DisplayBuffer rewrite, a DisplayBuffer is now a list of DisplayLines

Code is now greatly simplified using this architecture, and
DisplayAtoms no longer know their DisplayCoords and can be in any
order.

src/display_buffer.cc

@@ -1,188 +1,20 @@
 #include "display_buffer.hh"
 
 #include "assert.hh"
-#include <algorithm>
 
 namespace Kakoune
 {
 
-String DisplayAtom::content() const
+DisplayLine::iterator DisplayLine::split(iterator it, BufferIterator pos)
 {
-    switch (m_content_mode)
+    assert(it->content.type() == AtomContent::BufferRange);
-    {
+    assert(it->content.begin() < pos);
-    case BufferText:
+    assert(it->content.end() > pos);
-        return m_begin.buffer().string(m_begin, m_end);
-    case ReplacementText:
-        return m_replacement_text;
-    }
-    assert(false);
-    return "";
-}
 
-static DisplayCoord advance_coord(const DisplayCoord& pos,
+    DisplayAtom atom = *it;
-                                  const BufferIterator& begin,
+    atom.content.end() = pos;
-                                  const BufferIterator& end)
+    it->content.begin() = pos;
-{
+    return m_atoms.insert(it, std::move(atom));
-    if (begin.line() == end.line())
-        return DisplayCoord(pos.line, pos.column + end.column() - begin.column());
-    else
-        return DisplayCoord(pos.line + end.line() - begin.line(), end.column());
-}
-
-static DisplayCoord advance_coord(const DisplayCoord& pos,
-                                  const String& str)
-{
-    DisplayCoord res = pos;
-    for (auto c : str)
-    {
-        if (c == '\n')
-        {
-            ++res.line;
-            res.column = 0;
-        }
-        else
-            ++res.column;
-    }
-    return res;
-}
-
-DisplayCoord DisplayAtom::end_coord() const
-{
-    switch (m_content_mode)
-    {
-    case BufferText:
-        return advance_coord(m_coord, m_begin, m_end);
-    case ReplacementText:
-        return advance_coord(m_coord, m_replacement_text);
-    }
-    assert(false);
-    return { 0, 0 };
-}
-
-BufferIterator DisplayAtom::iterator_at(const DisplayCoord& coord) const
-{
-    if (m_content_mode != BufferText or coord <= m_coord)
-        return m_begin;
-
-    DisplayCoord pos = m_coord;
-    for (BufferIterator it = m_begin; it != m_end; ++it)
-    {
-        if (*it == '\n')
-        {
-            ++pos.line;
-            pos.column = 0;
-        }
-        else
-            ++pos.column;
-
-        if (coord <= pos)
-            return it+1;
-    }
-    return m_end;
-}
-
-DisplayCoord DisplayAtom::line_and_column_at(const BufferIterator& iterator) const
-{
-    assert(iterator >= m_begin and iterator < m_end);
-
-    if (m_content_mode != BufferText)
-        return m_coord;
-
-    return advance_coord(m_coord, m_begin, iterator);
-}
-
-DisplayBuffer::DisplayBuffer()
-{
-}
-
-DisplayBuffer::iterator DisplayBuffer::append(BufferIterator begin, BufferIterator end)
-{
-    DisplayCoord coord;
-    if (not m_atoms.empty())
-        coord = m_atoms.back().end_coord();
-    m_atoms.push_back(DisplayAtom(std::move(coord), std::move(begin), std::move(end)));
-    return --(this->end());
-}
-
-DisplayBuffer::iterator DisplayBuffer::insert_empty_atom_before(iterator where)
-{
-    assert(where != end());
-    iterator res = m_atoms.insert(
-        where, DisplayAtom(where->coord(), where->begin(), where->begin()));
-    return res;
-}
-
-DisplayBuffer::iterator DisplayBuffer::atom_containing(const BufferIterator& where)
-{
-    return atom_containing(where, m_atoms.begin());
-}
-
-DisplayBuffer::iterator DisplayBuffer::atom_containing(const BufferIterator& where,
-                                                       iterator start)
-{
-    if (start == end() or where < start->begin())
-        return end();
-
-    while (start != end())
-    {
-        if (start->end() > where)
-            break;
-        ++start;
-    }
-    return start;
-}
-
-DisplayBuffer::iterator DisplayBuffer::split(iterator atom, const BufferIterator& pos)
-{
-    assert(atom->splitable());
-    assert(pos > atom->begin());
-    assert(pos < atom->end());
-
-    BufferIterator end = atom->m_end;
-    atom->m_end = pos;
-
-    DisplayAtom new_atom(atom->end_coord(), pos, end,
-                         atom->fg_color(), atom->bg_color(), atom->attribute());
-
-    iterator insert_pos = atom;
-    ++insert_pos;
-    m_atoms.insert(insert_pos, std::move(new_atom));
-    check_invariant();
-    return atom;
-}
-
-void DisplayBuffer::check_invariant() const
-{
-    const_iterator prev_it;
-    for (const_iterator it = begin(); it != end(); ++it)
-    {
-        assert(it->end() >= it->begin());
-        if (it != begin())
-        {
-            assert(prev_it->end() == it->begin());
-            assert(prev_it->end_coord() == it->coord());
-        }
-        prev_it = it;
-    }
-}
-
-void DisplayBuffer::replace_atom_content(iterator atom,
-                                         const String& replacement)
-{
-    atom->m_content_mode = DisplayAtom::ReplacementText;
-    atom->m_replacement_text = replacement;
-
-    // update coordinates of subsequents atoms
-    DisplayCoord new_coord = atom->end_coord();
-    while (true)
-    {
-        new_coord = atom->end_coord();
-        ++atom;
-
-        if (atom == end() or new_coord == atom->m_coord)
-            break;
-        atom->m_coord = new_coord;
-    }
 }
 
 }

src/display_buffer.hh

@@ -28,8 +28,7 @@ enum Attributes
     Underline = 1,
     Reverse = 2,
     Blink = 4,
-    Bold = 8,
+    Bold = 8
-    Final = 16
 };
 
 enum class Color
@@ -45,83 +44,88 @@ enum class Color
     White
 };
 
-// A DisplayAtom is a string of text with it's display style.
+struct AtomContent
-//
-// The DisplayAtom class references the buffer string it represents
-// with it's begin/end iterators and may replace it with another
-// text stored in the replacement_string field.
-struct DisplayAtom
-{
-    const DisplayCoord&   coord()     const { return m_coord; }
-    const BufferIterator& begin()     const { return m_begin; }
-    const BufferIterator& end()       const { return m_end; }
-    const Color&          fg_color()  const { return m_fg_color; }
-    const Color&          bg_color()  const { return m_bg_color; }
-    const Attribute&      attribute() const { return m_attribute; }
-
-    enum ContentMode
-    {
-        BufferText,
-        ReplacementText
-    };
-    ContentMode    content_mode() const { return m_content_mode; }
-
-    Color&         fg_color()  { return m_fg_color; }
-    Color&         bg_color()  { return m_bg_color; }
-    Attribute&     attribute() { return m_attribute; }
-
-    String         content()    const;
-    DisplayCoord   end_coord()  const;
-    BufferIterator iterator_at(const DisplayCoord& coord) const;
-    DisplayCoord   line_and_column_at(const BufferIterator& iterator) const;
-
-    bool           splitable() const { return m_content_mode != ReplacementText; }
-
-private:
-    friend class DisplayBuffer;
-    DisplayAtom(DisplayCoord coord,
-                BufferIterator begin, BufferIterator end,
-                Color fg_color = Color::Default,
-                Color bg_color = Color::Default,
-                Attribute attribute = Attributes::Normal)
-        : m_content_mode(BufferText),
-          m_coord(std::move(coord)),
-          m_begin(std::move(begin)), m_end(std::move(end)),
-          m_fg_color(fg_color),
-          m_bg_color(bg_color),
-          m_attribute(attribute)
-    {}
-
-    ContentMode    m_content_mode;
-
-    DisplayCoord   m_coord;
-    BufferIterator m_begin;
-    BufferIterator m_end;
-    Color          m_fg_color;
-    Color          m_bg_color;
-    Attribute      m_attribute;
-    String         m_replacement_text;
-};
-
-// A DisplayBuffer is the visual content of a Window as a DisplayAtom list
-//
-// The DisplayBuffer class provides means to mutate and iterator on it's
-// DisplayAtoms.
-class DisplayBuffer
 {
 public:
-    typedef std::list<DisplayAtom> AtomList;
+    enum Type { BufferRange, ReplacedBufferRange, Text };
-    typedef AtomList::iterator iterator;
-    typedef AtomList::const_iterator const_iterator;
 
-    DisplayBuffer();
+    AtomContent(BufferIterator begin, BufferIterator end)
+        : m_type(BufferRange),
+          m_begin(std::move(begin)),
+          m_end(std::move(end)) {}
 
-    void clear() { m_atoms.clear(); }
+    AtomContent(String str)
-    iterator append(BufferIterator begin, BufferIterator end);
+        : m_type(Text), m_text(std::move(str)) {}
-    iterator insert_empty_atom_before(iterator where);
-    iterator split(iterator atom, const BufferIterator& pos);
 
-    void replace_atom_content(iterator atom, const String& replacement);
+    String content() const
+    {
+        switch (m_type)
+        {
+            case BufferRange:
+               return m_begin.buffer().string(m_begin, m_end);
+            case Text:
+            case ReplacedBufferRange:
+               return m_text;
+        }
+    }
+
+    BufferIterator& begin()
+    {
+        assert(has_buffer_range());
+        return m_begin;
+    }
+
+    BufferIterator& end()
+    {
+        assert(has_buffer_range());
+        return m_end;
+    }
+
+    void replace(String text)
+    {
+        assert(m_type == BufferRange);
+        m_type = ReplacedBufferRange;
+        m_text = std::move(text);
+    }
+
+    bool has_buffer_range() const
+    {
+        return m_type == BufferRange or m_type == ReplacedBufferRange;
+    }
+
+    Type type() const { return m_type; }
+
+private:
+    Type m_type;
+
+    BufferIterator m_begin;
+    BufferIterator m_end;
+    String m_text;
+};
+
+struct DisplayAtom
+{
+    Color          fg_color;
+    Color          bg_color;
+    Attribute      attribute;
+
+    AtomContent    content;
+
+    DisplayAtom(AtomContent content)
+       : content(std::move(content)), attribute(Normal),
+         fg_color(Color::Default), bg_color(Color::Default) {}
+};
+
+class DisplayLine
+{
+public:
+    using AtomList = std::vector<DisplayAtom>;
+    using iterator = AtomList::iterator;
+    using const_iterator = AtomList::const_iterator;
+
+    explicit DisplayLine(size_t buffer_line) : m_buffer_line(buffer_line) {}
+
+    size_t buffer_line() const { return m_buffer_line; }
 
     iterator begin() { return m_atoms.begin(); }
     iterator end() { return m_atoms.end(); }
@@ -129,17 +133,29 @@ public:
     const_iterator begin() const { return m_atoms.begin(); }
     const_iterator end() const { return m_atoms.end(); }
 
-    iterator atom_containing(const BufferIterator& where);
+    // Split atom pointed by it at pos, returns an iterator to the first atom
-    iterator atom_containing(const BufferIterator& where, iterator start);
+    iterator split(iterator it, BufferIterator pos);
 
-    const DisplayAtom& front() const { return m_atoms.front(); }
+    iterator insert(iterator it, DisplayAtom atom) { return m_atoms.insert(it, std::move(atom)); }
-    const DisplayAtom& back()  const { return m_atoms.back(); }
+    void     push_back(DisplayAtom atom) { m_atoms.push_back(std::move(atom)); }
 
-    void check_invariant() const;
 private:
+    size_t   m_buffer_line;
     AtomList m_atoms;
 };
 
+class DisplayBuffer
+{
+public:
+    using LineList = std::list<DisplayLine>;
+    DisplayBuffer() {}
+
+    LineList& lines() { return m_lines; }
+    const LineList& lines() const { return m_lines; }
+private:
+    LineList m_lines;
+};
+
 }
 
 #endif // display_buffer_hh_INCLUDED

src/highlighters.cc

@@ -2,7 +2,6 @@
 
 #include "assert.hh"
 #include "window.hh"
-#include "display_buffer.hh"
 #include "highlighter_registry.hh"
 #include "highlighter_group.hh"
 #include "regex.hh"
@@ -14,66 +13,57 @@ using namespace std::placeholders;
 
 typedef boost::regex_iterator<BufferIterator> RegexIterator;
 
-void colorize_regex_range(DisplayBuffer& display_buffer,
+template<typename T>
-                          const BufferIterator& range_begin,
+void highlight_range(DisplayBuffer& display_buffer,
-                          const BufferIterator& range_end,
+                     BufferIterator begin, BufferIterator end,
-                          const Regex& ex,
+                     bool skip_replaced, T func)
-                          Color fg_color, Color bg_color = Color::Default)
 {
-    assert(range_begin <= range_end);
+    for (auto& line : display_buffer.lines())
-
-    if (range_begin >= display_buffer.back().end() or
-        range_end <= display_buffer.front().begin())
-        return;
-
-    BufferIterator display_begin = std::max(range_begin,
-                                            display_buffer.front().begin());
-    BufferIterator display_end   = std::min(range_end,
-                                            display_buffer.back().end());
-
-    RegexIterator re_it(display_begin, display_end, ex, boost::match_nosubs);
-    RegexIterator re_end;
-    DisplayBuffer::iterator atom_it = display_buffer.begin();
-    for (; re_it != re_end; ++re_it)
     {
-        BufferIterator begin = (*re_it)[0].first;
+        if (line.buffer_line() >= begin.line() and line.buffer_line() <= end.line())
-        BufferIterator end   = (*re_it)[0].second;
-        assert(begin != end);
-
-        auto begin_atom_it = display_buffer.atom_containing(begin, atom_it);
-        assert(begin_atom_it != display_buffer.end());
-        if (begin_atom_it->begin() != begin)
         {
-            if (begin_atom_it->splitable())
+            for (auto atom_it = line.begin(); atom_it != line.end(); ++atom_it)
-                begin_atom_it = ++display_buffer.split(begin_atom_it, begin);
-            else
-                ++begin_atom_it;
-        }
-
-        auto end_atom_it = display_buffer.atom_containing(end, begin_atom_it);
-        if (end_atom_it != display_buffer.end() and
-            end_atom_it->begin() != end and end_atom_it->splitable())
-            end_atom_it = ++display_buffer.split(end_atom_it, end);
-
-        for (auto it = begin_atom_it; it != end_atom_it; ++it)
             {
-            if (it->attribute() & Attributes::Final)
+                bool is_replaced = atom_it->content.type() == AtomContent::ReplacedBufferRange;
+
+                if (not atom_it->content.has_buffer_range() or
+                    (skip_replaced and is_replaced))
                     continue;
 
-            it->fg_color() = fg_color;
+                if (end <= atom_it->content.begin() or begin >= atom_it->content.end())
-            it->bg_color() = bg_color;
+                    continue;
-        }
 
-        atom_it = end_atom_it;
+                if (not is_replaced and begin > atom_it->content.begin())
+                    atom_it = ++line.split(atom_it, begin);
+
+                if (not is_replaced and end < atom_it->content.end())
+                {
+                    atom_it = line.split(atom_it, end);
+                    func(*atom_it);
+                    ++atom_it;
+                }
+                else
+                    func(*atom_it);
+            }
+        }
     }
 }
 
 void colorize_regex(DisplayBuffer& display_buffer,
+                    const Buffer& buffer,
                     const Regex& ex,
                     Color fg_color, Color bg_color = Color::Default)
 {
-    colorize_regex_range(display_buffer, display_buffer.front().begin(),
+    RegexIterator re_it(buffer.begin(), buffer.end(), ex, boost::match_nosubs);
-                         display_buffer.back().end(), ex, fg_color, bg_color);
+    RegexIterator re_end;
+    for (; re_it != re_end; ++re_it)
+    {
+        highlight_range(display_buffer, (*re_it)[0].first, (*re_it)[0].second, true,
+                        [&](DisplayAtom& atom) {
+                            atom.fg_color = fg_color;
+                            atom.bg_color = bg_color;
+                        });
+    }
 }
 
 Color parse_color(const String& color)
@@ -103,25 +93,31 @@ HighlighterAndId colorize_regex_factory(Window& window,
 
     String id = "colre'" + params[0] + "'";
 
-    return HighlighterAndId(id, std::bind(colorize_regex, _1,
+    return HighlighterAndId(id, std::bind(colorize_regex,
+                                          _1, std::ref(window.buffer()),
                                           ex, fg_color, bg_color));
 }
 
 void expand_tabulations(Window& window, DisplayBuffer& display_buffer)
 {
     const int tabstop = window.option_manager()["tabstop"].as_int();
-    for (auto atom_it = display_buffer.begin();
+    for (auto& line : display_buffer.lines())
-         atom_it != display_buffer.end(); ++atom_it)
     {
-        for (BufferIterator it = atom_it->begin(); it != atom_it->end(); ++it)
+        for (auto atom_it = line.begin(); atom_it != line.end(); ++atom_it)
+        {
+            if (atom_it->content.type() != AtomContent::BufferRange)
+                continue;
+
+            auto begin = atom_it->content.begin();
+            auto end = atom_it->content.end();
+            for (BufferIterator it = begin; it != end; ++it)
             {
                 if (*it == '\t')
                 {
-                if (it != atom_it->begin())
+                    if (it != begin)
-                    atom_it = ++display_buffer.split(atom_it, it);
+                        atom_it = ++line.split(atom_it, it);
-
+                    if (it+1 != end)
-                if (it+1 != atom_it->end())
+                        atom_it = line.split(atom_it, it+1);
-                    atom_it = display_buffer.split(atom_it, it+1);
 
                     BufferCoord pos = it.buffer().line_and_column_at(it);
 
@@ -140,18 +136,17 @@ void expand_tabulations(Window& window, DisplayBuffer& display_buffer)
                     String padding;
                     for (int i = 0; i < count; ++i)
                         padding += ' ';
-                display_buffer.replace_atom_content(atom_it, padding);
+                    atom_it->content.replace(padding);
+                    break;
+                }
             }
         }
     }
 }
 
-void show_line_numbers(DisplayBuffer& display_buffer)
+void show_line_numbers(Window& window, DisplayBuffer& display_buffer)
 {
-    const Buffer& buffer = display_buffer.front().begin().buffer();
+    int last_line = window.buffer().line_count();
-    BufferCoord coord = buffer.line_and_column_at(display_buffer.begin()->begin());
-
-    int last_line = buffer.line_count();
     int digit_count = 0;
     for (int c = last_line; c > 0; c /= 10)
         ++digit_count;
@@ -159,118 +154,30 @@ void show_line_numbers(DisplayBuffer& display_buffer)
     char format[] = "%?d ";
     format[1] = '0' + digit_count;
 
-    for (; coord.line <= last_line-1; ++coord.line)
+    for (auto& line : display_buffer.lines())
     {
-        BufferIterator line_start = buffer.iterator_at(coord);
-        DisplayBuffer::iterator atom_it = display_buffer.atom_containing(line_start);
-        if (atom_it != display_buffer.end())
-        {
-            if (atom_it->begin() != line_start)
-            {
-                if (not atom_it->splitable())
-                    continue;
-
-                atom_it = ++display_buffer.split(atom_it, line_start);
-            }
-            atom_it = display_buffer.insert_empty_atom_before(atom_it);
-            atom_it->fg_color() = Color::Black;
-            atom_it->bg_color() = Color::White;
-            atom_it->attribute() = Attributes::Final;
-
         char buffer[10];
-            snprintf(buffer, 10, format, coord.line + 1);
+        snprintf(buffer, 10, format, line.buffer_line() + 1);
-            display_buffer.replace_atom_content(atom_it, buffer);
+        DisplayAtom atom = DisplayAtom(AtomContent(buffer));
-        }
+        atom.fg_color = Color::Black;
+        atom.bg_color = Color::White;
+        line.insert(line.begin(), std::move(atom));
     }
 }
 
 void highlight_selections(Window& window, DisplayBuffer& display_buffer)
 {
-    typedef std::pair<BufferIterator, BufferIterator> BufferRange;
-
-    std::vector<BufferRange> selections;
-    for (auto& sel : window.selections())
-        selections.push_back(BufferRange(sel.begin(), sel.end()));
-
-    std::sort(selections.begin(), selections.end(),
-              [](const BufferRange& lhs, const BufferRange& rhs)
-              { return lhs.first < rhs.first; });
-
-    auto atom_it = display_buffer.begin();
-    auto sel_it = selections.begin();
-
-    // underline each selections
-    while (atom_it != display_buffer.end()
-           and sel_it != selections.end())
-    {
-        BufferRange& sel = *sel_it;
-        DisplayAtom& atom = *atom_it;
-
-        if (atom.attribute() & Attributes::Final)
-        {
-            ++atom_it;
-            continue;
-        }
-        // [###------]
-        if (atom.begin() >= sel.first and atom.begin() < sel.second and
-            atom.end() > sel.second)
-        {
-            atom_it = display_buffer.split(atom_it, sel.second);
-            atom_it->attribute() |= Attributes::Underline;
-            ++atom_it;
-            ++sel_it;
-        }
-        // [---###---]
-        else if (atom.begin() < sel.first and atom.end() > sel.second)
-        {
-            atom_it = display_buffer.split(atom_it, sel.first);
-            atom_it = display_buffer.split(++atom_it, sel.second);
-            atom_it->attribute() |= Attributes::Underline;
-            ++atom_it;
-            ++sel_it;
-        }
-        // [------###]
-        else if (atom.begin() < sel.first and atom.end() > sel.first)
-        {
-            atom_it = ++display_buffer.split(atom_it, sel.first);
-            atom_it->attribute() |= Attributes::Underline;
-            ++atom_it;
-        }
-        // [#########]
-        else if (atom.begin() >= sel.first and atom.end() <= sel.second)
-        {
-            atom_it->attribute() |= Attributes::Underline;
-            ++atom_it;
-        }
-        // [---------]
-        else if (atom.begin() >= sel.second)
-            ++sel_it;
-        // [---------]
-        else if (atom.end() <= sel.first)
-            ++atom_it;
-        else
-            assert(false);
-    }
-
-    // invert selection last char
     for (auto& sel : window.selections())
     {
+        highlight_range(display_buffer, sel.begin(), sel.end(), false,
+                        [](DisplayAtom& atom) { atom.attribute |= Attributes::Underline; });
+
         const BufferIterator& last = sel.last();
-
+        highlight_range(display_buffer, last, last+1, false,
-        DisplayBuffer::iterator atom_it = display_buffer.atom_containing(last);
+                        [](DisplayAtom& atom) { atom.attribute |= Attributes::Reverse; });
-        if (atom_it == display_buffer.end() or not atom_it->splitable())
-            continue;
-
-        if (atom_it->begin() < last)
-            atom_it = ++display_buffer.split(atom_it, last);
-        if (atom_it->end() > last + 1)
-            atom_it = display_buffer.split(atom_it, last + 1);
-
-        atom_it->attribute() |= Attributes::Reverse;
     }
 }
 
-
 template<void (*highlighter_func)(DisplayBuffer&)>
 class SimpleHighlighterFactory
 {
@@ -316,7 +223,7 @@ void register_highlighters()
 
     registry.register_factory("highlight_selections", WindowHighlighterFactory<highlight_selections>("highlight_selections"));
     registry.register_factory("expand_tabs", WindowHighlighterFactory<expand_tabulations>("expand_tabs"));
-    registry.register_factory("number_lines", SimpleHighlighterFactory<show_line_numbers>("number_lines"));
+    registry.register_factory("number_lines", WindowHighlighterFactory<show_line_numbers>("number_lines"));
     registry.register_factory("regex", colorize_regex_factory);
     registry.register_factory("group", highlighter_group_factory);
 }

src/ncurses.cc

@@ -96,46 +96,30 @@ void NCursesClient::draw_window(Window& window)
     window.set_dimensions(DisplayCoord(max_y, max_x));
     window.update_display_buffer();
 
-    DisplayCoord position;
+    int line_index = 0;
-    for (const DisplayAtom& atom : window.display_buffer())
+    for (const DisplayLine& line : window.display_buffer().lines())
     {
-        assert(position == atom.coord());
+        move(line_index, 0);
-        const String content = atom.content();
-
-        set_attribute(A_UNDERLINE, atom.attribute() & Underline);
-        set_attribute(A_REVERSE, atom.attribute() & Reverse);
-        set_attribute(A_BLINK, atom.attribute() & Blink);
-        set_attribute(A_BOLD, atom.attribute() & Bold);
-
-        set_color(atom.fg_color(), atom.bg_color());
-
-        auto pos = content.begin();
-        while (true)
-        {
-            move(position.line, position.column);
         clrtoeol();
-            auto end = std::find(pos, content.end(), '\n');
+        for (const DisplayAtom& atom : line)
-            String line(pos, end);
-            addstr(line.c_str());
-
-            if (end != content.end())
         {
-                addch(' ');
+            set_attribute(A_UNDERLINE, atom.attribute & Underline);
-                position.line = position.line + 1;
+            set_attribute(A_REVERSE, atom.attribute & Reverse);
-                position.column = 0;
+            set_attribute(A_BLINK, atom.attribute & Blink);
-                pos = end + 1;
+            set_attribute(A_BOLD, atom.attribute & Bold);
 
-                if (position.line >= max_y)
+            set_color(atom.fg_color, atom.bg_color);
-                    break;
+
+            String content = atom.content.content();
+            if (content[content.length()-1] == '\n')
+            {
+                addnstr(content.c_str(), content.length() - 1);
+                addch(' ');
             }
             else
-            {
+                addstr(content.c_str());
-                position.column += line.length();
-                break;
         }
-        }
+        ++line_index;
-        if (position.line >= max_y)
-            break;
     }
 
     set_attribute(A_UNDERLINE, 0);
@@ -143,9 +127,9 @@ void NCursesClient::draw_window(Window& window)
     set_attribute(A_BLINK, 0);
     set_attribute(A_BOLD, 0);
     set_color(Color::Blue, Color::Black);
-    while (++position.line < max_y)
+    while (++line_index < max_y)
     {
-        move(position.line, 0);
+        move(line_index, 0);
         clrtoeol();
         addch('~');
     }

src/window.cc

@@ -39,7 +39,8 @@ void Window::update_display_buffer()
 {
     scroll_to_keep_cursor_visible_ifn();
 
-    m_display_buffer.clear();
+    DisplayBuffer::LineList& lines = m_display_buffer.lines();
+    lines.clear();
 
     for (auto line = 0; line < m_dimensions.line; ++line)
     {
@@ -50,16 +51,17 @@ void Window::update_display_buffer()
         BufferIterator line_begin = buffer().iterator_at_line_begin(pos);
         BufferIterator line_end   = buffer().iterator_at_line_end(pos);
 
-        if (line_begin != pos)
+        BufferIterator end;
-        {
+        if (line_end - pos > m_dimensions.column)
-            auto atom_it = m_display_buffer.append(line_begin, pos);
+            end = pos + m_dimensions.column;
-            m_display_buffer.replace_atom_content(atom_it, "");
+        else
-        }
+            end = line_end;
-        m_display_buffer.append(pos, line_end);
+
+        lines.push_back(DisplayLine(buffer_line));
+        lines.back().push_back(DisplayAtom(AtomContent(pos,end)));
     }
 
     m_highlighters(m_display_buffer);
-    m_display_buffer.check_invariant();
 }
 
 void Window::set_dimensions(const DisplayCoord& dimensions)