Files
simgear/simgear/canvas/layout/BoxLayout.cxx
2014-06-15 16:30:25 +02:00

468 lines
14 KiB
C++

// Align items horizontally or vertically in a box
//
// Copyright (C) 2014 Thomas Geymayer <tomgey@gmail.com>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
#include "BoxLayout.hxx"
#include "SpacerItem.hxx"
#include <simgear/canvas/Canvas.hxx>
namespace simgear
{
namespace canvas
{
//----------------------------------------------------------------------------
BoxLayout::BoxLayout(Direction dir):
_padding(5)
{
setDirection(dir);
}
//----------------------------------------------------------------------------
BoxLayout::~BoxLayout()
{
_parent.reset(); // No need to invalidate parent again...
clear();
}
//----------------------------------------------------------------------------
void BoxLayout::addItem(const LayoutItemRef& item)
{
return addItem(item, 0);
}
//----------------------------------------------------------------------------
void BoxLayout::addItem(const LayoutItemRef& item, int stretch)
{
insertItem(-1, item, stretch);
}
//----------------------------------------------------------------------------
void BoxLayout::addStretch(int stretch)
{
insertStretch(-1, stretch);
}
//----------------------------------------------------------------------------
void BoxLayout::addSpacing(int size)
{
insertSpacing(-1, size);
}
//----------------------------------------------------------------------------
void BoxLayout::insertItem(int index, const LayoutItemRef& item, int stretch)
{
ItemData item_data = {0};
item_data.layout_item = item;
item_data.stretch = std::max(0, stretch);
item->setCanvas(_canvas);
item->setParent(this);
if( index < 0 )
_layout_items.push_back(item_data);
else
_layout_items.insert(_layout_items.begin() + index, item_data);
invalidate();
}
//----------------------------------------------------------------------------
void BoxLayout::insertStretch(int index, int stretch)
{
insertItem(index, LayoutItemRef(new SpacerItem()), stretch);
}
//----------------------------------------------------------------------------
void BoxLayout::insertSpacing(int index, int size)
{
SGVec2i size_hint = horiz()
? SGVec2i(size, 0)
: SGVec2i(0, size),
max_size = size_hint;
insertItem(index, LayoutItemRef(new SpacerItem(size_hint, max_size)));
}
//----------------------------------------------------------------------------
size_t BoxLayout::count() const
{
return _layout_items.size();
}
//----------------------------------------------------------------------------
LayoutItemRef BoxLayout::itemAt(size_t index)
{
if( index >= _layout_items.size() )
return LayoutItemRef();
return _layout_items[index].layout_item;
}
//----------------------------------------------------------------------------
LayoutItemRef BoxLayout::takeAt(size_t index)
{
if( index >= _layout_items.size() )
return LayoutItemRef();
LayoutItems::iterator it = _layout_items.begin() + index;
LayoutItemRef item = it->layout_item;
item->onRemove();
_layout_items.erase(it);
invalidate();
return item;
}
//----------------------------------------------------------------------------
void BoxLayout::clear()
{
for( LayoutItems::iterator it = _layout_items.begin();
it != _layout_items.end();
++it )
{
it->layout_item->onRemove();
}
_layout_items.clear();
invalidate();
}
//----------------------------------------------------------------------------
void BoxLayout::setStretch(size_t index, int stretch)
{
if( index >= _layout_items.size() )
return;
_layout_items.at(index).stretch = std::max(0, stretch);
invalidate();
}
//----------------------------------------------------------------------------
int BoxLayout::stretch(size_t index) const
{
if( index >= _layout_items.size() )
return 0;
return _layout_items.at(index).stretch;
}
//----------------------------------------------------------------------------
void BoxLayout::setSpacing(int spacing)
{
if( spacing == _padding )
return;
_padding = spacing;
invalidate();
}
//----------------------------------------------------------------------------
int BoxLayout::spacing() const
{
return _padding;
}
//----------------------------------------------------------------------------
void BoxLayout::setDirection(Direction dir)
{
_direction = dir;
_get_layout_coord = &SGVec2i::x;
_get_fixed_coord = &SGVec2i::y;
if( !horiz() )
std::swap(_get_layout_coord, _get_fixed_coord);
invalidate();
}
//----------------------------------------------------------------------------
BoxLayout::Direction BoxLayout::direction() const
{
return _direction;
}
//----------------------------------------------------------------------------
bool BoxLayout::hasHeightForWidth() const
{
if( _flags & SIZE_INFO_DIRTY )
updateSizeHints();
return _layout_data.has_hfw;
}
//----------------------------------------------------------------------------
int BoxLayout::heightForWidth(int w) const
{
if( !hasHeightForWidth() )
return -1;
updateWFHCache(w);
return _hfw_height;
}
//----------------------------------------------------------------------------
int BoxLayout::minimumHeightForWidth(int w) const
{
if( !hasHeightForWidth() )
return -1;
updateWFHCache(w);
return _hfw_min_height;
}
//----------------------------------------------------------------------------
void BoxLayout::setCanvas(const CanvasWeakPtr& canvas)
{
_canvas = canvas;
for(size_t i = 0; i < _layout_items.size(); ++i)
_layout_items[i].layout_item->setCanvas(canvas);
}
//----------------------------------------------------------------------------
bool BoxLayout::horiz() const
{
return (_direction == LeftToRight) || (_direction == RightToLeft);
}
//----------------------------------------------------------------------------
void BoxLayout::updateSizeHints() const
{
SGVec2i min_size(0, 0),
max_size(0, 0),
size_hint(0, 0);
_layout_data.reset();
_hfw_width = _hfw_height = _hfw_min_height = -1;
bool is_first = true;
for(size_t i = 0; i < _layout_items.size(); ++i)
{
// TODO check visible
ItemData& item_data = _layout_items[i];
LayoutItem const& item = *item_data.layout_item;
item_data.min_size = (item.minimumSize().*_get_layout_coord)();
item_data.max_size = (item.maximumSize().*_get_layout_coord)();
item_data.size_hint = (item.sizeHint().*_get_layout_coord)();
item_data.has_hfw = item.hasHeightForWidth();
if( !dynamic_cast<SpacerItem*>(item_data.layout_item.get()) )
{
if( is_first )
{
item_data.padding_orig = 0;
is_first = false;
}
else
{
item_data.padding_orig = _padding;
_layout_data.padding += item_data.padding_orig;
}
}
// Add sizes of all children in layout direction
safeAdd(min_size.x(), item_data.min_size);
safeAdd(max_size.x(), item_data.max_size);
safeAdd(size_hint.x(), item_data.size_hint);
// Take maximum in fixed (non-layouted) direction
min_size.y() = std::max( min_size.y(),
(item.minimumSize().*_get_fixed_coord)() );
max_size.y() = std::max( max_size.y(),
(item.maximumSize().*_get_fixed_coord)() );
size_hint.y() = std::max( size_hint.y(),
(item.sizeHint().*_get_fixed_coord)() );
_layout_data.has_hfw = _layout_data.has_hfw || item.hasHeightForWidth();
}
safeAdd(min_size.x(), _layout_data.padding);
safeAdd(max_size.x(), _layout_data.padding);
safeAdd(size_hint.x(), _layout_data.padding);
_layout_data.min_size = min_size.x();
_layout_data.max_size = max_size.x();
_layout_data.size_hint = size_hint.x();
_min_size.x() = (min_size.*_get_layout_coord)();
_max_size.x() = (max_size.*_get_layout_coord)();
_size_hint.x() = (size_hint.*_get_layout_coord)();
_min_size.y() = (min_size.*_get_fixed_coord)();
_max_size.y() = (max_size.*_get_fixed_coord)();
_size_hint.y() = (size_hint.*_get_fixed_coord)();
_flags &= ~SIZE_INFO_DIRTY;
}
//----------------------------------------------------------------------------
void BoxLayout::updateWFHCache(int w) const
{
if( w == _hfw_width )
return;
_hfw_height = 0;
_hfw_min_height = 0;
if( horiz() )
{
_layout_data.size = w;
const_cast<BoxLayout*>(this)->distribute(_layout_items, _layout_data);
for(size_t i = 0; i < _layout_items.size(); ++i)
{
ItemData const& data = _layout_items[i];
_hfw_height = std::max(_hfw_height, data.hfw(data.size));
_hfw_min_height = std::max(_hfw_min_height, data.mhfw(data.size));
}
}
else
{
for(size_t i = 0; i < _layout_items.size(); ++i)
{
ItemData const& data = _layout_items[i];
_hfw_height += data.hfw(w) + data.padding_orig;
_hfw_min_height += data.mhfw(w) + data.padding_orig;
}
}
_hfw_width = w;
}
//----------------------------------------------------------------------------
SGVec2i BoxLayout::sizeHintImpl() const
{
updateSizeHints();
return _size_hint;
}
//----------------------------------------------------------------------------
SGVec2i BoxLayout::minimumSizeImpl() const
{
updateSizeHints();
return _min_size;
}
//----------------------------------------------------------------------------
SGVec2i BoxLayout::maximumSizeImpl() const
{
updateSizeHints();
return _max_size;
}
//----------------------------------------------------------------------------
void BoxLayout::doLayout(const SGRecti& geom)
{
if( _flags & SIZE_INFO_DIRTY )
updateSizeHints();
// Store current size hints because vertical layouts containing
// height-for-width items the size hints are update for the actual width of
// the layout
int min_size_save = _layout_data.min_size,
size_hint_save = _layout_data.size_hint;
_layout_data.size = (geom.size().*_get_layout_coord)();
// update width dependent data for layouting of vertical layouts
if( _layout_data.has_hfw && !horiz() )
{
for(size_t i = 0; i < _layout_items.size(); ++i)
{
ItemData& data = _layout_items[i];
if( data.has_hfw )
{
int w = SGMisc<int>::clip( geom.width(),
data.layout_item->minimumSize().x(),
data.layout_item->maximumSize().x() );
int d = data.layout_item->minimumHeightForWidth(w) - data.min_size;
data.min_size += d;
_layout_data.min_size += d;
d = data.layout_item->heightForWidth(w) - data.size_hint;
data.size_hint += d;
_layout_data.size_hint += d;
}
}
}
// now do the actual layouting
distribute(_layout_items, _layout_data);
// Restore size hints possibly changed by vertical layouting
_layout_data.min_size = min_size_save;
_layout_data.size_hint = size_hint_save;
// and finally set the layouted geometry for each item
int fixed_size = (geom.size().*_get_fixed_coord)();
SGVec2i cur_pos( (geom.pos().*_get_layout_coord)(),
(geom.pos().*_get_fixed_coord)() );
bool reverse = (_direction == RightToLeft) || (_direction == BottomToTop);
if( reverse )
cur_pos.x() += (geom.size().*_get_layout_coord)();
for(size_t i = 0; i < _layout_items.size(); ++i)
{
ItemData const& data = _layout_items[i];
cur_pos.x() += reverse ? -data.padding - data.size : data.padding;
SGVec2i size(
data.size,
std::min( (data.layout_item->maximumSize().*_get_fixed_coord)(),
fixed_size )
);
// Center in fixed direction (TODO allow specifying alignment)
int offset_fixed = (fixed_size - size.y()) / 2;
cur_pos.y() += offset_fixed;
data.layout_item->setGeometry(SGRecti(
(cur_pos.*_get_layout_coord)(),
(cur_pos.*_get_fixed_coord)(),
(size.*_get_layout_coord)(),
(size.*_get_fixed_coord)()
));
if( !reverse )
cur_pos.x() += data.size;
cur_pos.y() -= offset_fixed;
}
}
//----------------------------------------------------------------------------
HBoxLayout::HBoxLayout():
BoxLayout(LeftToRight)
{
}
//----------------------------------------------------------------------------
VBoxLayout::VBoxLayout():
BoxLayout(TopToBottom)
{
}
} // namespace canvas
} // namespace simgear