# File lib/RMagick.rb, line 844
844:             def initialize(view, width, height, rows)
845:                 @view = view
846:                 @width = width
847:                 @height = height
848:                 @rows = rows
849:             end

     # File lib/RMagick.rb, line 851
851:             def [](*args)
852:                 cols(args)
853: 
854:                 # Both View::Pixels and Magick::Pixel implement Observable
855:                 if @unique
856:                     pixels = @view[@rows[0]*@width + @cols[0]]
857:                     pixels.add_observer(self)
858:                 else
859:                     pixels = View::Pixels.new
860:                     each do |x|
861:                         p = @view[x]
862:                         p.add_observer(self)
863:                         pixels << p
864:                     end
865:                 end
866:                 pixels
867:             end

     # File lib/RMagick.rb, line 869
869:             def []=(*args)
870:                 rv = args.delete_at(-1)     # get rvalue
871:                 if ! rv.is_a?(Pixel)        # must be a Pixel or a color name
872:                     begin
873:                         rv = Pixel.from_color(rv)
874:                     rescue TypeError
875:                         raise TypeError, "cannot convert #{rv.class} into Pixel"
876:                     end
877:                 end
878:                 cols(args)
879:                 each { |x| @view[x] = rv.dup }
880:                 changed
881:                 notify_observers(self)
882:                 nil
883:             end

     # File lib/RMagick.rb, line 886
886:             def update(pixel)
887:                 changed
888:                 notify_observers(self)
889:                 pixel.delete_observer(self) # Don't need to hear again.
890:                 nil
891:             end

     # File lib/RMagick.rb, line 895
895:             def cols(*args)
896:                 @cols = args[0]     # remove the outermost array
897:                 @unique = false
898: 
899:                 # Convert @rows to an Enumerable object
900:                 case @rows.length
901:                     when 0                      # Create a Range for all the rows
902:                         @rows = Range.new(0, @height, true)
903:                     when 1                      # Range, Array, or a single integer
904:                         # if the single element is already an Enumerable
905:                         # object, get it.
906:                         if @rows.first.respond_to? :each
907:                             @rows = @rows.first
908:                         else
909:                             @rows = Integer(@rows.first)
910:                             if @rows < 0
911:                                 @rows += @height
912:                             end
913:                             if @rows < 0 || @rows > @height-1
914:                                 raise IndexError, "index [#{@rows}] out of range"
915:                             end
916:                             # Convert back to an array
917:                             @rows = Array.new(1, @rows)
918:                             @unique = true
919:                         end
920:                     when 2
921:                         # A pair of integers representing the starting column and the number of columns
922:                         start = Integer(@rows[0])
923:                         length = Integer(@rows[1])
924: 
925:                         # Negative start -> start from last row
926:                         if start < 0
927:                             start += @height
928:                         end
929: 
930:                         if start > @height || start < 0 || length < 0
931:                                 raise IndexError, "index [#{@rows.first}] out of range"
932:                         else
933:                             if start + length > @height
934:                                 length = @height - length
935:                                 length = [length, 0].max
936:                             end
937:                         end
938:                         # Create a Range for the specified set of rows
939:                         @rows = Range.new(start, start+length, true)
940:                 end
941: 
942:                 case @cols.length
943:                     when 0                  # all rows
944:                         @cols = Range.new(0, @width, true)  # convert to range
945:                         @unique = false
946:                     when 1                  # Range, Array, or a single integer
947:                         # if the single element is already an Enumerable
948:                         # object, get it.
949:                         if @cols.first.respond_to? :each
950:                             @cols = @cols.first
951:                             @unique = false
952:                         else
953:                             @cols = Integer(@cols.first)
954:                             if @cols < 0
955:                                 @cols += @width
956:                             end
957:                             if @cols < 0 || @cols > @width-1
958:                                 raise IndexError, "index [#{@cols}] out of range"
959:                             end
960:                             # Convert back to array
961:                             @cols = Array.new(1, @cols)
962:                             @unique &&= true
963:                         end
964:                     when 2
965:                         # A pair of integers representing the starting column and the number of columns
966:                         start = Integer(@cols[0])
967:                         length = Integer(@cols[1])
968: 
969:                         # Negative start -> start from last row
970:                         if start < 0
971:                             start += @width
972:                         end
973: 
974:                         if start > @width || start < 0 || length < 0
975:                             ; #nop
976:                         else
977:                             if start + length > @width
978:                                 length = @width - length
979:                                 length = [length, 0].max
980:                             end
981:                         end
982:                         # Create a Range for the specified set of columns
983:                         @cols = Range.new(start, start+length, true)
984:                         @unique = false
985:                 end
986: 
987:             end

      # File lib/RMagick.rb, line 990
 990:             def each
 991:                 maxrows = @height - 1
 992:                 maxcols = @width - 1
 993: 
 994:                 @rows.each do |j|
 995:                     if j > maxrows
 996:                         raise IndexError, "index [#{j}] out of range"
 997:                     end
 998:                     @cols.each do |i|
 999:                         if i > maxcols
1000:                             raise IndexError, "index [#{i}] out of range"
1001:                         end
1002:                         yield j*@width + i
1003:                     end
1004:                 end
1005:                 nil    # useless return value
1006:             end