Add support for Default face

The Default face is used to set default color values, if set
to default (the default), refers to terminal default colors.

src/display_buffer.hh

@@ -149,9 +149,13 @@ public:
     void optimize();
     void compute_range();
 
+    void set_default_face(const Face& face) { m_default_face = face; }
+    const Face& default_face() const { return m_default_face; }
+
 private:
     LineList m_lines;
     BufferRange m_range;
+    Face m_default_face;
 };
 
 }

src/face_registry.cc

@@ -91,6 +91,7 @@ CandidateList FaceRegistry::complete_alias_name(StringView prefix,
 
 FaceRegistry::FaceRegistry()
     : m_aliases{
+        { "Default", Face{ Color::Default, Color::Default } },
         { "PrimarySelection", Face{ Color::White, Color::Blue } },
         { "SecondarySelection", Face{ Color::Black, Color::Blue } },
         { "PrimaryCursor", Face{ Color::Black, Color::White } },

src/ncurses_ui.cc

@@ -206,13 +206,18 @@ static int get_color_pair(const Face& face)
     }
 }
 
-static void set_face(WINDOW* window, Face face)
+void set_face(WINDOW* window, Face face, const Face& default_face)
 {
     static int current_pair = -1;
 
     if (current_pair != -1)
         wattroff(window, COLOR_PAIR(current_pair));
 
+    if (face.fg == Color::Default)
+        face.fg = default_face.fg;
+    if (face.bg == Color::Default)
+        face.bg = default_face.bg;
+
     if (face.fg != Color::Default or face.bg != Color::Default)
     {
         current_pair = get_color_pair(face);
@@ -333,11 +338,12 @@ void NCursesUI::update_dimensions()
     --m_dimensions.line;
 }
 
-void NCursesUI::draw_line(const DisplayLine& line, CharCount col_index) const
+void NCursesUI::draw_line(const DisplayLine& line, CharCount col_index,
+                          const Face& default_face) const
 {
     for (const DisplayAtom& atom : line)
     {
-        set_face(m_window, atom.face);
+        set_face(m_window, atom.face, default_face);
 
         StringView content = atom.content();
         if (content.empty())
@@ -365,6 +371,9 @@ void NCursesUI::draw(const DisplayBuffer& display_buffer,
                      const DisplayLine& status_line,
                      const DisplayLine& mode_line)
 {
+    const Face& default_face = display_buffer.default_face();
+    wbkgdset(m_window, COLOR_PAIR(get_color_pair(default_face)));
+
     check_resize();
 
     LineCount line_index = m_status_on_top ? 1 : 0;
@@ -372,11 +381,11 @@ void NCursesUI::draw(const DisplayBuffer& display_buffer,
     {
         wmove(m_window, (int)line_index, 0);
         wclrtoeol(m_window);
-        draw_line(line, 0);
+        draw_line(line, 0, default_face);
         ++line_index;
     }
 
-    set_face(m_window, { Color::Blue, Color::Default });
+    set_face(m_window, { Color::Blue, Color::Default }, default_face);
     while (line_index < m_dimensions.line + (m_status_on_top ? 1 : 0))
     {
         wmove(m_window, (int)line_index++, 0);
@@ -387,14 +396,14 @@ void NCursesUI::draw(const DisplayBuffer& display_buffer,
     int status_line_pos = m_status_on_top ? 0 : (int)m_dimensions.line;
     wmove(m_window, status_line_pos, 0);
     wclrtoeol(m_window);
-    draw_line(status_line, 0);
+    draw_line(status_line, 0, default_face);
     const auto mode_len = mode_line.length();
     const auto remaining = m_dimensions.column - status_line.length();
     if (mode_len < remaining)
     {
         CharCount col = m_dimensions.column - mode_len;
         wmove(m_window, status_line_pos, (int)col);
-        draw_line(mode_line, col);
+        draw_line(mode_line, col, default_face);
     }
     else if (remaining > 2)
     {
@@ -405,7 +414,7 @@ void NCursesUI::draw(const DisplayBuffer& display_buffer,
 
         CharCount col = m_dimensions.column - remaining + 1;
         wmove(m_window, status_line_pos, (int)col);
-        draw_line(trimmed_mode_line, col);
+        draw_line(trimmed_mode_line, col, default_face);
     }
 
     const char* tsl = tigetstr((char*)"tsl");

src/ncurses_ui.hh

@@ -51,7 +51,8 @@ public:
 private:
     void check_resize();
     void redraw();
-    void draw_line(const DisplayLine& line, CharCount col_index) const;
+    void draw_line(const DisplayLine& line, CharCount col_index,
+                   const Face& default_face) const;
 
     NCursesWin* m_window = nullptr;
 

src/window.cc

@@ -2,6 +2,7 @@
 
 #include "assert.hh"
 #include "context.hh"
+#include "face_registry.hh"
 #include "highlighter.hh"
 #include "hook_manager.hh"
 #include "client.hh"
@@ -65,6 +66,7 @@ void Window::update_display_buffer(const Context& context)
     kak_assert(&buffer() == &context.buffer());
     scroll_to_keep_selection_visible_ifn(context);
 
+    m_display_buffer.set_default_face(get_face("Default"));
     DisplayBuffer::LineList& lines = m_display_buffer.lines();
     lines.clear();
 
@@ -283,6 +285,11 @@ ByteCoordAndTarget Window::offset_coord(ByteCoordAndTarget coord, LineCount offs
     return { find_buffer_coord(lines[1], buffer(), column), column };
 }
 
+void Window::clear_display_buffer()
+{
+    m_display_buffer = DisplayBuffer{};
+}
+
 void Window::on_option_changed(const Option& option)
 {
     run_hook_in_own_context("WinSetOption",

src/window.hh

@@ -44,7 +44,7 @@ public:
     ByteCoord offset_coord(ByteCoord coord, CharCount offset);
     ByteCoordAndTarget offset_coord(ByteCoordAndTarget coord, LineCount offset);
 
-    void clear_display_buffer() { m_display_buffer = DisplayBuffer{}; }
+    void clear_display_buffer();
 private:
     Window(const Window&) = delete;