Method: TkVariable#trace_remove_for_element

Defined in:

lib/tk/variable.rb

#trace_remove_for_element(elem, opts, cmd) ⇒ Object Also known as: trace_delete_for_element, trace_vdelete_for_element

# File 'lib/tk/variable.rb', line 1560

def trace_remove_for_element(elem,opts,cmd)
  if @elem
    fail(RuntimeError,
         "invalid for a TkVariable which denotes an element of Tcl's array")
  end
  return self unless @trace_elem.kind_of? Hash
  return self unless @trace_elem[elem].kind_of? Array

  opts = _check_trace_opt(opts)

  idx = -1
  if USE_OLD_TRACE_OPTION_STYLE
    @trace_elem[elem].each_with_index{|e, i|
      if idx < 0 && e[1] == cmd
        diff = false
        ['a', 'r', 'w', 'u'].each{|c|
          break if (diff = e[0].index(c) ^ opts.index(c))
        }
        unless diff
          #find
          idx = i
          next
        end
      end
    }
  else
    @trace_elem[elem].each_with_index{|e, i|
      if idx < 0 && e[1] == cmd &&
          e[0].size == opts.size && (e[0] - opts).empty?
        # find
        idx = i
        next
      end
    }
  end

  if idx >= 0
    @trace_elem[elem].delete_at(idx)
  else
    return self
  end

  if USE_OLD_TRACE_OPTION_STYLE
    newopts = ''
    @trace_var.each{|e|
      e[0].each_byte{|c| newopts.concat(c.chr) unless newopts.index(c.chr)}
    }
    @trace_elem.each{|elem|
      @trace_elem[elem].each{|e|
        e[0].each_byte{|c| newopts.concat(c.chr) unless newopts.index(c.chr)}
      }
    }
  else
    newopts = []
    @trace_var.each{|e|
      newopts |= e[0]
    }
    @trace_elem.each{|elem|
      @trace_elem[elem].each{|e|
        e[0].each_byte{|c| newopts.concat(c.chr) unless newopts.index(c.chr)}
      }
    }
  end

  if USE_OLD_TRACE_OPTION_STYLE
    diff = false
    @trace_opts.each_byte{|c| break if (diff = ! newopts.index(c))}
    if diff
      Tk.tk_call_without_enc('trace', 'vdelete',
                             @id, @trace_opts, 'rb_var ' << @id)
      @trace_opts.replace(newopts)
      unless @trace_opts.empty?
        Tk.tk_call_without_enc('trace', 'variable',
                               @id, @trace_opts, 'rb_var ' << @id)
      end
    end
  else
    unless (@trace_opts - newopts).empty?
      Tk.tk_call_without_enc('trace', 'remove', 'variable',
                             @id, @trace_opts, 'rb_var ' << @id)
      @trace_opts.replace(newopts)
      unless @trace_opts.empty?
        Tk.tk_call_without_enc('trace', 'add', 'variable',
                               @id, @trace_opts, 'rb_var ' << @id)
      end
    end
  end

  self
end