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



49
50
51
52
 
# 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



46
47
48
 
# File 'lib/android/axml_parser.rb', line 46

def strings
  @strings
end

Class Method Details

.axml?(data) ⇒ Boolean

Returns:

  • (Boolean) 


15
16
17
 
# 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 



151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
 
# File 'lib/android/axml_parser.rb', line 151

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) 


56
57
58
59
60
61
62
63
64
65
66
67
68
 
# 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



134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
 
# File 'lib/android/axml_parser.rb', line 134

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



88
89
90
91
 
# 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



94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
 
# 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
      #fix multi 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



82
83
84
85
 
# 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



74
75
76
77
 
# 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