1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef AAPT_LINKER_LINKERS_H 18 #define AAPT_LINKER_LINKERS_H 19 20 #include "Resource.h" 21 #include "process/IResourceTableConsumer.h" 22 #include "xml/XmlDom.h" 23 24 #include <set> 25 26 namespace aapt { 27 28 class ResourceTable; 29 class ResourceEntry; 30 struct ConfigDescription; 31 32 /** 33 * Defines the location in which a value exists. This determines visibility of other 34 * package's private symbols. 35 */ 36 struct CallSite { 37 ResourceNameRef resource; 38 }; 39 40 /** 41 * Determines whether a versioned resource should be created. If a versioned resource already 42 * exists, it takes precedence. 43 */ 44 bool shouldGenerateVersionedResource(const ResourceEntry* entry, const ConfigDescription& config, 45 const int sdkVersionToGenerate); 46 47 struct AutoVersioner : public IResourceTableConsumer { 48 bool consume(IAaptContext* context, ResourceTable* table) override; 49 }; 50 51 struct XmlAutoVersioner : public IXmlResourceConsumer { 52 bool consume(IAaptContext* context, xml::XmlResource* resource) override; 53 }; 54 55 /** 56 * If any attribute resource values are defined as public, this consumer will move all private 57 * attribute resource values to a private ^private-attr type, avoiding backwards compatibility 58 * issues with new apps running on old platforms. 59 * 60 * The Android platform ignores resource attributes it doesn't recognize, so an app developer can 61 * use new attributes in their layout XML files without worrying about versioning. This assumption 62 * actually breaks on older platforms. OEMs may add private attributes that are used internally. 63 * AAPT originally assigned all private attributes IDs immediately proceeding the public attributes' 64 * IDs. 65 * 66 * This means that on a newer Android platform, an ID previously assigned to a private attribute 67 * may end up assigned to a public attribute. 68 * 69 * App developers assume using the newer attribute is safe on older platforms because it will 70 * be ignored. Instead, the platform thinks the new attribute is an older, private attribute and 71 * will interpret it as such. This leads to unintended styling and exceptions thrown due to 72 * unexpected types. 73 * 74 * By moving the private attributes to a completely different type, this ID conflict will never 75 * occur. 76 */ 77 struct PrivateAttributeMover : public IResourceTableConsumer { 78 bool consume(IAaptContext* context, ResourceTable* table) override; 79 }; 80 81 /** 82 * Resolves attributes in the XmlResource and compiles string values to resource values. 83 * Once an XmlResource is processed by this linker, it is ready to be flattened. 84 */ 85 class XmlReferenceLinker : public IXmlResourceConsumer { 86 private: 87 std::set<int> mSdkLevelsFound; 88 89 public: 90 bool consume(IAaptContext* context, xml::XmlResource* resource) override; 91 92 /** 93 * Once the XmlResource has been consumed, this returns the various SDK levels in which 94 * framework attributes used within the XML document were defined. 95 */ getSdkLevels()96 inline const std::set<int>& getSdkLevels() const { 97 return mSdkLevelsFound; 98 } 99 }; 100 101 } // namespace aapt 102 103 #endif /* AAPT_LINKER_LINKERS_H */ 104