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)) )
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()
92 //----------------------------------------------------------------------------
93 int Layout::ItemData::hfw(int w) const
96 return layout_item->heightForWidth(w);
98 return layout_item->sizeHint().y();
101 //----------------------------------------------------------------------------
102 int Layout::ItemData::mhfw(int w) const
105 return layout_item->minimumHeightForWidth(w);
107 return layout_item->minimumSize().y();
110 //----------------------------------------------------------------------------
111 void Layout::safeAdd(int& a, int b)
113 if( SGLimits<int>::max() - b < a )
114 a = SGLimits<int>::max();
119 //----------------------------------------------------------------------------
120 void Layout::distribute(std::vector<ItemData>& items, const ItemData& space)
122 const int num_children = static_cast<int>(items.size());
123 _num_not_done = num_children;
127 "Layout::distribute(" << space.size << "px for "
128 << num_children << " items, s.t."
129 << " min=" << space.min_size
130 << ", hint=" << space.size_hint
131 << ", max=" << space.max_size << ")" );
133 if( space.size < space.min_size )
136 SG_LOG( SG_GUI, SG_WARN, "Layout: not enough size (not implemented)");
138 else if( space.size < space.max_size )
143 bool less_then_hint = space.size < space.size_hint;
145 // Give min_size/size_hint to all items
146 _space_left = space.size
147 - (less_then_hint ? space.min_size : space.size_hint);
148 for(int i = 0; i < num_children; ++i)
150 ItemData& d = items[i];
151 d.size = less_then_hint ? d.min_size : d.size_hint;
152 d.padding = d.padding_orig;
153 d.done = d.size >= (less_then_hint ? d.size_hint : d.max_size);
158 i << ") initial=" << d.size
159 << ", min=" << d.min_size
160 << ", hint=" << d.size_hint
161 << ", max=" << d.max_size
172 _sum_stretch += d.stretch;
173 _space_stretch += d.size;
177 // Distribute remaining space to increase the size of each item up to its
178 // size_hint/max_size
179 while( _space_left > 0 )
181 if( _num_not_done <= 0 )
183 SG_LOG(SG_GUI, SG_WARN, "space left, but no more items?");
187 int space_per_element = std::max(1, _space_left / _num_not_done);
189 SG_LOG(SG_GUI, SG_DEBUG, "space/element=" << space_per_element);
191 for(int i = 0; i < num_children; ++i)
193 ItemData& d = items[i];
198 i << ") left=" << _space_left
199 << ", not_done=" << _num_not_done
200 << ", sum=" << _sum_stretch
201 << ", stretch=" << _space_stretch
202 << ", stretch/unit=" << _space_stretch / std::max(1, _sum_stretch)
208 if( _sum_stretch > 0 && d.stretch <= 0 )
213 int max_size = less_then_hint ? d.size_hint : d.max_size;
215 if( _sum_stretch > 0 )
217 target_size = (d.stretch * (_space_left + _space_stretch))
220 // Item would be smaller than minimum size or larger than maximum
221 // size, so just keep bounded size and ignore stretch factor
222 if( target_size <= d.size || target_size >= max_size )
225 _sum_stretch -= d.stretch;
226 _space_stretch -= d.size;
228 if( target_size >= max_size )
229 target_size = max_size;
231 target_size = d.size;
234 _space_stretch += target_size - d.size;
238 // Give space evenly to all remaining elements in this round
239 target_size = d.size + std::min(_space_left, space_per_element);
241 if( target_size >= max_size )
244 target_size = max_size;
248 int old_size = d.size;
249 d.size = target_size;
250 _space_left -= d.size - old_size;
257 if( _sum_stretch <= 0 && d.stretch > 0 )
258 // Distribute remaining space evenly to all non-stretchable items
267 _space_left = space.size - space.max_size;
268 for(int i = 0; i < num_children; ++i)
270 ItemData& d = items[i];
273 // Add superfluous space as padding
274 d.padding = d.padding_orig + _space_left
275 // Padding after last child...
276 / (_num_not_done + 1);
278 _space_left -= d.padding - d.padding_orig;
283 SG_LOG(SG_GUI, SG_DEBUG, "distribute:");
284 for(int i = 0; i < num_children; ++i)
286 ItemData const& d = items[i];
289 i << ") pad=" << d.padding
290 << ", size = " << d.size );
294 } // namespace canvas
295 } // namespace simgear