svn/view/window.rb

# window.rb: the module definition of Edmaru::Window.
#
# 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 "cursor.rb"
require "modeline.rb"

module Edmaru

  #Abstract class to implement system specific window.
  module Window

    #Construct a window instance.
    #
    #=== Arguments
    #_view_ :: The parent view.
    #_config_ :: An instance of Edmaru::ConfigurationManager.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    #
    #=== Return
    #An initialized instance of Window.
    def initialize(view, config)
      @buffer = nil
      @view = view
      @config = config
      @cursor = Cursor.new(0, 0) # logical cursor
      @modeline = Edmaru::SYSTEM_MODELINE.new(self, config)
      @start_line = 0
      @focused = false

      init_ui
    end

    #The system specific initialization for this window.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived classes.
    def init_ui
    end

    #Discard the current buffer and set the specified new buffer.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    #
    #=== Argument
    #_new_buffer_ :: The buffer to be shown in this window.
    def buffer=(new_buffer)
      if @buffer != nil
        @buffer.unlink(self)
      end

      #Linked buffer to this window.
      @buffer = new_buffer
      @buffer.link(self)
      @cursor.row = @cursor.column = 0
      refresh

      # @modelin is nil, if this window is the mini window.
      if @modeline != nil
        @modeline.set_element_text("buffer-name", @buffer.name)
      end
    end

    def buffer
      @buffer
    end

    def modeline
      @modeline
    end

    #Remove all characters from this buffer.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    #
    def clear
      @cursor.row = @cursor.column = 0
      @buffer.clear
    end

    #Insert the specified string to the buffer shown in this window.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    #
    #=== Argument
    #_str_ :: String to be inserted.
    #_move_cursor_ :: _true_ to cause the cursor move to the end of the
    #inserted string.
    def insert_at_cursor(str, move_cursor = true)
      @view.hide_alert

      #Insert to the buffer.
      begin
        @buffer.insert(@cursor.row, @cursor.column, str)

        #Move the cursor to the end of inserted string.
        cursor_forward(str.size) if move_cursor
      rescue ReadOnlyException => e
        @view.show_alert(e.to_s)
      end
    end

    #Move the cursor forward.
    #
    #=== Argument
    #_n_ :: the number of times to forward the cursor.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def cursor_forward(n = 1)
      @view.hide_alert

      n.times{
        if @cursor.column >= @buffer.lines[@cursor.row].size &&
            @cursor.row == (@buffer.lines.size - 1)
          refresh_cursor
          @view.show_alert("End of buffer")
          return
        elsif @cursor.column >= @buffer.lines[@cursor.row].size
          #Go to the begin of the next line
          @cursor.row += 1
          @cursor.column = 0
        else
          @cursor.column += 1
        end
      }

      refresh_cursor
    end

    #Move the cursor backward.
    #
    #=== Argument
    #_n_ :: the number of times to backward the cursor.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def cursor_backward(n = 1)
      @view.hide_alert

      n.times{
        if @cursor.column == 0 && @cursor.row == 0
          refresh_cursor
          @view.show_alert("Beginning of buffer")
          return
        elsif @cursor.column == 0
          @cursor.row -= 1
          @cursor.column = @buffer.lines[@cursor.row].size
        else
          @cursor.column -= 1
        end
      }

      refresh_cursor
    end

    #Move the cursor to the begin of the current line.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def cursor_goto_line_head
      @view.hide_alert

      @cursor.column = 0
      refresh_cursor
    end

    #Move the cursor to the end of the current line.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def cursor_goto_line_tail
      @view.hide_alert

      @cursor.column = @buffer.lines[@cursor.row].size
      refresh_cursor
    end

    #Move the cursor to the beginning of the buffer.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived classes.
    def cursor_goto_beginning
      @view.hide_alert

      @cursor.row = @cursor.column = 0
      refresh_cursor
    end

    #Move the cursor to the end of the buffer.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived classes.
    def cursor_goto_end
      @view.hide_alert

      @cursor.row = @buffer.lines.size - 1
      @cursor.column = @buffer.lines[@cursor.row].size
      refresh_cursor
    end

    #Move the cursor to the next line.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def cursor_goto_next_line
      @view.hide_alert

      if @cursor.row == (@buffer.lines.size - 1)
        @view.show_alert("The last line")        
      else
        @cursor.row += 1
        if @buffer.lines[@cursor.row].size < @cursor.column
          @cursor.column = @buffer.lines[@cursor.row].size
        end

        refresh_cursor
      end
    end

    #Move the cursor to the previous line.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def cursor_goto_previous_line
      @view.hide_alert

      if @cursor.row == 0
        @view.show_alert("The first line")
      else
        @cursor.row -= 1
        if @buffer.lines[@cursor.row].size < @cursor.column
          @cursor.column = @buffer.lines[@cursor.row].size
        end

        refresh_cursor
      end
    end

    #Remove a character just in front of the cursor and move the cursor
    #backward.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def backspace
      @view.hide_alert

      pre_cursor = @cursor.clone

      begin
        if @cursor.column == 0 && @cursor.row == 0
          #ToDo: Alert that the cursor is at the begin of the current buffer.
          @view.show_alert("Beginning of buffer")
        elsif @cursor.column == 0 # && @cursor.row != 0
          #Concatenate the current lien into the previous line.
          @buffer.delete_at(@cursor.row -= 1,
                            @cursor.column = @buffer.lines[@cursor.row].size)
          refresh_cursor
        else
          @buffer.delete_at(@cursor.row, @cursor.column -= 1)
          refresh_cursor
        end
      rescue ReadOnlyException => e
        @cursor = pre_cursor
        @view.show_alert(e.to_s)
      end
    end

    #Remove a character beneath the cursor.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def delete_at_cursor
      @view.hide_alert

      begin
        @buffer.delete_at(@cursor.row, @cursor.column)
      rescue EndOfBufferException => e
        @view.show_alert(e.to_s)
      rescue ReadOnlyException => e
        @view.show_alert(e.to_s)
      end
    end

    #Remove the string in the current line behind the cursor and push it to
    #the kill ring.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def kill_line
      @view.hide_alert

      begin
        @view.push_to_kill_ring(@buffer.delete_line(@cursor.row, @cursor.column))
      rescue EdmaruException => e
        @view.show_alert(e.to_s)
      end
    end

    #Get a certain string from kill ring and insert it at the cursor position.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def yank
      @view.hide_alert
      insert_at_cursor(@view.yank_from_kill_ring)
    end

    #Scroll down this window.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived clases.
    def scroll_down
    end

    #Scroll up this window.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived clases.
    def scroll_up
    end

    #Redraw the cursor.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived clases.
    def refresh_cursor
    end

    #Redraw this window.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived clases.
    def refresh
    end

    #Focus on this window.
    #
    #=== Warning
    #This method *SHOULD* *NOT* be overrided in derived classes.
    def focus_in
      @focused = true

      refresh_cursor
    end

    #Focus out from this window.
    #
    #=== Warning
    #This method *SHOULD* *NOT* be overrided in derived classes.
    def focus_out
      @focused = false

      refresh_cursor
    end

    #Terminate this view instance.
    #
    #=== Warning
    #This method *MUST* *NOT* be overrided in derived classes.
    def terminate
      @modeline.terminate

      terminate_ui
    end

    #Free system specific resources.
    #
    #=== Warning
    #This method *SHOULD* be overrided in derived classes.
    def terminate_ui
    end
  end
end