1 // Basic class for canvas layouts
3 // Copyright (C) 2014 Thomas Geymayer <tomgey@gmail.com>
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Library General Public
7 // License as published by the Free Software Foundation; either
8 // version 2 of the License, or (at your option) any later version.
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Library General Public License for more details.
15 // You should have received a copy of the GNU Library General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
20 #include <simgear/debug/logstream.hxx>
27 //----------------------------------------------------------------------------
30 if( !(_flags & (LAYOUT_DIRTY | SIZE_INFO_DIRTY)) || !isVisible() )
35 _flags &= ~LAYOUT_DIRTY;
38 //----------------------------------------------------------------------------
39 void Layout::invalidate()
41 LayoutItem::invalidate();
42 _flags |= LAYOUT_DIRTY;
45 //----------------------------------------------------------------------------
46 void Layout::setGeometry(const SGRecti& geom)
48 if( geom != _geometry )
51 _flags |= LAYOUT_DIRTY;
57 //----------------------------------------------------------------------------
58 void Layout::removeItem(const LayoutItemRef& item)
61 while( LayoutItemRef child = itemAt(i) )
64 return (void)takeAt(i);
70 //----------------------------------------------------------------------------
77 //----------------------------------------------------------------------------
78 void Layout::ItemData::reset()
93 //----------------------------------------------------------------------------
94 int Layout::ItemData::hfw(int w) const
97 return layout_item->heightForWidth(w);
99 return layout_item->sizeHint().y();
102 //----------------------------------------------------------------------------
103 int Layout::ItemData::mhfw(int w) const
106 return layout_item->minimumHeightForWidth(w);
108 return layout_item->minimumSize().y();
111 //----------------------------------------------------------------------------
112 void Layout::distribute(std::vector<ItemData>& items, const ItemData& space)
114 const int num_children = static_cast<int>(items.size());
119 "Layout::distribute(" << space.size << "px for "
120 << num_children << " items, s.t."
121 << " min=" << space.min_size
122 << ", hint=" << space.size_hint
123 << ", max=" << space.max_size << ")" );
125 if( space.size < space.min_size )
128 SG_LOG( SG_GUI, SG_WARN, "Layout: not enough size (not implemented)");
130 else if( space.size < space.max_size )
135 bool less_then_hint = space.size < space.size_hint;
137 // Give min_size/size_hint to all items
138 _space_left = space.size
139 - (less_then_hint ? space.min_size : space.size_hint);
140 for(int i = 0; i < num_children; ++i)
142 ItemData& d = items[i];
146 d.size = less_then_hint ? d.min_size : d.size_hint;
147 d.padding = d.padding_orig;
148 d.done = d.size >= (less_then_hint ? d.size_hint : d.max_size);
153 i << ") initial=" << d.size
154 << ", min=" << d.min_size
155 << ", hint=" << d.size_hint
156 << ", max=" << d.max_size
165 _sum_stretch += d.stretch;
166 _space_stretch += d.size;
170 // Distribute remaining space to increase the size of each item up to its
171 // size_hint/max_size
172 while( _space_left > 0 )
174 if( _num_not_done <= 0 )
176 SG_LOG(SG_GUI, SG_WARN, "space left, but no more items?");
180 int space_per_element = std::max(1, _space_left / _num_not_done);
182 SG_LOG(SG_GUI, SG_DEBUG, "space/element=" << space_per_element);
184 for(int i = 0; i < num_children; ++i)
186 ItemData& d = items[i];
193 i << ") left=" << _space_left
194 << ", not_done=" << _num_not_done
195 << ", sum=" << _sum_stretch
196 << ", stretch=" << _space_stretch
197 << ", stretch/unit=" << _space_stretch / std::max(1, _sum_stretch)
203 if( _sum_stretch > 0 && d.stretch <= 0 )
208 int max_size = less_then_hint ? d.size_hint : d.max_size;
210 if( _sum_stretch > 0 )
212 target_size = (d.stretch * (_space_left + _space_stretch))
215 // Item would be smaller than minimum size or larger than maximum
216 // size, so just keep bounded size and ignore stretch factor
217 if( target_size <= d.size || target_size >= max_size )
220 _sum_stretch -= d.stretch;
221 _space_stretch -= d.size;
223 if( target_size >= max_size )
224 target_size = max_size;
226 target_size = d.size;
229 _space_stretch += target_size - d.size;
233 // Give space evenly to all remaining elements in this round
234 target_size = d.size + std::min(_space_left, space_per_element);
236 if( target_size >= max_size )
239 target_size = max_size;
243 int old_size = d.size;
244 d.size = target_size;
245 _space_left -= d.size - old_size;
252 if( _sum_stretch <= 0 && d.stretch > 0 )
253 // Distribute remaining space evenly to all non-stretchable items
262 _space_left = space.size - space.max_size;
263 for(int i = 0; i < num_children; ++i)
265 if( items[i].visible )
269 for(int i = 0; i < num_children; ++i)
271 ItemData& d = items[i];
277 // Add superfluous space as padding
278 d.padding = d.padding_orig + _space_left
279 // Padding after last child...
280 / (_num_not_done + 1);
282 _space_left -= d.padding - d.padding_orig;
287 SG_LOG(SG_GUI, SG_DEBUG, "distribute:");
288 for(int i = 0; i < num_children; ++i)
290 ItemData const& d = items[i];
292 SG_LOG(SG_GUI, SG_DEBUG, i << ") pad=" << d.padding
293 << ", size= " << d.size);
295 SG_LOG(SG_GUI, SG_DEBUG, i << ") [hidden]");
299 } // namespace canvas
300 } // namespace simgear