svn/view/mini_buffer.rb

# buffer.rb: the class definition of Edmaru::Buffer
#
# Copyright (C) 2007 Takashi Nakamoto
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301 USA.
#

require "exception.rb"

module Edmaru

  class ReadOnlyException < EdmaruException
    def initialize
      super("Text is read-only.")
    end
  end

  #The instance of this class represents one string sequence that doesn't
  #contain line feeds.
  class MiniBuffer < Buffer

    #Create a new buffer.
    #
    #=== Argument
    #_name_ :: The unique title of this buffer.
    #
    #=== Return
    #An initialized buffer.
    def initialize(name)
      @name = name
      @line = String.new

      @related_window = Array.new
    end


    #All lines in this buffer.
    #
    #=== Return
    #An array of string including only one element (line).
    def lines
      [@line]
    end
    
    #Check if the specified position is valid for this buffer.
    #
    #=== Arguments
    #
    #_row_ :: Row position or line number.
    #_col_ :: Column position.
    #
    #=== Return
    #_true_ if the specified position is valid for this buffer.
    #
    #=== Note
    #
    #The position is between two adjacent characters including line
    #feed character. Thus, this method returns true if _col_ is equal
    #to the size of the specified line, but false if _row_ is equal to
    #the size of Edmaru::Buffer#lines.
    def valid_position?(row, col)
      if row != 0
        # Invalid row position.
        return false
      elsif col < 0 || col > @line.size
        # Invalid column position.
        return false
      else
        return true
      end
    end

    #Insert the specified string to the specified position
    #
    #=== Arguments
    #_row_ :: Row position or line number.
    #_col_ :: Column position.
    #_str_ :: A string to be inserted.
    def insert(row, col, str)
      if !valid_position?(row, col)
        raise "Invalid position was specified for 'insert' method."
      end

      return if str.empty? # Nothing to be inserted.

      if str.include?("\n")
        new_lines = str.split(/\n/, -1)
        new_lines[0] =
          @lines[row][0, col] + new_lines[0]
        new_lines[new_lines.size - 1] <<
          @lines[row][col .. -1]
        @lines[row] = new_lines
        @lines.flatten!
      else
        current_line = @lines[row]
        @lines[row] = ""
        if col > 0
          @lines[row] = current_line[0, col]
        end
        @lines[row] << str
        @lines[row] << current_line[col .. -1]
      end

      refresh_windows
    end


  end
end