nana/source/paint/text_renderer.cpp
2019-06-20 04:35:29 +08:00

675 lines
18 KiB
C++

#include "../detail/platform_spec_selector.hpp"
#include <nana/paint/text_renderer.hpp>
#include <nana/unicode_bidi.hpp>
#include <nana/paint/detail/native_paint_interface.hpp>
namespace nana
{
namespace paint
{
namespace helper
{
template<typename F>
void for_each_line(const wchar_t * str, std::size_t len, int top, F & f)
{
auto const end = str + len;
for(auto i = str; i != end; ++i)
{
if('\n' == *i)
{
top += static_cast<int>(f(top, str, i - str));
str = i + 1;
}
}
if(str != end)
f(top, str, end - str);
}
class string_drawer
{
public:
string_drawer(graphics& graph, int left, int right, align ta, bool use_ellipsis):
graph_(graph),
left_(left),
right_(right),
text_align_(ta)
{
if (use_ellipsis)
{
#ifdef _nana_std_has_string_view
ellipsis_px_ = graph.text_extent_size(std::string_view{ "...", 3 }).width;
#else
ellipsis_px_ = graph.text_extent_size("...", 3).width;
#endif
}
}
unsigned operator()(const int top, const wchar_t * buf, std::size_t bufsize)
{
auto const drawable = graph_.handle();
auto const reordered = unicode_reorder(buf, bufsize);
unsigned return_max_height = 0;
unsigned string_px = 0;
std::vector<nana::size> word_metrics;
for (auto & ent : reordered)
{
auto word_sz = detail::text_extent_size(drawable, ent.begin, ent.end - ent.begin);
word_metrics.push_back(word_sz);
string_px += word_sz.width;
if (word_sz.height > return_max_height)
return_max_height = word_sz.height;
}
auto text_align = text_align_;
// Checks if ellipsis is enabled and the total pixels of string is larger than the space.
if (ellipsis_px_ && (static_cast<int>(string_px) > right_ - left_))
{
//The string should be drawn from left most point no matter what text align is.
text_align = align::left;
}
nana::point pos{ left_, top };
auto wdm = word_metrics.data();
switch (text_align)
{
case align::left:
for (auto & ent : reordered)
{
if (pos.x + static_cast<int>(wdm->width) > 0)
{
if (pos.x + static_cast<int>(wdm->width) <= right_ - static_cast<int>(ellipsis_px_))
{
//This word can be fully painted.
detail::draw_string(drawable, pos, ent.begin, ent.end - ent.begin);
}
else
{
//This word is painted partially. Firstly, paints the word on a dummy graphics buffer.
nana::rectangle r{ nana::size{ static_cast<unsigned>(right_ - ellipsis_px_) - pos.x, wdm->height } };
nana::paint::graphics dummy({ r.width, r.height });
dummy.typeface(graph_.typeface());
dummy.bitblt(r, graph_, pos);
#ifdef _nana_std_has_string_view
dummy.string({}, { ent.begin, static_cast<unsigned>(ent.end - ent.begin) }, graph_.palette(true));
#else
dummy.palette(true, graph_.palette(true));
dummy.string({}, ent.begin, ent.end - ent.begin);
#endif
r.x = pos.x;
r.y = top;
graph_.bitblt(r, dummy);
if (ellipsis_px_)
detail::draw_string(drawable, point{ right_ - static_cast<int>(ellipsis_px_), top }, L"...", 3);
break;
}
}
pos.x += static_cast<int>(wdm->width);
if (pos.x > right_ - static_cast<int>(ellipsis_px_))
break;
++wdm;
}
break;
case align::center:
pos.x = (right_ - left_ - string_px) / 2;
for (auto & ent : reordered)
{
detail::draw_string(drawable, pos, ent.begin, ent.end - ent.begin);
pos.x += (wdm++)->width;
}
break;
case align::right:
wdm = word_metrics.data() + word_metrics.size() - 1;
pos.x = right_;
for (auto i = reordered.crbegin(); i != reordered.crend(); ++i)
{
pos.x -= (wdm--)->width;
detail::draw_string(drawable, pos, i->begin, i->end - i->begin);
}
break;
}
return return_max_height;
}
private:
graphics& graph_;
const int left_, right_; //the range of rendering area in x-axis
const align text_align_;
unsigned ellipsis_px_{ 0 };
};
struct draw_string_auto_changing_lines
{
graphics & graph;
const int left, right;
const align text_align;
draw_string_auto_changing_lines(graphics& graph, int left, int right, align ta):
graph(graph),
left(left),
right(right),
text_align(ta)
{}
unsigned operator()(const int top, const wchar_t * buf, std::size_t bufsize)
{
unsigned return_max_height = 0;
auto const drawable = graph.handle();
unsigned string_px = 0;
std::vector<nana::size> word_metrics;
auto const reordered = unicode_reorder(buf, bufsize);
for(auto & i : reordered)
{
auto word_sz = detail::text_extent_size(drawable, i.begin, i.end - i.begin);
word_metrics.emplace_back(word_sz);
string_px += word_sz.width;
if (return_max_height < word_sz.height)
return_max_height = word_sz.height;
}
const nana::size* wdm = word_metrics.data();
//Test whether the text needs the new line.
if(left + static_cast<int>(string_px) > right)
{
unsigned max_height = 0;
nana::point pos{ left, top };
const int orig_top = top;
for(auto & i : reordered)
{
if(max_height < wdm->height)
max_height = wdm->height;
bool beyond_edge = (pos.x + static_cast<int>(wdm->width) > right);
if(beyond_edge)
{
const std::size_t len = i.end - i.begin;
if(len > 1)
{
//Find the char that should be splitted
#ifdef _nana_std_has_string_view
auto pixel_buf = graph.glyph_pixels({ i.begin, len });
#else
std::unique_ptr<unsigned[]> pixel_buf(new unsigned[len]);
graph.glyph_pixels(i.begin, len, pixel_buf.get());
#endif
std::size_t idx_head = 0, idx_splitted;
do
{
auto pxbuf = pixel_buf.get();
idx_splitted = find_splitted(idx_head, len, pos.x, right, pxbuf);
if(idx_splitted == len)
{
detail::draw_string(drawable, pos, i.begin + idx_head, idx_splitted - idx_head);
for(std::size_t i = idx_head; i < len; ++i)
pos.x += static_cast<int>(pxbuf[i]);
break;
}
//Check the word whether it is splittable.
if(splittable(i.begin, idx_splitted))
{
detail::draw_string(drawable, pos, i.begin + idx_head, idx_splitted - idx_head);
idx_head = idx_splitted;
pos.x = left;
pos.y += static_cast<int>(max_height);
}
else
{
//Search the splittable character from idx_head to idx_splitted
const wchar_t * u = i.begin + idx_splitted;
const wchar_t * const head = i.begin + idx_head;
for(; head < u; --u)
{
if(splittable(head, u - head))
break;
}
if(u != head)
{
detail::draw_string(drawable, pos, head, u - head);
idx_head += u - head;
pos.x = left;
pos.y += static_cast<int>(max_height);
}
else
{
u = i.begin + idx_splitted;
for(; u < i.begin + len; ++u)
{
if(splittable(head, u - head))
break;
}
std::size_t splen = u - head;
pos.y += static_cast<int>(max_height);
pos.x = left;
detail::draw_string(drawable, pos, head, splen);
for(std::size_t k = idx_head; k < idx_head + splen; ++k)
pos.x += static_cast<int>(pxbuf[k]);
if (pos.x >= right)
{
pos.x = left;
pos.y += static_cast<int>(wdm->height);
}
idx_head += splen;
}
}
max_height = wdm->height;
}while(idx_head < len);
}
else
{
pos.x = left;
pos.y += static_cast<int>(max_height);
detail::draw_string(drawable, pos, i.begin, 1);
pos.x += static_cast<int>(wdm->width);
}
max_height = 0;
}
else
{
detail::draw_string(drawable, pos, i.begin, i.end - i.begin);
pos.x += static_cast<int>(wdm->width);
}
++wdm;
}
return_max_height = (top - orig_top) + max_height;
}
else
{
point pos{ left, top };
//The text could be drawn in a line.
if((align::left == text_align) || (align::center == text_align))
{
if(align::center == text_align)
pos.x += (right - left - static_cast<int>(string_px)) / 2;
for(auto & ent : reordered)
{
if (pos.x + static_cast<int>(wdm->width) > 0)
detail::draw_string(drawable, pos, ent.begin, ent.end - ent.begin);
pos.x += static_cast<int>(wdm->width);
++wdm;
}
}
else if(align::right == text_align)
{
pos.x = right;
for(auto i = reordered.crbegin(); i != reordered.crend(); ++i)
{
if (pos.x < 0)
break;
auto & ent = *i;
std::size_t len = ent.end - ent.begin;
pos.x -= static_cast<int>(wdm->width);
detail::draw_string(drawable, pos, ent.begin, len);
++wdm;
}
}
}
return return_max_height;
}
static std::size_t find_splitted(std::size_t begin, std::size_t end, int x, int endpos, unsigned * pxbuf)
{
for (std::size_t i = begin; i < end; ++i)
{
if ((x += static_cast<int>(pxbuf[i])) > endpos)
return (begin == i ? i + 1 : i);
}
return end;
}
static bool splittable(const wchar_t * str, std::size_t index)
{
wchar_t ch = str[index];
if(('0' <= ch && ch <= '9') || ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z'))
{
if(index)
{
auto prch = str[index - 1];
if('0' <= ch && ch <= '9')
return !(('0' <= prch && prch <= '9') || (prch == '-'));
return (('z' < prch || prch < 'a') && ('Z' < prch || prch < 'A'));
}
else
return false;
}
return true;
}
};
struct extent_auto_changing_lines
{
graphics & graph;
const int left, right;
unsigned extents;
extent_auto_changing_lines(graphics& graph, int left, int right):
graph(graph),
left(left),
right(right),
extents(0)
{}
unsigned operator()(int top, const wchar_t * buf, std::size_t bufsize)
{
unsigned return_max_height = 0;
auto drawable = graph.handle();
std::vector<nana::size> word_metrics;
unsigned string_px = 0;
auto const reordered = unicode_reorder(buf, bufsize);
for(auto & i : reordered)
{
auto word_sz = detail::text_extent_size(drawable, i.begin, i.end - i.begin);
word_metrics.emplace_back(word_sz);
string_px += word_sz.width;
if (return_max_height < word_sz.height)
return_max_height = word_sz.height;
}
//Test whether the text needs the new line.
if(left + static_cast<int>(string_px) > right)
{
unsigned max_height = 0;
int xpos = left;
const int orig_top = top;
auto wdm = word_metrics.data();
for(auto & i : reordered)
{
if(max_height < wdm->height)
max_height = wdm->height;
bool beyond_edge = (xpos + static_cast<int>(wdm->width) > right);
if(beyond_edge)
{
std::size_t len = i.end - i.begin;
if(len > 1)
{
//Find the char that should be splitted
#ifdef _nana_std_has_string_view
auto scope_res = graph.glyph_pixels({ i.begin, len });
auto pxbuf = scope_res.get();
#else
std::unique_ptr<unsigned[]> scope_res(new unsigned[len]);
auto pxbuf = scope_res.get();
graph.glyph_pixels(i.begin, len, pxbuf);
#endif
std::size_t idx_head = 0, idx_splitted;
do
{
idx_splitted = draw_string_auto_changing_lines::find_splitted(idx_head, len, xpos, right, pxbuf);
if(idx_splitted == len)
{
for(std::size_t i = idx_head; i < len; ++i)
xpos += static_cast<int>(pxbuf[i]);
break;
}
//Check the word whether it is splittable.
if(draw_string_auto_changing_lines::splittable(i.begin, idx_splitted))
{
idx_head = idx_splitted;
xpos = left;
top += max_height;
max_height = wdm->height;
}
else
{
//Search the splittable character from idx_head to idx_splitted
const wchar_t * u = i.begin + idx_splitted;
const wchar_t * head = i.begin + idx_head;
for(; head < u; --u)
{
if(draw_string_auto_changing_lines::splittable(head, u - head))
break;
}
xpos = left;
top += max_height;
max_height = wdm->height;
if(u == head)
{
u = i.begin + idx_splitted;
const wchar_t * end = i.begin + len;
for(; u < end; ++u)
{
if(draw_string_auto_changing_lines::splittable(head, u - head))
break;
}
std::size_t splen = u - head;
for(std::size_t k = idx_head; k < idx_head + splen; ++k)
xpos += static_cast<int>(pxbuf[k]);
if(xpos >= right)
{
xpos = left;
top += max_height;
}
idx_head += splen;
}
else
idx_head += u - head;
}
}while(idx_head < len);
}
else
xpos = left + static_cast<int>(wdm->width);
max_height = 0;
}
else
xpos += static_cast<int>(wdm->width);
++wdm;
}
return_max_height = (top - orig_top) + max_height;
}
extents += return_max_height;
return return_max_height;
}
};
}//end namespace helper
//class text_renderer
text_renderer::text_renderer(graph_reference graph, align ta):
graph_(graph),
text_align_(ta)
{}
nana::size text_renderer::extent_size(int x, int y, const wchar_t* str, std::size_t len, unsigned restricted_pixels) const
{
nana::size extents;
if(graph_)
{
helper::extent_auto_changing_lines eacl(graph_, x, x + static_cast<int>(restricted_pixels));
helper::for_each_line(str, len, y, eacl);
extents.width = restricted_pixels;
extents.height = eacl.extents;
}
return extents;
}
void text_renderer::render(const point& pos, const wchar_t * str, std::size_t len)
{
if (graph_)
{
helper::string_drawer sd{ graph_, pos.x, pos.x + static_cast<int>(graph_.width()), text_align_, false };
helper::for_each_line(str, len, pos.y, sd);
}
}
void text_renderer::render(const point& pos, const wchar_t* str, std::size_t len, unsigned space_pixels, mode rendering_mode)
{
if (graph_ && str && len && space_pixels)
{
if (mode::truncate_letter_with_ellipsis == rendering_mode || mode::truncate_with_ellipsis == rendering_mode)
{
helper::string_drawer sd{ graph_, pos.x, pos.x + static_cast<int>(space_pixels), text_align_, true };
helper::for_each_line(str, len, pos.y, sd);
}
else if (mode::word_wrap == rendering_mode)
{
helper::draw_string_auto_changing_lines dsacl(graph_, pos.x, pos.x + static_cast<int>(space_pixels), text_align_);
helper::for_each_line(str, len, pos.y, dsacl);
}
}
}
//end class text_renderer
//class aligner
//Constructor
aligner::aligner(graph_reference graph, align text_align)
: aligner{ graph, text_align, text_align }
{}
aligner::aligner(graph_reference graph, align text_align, align text_align_ex) :
graph_(graph),
text_align_(text_align),
text_align_ex_(text_align_ex)
{}
// Draws a text with specified text alignment.
void aligner::draw(const std::string& text, point pos, unsigned width)
{
draw(to_wstring(text), pos, width);
}
void aligner::draw(const std::wstring& text, point pos, unsigned width)
{
auto text_px = graph_.text_extent_size(text).width;
if (text_px <= width)
{
switch (text_align_)
{
case align::center:
pos.x += static_cast<int>(width - text_px) / 2;
break;
case align::right:
pos.x += static_cast<int>(width - text_px);
default:
break;
}
#ifdef _nana_std_has_string_view
graph_.bidi_string(pos, text);
#else
graph_.bidi_string(pos, text.c_str(), text.size());
#endif
return;
}
#ifdef _nana_std_has_string_view
const auto ellipsis = graph_.text_extent_size(std::string_view{ "...", 3 }).width;
auto pixels = graph_.glyph_pixels({ text.c_str(), text.size() });
#else
const auto ellipsis = graph_.text_extent_size("...", 3).width;
std::unique_ptr<unsigned[]> pixels(new unsigned[text.size()]);
graph_.glyph_pixels(text.c_str(), text.size(), pixels.get());
#endif
std::size_t substr_len = 0;
unsigned substr_px = 0;
if (align::right == text_align_ex_)
{
auto end = pixels.get();
auto p = end + text.size();
do
{
--p;
if (substr_px + *p + ellipsis > width)
{
substr_len = p - pixels.get() + 1;
break;
}
substr_px += *p;
} while (p != end);
pos.x += static_cast<int>(width - ellipsis - substr_px) + ellipsis;
#ifdef _nana_std_has_string_view
graph_.bidi_string(pos, { text.c_str() + substr_len, text.size() - substr_len });
#else
graph_.bidi_string(pos, text.c_str() + substr_len, text.size() - substr_len);
#endif
pos.x -= ellipsis;
}
else
{
for (auto p = pixels.get(), end = pixels.get() + text.size(); p != end; ++p)
{
if (substr_px + *p + ellipsis > width)
{
substr_len = p - pixels.get();
break;
}
substr_px += *p;
}
if (align::center == text_align_ex_)
pos.x += (width - substr_px - ellipsis) / 2;
#ifdef _nana_std_has_string_view
graph_.bidi_string(pos, { text.c_str(), substr_len });
#else
graph_.bidi_string(pos, text.c_str(), substr_len);
#endif
pos.x += substr_px;
}
graph_.string(pos, "...");
}
//end class string
}
}