psemek/libs/ui/source/label.cpp

758 lines
18 KiB
C++

#include <psemek/ui/label.hpp>
#include <psemek/geom/contains.hpp>
#include <psemek/sdl2/cursor.hpp>
#include <stdexcept>
#include <cctype>
#include <unordered_map>
namespace psemek::ui
{
label::label(std::string text)
{
set_text(std::move(text));
}
void label::set_text(std::string text)
{
text_ = std::move(text);
chunks_.clear();
chunks_.push_back(text_chunk{{text_.data(), text_.size()}, text_style{}, std::nullopt, std::nullopt});
on_state_changed();
}
static std::unordered_set<std::string_view> const known_tags
{
"bold",
"uline",
"strike",
"color",
"link",
};
void check_attribute(std::string_view tag, std::optional<std::string_view> const & attribute)
{
if (tag == "bold" || tag == "uline" || tag == "strike")
{
if (attribute)
throw std::runtime_error("tag [" + std::string(tag) + " doesn't support attributes");
}
else if (tag == "color")
{
if (!attribute)
throw std::runtime_error("tag [color] requires an attribute");
if (!gfx::parse_color(*attribute))
throw std::runtime_error("failed to parse color \"" + std::string(*attribute) + "\"");
}
else if (tag == "link")
{
if (!attribute)
throw std::runtime_error("tag [link] requires an attribute");
}
}
void label::set_tagged_text(std::string text)
{
text_ = std::move(text);
selected_link_ = std::nullopt;
chunks_.clear();
auto parse_result = tagged_text::parse(text_);
std::unordered_map<std::string_view, std::vector<std::optional<std::string_view>>> tags_stack;
for (auto const & token : parse_result.tokens)
{
if (auto text = std::get_if<std::string_view>(&token))
{
text_chunk chunk;
if (!tags_stack["bold"].empty())
chunk.style.set(text_style_flag::bold);
if (!tags_stack["uline"].empty())
chunk.style.set(text_style_flag::underline);
if (!tags_stack["strike"].empty())
chunk.style.set(text_style_flag::strikethrough);
if (!tags_stack["color"].empty())
chunk.color = *gfx::parse_color(*tags_stack["color"].back());
if (!tags_stack["link"].empty())
chunk.link = tags_stack["link"].back();
chunk.text = *text;
chunks_.push_back(chunk);
}
else if (auto tag = std::get_if<tagged_text::opening_tag>(&token))
{
if (tag->type == "image")
{
if (!tag->attribute)
throw std::runtime_error("tag [image] requires an attribute");
image_chunk chunk;
chunk.id = *tag->attribute;
if (!tags_stack["color"].empty())
chunk.color = *gfx::parse_color(*tags_stack["color"].back());
if (!tags_stack["link"].empty())
chunk.link = tags_stack["link"].back();
chunks_.push_back(chunk);
}
else if (known_tags.contains(tag->type))
{
check_attribute(tag->type, tag->attribute);
if (tag->type == "link" && !tags_stack["link"].empty())
throw std::runtime_error("tag [link] cannot be nested");
tags_stack[tag->type].push_back(tag->attribute);
}
else
throw std::runtime_error("unknown tag [" + std::string(tag->type) + "]");
}
else if (auto tag = std::get_if<tagged_text::closing_tag>(&token))
{
if (!known_tags.contains(tag->type))
throw std::runtime_error("unknown closing tag [" + std::string(tag->type) + "]");
if (tags_stack[tag->type].empty())
throw std::runtime_error("mismatched opening & closing tags for [" + std::string(tag->type) + "]");
tags_stack[tag->type].pop_back();
}
}
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_wrap(bool value)
{
wrap_ = value;
on_state_changed();
}
void label::set_skip_spaces(bool value)
{
skip_spaces_ = value;
on_state_changed();
}
image_provider * label::set_image_provider(struct image_provider * provider)
{
std::swap(provider, image_provider_);
on_state_changed();
return provider;
}
void label::on_link_click(link_callback callback)
{
link_callback_ = std::move(callback);
}
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();
}
bool label::on_event(ui::mouse_move const & e)
{
if (cached_state_)
{
std::optional<std::string_view> new_selected_link;
auto const p = geom::cast<float>(e.position);
for (auto const & b : cached_state_->link_bboxes)
{
if (geom::contains(b.first, p))
{
new_selected_link = b.second;
break;
}
}
if (new_selected_link != selected_link_)
{
if (new_selected_link)
sdl2::set_cursor(sdl2::cursor_type::hand);
else
sdl2::set_cursor(sdl2::cursor_type::arrow);
selected_link_ = new_selected_link;
mouse_down_ = false;
on_state_changed();
}
}
return false;
}
bool label::on_event(ui::mouse_click const & e)
{
if (e.button == mouse_button::left)
{
if (e.down)
{
if (selected_link_)
{
if (!mouse_down_)
{
mouse_down_ = true;
if (link_callback_)
post([cb = link_callback_, text = *selected_link_]{ cb(text); });
on_state_changed();
return true;
}
}
}
else
{
if (mouse_down_)
{
mouse_down_ = false;
on_state_changed();
}
}
}
return false;
}
geom::box<float, 2> label::size_constraints() const
{
static float const inf = std::numeric_limits<float>::infinity();
if (!cached_state_inf_)
cached_state_inf_ = cached_state_for({{{0.f, inf}, {0.f, inf}}});
return {{{cached_state_inf_->size[0], inf}, {cached_state_inf_->size[1], inf}}};
}
geom::interval<float> label::width_constraints(float height) const
{
static float const inf = std::numeric_limits<float>::infinity();
auto state = cached_state_for({{{0.f, inf}, {0.f, height}}});
return {state.size[0], inf};
}
geom::interval<float> label::height_constraints(float width) const
{
static float const inf = std::numeric_limits<float>::infinity();
auto state = cached_state_for({{{0.f, width}, {0.f, inf}}});
return {state.size[1], inf};
}
void label::style_updated() const
{
element::style_updated();
cached_state_.reset();
cached_state_inf_.reset();
}
void label::own_style_updated() const
{
element::own_style_updated();
cached_state_.reset();
cached_state_inf_.reset();
}
void label::draw(painter & p) const
{
if (!cached_state_)
update_cached_state();
auto st = merged_own_style();
if (!st) return;
if (st->text_shadow_offset != geom::vector{0, 0})
{
auto const offset = geom::cast<float>(*st->text_shadow_offset);
for (auto const & batch : cached_state_->batches)
{
if (!batch.text) continue;
auto color = *st->shadow_color;
color[3] = (color[3] * 1.f * batch.color[3]) / 255.f;
for (auto const & image : batch.images)
p.draw_image(image.position + offset, gfx::texture_view_2d{batch.texture, image.texcoords}, {color, painter::color_mode::multiply});
}
}
for (auto const & batch : cached_state_->batches)
for (auto const & image : batch.images)
p.draw_image(image.position, gfx::texture_view_2d{batch.texture, image.texcoords}, {batch.color, batch.text ? painter::color_mode::multiply : painter::color_mode::mix});
}
void label::on_state_changed()
{
cached_state_.reset();
cached_state_inf_.reset();
post_reshape();
}
static bool is_newline(char32_t c)
{
return (c == '\n') || (c == '\r');
}
void label::update_cached_state() const
{
cached_state_ = cached_state_for(shape_.box);
}
label::cached_state label::cached_state_for(geom::box<float, 2> const & bbox) const
{
auto state = cached_state{};
if (chunks_.empty()) return state;
auto st = merged_own_style();
auto const font_height = st->font->size()[1] * (*st->text_scale);
// Shape items (glyphs/images) chunk by chunk
// All items within a chunk have
// the exact same properties
struct item
{
geom::box<float, 2> position;
std::optional<char32_t> character;
};
struct item_chunk
{
std::size_t end;
text_style style;
gfx::color_rgba color;
gfx::texture_view_2d image;
std::optional<std::string_view> link;
};
std::vector<item> items;
std::vector<item_chunk> item_chunks;
{
geom::point<float, 2> pen{0.f, 0.f};
shape_options opts;
opts.scale = *st->text_scale;
for (auto const & chunk : chunks_)
{
if (auto text = std::get_if<text_chunk>(&chunk))
{
auto text_style = *st->text_style | text->style;
if (text->link)
{
if (selected_link_ && *text->link == *selected_link_)
{
if (mouse_down_)
text_style |= *st->link_click_style;
else
text_style |= *st->link_hover_style;
}
else
text_style |= *st->link_style;
}
gfx::color_rgba color;
if (text->color)
color = *text->color;
else if (text->link)
{
if (selected_link_ && *text->link == *selected_link_)
{
if (mouse_down_)
color = *st->link_click_color;
else
color = *st->link_hover_color;
}
else
color = *st->link_color;
}
else
color = *st->text_color;
bool const bold = text_style.is_set(text_style_flag::bold);
auto font = bold ? st->bold_font.get() : st->font.get();
auto glyphs = font->shape(text->text, opts, pen);
items.reserve(items.size() + glyphs.size());
for (auto const & g : glyphs)
items.push_back(item{g.position, g.character});
item_chunks.push_back({items.size(), text_style, color, {}, text->link});
}
else if (auto image = std::get_if<image_chunk>(&chunk))
{
auto color = image->color ? *image->color : gfx::color_rgba{255, 255, 255, 0};
if (!image_provider_)
throw std::runtime_error("cannot use [image] tag without image provider");
auto texture = image_provider_->get(image->id);
float const scale = *st->text_scale;
geom::box<float, 2> position;
position[0].min = pen[0];
position[0].max = pen[0] + texture.width() * scale;
position[1].min = pen[1] + font_height / 2.f - texture.height() * scale / 2.f;
position[1].max = position[1].min + texture.height() * scale;
pen[0] = position[0].max;
items.push_back({position, {}});
item_chunks.push_back({items.size(), {}, color, texture, image->link});
}
}
}
// Break items into lines
struct line_range
{
std::size_t begin;
std::size_t end;
};
std::vector<line_range> lines;
{
std::size_t current_item = 0;
while (true)
{
if (skip_spaces_)
{
while (current_item < items.size() && items[current_item].character && std::isspace(*items[current_item].character))
++current_item;
}
std::size_t line_begin = current_item;
bool newline_end = false;
bool wrap_end = false;
geom::interval<float> x_range;
while (current_item < items.size())
{
if (items[current_item].character && is_newline(*items[current_item].character))
{
newline_end = true;
break;
}
x_range |= items[current_item].position[0];
if (x_range.length() > bbox[0].length() && wrap_)
{
wrap_end = true;
break;
}
++current_item;
}
if (wrap_end && current_item == line_begin)
break;
if (wrap_end && current_item > line_begin)
{
std::size_t space_pos = current_item - 1;
while (space_pos > line_begin && (!items[space_pos].character || !std::isspace(*items[space_pos].character)))
--space_pos;
if (space_pos > line_begin)
current_item = space_pos;
}
lines.push_back({line_begin, current_item});
if (current_item == items.size())
break;
if (newline_end)
++current_item;
}
}
// Compute line bboxes
std::vector<geom::box<float, 2>> line_bbox(lines.size());
for (std::size_t l = 0; l < lines.size(); ++l)
{
geom::box<float, 2> bbox;
// Glyphs might be smaller than total text height, so
// hardcode font height as min line height
bbox[1] = {0.f, 1.f * font_height};
for (std::size_t i = lines[l].begin; i < lines[l].end; ++i)
bbox |= items[i].position;
line_bbox[l] = bbox;
}
// Compute total text size
geom::vector<float, 2> text_size{0.f, 0.f};
for (auto const & l : line_bbox)
{
text_size[0] = std::max(text_size[0], l[0].length());
text_size[1] += l[1].length();
}
// TODO: handle text overflow
// Position lines & items inside label bbox
std::vector<geom::vector<float, 2>> line_offset(lines.size());
{
float current_y;
switch (valign_)
{
case valignment::top:
current_y = bbox[1].min;
break;
case valignment::center:
current_y = bbox[1].center() - text_size[1] / 2.f;
break;
case valignment::bottom:
current_y = bbox[1].max - text_size[1];
break;
}
for (std::size_t l = 0; l < lines.size(); ++l)
{
int spaces = 0;
for (std::size_t i = lines[l].begin; i < lines[l].end; ++i)
if (items[i].character && std::isspace(*items[i].character))
++spaces;
geom::vector<float, 2> offset{0.f, current_y};
float space_extra = 0.f;
switch (halign_)
{
case halignment::left:
offset[0] = bbox[0].min - line_bbox[l][0].min;
break;
case halignment::center:
offset[0] = bbox[0].center() - line_bbox[l][0].length() / 2.f - line_bbox[l][0].min;
break;
case halignment::right:
offset[0] = bbox[0].max - line_bbox[l][0].length() - line_bbox[l][0].min;
break;
case halignment::stretch:
offset[0] = bbox[0].min - line_bbox[l][0].min;
if ((l + 1 != lines.size() && text_[lines[l].end] != '\n') && spaces > 0)
space_extra = (bbox[0].length() - line_bbox[l][0].length()) / spaces;
break;
}
line_offset[l] = offset;
for (std::size_t i = lines[l].begin; i < lines[l].end; ++i)
{
items[i].position += offset;
if (items[i].character && std::isspace(*items[i].character))
offset[0] += space_extra;
}
current_y += line_bbox[l][1].length();
}
}
// Convert chunks into image batches
{
std::size_t begin = 0;
for (auto const & ch : item_chunks)
{
auto & batch = state.batches.emplace_back();
if (ch.image)
{
batch.texture = ch.image.texture;
batch.color = ch.color;
batch.text = false;
for (std::size_t i = begin; i < ch.end; ++i)
{
auto & g = items[i];
g.position[0] += (std::round(g.position[0].min) - g.position[0].min);
g.position[1] += (std::round(g.position[1].min) - g.position[1].min);
auto & image = batch.images.emplace_back();
image.position = g.position;
image.texcoords = ch.image.part;
}
}
else
{
auto font = ch.style.is_set(text_style_flag::bold) ? st->bold_font.get() : st->font.get();
batch.texture = &font->atlas();
batch.color = ch.color;
batch.text = true;
for (std::size_t i = begin; i < ch.end; ++i)
{
auto & g = items[i];
auto tc = font->texcoords(*g.character);
if (!tc) continue;
g.position[0] += (std::round(g.position[0].min) - g.position[0].min);
g.position[1] += (std::round(g.position[1].min) - g.position[1].min);
auto & image = batch.images.emplace_back();
image.position = g.position;
image.texcoords = *tc;
}
}
begin = ch.end;
}
}
// Convert chunks into underline & strikethrough batches
{
float const line_width = 1.f * (*st->text_scale);
auto get_batch = [&](gfx::color_rgba const & color) -> cached_state::batch & {
auto texture = single_white_pixel_texture().get();
if (state.batches.empty() || state.batches.back().texture != texture || state.batches.back().color != color)
{
auto & b = state.batches.emplace_back();
b.texture = texture;
b.color = color;
b.text = true;
}
return state.batches.back();
};
std::size_t ch_begin = 0;
std::size_t ch = 0;
for (std::size_t l = 0; l < lines.size(); ++l)
{
float underline_y = std::round(line_offset[l][1] + font_height - line_width);
float strikethrough_y = std::round(line_offset[l][1] + font_height / 2.f - line_width / 2.f);
std::optional<float> last_underline_end;
std::optional<float> last_strikethrough_end;
for (; ch < item_chunks.size(); ++ch)
{
auto const & chunk = item_chunks[ch];
bool const underline = chunk.style.is_set(text_style_flag::underline);
bool const strikethrough = chunk.style.is_set(text_style_flag::strikethrough);
std::size_t ibegin = std::max(ch_begin, lines[l].begin);
std::size_t iend = std::min(chunk.end, lines[l].end);
if (ibegin < iend)
{
geom::interval<float> x_range;
for (std::size_t i = ibegin; i < iend; ++i)
x_range |= items[i].position[0];
if (underline)
{
auto & image = get_batch(chunk.color).images.emplace_back();
image.position[0] = x_range;
if (last_underline_end)
image.position[0] |= *last_underline_end;
image.position[1] = {underline_y, underline_y + line_width};
last_underline_end = image.position[0].max;
}
else
last_underline_end = std::nullopt;
if (strikethrough)
{
auto & image = get_batch(chunk.color).images.emplace_back();
image.position[0] = x_range;
if (last_strikethrough_end)
image.position[0] |= *last_strikethrough_end;
image.position[1] = {strikethrough_y, strikethrough_y + line_width};
last_strikethrough_end = image.position[0].max;
}
else
last_strikethrough_end = std::nullopt;
}
if (chunk.end > lines[l].end)
break;
ch_begin = chunk.end;
}
}
}
// Generate link bboxes
{
std::size_t begin = 0;
for (auto const & ch : item_chunks)
{
if (ch.link)
{
geom::box<float, 2> bbox;
for (std::size_t i = begin; i < ch.end; ++i)
bbox |= items[i].position;
state.link_bboxes.push_back({bbox, *ch.link});
}
begin = ch.end;
}
}
state.size = text_size;
return state;
}
std::shared_ptr<gfx::texture_2d> label::single_white_pixel_texture() const
{
static std::weak_ptr<gfx::texture_2d> texture;
if (!single_white_pixel_texture_)
{
std::shared_ptr<gfx::texture_2d> ptr;
if (!(ptr = texture.lock()))
{
ptr = std::make_shared<gfx::texture_2d>();
gfx::pixmap_rgba pm({1, 1}, {255, 255, 255, 255});
ptr->load(pm);
ptr->nearest_filter();
texture = ptr;
}
single_white_pixel_texture_ = ptr;
}
return single_white_pixel_texture_;
}
}