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LibVT+Terminal: Implement line wrapping

This commit implements line wrapping in the terminal, and tries its best
to move the cursor to the "correct" position.
This commit is contained in:
Ali Mohammad Pur 2021-06-19 03:53:03 +04:30 committed by Andreas Kling
parent 424965954f
commit 2f2b7814d1
5 changed files with 206 additions and 22 deletions

View file

@ -10,19 +10,101 @@ namespace VT {
Line::Line(size_t length)
{
set_length(length);
set_length(length, nullptr, nullptr);
}
Line::~Line()
{
}
void Line::set_length(size_t new_length)
void Line::set_length(size_t new_length, Line* next_line, CursorPosition* cursor, bool cursor_is_on_next_line)
{
size_t old_length = length();
if (old_length == new_length)
return;
m_cells.resize(new_length);
// Drop the empty cells
if (m_terminated_at.has_value())
m_cells.remove(m_terminated_at.value(), m_cells.size() - m_terminated_at.value());
if (!next_line)
return m_cells.resize(new_length);
if (old_length < new_length)
take_cells_from_next_line(old_length, new_length, next_line, cursor_is_on_next_line, cursor);
else
push_cells_into_next_line(old_length, new_length, next_line, cursor_is_on_next_line, cursor);
m_cells.resize(max(new_length, static_cast<size_t>(m_terminated_at.value_or(new_length))));
}
void Line::push_cells_into_next_line(size_t old_length, size_t new_length, Line* next_line, bool cursor_is_on_next_line, CursorPosition* cursor)
{
// Push as many cells as _wouldn't_ fit into the next line.
auto cells_to_preserve = !next_line->m_terminated_at.has_value() && next_line->is_empty() ? 0 : m_terminated_at.value_or(0);
auto cells_to_push_into_next_line = min(old_length - new_length, length() - cells_to_preserve);
if (!cells_to_push_into_next_line)
return;
auto preserved_cells = length() - cells_to_push_into_next_line;
if (next_line->m_terminated_at.has_value())
next_line->m_terminated_at = next_line->m_terminated_at.value() + cells_to_push_into_next_line;
if (m_terminated_at.has_value() && cells_to_preserve == 0) {
m_terminated_at.clear();
if (!next_line->m_terminated_at.has_value())
next_line->m_terminated_at = cells_to_push_into_next_line;
}
if (cursor) {
if (cursor_is_on_next_line) {
cursor->column += cells_to_push_into_next_line;
} else if (cursor->column >= preserved_cells) {
cursor->row++;
cursor->column = cursor->column - preserved_cells;
}
}
next_line->m_cells.prepend(m_cells.span().slice_from_end(cells_to_push_into_next_line).data(), cells_to_push_into_next_line);
m_cells.remove(m_cells.size() - cells_to_push_into_next_line, cells_to_push_into_next_line);
if (m_terminated_at.has_value())
m_terminated_at = m_terminated_at.value() - cells_to_push_into_next_line;
}
void Line::take_cells_from_next_line(size_t old_length, size_t new_length, Line* next_line, bool cursor_is_on_next_line, CursorPosition* cursor)
{
// Take as many cells as would fit from the next line
if (m_terminated_at.has_value())
return;
auto cells_to_grab_from_next_line = min(new_length - old_length, next_line->length());
auto clear_next_line = false;
if (next_line->m_terminated_at.has_value()) {
cells_to_grab_from_next_line = min(cells_to_grab_from_next_line, static_cast<size_t>(next_line->m_terminated_at.value()));
if (cells_to_grab_from_next_line == *next_line->m_terminated_at) {
m_terminated_at = old_length + *next_line->m_terminated_at;
next_line->m_terminated_at.clear();
clear_next_line = true;
} else {
next_line->m_terminated_at = next_line->m_terminated_at.value() - cells_to_grab_from_next_line;
}
}
if (cells_to_grab_from_next_line) {
if (cursor && cursor_is_on_next_line) {
if (cursor->column <= cells_to_grab_from_next_line) {
cursor->row--;
cursor->column += m_cells.size();
} else {
cursor->column -= cells_to_grab_from_next_line;
}
}
m_cells.append(next_line->m_cells.data(), cells_to_grab_from_next_line);
next_line->m_cells.remove(0, cells_to_grab_from_next_line);
}
if (clear_next_line)
next_line->m_cells.clear();
}
void Line::clear_range(size_t first_column, size_t last_column, const Attribute& attribute)