Class: Samovar::Output::LineWrapping

Inherits:
Object
  • Object
show all
Defined in:
lib/samovar/output/line_wrapper.rb

Overview

This is an incomplete implementation of an automatic line wrapping output buffer which handles any kind of output, provided it has special wrapping markers.

Constant Summary collapse

MARKER = 
"\e[0;0m".freeze
ESCAPE_SEQUENCE = 
/(.*?)(\e\[.*?m|$)/

Instance Method Summary collapse

Constructor Details

#initialize(output, wrapping_width = 80, minimum_width = 20) ⇒ LineWrapping

Returns a new instance of LineWrapping.



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# File 'lib/samovar/output/line_wrapper.rb', line 27

def initialize(output, wrapping_width = 80, minimum_width = 20)
	@output = output
	@wrapping_width = wrapping_width
	@minimum_width = minimum_width
end

Instance Method Details

#printable_width(text) ⇒ Object 



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# File 'lib/samovar/output/line_wrapper.rb', line 35

def printable_width(text)
	text.size
end

#puts(*lines) ⇒ Object 



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# File 'lib/samovar/output/line_wrapper.rb', line 80

def puts(*lines)
	lines = lines.flat_map{|line| wrap(line)}
	
	@output.puts(*lines)
end

#wrap(line) ⇒ Object 



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# File 'lib/samovar/output/line_wrapper.rb', line 39

def wrap(line)
	wrapping_offset = nil
	offset = 0
	buffer = String.new
	lines = []
	prefix = nil
	
	line.scan(ESCAPE_SEQUENCE) do |text, escape_sequence|
		width = printable_width(text)
		next_offset = offset + printable_width
		
		if next_offset > @wrapping_width
			if wrapping_offset
				text_wrap_offset = @wrapping_width - offset
				
				# This text flows past the end of the line and we have a valid wrapping offset. We need to wrap this text.
				if best_split_index = text.rindex(/\s/, text_wrap_offset) and best_split_index >= @minimum_width
					# We have enough space to wrap.
					buffer << text[0...best_split_index]
					lines << buffer
					buffer = String.new()
				else
					# In this case we can't really wrap on the current line. We fall back to letting the terminal wrap.
					return line
				end
			else
				# We don't have a specific wrapping offset, and the text flows longer than the wrapping width. We can't do anything - let the terminal wrap.
				return line
			end
		else
			buffer << text << escape_sequence
		end
		
		offset = next_offset
		
		if wrapping_offset.nil? and offset < @wrapping_width and escape_sequence == MARKER
			wrapping_offset = offset
		end
	end
end