Class: Android::AXMLParser

Inherits:
Object
  • Object
show all
Defined in:
lib/android/axml_parser.rb

Overview

Note:

refer to Android OS framework code:

/frameworks/base/include/androidfw/ResourceTypes.h,

/frameworks/base/libs/androidfw/ResourceTypes.cpp

binary AXML parser

See Also:

Defined Under Namespace

Classes: ReadError

Constant Summary collapse

TAG_START_DOC = 
0x00100100
TAG_END_DOC = 
0x00100101
TAG_START = 
0x00100102
TAG_END = 
0x00100103
TAG_TEXT = 
0x00100104
TAG_CDSECT = 
0x00100105
TAG_ENTITY_REF = 
0x00100106
VAL_TYPE_NULL = 
0
VAL_TYPE_REFERENCE = 
1
VAL_TYPE_ATTRIBUTE = 
2
VAL_TYPE_STRING = 
3
VAL_TYPE_FLOAT = 
4
VAL_TYPE_DIMENSION = 
5
VAL_TYPE_FRACTION = 
6
VAL_TYPE_INT_DEC = 
16
VAL_TYPE_INT_HEX = 
17
VAL_TYPE_INT_BOOLEAN = 
18
VAL_TYPE_INT_COLOR_ARGB8 = 
28
VAL_TYPE_INT_COLOR_RGB8 = 
29
VAL_TYPE_INT_COLOR_ARGB4 = 
30
VAL_TYPE_INT_COLOR_RGB4 = 
31

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(axml) ⇒ AXMLParser

Returns a new instance of AXMLParser.

Parameters:

  • axml (String) —

    binary xml data



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# File 'lib/android/axml_parser.rb', line 49

def initialize(axml)
  @io = StringIO.new(axml, "rb")
  @strings = []
end

Instance Attribute Details

#strings ⇒ Array<String> (readonly)

Returns strings defined in axml.

Returns:

  • (Array<String>) —

    strings defined in axml



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# File 'lib/android/axml_parser.rb', line 46

def strings
  @strings
end

Class Method Details

.axml?(data) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/android/axml_parser.rb', line 15

def self.axml?(data)
  (data[0..3] == "\x03\x00\x08\x00")
end

Instance Method Details

#convert_value(val_str_id, flags, val) ⇒ Object 



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# File 'lib/android/axml_parser.rb', line 150

def convert_value(val_str_id, flags, val)
  unless val_str_id == 0xFFFFFFFF
    value = @strings[val_str_id]
  else
    type = flags >> 24
    case type
    when VAL_TYPE_NULL
      value = nil
    when VAL_TYPE_REFERENCE
      value = "@%#x" % val # refered resource id.
    when VAL_TYPE_INT_DEC
      value = val
    when VAL_TYPE_INT_HEX
      value = "%#x" % val
    when VAL_TYPE_INT_BOOLEAN
      value = ((val == 0xFFFFFFFF) || (val==1)) ? true : false
    else
      value = "[%#x, flag=%#x]" % [val, flags]
    end
  end
end

#parse ⇒ REXML::Document

parse binary xml

Returns:

  • (REXML::Document) 


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# File 'lib/android/axml_parser.rb', line 56

def parse
  @doc = REXML::Document.new
  @doc << REXML::XMLDecl.new

  @num_str = word(4*4)
  @xml_offset = word(3*4)

  @parents = [@doc]
  @ns = []
  parse_strings
  parse_tags
  @doc
end

#parse_attribute ⇒ Object

parse attribute of a element



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# File 'lib/android/axml_parser.rb', line 133

def parse_attribute
  ns_id, name_id, val_str_id, flags, val = @io.read(4*5).unpack("V*")
  key = @strings[name_id]
  unless ns_id == 0xFFFFFFFF
    ns = @strings[ns_id] 
    prefix = ns.sub(/.*\//,'')
    unless @ns.include? ns
      @ns << ns
      @doc.root.add_namespace(prefix, ns)
    end
    key = "#{prefix}:#{key}"
  end
  value = convert_value(val_str_id, flags, val)
  return key, value
end

#parse_strings ⇒ Object

relace string table parser



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# File 'lib/android/axml_parser.rb', line 88

def parse_strings
  strpool = Resource::ResStringPool.new(@io.string, 8) # ugh!
  @strings = strpool.strings
end

#parse_tags ⇒ Object

parse tag



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# File 'lib/android/axml_parser.rb', line 94

def parse_tags
  # skip until START_TAG
  pos = @xml_offset
  pos += 4 until (word(pos) == TAG_START) #ugh!
  @io.pos -= 4

  # read tags
  #puts "start tag parse: %d(%#x)" % [@io.pos, @io.pos]
  until @io.eof?
    last_pos = @io.pos
    tag, tag1, line, tag3, ns_id, name_id = @io.read(4*6).unpack("V*")
    case tag
    when TAG_START
      tag6, num_attrs, tag8  = @io.read(4*3).unpack("V*")
      elem = REXML::Element.new(@strings[name_id])
      #puts "start tag %d(%#x): #{@strings[name_id]} attrs:#{num_attrs}" % [last_pos, last_pos]
      @parents.last.add_element elem
      num_attrs.times do
        key, val = parse_attribute
        elem.add_attribute(key, val)
      end
      @parents.push elem
    when TAG_END
      @parents.pop
    when TAG_END_DOC
      break
    when TAG_TEXT
      text = REXML::Text.new(@strings[ns_id])
      @parents.last.text = text
      dummy = @io.read(4*1).unpack("V*") # skip 4bytes
    when TAG_START_DOC, TAG_CDSECT, TAG_ENTITY_REF
      # not implemented yet.
    else
      raise ReadError, "pos=%d(%#x)[tag:%#x]" % [last_pos, last_pos, tag]
    end
  end
end

#short(offset) ⇒ Integer

read 2byte as short integer

Parameters:

  • offset (Integer) —

    offset from top position. current position is used if ofset is nil

Returns:

  • (Integer) —

    little endian unsign short value



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# File 'lib/android/axml_parser.rb', line 82

def short(offset)
  @io.pos = offset unless offset.nil?
  @io.read(2).unpack("v")[0]
end

#word(offset = nil) ⇒ Integer

read one word(4byte) as integer

Parameters:

  • offset (Integer) (defaults to: nil) —

    offset from top position. current position is used if ofset is nil

Returns:

  • (Integer) —

    little endian word value



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# File 'lib/android/axml_parser.rb', line 74

def word(offset=nil)
  @io.pos = offset unless offset.nil?
  @io.read(4).unpack("V")[0]
end