psemek/libs/ui/source/label.cpp

127 lines
2.4 KiB
C++

#include <psemek/ui/label.hpp>
namespace psemek::ui
{
void label::set_text(std::string text)
{
text_ = std::move(text);
on_state_changed();
}
void label::set_halign(halignment value)
{
halign_ = value;
on_state_changed();
}
void label::set_valign(valignment value)
{
valign_ = value;
on_state_changed();
}
void label::set_multiline(multiline_mode value)
{
multiline_ = value;
on_state_changed();
}
void label::set_overflow(overflow_mode value)
{
overflow_ = value;
on_state_changed();
}
void label::reshape(geom::box<float, 2> const & bbox)
{
shape_.box = bbox;
cached_state_.reset();
}
geom::box<float, 2> label::size_constraints() const
{
if (!cached_state_)
update_cached_state();
static float const inf = std::numeric_limits<float>::infinity();
return {{{cached_state_->size[0], inf}, {cached_state_->size[1], inf}}};
}
void label::draw(painter & p) const
{
if (!cached_state_)
update_cached_state();
if (!cached_state_->font) return;
auto st = style();
if (!st) return;
for (auto & g : cached_state_->glyphs)
p.draw_glyph(*(cached_state_->font), g.character, g.position, st->text_color);
}
void label::on_state_changed()
{
cached_state_.reset();
post_reshape();
}
void label::update_cached_state() const
{
cached_state_ = cached_state{};
if (text_.empty()) return;
auto st = style();
if (!st) return;
if (!st->font) return;
cached_state_->font = st->font.get();
shape_options opts;
opts.scale = st->text_scale;
cached_state_->glyphs = st->font->shape(text_, opts);
geom::box<float, 2> bbox;
for (auto const & g : cached_state_->glyphs)
bbox |= g.position;
int lines = 1;
geom::vector<float, 2> offset;
switch (halign_)
{
case halignment::left:
offset[0] = shape_.box[0].min;
break;
case halignment::center:
offset[0] = shape_.box[0].center() - bbox[0].length() / 2.f;
break;
case halignment::right:
offset[0] = shape_.box[0].max - bbox[0].length();
break;
}
switch (valign_)
{
case valignment::top:
offset[1] = shape_.box[1].min;
break;
case valignment::center:
offset[1] = shape_.box[1].center() - lines * st->text_scale * st->font->size()[1] / 2.f;
break;
case valignment::bottom:
offset[1] = shape_.box[1].max - lines * st->text_scale * st->font->size()[1];
break;
}
for (auto & g : cached_state_->glyphs)
g.position += offset;
cached_state_->size = bbox.dimensions();
}
}