
*/
|
|
gint
|
|
gtk_distribute_natural_allocation (gint extra_space,
|
|
guint n_requested_sizes,
|
|
GtkRequestedSize *sizes)
|
|
{
|
|
guint *spreading;
|
|
gint i;
|
|
|
|
g_return_val_if_fail (extra_space >= 0, 0);
|
|
|
|
spreading = g_newa (guint, n_requested_sizes);
|
|
|
|
for (i = 0; i < n_requested_sizes; i++)
|
|
spreading[i] = i;
|
|
|
|
/* Distribute the container's extra space c_gap. We want to assign
|
|
* this space such that the sum of extra space assigned to children
|
|
* (c^i_gap) is equal to c_cap. The case that there's not enough
|
|
* space for all children to take their natural size needs some
|
|
* attention. The goals we want to achieve are:
|
|
*
|
|
* a) Maximize number of children taking their natural size.
|
|
* b) The allocated size of children should be a continuous
|
|
* function of c_gap. That is, increasing the container size by
|
|
* one pixel should never make drastic changes in the distribution.
|
|
* c) If child i takes its natural size and child j doesn't,
|
|
* child j should have received at least as much gap as child i.
|
|
*
|
|
* The following code distributes the additional space by following
|
|
* these rules.
|
|
*/
|
|
|
|
/* Sort descending by gap and position. */
|
|
g_qsort_with_data (spreading,
|
|
n_requested_sizes, sizeof (guint),
|
|
compare_gap, sizes);
|
|
|
|
/* Distribute available space.
|
|
* This master piece of a loop was conceived by Behdad Esfahbod.
|
|
*/
|
|
for (i = n_requested_sizes - 1; extra_space > 0 && i >= 0; --i)
|
|
{
|
|
/* Divide remaining space by number of remaining children.
|
|
* Sort order and reducing remaining space by assigned space
|
|
* ensures that space is distributed equally.
|
|
*/
|
|
gint glue = (extra_space + i) / (i + 1);
|
|
gint gap = sizes[(spreading[i])].natural_size
|
|
- sizes[(spreading[i])].minimum_size;
|
|
|
|
gint extra = MIN (glue, gap);
|
|
|
|
sizes[spreading[i]].minimum_size += extra;
|
|
|
|
extra_space -= extra;
|
|
}
|
|
|
|
return extra_space;
|
|
}
|
|
|