Class | ChunkyPNG::Chunk::CompressedText |
In: |
lib/chunky_png/chunk.rb
|
Parent: | Base |
The CompressedText (zTXt) chunk contains keyword/value metadata about the PNG stream. In this chunk, the value is compressed using Deflate compression.
@see ChunkyPNG::Chunk::CompressedText @see ChunkyPNG::Chunk::InternationalText
keyword | [RW] | |
value | [RW] |
# File lib/chunky_png/chunk.rb, line 281 281: def initialize(keyword, value) 282: super('zTXt') 283: @keyword, @value = keyword, value 284: end
# File lib/chunky_png/chunk.rb, line 286 286: def self.read(type, content) 287: keyword, compression, value = content.unpack('Z*Ca*') 288: raise ChunkyPNG::NotSupported, "Compression method #{compression.inspect} not supported!" unless compression == ChunkyPNG::COMPRESSION_DEFAULT 289: new(keyword, Zlib::Inflate.inflate(value)) 290: end
Creates the content to write to the stream, by concatenating the keyword with the deflated value, joined by a null character.
@return The content that should be written to the datastream.
# File lib/chunky_png/chunk.rb, line 296 296: def content 297: [keyword, ChunkyPNG::COMPRESSION_DEFAULT, Zlib::Deflate.deflate(value)].pack('Z*Ca*') 298: end