Class: Canis::DefaultKeyReader

Inherits:

Object

• Object
• Canis::DefaultKeyReader

Defined in:

lib/canis/core/system/window.rb

Overview

created on 2014-04-20 - 00:19 so that user can install own handler

A class that reads keys and handles function, shifted function, control, alt, and other extended keys. THis essentially consists of a method getchar which will be called by the application to get keys in a loop. Application may also call getchar to get one key in some situations.

Originally, rbcurse returned an int, but we are movign to a string, so that user can use the exact control codes he gets on the terminal using C-v and map them here.

Constant Summary

KEY_S_F1 =

''

Instance Method Summary

• #_get_int_for_newkey(x) ⇒ Object

  Generate and return an int for a newkey which user has specified in yml file.

• #getch ⇒ Object

  return an int for the key read.

• #getchar ⇒ Object

  NOTE: This is a reworked and much simpler version of the original getchar which was taken from manveru’s codebase.

• #getchar_as_char ⇒ Object
• #initialize(win) ⇒ DefaultKeyReader constructor

  — {{{.

Constructor Details

#initialize(win) ⇒ DefaultKeyReader

— {{{

# File 'lib/canis/core/system/window.rb', line 784

def initialize win
  @window = win
  #@stack = []
end

Instance Method Details

#_get_int_for_newkey(x) ⇒ Object

Generate and return an int for a newkey which user has specified in yml file. We use hash, which won’t allow me to derive key string in case loop user can do:

when KEY_ENTER
when 32
when $kh_int["S-F2"]

# File 'lib/canis/core/system/window.rb', line 1078

def _get_int_for_newkey x
  # FIXME put the declaration somewhere else maybe in window cons ???
  y = $kh_int[x]
  # when i give user the hash, he can get the string back ???
  $kh_int[y] = x unless $kh_int.key? y
  return y
end

#getch ⇒ Object

return an int for the key read. this is just a single int, and is not interpreted for control or function keys. it also will return -1 when no action. You may re-implenent it or call the original one.

# File 'lib/canis/core/system/window.rb', line 793

def getch
  @window.getch
end

#getchar ⇒ Object

NOTE: This is a reworked and much simpler version of the original getchar which was taken from manveru’s codebase. This also currently returns the keycode as int while placing the char version in a global $key_chr. Until we are ready to return a char, we use this.

FIXME : I have tried very hard to revert to nodelay but it does not seem to have an effect when ESC is pressed. Somewhere, there is a delay when ESC is pressed. I not longer wish to provide the feature of pressing ESC and then a key to be evaluated as Meta-key. This slows down when a user just presses ESC.

Read a char from the window (from user) and returns int code. In some cases, such as codes entered in the $kh hash, we do not yet have a keycode defined so we return 9999 and the user can access $key_chr.

NOTE: Do not convert to string, that is doing two things. Allow user to convert if required using ‘key_tos`

# File 'lib/canis/core/system/window.rb', line 844

def getchar
  $key_chr = nil
    c = nil
    while true
      c = self.getch
      break if c != -1
    end

    cn = c
    $key_int = c
    # handle control codes 0 to 127 but not escape
    if cn >= 0 && cn < 128 && cn != 27
      #$key_chr = key_tos(c)
      return c
    end
    
    # if escape then get into a loop and keep checking till -1 or another escape
    #
    if c == 27
      buff=c.chr
      # if there is another escape coming through then 2 keys were pressed so
      # evaluate upon hitting an escape
      # NOTE : i think only if ESc is followed by [ should be keep collectig
      # otherwise the next char should evaluate. cases like F1 are already being sent in as high integer codes
      while true
        #$log.debug " #{Time.now.to_f} inside LOOP before getch "
        # This getch seems to take enough time not to return a -1 for almost a second
        # even if nodelay is true ??? XXX
        FFI::NCurses.set_escdelay(5)
        k = self.getch
        #$log.debug "elapsed #{elapsed} millis  inside LOOP AFTER getch #{k} (#{elapsed1})"
        $log.debug "inside LOOP AFTER getch #{k} "

        if k == 27
          # seems like two Meta keys pressed in quick succession without chance for -1 to kick in
          # but this still does not catch meta char followed by single char. M-za , it does.
          if $esc_esc
            if buff == 27.chr
              $key_chr = "<ESC-ESC>"
              return 2727
            else
              alert "buff is #{buff}"
            end
          end
          $log.debug "  1251 before evaluate "
          x = _evaluate_buff buff
          # return ESC so it can be interpreted again.
          @window.ungetch k
          $key_chr = x if x
          return $key_int if x
          $log.warn "getchar: window.rb 1200 Found no mapping for #{buff} "
          $key_chr = buff
          return $key_int
          #return buff # otherwise caught in loop ???
        elsif k > -1
          # FIXME next lne crashes if M-C-h pressed which gives 263
          if k > 255
            $log.warn "getchar: window.rb 1247 Found no mapping for #{buff} #{k} "
            $key_int = k + 128
            return $key_int
            # this contains ESc followed by a high number
=begin
            ka = key_tos(k)
            if ka
              $key_chr = "<M-" + ka[1..-1]
              $key_int = k + 128
              return $key_int
            else
              $key_chr = "UNKNOWN: Meta + #{k}"
              return 9999
            end
=end
          end

          buff += k.chr
          # this is an alt/meta code. All other complex codes seem to have a [ after the escape
          # so we will keep accumulating them.
          # NOTE this still means that user can press Alt-[ and some letter in quick succession
          # and it will accumulate rather than be interpreted as M-[.
          #
          if buff.length == 2 and k == 79
            # this is Alt-O and can be a F key in some terms like xterm-color
          elsif buff.length == 2 and k.chr != '['
            x = _evaluate_buff buff
    
            $key_chr = x
            return $key_int if x
          end
          #$log.debug "XXX:  getchar adding #{k}, #{k.chr} to buff #{buff} "
        else
          #$log.debug "  GOT -1 in escape "
          # it is -1 so evaluate
          x = _evaluate_buff buff
          $key_chr = x if x
          return $key_int if x
          $log.warn "getchar: window.rb 1256 Found no mapping for #{buff} "
          $key_chr = buff
          return $key_int
        end
      end
    end
    
    # what if keyname does not return anything
    if c > 127
      #$log.info "xxxgetchar: window.rb sending #{c} "
=begin
      ch =  FFI::NCurses::keyname(c) 
      # remove those ugly brackets around function keys
      if ch && ch[-1]==')'
        ch = ch.gsub(/[()]/,'')
      end
      if ch && ch.index("KEY_")
        ch = ch.gsub(/KEY_/,'')
      end
      ch = "<#{ch}>" if ch
      #return ch if ch
      $key_chr = ch if ch
      $key_chr = "UNKNOWN:#{c}" unless ch
      $log.warn "getchar: window.rb 1234 Found no mapping for #{c} " unless ch
=end
      #$key_chr = key_tos(ch)
      return c
    end
    if c
      #$key_chr =  c.chr 
      return c 
    end
end

#getchar_as_char ⇒ Object

# File 'lib/canis/core/system/window.rb', line 974

def getchar_as_char
  $key_int = getchar
  $key_chr = key_tos( $key_int )
  return $key_chr
end