libs/androidfw/AttributeResolution.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "androidfw/AttributeResolution.h"

 #include <cstdint>

 #include <log/log.h>

 #include "androidfw/AttributeFinder.h"
 #include "androidfw/ResourceTypes.h"

 constexpr bool kDebugStyles = false;

 namespace android {

 class XmlAttributeFinder
     : public BackTrackingAttributeFinder<XmlAttributeFinder, size_t> {
  public:
   explicit XmlAttributeFinder(const ResXMLParser* parser)
       : BackTrackingAttributeFinder(
             0, parser != nullptr ? parser->getAttributeCount() : 0),
         parser_(parser) {}

   inline uint32_t GetAttribute(size_t index) const {
     return parser_->getAttributeNameResID(index);
   }

  private:
   const ResXMLParser* parser_;
 };

 class BagAttributeFinder
     : public BackTrackingAttributeFinder<BagAttributeFinder, const ResTable::bag_entry*> {
  public:
   BagAttributeFinder(const ResTable::bag_entry* start,
                      const ResTable::bag_entry* end)
       : BackTrackingAttributeFinder(start, end) {}

   inline uint32_t GetAttribute(const ResTable::bag_entry* entry) const {
     return entry->map.name.ident;
   }
 };

 bool ResolveAttrs(ResTable::Theme* theme, uint32_t def_style_attr,
                   uint32_t def_style_res, uint32_t* src_values,
                   size_t src_values_length, uint32_t* attrs,
                   size_t attrs_length, uint32_t* out_values,
                   uint32_t* out_indices) {
   if (kDebugStyles) {
     ALOGI("APPLY STYLE: theme=0x%p defStyleAttr=0x%x defStyleRes=0x%x", theme,
           def_style_attr, def_style_res);
   }

   const ResTable& res = theme->getResTable();
   ResTable_config config;
   Res_value value;

   int indices_idx = 0;

   // Load default style from attribute, if specified...
   uint32_t def_style_bag_type_set_flags = 0;
   if (def_style_attr != 0) {
     Res_value value;
     if (theme->getAttribute(def_style_attr, &value, &def_style_bag_type_set_flags) >= 0) {
       if (value.dataType == Res_value::TYPE_REFERENCE) {
         def_style_res = value.data;
       }
     }
   }

   // Now lock down the resource object and start pulling stuff from it.
   res.lock();

   // Retrieve the default style bag, if requested.
   const ResTable::bag_entry* def_style_start = nullptr;
   uint32_t def_style_type_set_flags = 0;
   ssize_t bag_off = def_style_res != 0
                         ? res.getBagLocked(def_style_res, &def_style_start,
                                            &def_style_type_set_flags)
                         : -1;
   def_style_type_set_flags |= def_style_bag_type_set_flags;
   const ResTable::bag_entry* const def_style_end =
       def_style_start + (bag_off >= 0 ? bag_off : 0);
   BagAttributeFinder def_style_attr_finder(def_style_start, def_style_end);

   // Now iterate through all of the attributes that the client has requested,
   // filling in each with whatever data we can find.
   for (size_t ii = 0; ii < attrs_length; ii++) {
     const uint32_t cur_ident = attrs[ii];

     if (kDebugStyles) {
       ALOGI("RETRIEVING ATTR 0x%08x...", cur_ident);
     }

     ssize_t block = -1;
     uint32_t type_set_flags = 0;

     value.dataType = Res_value::TYPE_NULL;
     value.data = Res_value::DATA_NULL_UNDEFINED;
     config.density = 0;

     // Try to find a value for this attribute...  we prioritize values
     // coming from, first XML attributes, then XML style, then default
     // style, and finally the theme.

     // Retrieve the current input value if available.
     if (src_values_length > 0 && src_values[ii] != 0) {
       value.dataType = Res_value::TYPE_ATTRIBUTE;
       value.data = src_values[ii];
       if (kDebugStyles) {
         ALOGI("-> From values: type=0x%x, data=0x%08x", value.dataType,
               value.data);
       }
     } else {
       const ResTable::bag_entry* const def_style_entry = def_style_attr_finder.Find(cur_ident);
       if (def_style_entry != def_style_end) {
         block = def_style_entry->stringBlock;
         type_set_flags = def_style_type_set_flags;
         value = def_style_entry->map.value;
         if (kDebugStyles) {
           ALOGI("-> From def style: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
       }
     }

     uint32_t resid = 0;
     if (value.dataType != Res_value::TYPE_NULL) {
       // Take care of resolving the found resource to its final value.
       ssize_t new_block =
           theme->resolveAttributeReference(&value, block, &resid, &type_set_flags, &config);
       if (new_block >= 0) block = new_block;
       if (kDebugStyles) {
         ALOGI("-> Resolved attr: type=0x%x, data=0x%08x", value.dataType, value.data);
       }
     } else if (value.data != Res_value::DATA_NULL_EMPTY) {
       // If we still don't have a value for this attribute, try to find
       // it in the theme!
       ssize_t new_block = theme->getAttribute(cur_ident, &value, &type_set_flags);
       if (new_block >= 0) {
         if (kDebugStyles) {
           ALOGI("-> From theme: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
         new_block = res.resolveReference(&value, new_block, &resid, &type_set_flags, &config);
         if (new_block >= 0) block = new_block;
         if (kDebugStyles) {
           ALOGI("-> Resolved theme: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
       }
     }

     // Deal with the special @null value -- it turns back to TYPE_NULL.
     if (value.dataType == Res_value::TYPE_REFERENCE && value.data == 0) {
       if (kDebugStyles) {
         ALOGI("-> Setting to @null!");
       }
       value.dataType = Res_value::TYPE_NULL;
       value.data = Res_value::DATA_NULL_UNDEFINED;
       block = -1;
     }

     if (kDebugStyles) {
       ALOGI("Attribute 0x%08x: type=0x%x, data=0x%08x", cur_ident, value.dataType, value.data);
     }

     // Write the final value back to Java.
     out_values[STYLE_TYPE] = value.dataType;
     out_values[STYLE_DATA] = value.data;
     out_values[STYLE_ASSET_COOKIE] =
         block != -1 ? static_cast<uint32_t>(res.getTableCookie(block))
                     : static_cast<uint32_t>(-1);
     out_values[STYLE_RESOURCE_ID] = resid;
     out_values[STYLE_CHANGING_CONFIGURATIONS] = type_set_flags;
     out_values[STYLE_DENSITY] = config.density;

     if (out_indices != nullptr &&
         (value.dataType != Res_value::TYPE_NULL || value.data == Res_value::DATA_NULL_EMPTY)) {
       indices_idx++;
       out_indices[indices_idx] = ii;
     }

     out_values += STYLE_NUM_ENTRIES;
   }

   res.unlock();

   if (out_indices != nullptr) {
     out_indices[0] = indices_idx;
   }
   return true;
 }

 void ApplyStyle(ResTable::Theme* theme, ResXMLParser* xml_parser, uint32_t def_style_attr,
                 uint32_t def_style_res, const uint32_t* attrs, size_t attrs_length,
                 uint32_t* out_values, uint32_t* out_indices) {
   if (kDebugStyles) {
     ALOGI("APPLY STYLE: theme=0x%p defStyleAttr=0x%x defStyleRes=0x%x xml=0x%p",
           theme, def_style_attr, def_style_res, xml_parser);
   }

   const ResTable& res = theme->getResTable();
   ResTable_config config;
   Res_value value;

   int indices_idx = 0;

   // Load default style from attribute, if specified...
   uint32_t def_style_bag_type_set_flags = 0;
   if (def_style_attr != 0) {
     Res_value value;
     if (theme->getAttribute(def_style_attr, &value,
                             &def_style_bag_type_set_flags) >= 0) {
       if (value.dataType == Res_value::TYPE_REFERENCE) {
         def_style_res = value.data;
       }
     }
   }

   // Retrieve the style class associated with the current XML tag.
   int style = 0;
   uint32_t style_bag_type_set_flags = 0;
   if (xml_parser != nullptr) {
     ssize_t idx = xml_parser->indexOfStyle();
     if (idx >= 0 && xml_parser->getAttributeValue(idx, &value) >= 0) {
       if (value.dataType == value.TYPE_ATTRIBUTE) {
         if (theme->getAttribute(value.data, &value, &style_bag_type_set_flags) < 0) {
           value.dataType = Res_value::TYPE_NULL;
         }
       }
       if (value.dataType == value.TYPE_REFERENCE) {
         style = value.data;
       }
     }
   }

   // Now lock down the resource object and start pulling stuff from it.
   res.lock();

   // Retrieve the default style bag, if requested.
   const ResTable::bag_entry* def_style_attr_start = nullptr;
   uint32_t def_style_type_set_flags = 0;
   ssize_t bag_off = def_style_res != 0
                         ? res.getBagLocked(def_style_res, &def_style_attr_start,
                                            &def_style_type_set_flags)
                         : -1;
   def_style_type_set_flags |= def_style_bag_type_set_flags;
   const ResTable::bag_entry* const def_style_attr_end =
       def_style_attr_start + (bag_off >= 0 ? bag_off : 0);
   BagAttributeFinder def_style_attr_finder(def_style_attr_start,
                                            def_style_attr_end);

   // Retrieve the style class bag, if requested.
   const ResTable::bag_entry* style_attr_start = nullptr;
   uint32_t style_type_set_flags = 0;
   bag_off =
       style != 0
           ? res.getBagLocked(style, &style_attr_start, &style_type_set_flags)
           : -1;
   style_type_set_flags |= style_bag_type_set_flags;
   const ResTable::bag_entry* const style_attr_end =
       style_attr_start + (bag_off >= 0 ? bag_off : 0);
   BagAttributeFinder style_attr_finder(style_attr_start, style_attr_end);

   // Retrieve the XML attributes, if requested.
   static const ssize_t kXmlBlock = 0x10000000;
   XmlAttributeFinder xml_attr_finder(xml_parser);
   const size_t xml_attr_end =
       xml_parser != nullptr ? xml_parser->getAttributeCount() : 0;

   // Now iterate through all of the attributes that the client has requested,
   // filling in each with whatever data we can find.
   for (size_t ii = 0; ii < attrs_length; ii++) {
     const uint32_t cur_ident = attrs[ii];

     if (kDebugStyles) {
       ALOGI("RETRIEVING ATTR 0x%08x...", cur_ident);
     }

     ssize_t block = kXmlBlock;
     uint32_t type_set_flags = 0;

     value.dataType = Res_value::TYPE_NULL;
     value.data = Res_value::DATA_NULL_UNDEFINED;
     config.density = 0;

     // Try to find a value for this attribute...  we prioritize values
     // coming from, first XML attributes, then XML style, then default
     // style, and finally the theme.

     // Walk through the xml attributes looking for the requested attribute.
     const size_t xml_attr_idx = xml_attr_finder.Find(cur_ident);
     if (xml_attr_idx != xml_attr_end) {
       // We found the attribute we were looking for.
       xml_parser->getAttributeValue(xml_attr_idx, &value);
       if (kDebugStyles) {
         ALOGI("-> From XML: type=0x%x, data=0x%08x", value.dataType, value.data);
       }
     }

     if (value.dataType == Res_value::TYPE_NULL && value.data != Res_value::DATA_NULL_EMPTY) {
       // Walk through the style class values looking for the requested attribute.
       const ResTable::bag_entry* const style_attr_entry = style_attr_finder.Find(cur_ident);
       if (style_attr_entry != style_attr_end) {
         // We found the attribute we were looking for.
         block = style_attr_entry->stringBlock;
         type_set_flags = style_type_set_flags;
         value = style_attr_entry->map.value;
         if (kDebugStyles) {
           ALOGI("-> From style: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
       }
     }

     if (value.dataType == Res_value::TYPE_NULL && value.data != Res_value::DATA_NULL_EMPTY) {
       // Walk through the default style values looking for the requested attribute.
       const ResTable::bag_entry* const def_style_attr_entry = def_style_attr_finder.Find(cur_ident);
       if (def_style_attr_entry != def_style_attr_end) {
         // We found the attribute we were looking for.
         block = def_style_attr_entry->stringBlock;
         type_set_flags = style_type_set_flags;
         value = def_style_attr_entry->map.value;
         if (kDebugStyles) {
           ALOGI("-> From def style: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
       }
     }

     uint32_t resid = 0;
     if (value.dataType != Res_value::TYPE_NULL) {
       // Take care of resolving the found resource to its final value.
       ssize_t new_block =
           theme->resolveAttributeReference(&value, block, &resid, &type_set_flags, &config);
       if (new_block >= 0) {
         block = new_block;
       }

       if (kDebugStyles) {
         ALOGI("-> Resolved attr: type=0x%x, data=0x%08x", value.dataType, value.data);
       }
     } else if (value.data != Res_value::DATA_NULL_EMPTY) {
       // If we still don't have a value for this attribute, try to find it in the theme!
       ssize_t new_block = theme->getAttribute(cur_ident, &value, &type_set_flags);
       if (new_block >= 0) {
         if (kDebugStyles) {
           ALOGI("-> From theme: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
         new_block = res.resolveReference(&value, new_block, &resid, &type_set_flags, &config);
         if (new_block >= 0) {
           block = new_block;
         }

         if (kDebugStyles) {
           ALOGI("-> Resolved theme: type=0x%x, data=0x%08x", value.dataType, value.data);
         }
       }
     }

     // Deal with the special @null value -- it turns back to TYPE_NULL.
     if (value.dataType == Res_value::TYPE_REFERENCE && value.data == 0) {
       if (kDebugStyles) {
         ALOGI("-> Setting to @null!");
       }
       value.dataType = Res_value::TYPE_NULL;
       value.data = Res_value::DATA_NULL_UNDEFINED;
       block = kXmlBlock;
     }

     if (kDebugStyles) {
       ALOGI("Attribute 0x%08x: type=0x%x, data=0x%08x", cur_ident, value.dataType, value.data);
     }

     // Write the final value back to Java.
     out_values[STYLE_TYPE] = value.dataType;
     out_values[STYLE_DATA] = value.data;
     out_values[STYLE_ASSET_COOKIE] =
         block != kXmlBlock ? static_cast<uint32_t>(res.getTableCookie(block))
                            : static_cast<uint32_t>(-1);
     out_values[STYLE_RESOURCE_ID] = resid;
     out_values[STYLE_CHANGING_CONFIGURATIONS] = type_set_flags;
     out_values[STYLE_DENSITY] = config.density;

     if (value.dataType != Res_value::TYPE_NULL || value.data == Res_value::DATA_NULL_EMPTY) {
       indices_idx++;

       // out_indices must NOT be nullptr.
       out_indices[indices_idx] = ii;
     }

     out_values += STYLE_NUM_ENTRIES;
   }

   res.unlock();

   // out_indices must NOT be nullptr.
   out_indices[0] = indices_idx;
 }

 bool RetrieveAttributes(const ResTable* res, ResXMLParser* xml_parser,
                         uint32_t* attrs, size_t attrs_length,
                         uint32_t* out_values, uint32_t* out_indices) {
   ResTable_config config;
   Res_value value;

   int indices_idx = 0;

   // Now lock down the resource object and start pulling stuff from it.
   res->lock();

   // Retrieve the XML attributes, if requested.
   const size_t xml_attr_count = xml_parser->getAttributeCount();
   size_t ix = 0;
   uint32_t cur_xml_attr = xml_parser->getAttributeNameResID(ix);

   static const ssize_t kXmlBlock = 0x10000000;

   // Now iterate through all of the attributes that the client has requested,
   // filling in each with whatever data we can find.
   for (size_t ii = 0; ii < attrs_length; ii++) {
     const uint32_t cur_ident = attrs[ii];
     ssize_t block = kXmlBlock;
     uint32_t type_set_flags = 0;

     value.dataType = Res_value::TYPE_NULL;
     value.data = Res_value::DATA_NULL_UNDEFINED;
     config.density = 0;

     // Try to find a value for this attribute...
     // Skip through XML attributes until the end or the next possible match.
     while (ix < xml_attr_count && cur_ident > cur_xml_attr) {
       ix++;
       cur_xml_attr = xml_parser->getAttributeNameResID(ix);
     }
     // Retrieve the current XML attribute if it matches, and step to next.
     if (ix < xml_attr_count && cur_ident == cur_xml_attr) {
       xml_parser->getAttributeValue(ix, &value);
       ix++;
       cur_xml_attr = xml_parser->getAttributeNameResID(ix);
     }

     uint32_t resid = 0;
     if (value.dataType != Res_value::TYPE_NULL) {
       // Take care of resolving the found resource to its final value.
       // printf("Resolving attribute reference\n");
       ssize_t new_block = res->resolveReference(&value, block, &resid,
                                                 &type_set_flags, &config);
       if (new_block >= 0) block = new_block;
     }

     // Deal with the special @null value -- it turns back to TYPE_NULL.
     if (value.dataType == Res_value::TYPE_REFERENCE && value.data == 0) {
       value.dataType = Res_value::TYPE_NULL;
       value.data = Res_value::DATA_NULL_UNDEFINED;
       block = kXmlBlock;
     }

     // Write the final value back to Java.
     out_values[STYLE_TYPE] = value.dataType;
     out_values[STYLE_DATA] = value.data;
     out_values[STYLE_ASSET_COOKIE] =
         block != kXmlBlock ? static_cast<uint32_t>(res->getTableCookie(block))
                            : static_cast<uint32_t>(-1);
     out_values[STYLE_RESOURCE_ID] = resid;
     out_values[STYLE_CHANGING_CONFIGURATIONS] = type_set_flags;
     out_values[STYLE_DENSITY] = config.density;

     if (out_indices != nullptr &&
         (value.dataType != Res_value::TYPE_NULL || value.data == Res_value::DATA_NULL_EMPTY)) {
       indices_idx++;
       out_indices[indices_idx] = ii;
     }

     out_values += STYLE_NUM_ENTRIES;
   }

   res->unlock();

   if (out_indices != nullptr) {
     out_indices[0] = indices_idx;
   }
   return true;
 }

 }  // namespace android
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "androidfw/AttributeResolution.h"

	#include <cstdint>

	#include <log/log.h>

	#include "androidfw/AttributeFinder.h"
	#include "androidfw/ResourceTypes.h"

	constexpr bool kDebugStyles = false;

	namespace android {

	class XmlAttributeFinder
	: public BackTrackingAttributeFinder<XmlAttributeFinder, size_t> {
	public:
	explicit XmlAttributeFinder(const ResXMLParser* parser)
	: BackTrackingAttributeFinder(
	0, parser != nullptr ? parser->getAttributeCount() : 0),
	parser_(parser) {}

	inline uint32_t GetAttribute(size_t index) const {
	return parser_->getAttributeNameResID(index);
	}

	private:
	const ResXMLParser* parser_;
	};

	class BagAttributeFinder
	: public BackTrackingAttributeFinder<BagAttributeFinder, const ResTable::bag_entry*> {
	public:
	BagAttributeFinder(const ResTable::bag_entry* start,
	const ResTable::bag_entry* end)
	: BackTrackingAttributeFinder(start, end) {}

	inline uint32_t GetAttribute(const ResTable::bag_entry* entry) const {
	return entry->map.name.ident;
	}
	};

	bool ResolveAttrs(ResTable::Theme* theme, uint32_t def_style_attr,
	uint32_t def_style_res, uint32_t* src_values,
	size_t src_values_length, uint32_t* attrs,
	size_t attrs_length, uint32_t* out_values,
	uint32_t* out_indices) {
	if (kDebugStyles) {
	ALOGI("APPLY STYLE: theme=0x%p defStyleAttr=0x%x defStyleRes=0x%x", theme,
	def_style_attr, def_style_res);
	}

	const ResTable& res = theme->getResTable();
	ResTable_config config;
	Res_value value;

	int indices_idx = 0;

	// Load default style from attribute, if specified...
	uint32_t def_style_bag_type_set_flags = 0;
	if (def_style_attr != 0) {
	Res_value value;
	if (theme->getAttribute(def_style_attr, &value, &def_style_bag_type_set_flags) >= 0) {
	if (value.dataType == Res_value::TYPE_REFERENCE) {
	def_style_res = value.data;
	}
	}
	}

	// Now lock down the resource object and start pulling stuff from it.
	res.lock();

	// Retrieve the default style bag, if requested.
	const ResTable::bag_entry* def_style_start = nullptr;
	uint32_t def_style_type_set_flags = 0;
	ssize_t bag_off = def_style_res != 0
	? res.getBagLocked(def_style_res, &def_style_start,
	&def_style_type_set_flags)
	: -1;
	def_style_type_set_flags \|= def_style_bag_type_set_flags;
	const ResTable::bag_entry* const def_style_end =
	def_style_start + (bag_off >= 0 ? bag_off : 0);
	BagAttributeFinder def_style_attr_finder(def_style_start, def_style_end);

	// Now iterate through all of the attributes that the client has requested,
	// filling in each with whatever data we can find.
	for (size_t ii = 0; ii < attrs_length; ii++) {
	const uint32_t cur_ident = attrs[ii];

	if (kDebugStyles) {
	ALOGI("RETRIEVING ATTR 0x%08x...", cur_ident);
	}

	ssize_t block = -1;
	uint32_t type_set_flags = 0;

	value.dataType = Res_value::TYPE_NULL;
	value.data = Res_value::DATA_NULL_UNDEFINED;
	config.density = 0;

	// Try to find a value for this attribute... we prioritize values
	// coming from, first XML attributes, then XML style, then default
	// style, and finally the theme.

	// Retrieve the current input value if available.
	if (src_values_length > 0 && src_values[ii] != 0) {
	value.dataType = Res_value::TYPE_ATTRIBUTE;
	value.data = src_values[ii];
	if (kDebugStyles) {
	ALOGI("-> From values: type=0x%x, data=0x%08x", value.dataType,
	value.data);
	}
	} else {
	const ResTable::bag_entry* const def_style_entry = def_style_attr_finder.Find(cur_ident);
	if (def_style_entry != def_style_end) {
	block = def_style_entry->stringBlock;
	type_set_flags = def_style_type_set_flags;
	value = def_style_entry->map.value;
	if (kDebugStyles) {
	ALOGI("-> From def style: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	}
	}

	uint32_t resid = 0;
	if (value.dataType != Res_value::TYPE_NULL) {
	// Take care of resolving the found resource to its final value.
	ssize_t new_block =
	theme->resolveAttributeReference(&value, block, &resid, &type_set_flags, &config);
	if (new_block >= 0) block = new_block;
	if (kDebugStyles) {
	ALOGI("-> Resolved attr: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	} else if (value.data != Res_value::DATA_NULL_EMPTY) {
	// If we still don't have a value for this attribute, try to find
	// it in the theme!
	ssize_t new_block = theme->getAttribute(cur_ident, &value, &type_set_flags);
	if (new_block >= 0) {
	if (kDebugStyles) {
	ALOGI("-> From theme: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	new_block = res.resolveReference(&value, new_block, &resid, &type_set_flags, &config);
	if (new_block >= 0) block = new_block;
	if (kDebugStyles) {
	ALOGI("-> Resolved theme: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	}
	}

	// Deal with the special @null value -- it turns back to TYPE_NULL.
	if (value.dataType == Res_value::TYPE_REFERENCE && value.data == 0) {
	if (kDebugStyles) {
	ALOGI("-> Setting to @null!");
	}
	value.dataType = Res_value::TYPE_NULL;
	value.data = Res_value::DATA_NULL_UNDEFINED;
	block = -1;
	}

	if (kDebugStyles) {
	ALOGI("Attribute 0x%08x: type=0x%x, data=0x%08x", cur_ident, value.dataType, value.data);
	}

	// Write the final value back to Java.
	out_values[STYLE_TYPE] = value.dataType;
	out_values[STYLE_DATA] = value.data;
	out_values[STYLE_ASSET_COOKIE] =
	block != -1 ? static_cast<uint32_t>(res.getTableCookie(block))
	: static_cast<uint32_t>(-1);
	out_values[STYLE_RESOURCE_ID] = resid;
	out_values[STYLE_CHANGING_CONFIGURATIONS] = type_set_flags;
	out_values[STYLE_DENSITY] = config.density;

	if (out_indices != nullptr &&
	(value.dataType != Res_value::TYPE_NULL \|\| value.data == Res_value::DATA_NULL_EMPTY)) {
	indices_idx++;
	out_indices[indices_idx] = ii;
	}

	out_values += STYLE_NUM_ENTRIES;
	}

	res.unlock();

	if (out_indices != nullptr) {
	out_indices[0] = indices_idx;
	}
	return true;
	}

	void ApplyStyle(ResTable::Theme* theme, ResXMLParser* xml_parser, uint32_t def_style_attr,
	uint32_t def_style_res, const uint32_t* attrs, size_t attrs_length,
	uint32_t* out_values, uint32_t* out_indices) {
	if (kDebugStyles) {
	ALOGI("APPLY STYLE: theme=0x%p defStyleAttr=0x%x defStyleRes=0x%x xml=0x%p",
	theme, def_style_attr, def_style_res, xml_parser);
	}

	const ResTable& res = theme->getResTable();
	ResTable_config config;
	Res_value value;

	int indices_idx = 0;

	// Load default style from attribute, if specified...
	uint32_t def_style_bag_type_set_flags = 0;
	if (def_style_attr != 0) {
	Res_value value;
	if (theme->getAttribute(def_style_attr, &value,
	&def_style_bag_type_set_flags) >= 0) {
	if (value.dataType == Res_value::TYPE_REFERENCE) {
	def_style_res = value.data;
	}
	}
	}

	// Retrieve the style class associated with the current XML tag.
	int style = 0;
	uint32_t style_bag_type_set_flags = 0;
	if (xml_parser != nullptr) {
	ssize_t idx = xml_parser->indexOfStyle();
	if (idx >= 0 && xml_parser->getAttributeValue(idx, &value) >= 0) {
	if (value.dataType == value.TYPE_ATTRIBUTE) {
	if (theme->getAttribute(value.data, &value, &style_bag_type_set_flags) < 0) {
	value.dataType = Res_value::TYPE_NULL;
	}
	}
	if (value.dataType == value.TYPE_REFERENCE) {
	style = value.data;
	}
	}
	}

	// Now lock down the resource object and start pulling stuff from it.
	res.lock();

	// Retrieve the default style bag, if requested.
	const ResTable::bag_entry* def_style_attr_start = nullptr;
	uint32_t def_style_type_set_flags = 0;
	ssize_t bag_off = def_style_res != 0
	? res.getBagLocked(def_style_res, &def_style_attr_start,
	&def_style_type_set_flags)
	: -1;
	def_style_type_set_flags \|= def_style_bag_type_set_flags;
	const ResTable::bag_entry* const def_style_attr_end =
	def_style_attr_start + (bag_off >= 0 ? bag_off : 0);
	BagAttributeFinder def_style_attr_finder(def_style_attr_start,
	def_style_attr_end);

	// Retrieve the style class bag, if requested.
	const ResTable::bag_entry* style_attr_start = nullptr;
	uint32_t style_type_set_flags = 0;
	bag_off =
	style != 0
	? res.getBagLocked(style, &style_attr_start, &style_type_set_flags)
	: -1;
	style_type_set_flags \|= style_bag_type_set_flags;
	const ResTable::bag_entry* const style_attr_end =
	style_attr_start + (bag_off >= 0 ? bag_off : 0);
	BagAttributeFinder style_attr_finder(style_attr_start, style_attr_end);

	// Retrieve the XML attributes, if requested.
	static const ssize_t kXmlBlock = 0x10000000;
	XmlAttributeFinder xml_attr_finder(xml_parser);
	const size_t xml_attr_end =
	xml_parser != nullptr ? xml_parser->getAttributeCount() : 0;

	// Now iterate through all of the attributes that the client has requested,
	// filling in each with whatever data we can find.
	for (size_t ii = 0; ii < attrs_length; ii++) {
	const uint32_t cur_ident = attrs[ii];

	if (kDebugStyles) {
	ALOGI("RETRIEVING ATTR 0x%08x...", cur_ident);
	}

	ssize_t block = kXmlBlock;
	uint32_t type_set_flags = 0;

	value.dataType = Res_value::TYPE_NULL;
	value.data = Res_value::DATA_NULL_UNDEFINED;
	config.density = 0;

	// Try to find a value for this attribute... we prioritize values
	// coming from, first XML attributes, then XML style, then default
	// style, and finally the theme.

	// Walk through the xml attributes looking for the requested attribute.
	const size_t xml_attr_idx = xml_attr_finder.Find(cur_ident);
	if (xml_attr_idx != xml_attr_end) {
	// We found the attribute we were looking for.
	xml_parser->getAttributeValue(xml_attr_idx, &value);
	if (kDebugStyles) {
	ALOGI("-> From XML: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	}

	if (value.dataType == Res_value::TYPE_NULL && value.data != Res_value::DATA_NULL_EMPTY) {
	// Walk through the style class values looking for the requested attribute.
	const ResTable::bag_entry* const style_attr_entry = style_attr_finder.Find(cur_ident);
	if (style_attr_entry != style_attr_end) {
	// We found the attribute we were looking for.
	block = style_attr_entry->stringBlock;
	type_set_flags = style_type_set_flags;
	value = style_attr_entry->map.value;
	if (kDebugStyles) {
	ALOGI("-> From style: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	}
	}

	if (value.dataType == Res_value::TYPE_NULL && value.data != Res_value::DATA_NULL_EMPTY) {
	// Walk through the default style values looking for the requested attribute.
	const ResTable::bag_entry* const def_style_attr_entry = def_style_attr_finder.Find(cur_ident);
	if (def_style_attr_entry != def_style_attr_end) {
	// We found the attribute we were looking for.
	block = def_style_attr_entry->stringBlock;
	type_set_flags = style_type_set_flags;
	value = def_style_attr_entry->map.value;
	if (kDebugStyles) {
	ALOGI("-> From def style: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	}
	}

	uint32_t resid = 0;
	if (value.dataType != Res_value::TYPE_NULL) {
	// Take care of resolving the found resource to its final value.
	ssize_t new_block =
	theme->resolveAttributeReference(&value, block, &resid, &type_set_flags, &config);
	if (new_block >= 0) {
	block = new_block;
	}

	if (kDebugStyles) {
	ALOGI("-> Resolved attr: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	} else if (value.data != Res_value::DATA_NULL_EMPTY) {
	// If we still don't have a value for this attribute, try to find it in the theme!
	ssize_t new_block = theme->getAttribute(cur_ident, &value, &type_set_flags);
	if (new_block >= 0) {
	if (kDebugStyles) {
	ALOGI("-> From theme: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	new_block = res.resolveReference(&value, new_block, &resid, &type_set_flags, &config);
	if (new_block >= 0) {
	block = new_block;
	}

	if (kDebugStyles) {
	ALOGI("-> Resolved theme: type=0x%x, data=0x%08x", value.dataType, value.data);
	}
	}
	}

	// Deal with the special @null value -- it turns back to TYPE_NULL.
	if (value.dataType == Res_value::TYPE_REFERENCE && value.data == 0) {
	if (kDebugStyles) {
	ALOGI("-> Setting to @null!");
	}
	value.dataType = Res_value::TYPE_NULL;
	value.data = Res_value::DATA_NULL_UNDEFINED;
	block = kXmlBlock;
	}

	if (kDebugStyles) {
	ALOGI("Attribute 0x%08x: type=0x%x, data=0x%08x", cur_ident, value.dataType, value.data);
	}

	// Write the final value back to Java.
	out_values[STYLE_TYPE] = value.dataType;
	out_values[STYLE_DATA] = value.data;
	out_values[STYLE_ASSET_COOKIE] =
	block != kXmlBlock ? static_cast<uint32_t>(res.getTableCookie(block))
	: static_cast<uint32_t>(-1);
	out_values[STYLE_RESOURCE_ID] = resid;
	out_values[STYLE_CHANGING_CONFIGURATIONS] = type_set_flags;
	out_values[STYLE_DENSITY] = config.density;

	if (value.dataType != Res_value::TYPE_NULL \|\| value.data == Res_value::DATA_NULL_EMPTY) {
	indices_idx++;

	// out_indices must NOT be nullptr.
	out_indices[indices_idx] = ii;
	}

	out_values += STYLE_NUM_ENTRIES;
	}

	res.unlock();

	// out_indices must NOT be nullptr.
	out_indices[0] = indices_idx;
	}

	bool RetrieveAttributes(const ResTable* res, ResXMLParser* xml_parser,
	uint32_t* attrs, size_t attrs_length,
	uint32_t* out_values, uint32_t* out_indices) {
	ResTable_config config;
	Res_value value;

	int indices_idx = 0;

	// Now lock down the resource object and start pulling stuff from it.
	res->lock();

	// Retrieve the XML attributes, if requested.
	const size_t xml_attr_count = xml_parser->getAttributeCount();
	size_t ix = 0;
	uint32_t cur_xml_attr = xml_parser->getAttributeNameResID(ix);

	static const ssize_t kXmlBlock = 0x10000000;

	// Now iterate through all of the attributes that the client has requested,
	// filling in each with whatever data we can find.
	for (size_t ii = 0; ii < attrs_length; ii++) {
	const uint32_t cur_ident = attrs[ii];
	ssize_t block = kXmlBlock;
	uint32_t type_set_flags = 0;

	value.dataType = Res_value::TYPE_NULL;
	value.data = Res_value::DATA_NULL_UNDEFINED;
	config.density = 0;

	// Try to find a value for this attribute...
	// Skip through XML attributes until the end or the next possible match.
	while (ix < xml_attr_count && cur_ident > cur_xml_attr) {
	ix++;
	cur_xml_attr = xml_parser->getAttributeNameResID(ix);
	}
	// Retrieve the current XML attribute if it matches, and step to next.
	if (ix < xml_attr_count && cur_ident == cur_xml_attr) {
	xml_parser->getAttributeValue(ix, &value);
	ix++;
	cur_xml_attr = xml_parser->getAttributeNameResID(ix);
	}

	uint32_t resid = 0;
	if (value.dataType != Res_value::TYPE_NULL) {
	// Take care of resolving the found resource to its final value.
	// printf("Resolving attribute reference\n");
	ssize_t new_block = res->resolveReference(&value, block, &resid,
	&type_set_flags, &config);
	if (new_block >= 0) block = new_block;
	}

	// Deal with the special @null value -- it turns back to TYPE_NULL.
	if (value.dataType == Res_value::TYPE_REFERENCE && value.data == 0) {
	value.dataType = Res_value::TYPE_NULL;
	value.data = Res_value::DATA_NULL_UNDEFINED;
	block = kXmlBlock;
	}

	// Write the final value back to Java.
	out_values[STYLE_TYPE] = value.dataType;
	out_values[STYLE_DATA] = value.data;
	out_values[STYLE_ASSET_COOKIE] =
	block != kXmlBlock ? static_cast<uint32_t>(res->getTableCookie(block))
	: static_cast<uint32_t>(-1);
	out_values[STYLE_RESOURCE_ID] = resid;
	out_values[STYLE_CHANGING_CONFIGURATIONS] = type_set_flags;
	out_values[STYLE_DENSITY] = config.density;

	if (out_indices != nullptr &&
	(value.dataType != Res_value::TYPE_NULL \|\| value.data == Res_value::DATA_NULL_EMPTY)) {
	indices_idx++;
	out_indices[indices_idx] = ii;
	}

	out_values += STYLE_NUM_ENTRIES;
	}

	res->unlock();

	if (out_indices != nullptr) {
	out_indices[0] = indices_idx;
	}
	return true;
	}

	} // namespace android