[Android] Warning if Left/Right attributes are used in layout and style xmls.

build/android/gyp/generate_v14_resources.py

 #!/usr/bin/env python
 #
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Convert Android xml resources to API 14 compatible.
 
 There are two reasons that we cannot just use API attributes,
 so we are generating another set of resources by this script.
 
 1. paddingStart attribute can cause a crash on Galaxy Tab 2.
 2. There is a bug that paddingStart does not override paddingLeft on
    JB-MR1. This is fixed on JB-MR2.
 
 Therefore, this resource generation script can be removed when
 we drop the support for JB-MR1.
 
 Please refer to http://crbug.com/235118 for the details.
 """
 
 import optparse
 import os
 import re
 import sys
 import xml.dom.minidom as minidom
 
 from util import build_utils
 
+# Note that we are assuming 'android:' is an alias of
+# the namespace 'http://schemas.android.com/apk/res/android'.
 
-ATTRIBUTE_NAMESPACE = 'http://schemas.android.com/apk/res/android'
+GRAVITY_ATTRIBUTES = ('android:gravity', 'android:layout_gravity')
 
 # Almost all the attributes that has "Start" or "End" in
 # its name should be mapped.
 ATTRIBUTES_TO_MAP = {'paddingStart' : 'paddingLeft',
                      'drawableStart' : 'drawableLeft',
                      'layout_alignStart' : 'layout_alignLeft',
                      'layout_marginStart' : 'layout_marginLeft',
                      'layout_alignParentStart' : 'layout_alignParentLeft',
                      'layout_toStartOf' : 'layout_toLeftOf',
                      'paddingEnd' : 'paddingRight',
                      'drawableEnd' : 'drawableRight',
                      'layout_alignEnd' : 'layout_alignRight',
                      'layout_marginEnd' : 'layout_marginRight',
                      'layout_alignParentEnd' : 'layout_alignParentRight',
                      'layout_toEndOf' : 'layout_toRightOf'}
 
-ATTRIBUTES_TO_MAP_NS = {}
+ATTRIBUTES_TO_MAP = dict(['android:' + k, 'android:' + v] for k, v
+                         in ATTRIBUTES_TO_MAP.iteritems())
 
-for k, v in ATTRIBUTES_TO_MAP.items():
-  ATTRIBUTES_TO_MAP_NS[(ATTRIBUTE_NAMESPACE, k)] = (ATTRIBUTE_NAMESPACE, v)
-
-ATTRIBUTES_TO_MAP_NS_VALUES = set(ATTRIBUTES_TO_MAP_NS.values())
+ATTRIBUTES_TO_MAP_REVERSED = dict([v,k] for k, v
+                                  in ATTRIBUTES_TO_MAP.iteritems())
 
 
 def IterateXmlElements(node):
   """minidom helper function that iterates all the element nodes.
   Iteration order is pre-order depth-first."""
   if node.nodeType == node.ELEMENT_NODE:
     yield node
   for child_node in node.childNodes:
     for child_node_element in IterateXmlElements(child_node):
       yield child_node_element
 
 
-def GenerateV14StyleResource(dom, output_file):
+def WarnDeprecatedAttribute(name, value, filename):
+  if name in ATTRIBUTES_TO_MAP_REVERSED:
+    print >> sys.stderr, ('warning: ' + filename + ' should use ' +
+                          ATTRIBUTES_TO_MAP_REVERSED[name] +
+                          ' instead of ' + name)
+  elif name in GRAVITY_ATTRIBUTES and ('left' in value or 'right' in value):
+    print >> sys.stderr, ('warning: ' + filename +
+                          ' should use start/end instead of left/right for ' +
+                          name)
+
+
+def GenerateV14StyleResource(input_filename, output_filename):
   """Convert style resource to API 14 compatible style resource.
 
   It's mostly a simple replacement, s/Start/Left s/End/Right,
   on the attribute names specified by <item> element.
+  If input_filename does not contain style resources, do nothing.
   """
-  for style_element in dom.getElementsByTagName('style'):
+  dom = minidom.parse(input_filename)
+  style_elements = dom.getElementsByTagName('style')
+
+  if not style_elements:
+    return
+
+  for style_element in style_elements:
     for item_element in style_element.getElementsByTagName('item'):
-      namespace, name = item_element.attributes['name'].value.split(':')
-      # Note: namespace == 'android' is not precise because
-      # we are looking for 'http://schemas.android.com/apk/res/android' and
-      # 'android' can be aliased to another name in layout xml files where
-      # this style is used. e.g. xmlns:android="http://crbug.com/".
-      if namespace == 'android' and name in ATTRIBUTES_TO_MAP:
-        mapped_name = ATTRIBUTES_TO_MAP[name]
-        item_element.attributes['name'] = namespace + ':' + mapped_name
+      name = item_element.attributes['name'].value
+      value = item_element.childNodes[0].nodeValue
+      if name in ATTRIBUTES_TO_MAP:
+        item_element.attributes['name'].value = ATTRIBUTES_TO_MAP[name]
+      else:
+        WarnDeprecatedAttribute(name, value, input_filename)
 
-  build_utils.MakeDirectory(os.path.dirname(output_file))
-  with open(output_file, 'w') as f:
+  build_utils.MakeDirectory(os.path.dirname(output_filename))
+  with open(output_filename, 'w') as f:
     dom.writexml(f, '', '  ', '\n', encoding='utf-8')
 
 
-def GenerateV14LayoutResource(input_file, output_file):
+def GenerateV14LayoutResource(input_filename, output_filename):
   """Convert layout resource to API 14 compatible layout resource.
 
   It's mostly a simple replacement, s/Start/Left s/End/Right,
   on the attribute names.
   """
-  dom = minidom.parse(input_file)
+  dom = minidom.parse(input_filename)
 
+  # Iterate all the elements' attributes to find attributes to convert.
   for element in IterateXmlElements(dom):
-    all_names = element.attributes.keysNS()
-
-    # Iterate all the attributes to find attributes to convert.
-    # Note that name variable is actually a tuple that has namespace and name.
-    # For example,
-    # name == ('http://schemas.android.com/apk/res/android', 'paddingStart')
-    for name, value in list(element.attributes.itemsNS()):
+    for name, value in list(element.attributes.items()):
+      # Convert any other API 17 Start/End attributes to Left/Right attributes.
+      # For example, from paddingStart="10dp" to paddingLeft="10dp"
       # Note: gravity attributes are not necessary to convert because
       # start/end values are backward-compatible. Explained at
       # https://plus.sandbox.google.com/+RomanNurik/posts/huuJd8iVVXY?e=Showroom
+      if name in ATTRIBUTES_TO_MAP:
+        element.setAttribute(ATTRIBUTES_TO_MAP[name], value)
+        del element.attributes[name]
+      else:
+        WarnDeprecatedAttribute(name, value, input_filename)
 
-      # Convert any other API 17 Start/End attributes to Left/Right attributes.
-      # For example, from paddingStart="10dp" to paddingLeft="10dp"
-      if name in ATTRIBUTES_TO_MAP_NS:
-        mapped_name = ATTRIBUTES_TO_MAP_NS[name]
-
-        # Add the new mapped attribute and remove the original attribute.
-        # For example, add paddingLeft and remove paddingStart.
-        # Note that instead of element.setAttribute(...), this is more correct.
-        # element.setAttributeNS(mapped_name[0], mapped_name[1], value)
-        # However, there is a minidom bug that doesn't print namespace set by
-        # setAttributeNS. Hence this workaround.
-        # This is a similar bug discussion about minidom namespace normalizing.
-        # http://stackoverflow.com/questions/863774/how-to-generate-xml-documents-with-namespaces-in-python
-        element.setAttribute('android:' + mapped_name[1], value)
-        del element.attributes[name]
-      elif name in ATTRIBUTES_TO_MAP_NS_VALUES:
-        # TODO(kkimlabs): Enable  warning once layouts have been converted
-        # print >> sys.stderror, 'Warning: layout should use xxx instead of yyy'
-        pass
-
-  build_utils.MakeDirectory(os.path.dirname(output_file))
-  with open(output_file, 'w') as f:
+  build_utils.MakeDirectory(os.path.dirname(output_filename))
+  with open(output_filename, 'w') as f:
     dom.writexml(f, '', '  ', '\n', encoding='utf-8')
 
 
 def GenerateV14XmlResourcesInDir(input_dir, output_dir, only_styles=False):
   """Convert resources to API 14 compatible XML resources in the directory."""
-  for input_file in build_utils.FindInDirectory(input_dir, '*.xml'):
-    output_file = os.path.join(output_dir,
-                               os.path.relpath(input_file, input_dir))
+  for input_filename in build_utils.FindInDirectory(input_dir, '*.xml'):
+    output_filename = os.path.join(output_dir,
+                               os.path.relpath(input_filename, input_dir))
     if only_styles:
-      dom = minidom.parse(input_file)
-      if not dom.getElementsByTagName('style'):
-        continue
-      GenerateV14StyleResource(dom, output_file)
+      GenerateV14StyleResource(input_filename, output_filename)
     else:
-      GenerateV14LayoutResource(input_file, output_file)
+      GenerateV14LayoutResource(input_filename, output_filename)
 
 
 def ParseArgs():
   """Parses command line options.
 
   Returns:
     An options object as from optparse.OptionsParser.parse_args()
   """
   parser = optparse.OptionParser()
   parser.add_option('--res-dir',
@@ skipping 44 matching lines @@
       GenerateV14XmlResourcesInDir(input_dir, output_dir)
     elif resource_type in ('values'):
       GenerateV14XmlResourcesInDir(input_dir, output_dir, only_styles=True)
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))