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#  Copyright (c) 2012, Image Engine Design Inc. All rights reserved.
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from PathFilter import PathFilter

## A PathFilter which filters based on an item from Path.info() and an
# arbitrary match function.
class InfoPathFilter( PathFilter ) :

	def __init__( self, infoKey, matcher, leafOnly=True, userData={} ) :

		PathFilter.__init__( self, userData )
		
		self.__infoKey = infoKey
		self.__matcher = matcher
		self.__leafOnly = leafOnly
	
	## Matcher and infoKey are set with one call, as otherwise
	# the intermediate state may yield a new matcher which doesn't work
	# with the old key.
	def setMatcher( self, infoKey, matcher ) :
		
		self.__infoKey = infoKey
		self.__matcher = matcher
		self.changedSignal()( self )
				
	def getMatcher( self ) :
	
		return self.__infoKey, self.__matcher
	
	def _filter( self, paths ) :
		
		if self.__matcher is None :
			return paths
		
		result = []
		for p in paths :
			if self.__leafOnly and not p.isLeaf() :
				result.append( p )
			else :
				i = p.info()
				if self.__infoKey in i :
					if self.__matcher( i[self.__infoKey] ) :
						result.append( p )
			
		return result
