import DefaultTable
import struct
from fontTools.misc.textTools import safeEval


GASP_SYMMETRIC_GRIDFIT = 0x0004
GASP_SYMMETRIC_SMOOTHING = 0x0008
GASP_DOGRAY = 0x0002
GASP_GRIDFIT = 0x0001

class table__g_a_s_p(DefaultTable.DefaultTable):
	
	def decompile(self, data, ttFont):
		self.version, numRanges = struct.unpack(">HH", data[:4])
		assert 0 <= self.version <= 1, "unknown 'gasp' format: %s" % self.version
		data = data[4:]
		self.gaspRange = {}
		for i in range(numRanges):
			rangeMaxPPEM, rangeGaspBehavior = struct.unpack(">HH", data[:4])
			self.gaspRange[int(rangeMaxPPEM)] = int(rangeGaspBehavior)
			data = data[4:]
		assert not data, "too much data"
	
	def compile(self, ttFont):
		version = 0 # ignore self.version
		numRanges = len(self.gaspRange)
		data = ""
		items = self.gaspRange.items()
		items.sort()
		for rangeMaxPPEM, rangeGaspBehavior in items:
			data = data + struct.pack(">HH", rangeMaxPPEM, rangeGaspBehavior)
			if rangeGaspBehavior & ~(GASP_GRIDFIT | GASP_DOGRAY):
				version = 1
		data = struct.pack(">HH", version, numRanges) + data
		return data
	
	def toXML(self, writer, ttFont):
		items = self.gaspRange.items()
		items.sort()
		for rangeMaxPPEM, rangeGaspBehavior in items:
			writer.simpletag("gaspRange", [
					("rangeMaxPPEM", rangeMaxPPEM),
					("rangeGaspBehavior", rangeGaspBehavior)])
			writer.newline()
	
	def fromXML(self, (name, attrs, content), ttFont):
		if name <> "gaspRange":
			return
		if not hasattr(self, "gaspRange"):
			self.gaspRange = {}
		self.gaspRange[safeEval(attrs["rangeMaxPPEM"])] = safeEval(attrs["rangeGaspBehavior"])

