Replace curses with pure ruby terminal

lib/textbringer.rb

@@ -3,6 +3,7 @@
 require_relative "textbringer/errors"
 require_relative "textbringer/ring"
 require_relative "textbringer/buffer"
+require_relative "textbringer/terminal"
 require_relative "textbringer/window"
 require_relative "textbringer/floating_window"
 require_relative "textbringer/keymap"

lib/textbringer/color.rb

@@ -1,17 +1,17 @@
-require "curses"
+require_relative "terminal"
 
 module Textbringer
   module Color
     BASIC_COLORS = {
       "default" => -1,
-      "black" => Curses::COLOR_BLACK,
-      "red" => Curses::COLOR_RED,
-      "green" => Curses::COLOR_GREEN,
-      "yellow" => Curses::COLOR_YELLOW,
-      "blue" => Curses::COLOR_BLUE,
-      "magenta" => Curses::COLOR_MAGENTA,
-      "cyan" => Curses::COLOR_CYAN,
-      "white" => Curses::COLOR_WHITE,
+      "black" => Terminal::COLOR_BLACK,
+      "red" => Terminal::COLOR_RED,
+      "green" => Terminal::COLOR_GREEN,
+      "yellow" => Terminal::COLOR_YELLOW,
+      "blue" => Terminal::COLOR_BLUE,
+      "magenta" => Terminal::COLOR_MAGENTA,
+      "cyan" => Terminal::COLOR_CYAN,
+      "white" => Terminal::COLOR_WHITE,
       "brightblack" => 8,
       "brightred" => 9,
       "brightgreen" => 10,

lib/textbringer/commands/lsp.rb

@@ -323,7 +323,7 @@ def lsp_show_signature_window(label)
       # Close any existing signature window
       lsp_close_signature_window
 
-      columns = [[Buffer.display_width(label) + 2, Curses.cols - 2].min, 1].max
+      columns = [[Buffer.display_width(label) + 2, Terminal.cols - 2].min, 1].max
       win = FloatingWindow.at_cursor(
         lines: 1,
         columns: columns

lib/textbringer/commands/misc.rb

@@ -18,8 +18,11 @@ module Commands
     end
 
     define_command(:suspend_textbringer) do
-      Curses.close_screen
+      Terminal.close_screen
       Process.kill(:STOP, 0)
+      Terminal.reinit_screen
+      Window.resize
+      Window.redraw
     end
 
     define_command(:execute_command) do

lib/textbringer/face.rb

@@ -1,4 +1,4 @@
-require "curses"
+require_relative "terminal"
 
 module Textbringer
   class Face
@@ -37,13 +37,13 @@ def update(foreground: -1, background: -1,
       @bold = bold
       @underline = underline
       @reverse = reverse
-      Curses.init_pair(@color_pair,
+      Terminal.init_pair(@color_pair,
                        Color[foreground], Color[background])
       @text_attrs = 0
-      @text_attrs |= Curses::A_BOLD if bold
-      @text_attrs |= Curses::A_UNDERLINE if underline
-      @text_attrs |= Curses::A_REVERSE if reverse
-      @attributes = Curses.color_pair(@color_pair) | @text_attrs
+      @text_attrs |= Terminal::A_BOLD if bold
+      @text_attrs |= Terminal::A_UNDERLINE if underline
+      @text_attrs |= Terminal::A_REVERSE if reverse
+      @attributes = Terminal.color_pair(@color_pair) | @text_attrs
       self
     end
   end

lib/textbringer/floating_window.rb

@@ -1,4 +1,4 @@
-require "curses"
+require_relative "terminal"
 
 module Textbringer
   class FloatingWindow < Window
@@ -55,8 +55,8 @@ def self.at_cursor(lines:, columns:, window: Window.current, buffer: nil, face:
     end
 
     def self.centered(lines:, columns:, buffer: nil, face: :floating_window, current_line_face: nil)
-      y = (Curses.lines - lines) / 2
-      x = (Curses.cols - columns) / 2
+      y = (Terminal.lines - lines) / 2
+      x = (Terminal.cols - columns) / 2
       new(lines, columns, y, x, buffer: buffer, face: face, current_line_face: current_line_face)
     end
 
@@ -263,9 +263,9 @@ def redisplay
 
     private
 
-    # Override to create Curses::Pad instead of Curses::Window
+    # Override to create Terminal::Pad instead of Terminal::Window
     def initialize_window(num_lines, num_columns, y, x)
-      @window = Curses::Pad.new(num_lines, num_columns)
+      @window = Terminal::Pad.new(num_lines, num_columns)
       # Note: Pad position is set during refresh, not at creation
       # No mode_line for floating windows
       @mode_line = nil
@@ -277,7 +277,7 @@ def self.calculate_cursor_position(lines, columns, window)
       cursor_x = window.x + window.cursor.x
 
       # Prefer below cursor
-      space_below = Curses.lines - cursor_y - 2  # -2 for echo area
+      space_below = Terminal.lines - cursor_y - 2  # -2 for echo area
       space_above = cursor_y  # Screen space above cursor
 
       if space_below >= lines
@@ -286,14 +286,14 @@ def self.calculate_cursor_position(lines, columns, window)
         y = cursor_y - lines
       else
         # Not enough space, show below and clip
-        y = [cursor_y + 1, Curses.lines - lines - 1].max
+        y = [cursor_y + 1, Terminal.lines - lines - 1].max
         y = [y, 0].max
       end
 
       # Adjust x to prevent overflow
       x = cursor_x
-      if x + columns > Curses.cols
-        x = [Curses.cols - columns, 0].max
+      if x + columns > Terminal.cols
+        x = [Terminal.cols - columns, 0].max
       end
 
       [y, x]

lib/textbringer/terminal.rb

@@ -0,0 +1,240 @@
+require_relative "terminal/attributes"
+require_relative "terminal/screen_buffer"
+require_relative "terminal/input"
+require_relative "terminal/window"
+require_relative "terminal/pad"
+
+module Textbringer
+  module Terminal
+    module Termios
+      # TIOCGWINSZ: get terminal window size
+      TIOCGWINSZ = case RUBY_PLATFORM
+                   when /linux/  then 0x5413
+                   when /darwin/ then 0x40087468
+                   else               0x5413
+                   end
+    end
+    @color_pairs = {}  # pair_number => [fg, bg]
+    @virtual_screen = nil
+    @physical_screen = nil
+    @input_reader = nil
+    @lines = 24
+    @cols = 80
+    @old_tio = nil
+    @colors = 256
+    @cursor_y = 0
+    @cursor_x = 0
+
+    class << self
+      attr_reader :virtual_screen, :physical_screen, :input_reader
+
+      def init_screen
+        # Query terminal size
+        update_size
+        # Set up raw mode
+        @old_stty = `stty -g`.chomp
+        system("stty raw -echo -icanon -isig")
+        # Enable alternate screen buffer
+        STDOUT.write("\e[?1049h")
+        # Enable mouse tracking could go here
+        # Hide cursor during updates
+        STDOUT.write("\e[?25l")
+        # Clear screen
+        STDOUT.write("\e[2J\e[H")
+        STDOUT.flush
+
+        # Set up screen buffers
+        @virtual_screen = ScreenBuffer.new(@lines, @cols)
+        @physical_screen = ScreenBuffer.new(@lines, @cols)
+
+        # Set up input reader
+        @input_reader = Input::Reader.new(STDIN)
+
+        # Handle SIGWINCH
+        install_sigwinch_handler
+
+        # Enable keypad sequences
+        STDOUT.write("\e[?1h")  # Application cursor keys
+        STDOUT.flush
+      end
+
+      def close_screen
+        return unless @old_stty
+        # Show cursor
+        STDOUT.write("\e[?25h")
+        # Reset attributes
+        STDOUT.write("\e[0m")
+        # Disable alternate screen buffer
+        STDOUT.write("\e[?1049l")
+        # Reset cursor keys to normal mode
+        STDOUT.write("\e[?1l")
+        STDOUT.flush
+        # Restore terminal settings
+        system("stty #{@old_stty}")
+        @old_stty = nil
+        @virtual_screen = nil
+        @physical_screen = nil
+        @input_reader = nil
+      end
+
+      def reinit_screen
+        # Re-initialize after suspend/resume
+        update_size
+        @old_stty = `stty -g`.chomp
+        system("stty raw -echo -icanon -isig")
+        STDOUT.write("\e[?1049h")
+        STDOUT.write("\e[?25l")
+        STDOUT.write("\e[0m\e[2J\e[H")
+        STDOUT.write("\e[?1h")
+        STDOUT.flush
+
+        @virtual_screen = ScreenBuffer.new(@lines, @cols)
+        @physical_screen = ScreenBuffer.new(@lines, @cols, dirty: true)
+        @input_reader = Input::Reader.new(STDIN)
+      end
+
+      def echo
+        # No-op for our implementation
+      end
+
+      def noecho
+        # Already handled in raw mode
+      end
+
+      def raw
+        # Already handled in init_screen
+      end
+
+      def noraw
+        # No-op; restored in close_screen
+      end
+
+      def nl
+        # No-op
+      end
+
+      def nonl
+        # No-op
+      end
+
+      def has_colors?
+        # Check if terminal supports colors via TERM
+        term = ENV["TERM"] || ""
+        !term.empty? && term != "dumb"
+      end
+
+      def start_color
+        # Already available via ANSI sequences
+      end
+
+      def use_default_colors
+        # Already supported
+      end
+
+      def colors
+        @colors
+      end
+
+      def assume_default_colors(fg, bg)
+        # Store and apply default colors
+        @default_fg = fg
+        @default_bg = bg
+      end
+
+      def init_pair(pair_num, fg, bg)
+        @color_pairs[pair_num] = [fg, bg]
+      end
+
+      def color_pair(pair_num)
+        pair_num << COLOR_PAIR_SHIFT
+      end
+
+      def pair_info(pair_num)
+        @color_pairs[pair_num]
+      end
+
+      def lines
+        @lines
+      end
+
+      def cols
+        @cols
+      end
+
+      def beep
+        STDOUT.write("\a")
+        STDOUT.flush
+      end
+
+      def doupdate
+        return unless @virtual_screen && @physical_screen
+
+        output = @virtual_screen.flush_diff(@physical_screen)
+        unless output.empty?
+          STDOUT.write(output)
+        end
+        # Move cursor to the position set by the last noutrefresh
+        STDOUT.write("\e[#{@cursor_y + 1};#{@cursor_x + 1}H")
+        # Always reset SGR so the terminal is never left in a face's state
+        STDOUT.write("\e[0m")
+        STDOUT.write("\e[?25h")
+        STDOUT.flush
+      end
+
+      def set_cursor(y, x)
+        @cursor_y = y
+        @cursor_x = x
+      end
+
+      def unget_char(ch)
+        # Not commonly used, but support it via input reader
+      end
+
+      def save_key_modifiers(flag)
+        # Not applicable for ANSI terminals
+      end
+
+      private
+
+      def update_size
+        # TIOCGWINSZ ioctl fills a winsize struct: rows, cols, xpixel, ypixel (each uint16)
+        buf = "\x00" * 8
+        if STDOUT.respond_to?(:ioctl) &&
+            STDOUT.ioctl(Termios::TIOCGWINSZ, buf) >= 0
+          rows, cols = buf.unpack("S!S!")
+          if rows > 0 && cols > 0
+            @lines = rows
+            @cols = cols
+            return
+          end
+        end
+        @lines = (ENV["LINES"] || 24).to_i
+        @cols = (ENV["COLUMNS"] || 80).to_i
+      rescue Errno::ENOTTY, NotImplementedError
+        @lines = (ENV["LINES"] || 24).to_i
+        @cols = (ENV["COLUMNS"] || 80).to_i
+      end
+
+      def install_sigwinch_handler
+        Signal.trap(:WINCH) do
+          old_lines = @lines
+          old_cols = @cols
+          update_size
+          if @lines != old_lines || @cols != old_cols
+            @virtual_screen = ScreenBuffer.new(@lines, @cols)
+            # Dirty physical forces flush_diff to re-render every cell,
+            # ensuring correct SGR even for spaces and line endings.
+            @physical_screen = ScreenBuffer.new(@lines, @cols, dirty: true)
+            # Reset SGR before clearing so \e[2J uses default background.
+            STDOUT.write("\e[0m\e[2J")
+            STDOUT.flush
+            # Push a resize event
+            @input_reader&.instance_variable_get(:@buf)&.push(
+              Input::KEY_RESIZE
+            )
+          end
+        end
+      end
+    end
+  end
+end