Class: Fatty::Curses::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/fatty/curses/context.rb

Overview

Context represents the active curses environment.

It owns:

- curses initialization and shutdown
- terminal mode configuration
- window lifecycle

Context does NOT:

- read input
- decode keys
- render UI

Those responsibilities belong to EventSource and Renderer.

Context exists so that all curses state is centralized and never leaks into Sessions or Terminal.

Constant Summary collapse

DEFAULT_ESC_DELAY = 
0

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Context

Returns a new instance of Context.



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# File 'lib/fatty/curses/context.rb', line 29

def initialize
  @started = false
end

Instance Attribute Details

#alert_win ⇒ Object (readonly)

Returns the value of attribute alert_win.



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# File 'lib/fatty/curses/context.rb', line 26

def alert_win
  @alert_win
end

#cols ⇒ Object (readonly)

Returns the value of attribute cols.



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# File 'lib/fatty/curses/context.rb', line 27

def cols
  @cols
end

#input_win ⇒ Object (readonly)

Returns the value of attribute input_win.



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# File 'lib/fatty/curses/context.rb', line 26

def input_win
  @input_win
end

#output_win ⇒ Object (readonly)

Returns the value of attribute output_win.



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# File 'lib/fatty/curses/context.rb', line 26

def output_win
  @output_win
end

#palette ⇒ Object (readonly)

Returns the value of attribute palette.



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# File 'lib/fatty/curses/context.rb', line 27

def palette
  @palette
end

#rows ⇒ Object (readonly)

Returns the value of attribute rows.



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# File 'lib/fatty/curses/context.rb', line 27

def rows
  @rows
end

#status_win ⇒ Object (readonly)

Returns the value of attribute status_win.



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# File 'lib/fatty/curses/context.rb', line 26

def status_win
  @status_win
end

#truecolor ⇒ Object (readonly)

Returns the value of attribute truecolor.



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# File 'lib/fatty/curses/context.rb', line 27

def truecolor
  @truecolor
end

Instance Method Details

#ansi_pair_for(fg, bg, fallback_pair_id:) ⇒ Object

Return a curses color-pair id for an ANSI foreground/background pair.

This owns the dynamic ANSI pair cache. Renderers decide which fg/bg indexes they want; Context decides whether a pair can be allocated.



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# File 'lib/fatty/curses/context.rb', line 198

def ansi_pair_for(fg, bg, fallback_pair_id:)
  return fallback_pair_id unless ::Curses.has_colors?

  @ansi_pairs ||= {}
  @ansi_pair_limit ||= begin
                         ::Curses.color_pairs.to_i
                       rescue StandardError
                         256
                       end

  key = [fg.nil? ? -1 : fg.to_i, bg.nil? ? -1 : bg.to_i]
  cached = @ansi_pairs[key]
  return cached if cached

  start_id = Fatty::Colors::Pairs::ROLE_TO_PAIR.values.max + 1
  @ansi_next_pair_id ||= start_id
  @ansi_next_pair_id = start_id if @ansi_next_pair_id < start_id

  if @ansi_pair_limit.positive? && @ansi_next_pair_id >= @ansi_pair_limit
    Fatty.debug(
      "ansi_pair_for exhausted next=#{@ansi_next_pair_id.inspect} " \
      "limit=#{@ansi_pair_limit.inspect} fg=#{fg.inspect} bg=#{bg.inspect} " \
      "fallback=#{fallback_pair_id.inspect}",
      tag: :theme,
    )
    @ansi_pairs[key] = fallback_pair_id
  else
    pair_id = @ansi_next_pair_id
    @ansi_next_pair_id += 1

    ::Curses.init_pair(
      pair_id,
      fg.nil? ? -1 : fg.to_i,
      bg.nil? ? -1 : bg.to_i,
    )

    @ansi_pairs[key] = pair_id
  end

  @ansi_pairs[key]
end

#apply_layout(screen) ⇒ Object

Allocate or reallocate windows using Screen layout.



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# File 'lib/fatty/curses/context.rb', line 111

def apply_layout(screen)
  ensure_started!

  @rows = screen.rows
  @cols = screen.cols

  close_windows

  out = screen.output_rect
  sts = screen.status_rect
  inp = screen.input_rect
  alr = screen.alert_rect

  @output_win = ::Curses::Window.new(out.rows, out.cols, out.row, out.col)
  @status_win = ::Curses::Window.new(sts.rows, sts.cols, sts.row, sts.col)
  @input_win  = ::Curses::Window.new(inp.rows, inp.cols, inp.row, inp.col)
  @alert_win  = ::Curses::Window.new(alr.rows, alr.cols, alr.row, alr.col)

  # We do our own viewport/paging; allowing curses to scroll introduces
  # “mystery” blank lines if a newline slips into output
  @output_win.scrollok(true)
  @input_win.keypad(true)
  self
end

#apply_palette(palette) ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 177

def apply_palette(palette)
  reset_ansi_pairs!

  if ::Curses.has_colors?
    ::Curses.start_color
    ::Curses.use_default_colors if ::Curses.respond_to?(:use_default_colors)

    palette.each_value do |entry|
      next unless entry[:pair]

      ::Curses.init_pair(entry[:pair], entry[:fg], entry[:bg])
    end
  end

  @palette = palette
end

#close ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 136

def close
  close_windows
  disable_bracketed_paste! if @started
  ::Curses.close_screen if @started
  @started = false
end

#configure_escape_delay! ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 79

def configure_escape_delay!
  delay =
    if ENV["ESCDELAY"]
      ENV["ESCDELAY"].to_i
    else
      Fatty::Config.config.dig(:esc_delay)&.to_i
    end
  delay = DEFAULT_ESC_DELAY if delay.nil? || delay.negative?
  if ::Curses.respond_to?(:set_escdelay)
    ::Curses.set_escdelay(delay)
  else
    ENV["ESCDELAY"] = delay.to_s
  end
  Fatty.info("ESC delay set to #{delay} ms", tag: :input)
end

#environment ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 56

def environment
  data = {
    started: started?,
    truecolor: truecolor,
    key_min: ::Curses::KEY_MIN,
    key_max: ::Curses::KEY_MAX,
  }
  if started?
    data.merge(
      lines: ::Curses.lines,
      cols: ::Curses.cols,
      has_colors: ::Curses.has_colors?,
      colors: ::Curses.colors,
      color_pairs: ::Curses.color_pairs,
      can_change_color: ::Curses.can_change_color?,
    )
  else
    data
  end
rescue StandardError
  {}
end

#reset_ansi_pairs! ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 240

def reset_ansi_pairs!
  @ansi_pairs = {}
  @ansi_next_pair_id = nil
  @ansi_pair_limit = nil
end

#setup_colors ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 95

def setup_colors
  return unless ::Curses.has_colors?

  reset_ansi_pairs!
  ::Curses.start_color
  ::Curses.use_default_colors if ::Curses.respond_to?(:use_default_colors)

  theme_spec = Fatty::Themes::Manager.roles(Fatty::Themes::Manager.current) || {}
  palette = Fatty::Colors::Palette.compile(
    theme_spec,
    available_colors: ::Curses.colors,
  )
  apply_palette(palette)
end

#start ⇒ Object 



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# File 'lib/fatty/curses/context.rb', line 33

def start
  return self if @started

  configure_escape_delay!
  ::Curses.init_screen
  MouseConstants.ensure!

  ::Curses.raw
  ::Curses.noecho
  ::Curses.curs_set(1)
  ::Curses.stdscr.keypad(true)
  ::Curses.mousemask(::Curses::ALL_MOUSE_EVENTS)
  enable_bracketed_paste!
  setup_colors
  @truecolor = truecolor_enabled?
  @started = true
  self
end

#started? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fatty/curses/context.rb', line 52

def started?
  @started
end

#truecolor_enabled? ⇒ Boolean

Map a Fatty::Ansi::Style to a curses attribute.

  • If style has no explicit fg/bg, we keep the themed role pair.
  • If style specifies fg/bg, we allocate/init a curses pair on demand.

Note: this is intentionally independent of theme roles; it is for SGR output runs inside the output pane.

Returns:

  • (Boolean) 


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# File 'lib/fatty/curses/context.rb', line 150

def truecolor_enabled?
  cfg = Fatty::Config.config

  setting =
    if cfg.key?(:truecolor)
      cfg[:truecolor]
    else
      "auto"
    end
  @truecolor =
    case setting.to_s.downcase
    when "true", "yes", "on", "1"
      true
    when "false", "no", "off", "0"
      false
    else
      Fatty::Env.truecolor_detected?
    end
  Fatty.info(
    "truecolor=#{@truecolor} setting=#{setting.inspect} " \
      "TERM=#{ENV['TERM'].inspect} COLORTERM=#{ENV['COLORTERM'].inspect} " \
      "TERM_PROGRAM=#{ENV['TERM_PROGRAM'].inspect} TMUX=#{ENV.key?('TMUX')}",
    tag: :theme,
  )
  @truecolor
end