65 lines
1.4 KiB
Ruby
65 lines
1.4 KiB
Ruby
# this class is used to track changes to an arbitrary buffer
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class ContentBuffer
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def initialize(initial_content)
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@initial_content = initial_content
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@lines = @initial_content.split("\n")
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end
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def apply_transform!(transform)
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start_row = transform[:start][:row]
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start_col = transform[:start][:col]
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finish_row = transform[:finish][:row] if transform[:finish]
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finish_col = transform[:finish][:col] if transform[:finish]
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text = transform[:text]
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if transform[:operation] == :delete
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# fix first line
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l = @lines[start_row]
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l = l[0...start_col]
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if (finish_row == start_row)
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l << @lines[start_row][finish_col..-1]
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@lines[start_row] = l
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return
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end
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@lines[start_row] = l
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# remove middle lines
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(finish_row - start_row).times do
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l = @lines.delete_at start_row + 1
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end
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# fix last line
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@lines[start_row] << @lines[finish_row][finish_col - 1..-1]
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end
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if transform[:operation] == :insert
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@lines[start_row].insert(start_col, text)
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split = @lines[start_row].split("\n")
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if split.length > 1
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@lines[start_row] = split[0]
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i = 1
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split[1..-2].each do |line|
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@lines.insert(start_row + i, line)
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i += 1
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end
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@lines.insert(i, "") unless @lines.length > i
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@lines[i] = split[-1] + @lines[i]
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end
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end
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end
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def to_s
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@lines.join("\n")
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end
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end
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