Class: Rcalc::Terminal

Inherits:
Object
  • Object
show all
Defined in:
lib/rcalc/terminal.rb

Overview

This class contains utilities related to terminal. Its initializer does not take any arguments.

Instance Method Summary collapse

Instance Method Details

#bgcolor!(id) ⇒ Object

Sets the current background color to a number

Examples:

set background color to red

t = Rcalc::Terminal.new
t.bgcolor!(Rcalc::TERMINAL_COLORS[:red])


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# File 'lib/rcalc/terminal.rb', line 115

def bgcolor!(id)
  e! "48;5;#{id}m"
end

#bgrgb!(r, g, b) ⇒ Object

Sets the current background color to a RGB value

Examples:

set background color to red

t = Rcalc::Terminal.new
t.bgrgb!(255,0,0)


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# File 'lib/rcalc/terminal.rb', line 147

def bgrgb!(r, g, b)
  e! "48;2;#{r};#{g};#{b}m"
end

#blocking_console_query(query, listen_until) ⇒ Object

Performs a blocking console query. Used by other functions in this class



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# File 'lib/rcalc/terminal.rb', line 9

def blocking_console_query(query, listen_until)
  # send query and block wait for response
  res = ''
  $stdin.raw do |stdin|
    $stdout << "#{esc}#{query}"
    $stdout.flush

    finished = false
    loop do
      c = stdin.getc
      res << c if c
      listen_until.split.each do |d|
        finished = true if c == d
      end
      break if finished
    end
  end
  res
end

#color!(id) ⇒ Object

Sets the current text color to a number

Examples:

set text color to red

t = Rcalc::Terminal.new
t.color!(Rcalc::TERMINAL_COLORS[:red])


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# File 'lib/rcalc/terminal.rb', line 104

def color!(id)
  e! "38;5;#{id}m"
end

#e!(command) ⇒ Object

Function to print the CSI sequence followed by some command. Used by other functions in the class



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# File 'lib/rcalc/terminal.rb', line 77

def e!(command)
  print "#{esc}#{command}"
end

#esc ⇒ Object

Function to get the CSI sequence. Used by other functions in the class



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# File 'lib/rcalc/terminal.rb', line 70

def esc
  "\e["
end

#goto!(x, y) ⇒ Object

Sets cursor position

Examples:

set cursor to 10,10

t = Rcalc::Terminal.new
t.goto!(10, 10)


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# File 'lib/rcalc/terminal.rb', line 158

def goto!(x, y)
  e! "#{y};#{x}f"
end

#listen!(&block) ⇒ Object

Listen for keypresses on the terminal

Examples:

t = Rcalc::Terminal.new
t.listen! do |key|
  print key
end


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# File 'lib/rcalc/terminal.rb', line 204

def listen!(&block)
  $stdin.raw do |stdin|
    collect = ''

    finished = false
    loop do
      c = stdin.getch(min: 0, time: 0.01)

      if c.nil?
        if collect.length.positive?

          # sometimes multiple tokens appear inside a result
          # so we split it out and send them to the block
          split(collect).each do |token|
            finished = block.call(token)
          end
        end
        collect = ''

      else
        collect += c
      end

      break if finished
    end
  end
end

#pos ⇒ Integer

Gets the cursor position in the terminal. Returns two variables, x and y. Takes no arguments.

Examples:

t = Rcalc::Terminal.new
x, y = t.pos

Returns:

  • (Integer, Integer) —

    x and y, or column, row in that order.



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# File 'lib/rcalc/terminal.rb', line 38

def pos
  m = blocking_console_query('6n', 'R').match(/(?<row>\d+);(?<column>\d+)/)
  [Integer(m[:column]), Integer(m[:row])]
end

#rgb!(r, g, b) ⇒ Object

Sets the current text color to a RGB value

Examples:

set text color to red

t = Rcalc::Terminal.new
t.rgb!(255,0,0)


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# File 'lib/rcalc/terminal.rb', line 136

def rgb!(r, g, b)
  e! "38;2;#{r};#{g};#{b}m"
end

#size ⇒ Integer

Gets the size of the terminal in characters. Returns two variables, width and height. Takes no arguments.

Examples:

t = Rcalc::Terminal.new
w, h = t.size

Returns:

  • (Integer, Integer) —

    width and height, or columns, rows in that order.



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# File 'lib/rcalc/terminal.rb', line 51

def size
  # get current position
  x, y = pos

  # try go to the ends of the earth
  goto!(9999, 9999)

  # get that position
  tx, ty = pos

  # go back to current pos
  goto!(x, y)

  [tx, ty]
end

#split(collect) ⇒ Object 



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# File 'lib/rcalc/terminal.rb', line 162

def split(collect)
  res = []

  inside_esc = false
  current = ''
  collect.each_char do |chr|
    # start of esc
    if chr == "\e"
      inside_esc = true

      # if there already is escaped content in the buffer,
      #  send it out and clear the buffer
      unless current.empty?
        res << current
        current = ''
      end
    end

    if inside_esc
      # if we are inside an escape, add chars to the buffer
      current << chr
    else
      # for all other characters, we just
      res << chr
    end
  end

  # if we were inside an escape, we need to send out the final set
  res << current if inside_esc

  res
end