kakoune/src/line_modification.cc
2014-09-18 10:47:59 +01:00

109 lines
3.2 KiB
C++

#include "line_modification.hh"
#include "buffer.hh"
namespace Kakoune
{
namespace
{
struct LineChange
{
LineChange(const Buffer::Change& change)
{
ByteCoord begin = change.begin;
ByteCoord end = change.end;
if (change.type == Buffer::Change::Insert)
{
if (change.at_end and begin != ByteCoord{0,0})
{
kak_assert(begin.column == 0);
--begin.line;
}
pos = begin.line;
num = end.line - begin.line;
}
else
{
if (change.at_end and begin != ByteCoord{0,0})
{
kak_assert(begin.column == 0);
--begin.line;
}
pos = begin.line;
num = begin.line - end.line;
}
}
LineCount pos;
LineCount num;
};
}
std::vector<LineModification> compute_line_modifications(const Buffer& buffer, size_t timestamp)
{
std::vector<LineModification> res;
for (auto& buf_change : buffer.changes_since(timestamp))
{
const LineChange change(buf_change);
auto pos = std::upper_bound(res.begin(), res.end(), change.pos,
[](const LineCount& l, const LineModification& c)
{ return l < c.new_line; });
if (pos != res.begin())
{
auto& prev = *(pos-1);
if (change.pos <= prev.new_line + prev.num_added)
--pos;
else
pos = res.insert(pos, {change.pos - prev.diff(), change.pos, 0, 0});
}
else
pos = res.insert(pos, {change.pos, change.pos, 0, 0});
auto& modif = *pos;
auto next = pos + 1;
if (change.num > 0)
{
modif.num_added += change.num;
for (auto it = next; it != res.end(); ++it)
it->new_line += change.num;
}
if (change.num < 0)
{
const LineCount num_removed = -change.num;
auto delend = std::upper_bound(next, res.end(), change.pos + num_removed,
[](const LineCount& l, const LineModification& c)
{ return l < c.new_line; });
for (auto it = next; it != delend; ++it)
{
LineCount removed_from_it = (change.pos + num_removed - it->new_line);
modif.num_removed += it->num_removed - std::min(removed_from_it, it->num_added);
modif.num_added += std::max(0_line, it->num_added - removed_from_it);
}
next = res.erase(next, delend);
const LineCount num_added_after_pos =
modif.new_line + modif.num_added - change.pos;
const LineCount num_removed_from_added =
std::min(num_removed, num_added_after_pos);
kak_assert(modif.num_added >= num_removed_from_added);
modif.num_added -= num_removed_from_added;
modif.num_removed += num_removed - num_removed_from_added;
for (auto it = next; it != res.end(); ++it)
it->new_line -= num_removed;
}
}
return res;
}
}