Class: Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/tabscroll/engine.rb

Overview

The main interface with Curses.

This acts as a middleman, abstracting away Curses’ details.

Constant Summary collapse

Colors =

All possible colors.

{
  :black   => 1,
  :white   => 2,
  :red     => 3,
  :yellow  => 4,
  :magenta => 5,
  :blue    => 6,
  :green   => 7,
  :cyan    => 8
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(min_width = nil, min_height = nil) ⇒ Engine

Initializes Ncurses with minimal width and height.



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# File 'lib/tabscroll/engine.rb', line 23

def initialize(min_width=nil, min_height=nil)
  @has_colors = nil

  @screen = Curses::init_screen
  return nil if not @screen

  if min_width and min_height
    cur_width  = @screen.maxx
    cur_height = @screen.maxy

    if cur_width < @width or cur_height < @height
      self.exit
      $stderr << "Error: Screen size too small (#{cur_width}x#{cur_height})\n"
      $stderr << "Please resize your terminal to at least #{@width}x#{@height}\n"
      return nil
    end
  end

  @has_colors = Curses.has_colors?
  if @has_colors
    Curses.start_color
    Curses.use_default_colors # will use default background

    # Initializes:   constant          foreground             bg
    Curses.init_pair(Colors[:white],   Curses::COLOR_BLACK,   -1)
    Curses.init_pair(Colors[:blue],    Curses::COLOR_BLUE,    -1)
    Curses.init_pair(Colors[:red],     Curses::COLOR_RED,     -1)
    Curses.init_pair(Colors[:green],   Curses::COLOR_GREEN,   -1)
    Curses.init_pair(Colors[:magenta], Curses::COLOR_MAGENTA, -1)
    Curses.init_pair(Colors[:yellow],  Curses::COLOR_YELLOW,  -1)
    Curses.init_pair(Colors[:cyan],    Curses::COLOR_CYAN,    -1)
  end

  Curses::cbreak
  Curses::curs_set 0
  Curses::noecho
  Curses::nonl
  Curses::stdscr.keypad = true # extra keys
end

Instance Method Details

#exit ⇒ Object 



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# File 'lib/tabscroll/engine.rb', line 71

def exit
  Curses::refresh
  Curses::close_screen
end

#getchar ⇒ Object 



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# File 'lib/tabscroll/engine.rb', line 85

def getchar
  return Curses::getch
end

#height ⇒ Object 



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# File 'lib/tabscroll/engine.rb', line 67

def height
  return Curses::lines
end

#set_color(color) ⇒ Object 



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# File 'lib/tabscroll/engine.rb', line 76

def set_color color
  if @has_colors
    @screen.attron Curses::color_pair(color)
    return self
  else
    return nil
  end
end

#timeout(timeout) ⇒ Object

timeout says how many milliseconds we wait for a key to be pressed.



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# File 'lib/tabscroll/engine.rb', line 91

def timeout timeout
  Curses::timeout = timeout
end

#width ⇒ Object 



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# File 'lib/tabscroll/engine.rb', line 63

def width
  return Curses::cols
end