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/*
* Copyright (C) 2015 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.
*/
#ifndef AAPT_XML_DOM_H
#define AAPT_XML_DOM_H
#include <memory>
#include <string>
#include <vector>
#include "androidfw/StringPiece.h"
#include "Diagnostics.h"
#include "Resource.h"
#include "ResourceValues.h"
#include "io/Io.h"
#include "util/Util.h"
#include "xml/XmlUtil.h"
namespace aapt {
namespace xml {
class Element;
class Visitor;
class ConstVisitor;
// Base class for all XML nodes.
class Node {
public:
virtual ~Node() = default;
Element* parent = nullptr;
size_t line_number = 0u;
size_t column_number = 0u;
std::string comment;
virtual void Accept(Visitor* visitor) = 0;
virtual void Accept(ConstVisitor* visitor) const = 0;
using ElementCloneFunc = std::function<void(const Element&, Element*)>;
// Clones the Node subtree, using the given function to decide how to clone an Element.
virtual std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) const = 0;
};
// A namespace declaration (xmlns:prefix="uri").
struct NamespaceDecl {
std::string prefix;
std::string uri;
size_t line_number = 0u;
size_t column_number = 0u;
};
struct AaptAttribute {
explicit AaptAttribute(const ::aapt::Attribute& attr, const Maybe<ResourceId>& resid = {})
: attribute(attr), id(resid) {
}
aapt::Attribute attribute;
Maybe<ResourceId> id;
};
// An XML attribute.
struct Attribute {
std::string namespace_uri;
std::string name;
std::string value;
Maybe<AaptAttribute> compiled_attribute;
std::unique_ptr<Item> compiled_value;
};
// An Element XML node.
class Element : public Node {
public:
// Ordered namespace prefix declarations.
std::vector<NamespaceDecl> namespace_decls;
std::string namespace_uri;
std::string name;
std::vector<Attribute> attributes;
std::vector<std::unique_ptr<Node>> children;
void AppendChild(std::unique_ptr<Node> child);
void InsertChild(size_t index, std::unique_ptr<Node> child);
Attribute* FindAttribute(const android::StringPiece& ns, const android::StringPiece& name);
const Attribute* FindAttribute(const android::StringPiece& ns,
const android::StringPiece& name) const;
Attribute* FindOrCreateAttribute(const android::StringPiece& ns,
const android::StringPiece& name);
void RemoveAttribute(const android::StringPiece& ns,
const android::StringPiece& name);
Element* FindChild(const android::StringPiece& ns, const android::StringPiece& name);
const Element* FindChild(const android::StringPiece& ns, const android::StringPiece& name) const;
Element* FindChildWithAttribute(const android::StringPiece& ns, const android::StringPiece& name,
const android::StringPiece& attr_ns,
const android::StringPiece& attr_name,
const android::StringPiece& attr_value);
const Element* FindChildWithAttribute(const android::StringPiece& ns,
const android::StringPiece& name,
const android::StringPiece& attr_ns,
const android::StringPiece& attr_name,
const android::StringPiece& attr_value) const;
std::vector<Element*> GetChildElements();
// Due to overriding of subtypes not working with unique_ptr, define a convenience Clone method
// that knows cloning an element returns an element.
std::unique_ptr<Element> CloneElement(const ElementCloneFunc& el_cloner) const;
std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) const override;
void Accept(Visitor* visitor) override;
void Accept(ConstVisitor* visitor) const override;
};
// A Text (CDATA) XML node. Can not have any children.
class Text : public Node {
public:
std::string text;
std::unique_ptr<Node> Clone(const ElementCloneFunc& el_cloner) const override;
void Accept(Visitor* visitor) override;
void Accept(ConstVisitor* visitor) const override;
};
// An XML resource with a source, name, and XML tree.
class XmlResource {
public:
ResourceFile file;
// StringPool must come before the xml::Node. Destructors are called in reverse order, and
// the xml::Node may have StringPool references that need to be destroyed before the StringPool
// is destroyed.
StringPool string_pool;
std::unique_ptr<xml::Element> root;
std::unique_ptr<XmlResource> Clone() const;
};
// Inflates an XML DOM from an InputStream, logging errors to the logger.
std::unique_ptr<XmlResource> Inflate(io::InputStream* in, IDiagnostics* diag, const Source& source);
// Inflates an XML DOM from a binary ResXMLTree.
std::unique_ptr<XmlResource> Inflate(const void* data, size_t len,
std::string* out_error = nullptr);
Element* FindRootElement(Node* node);
// Visitor whose default implementation visits the children nodes of any node.
class Visitor {
public:
virtual ~Visitor() = default;
virtual void Visit(Element* el) {
VisitChildren(el);
}
virtual void Visit(Text* text) {
}
protected:
Visitor() = default;
void VisitChildren(Element* el) {
for (auto& child : el->children) {
child->Accept(this);
}
}
virtual void BeforeVisitElement(Element* el) {
}
virtual void AfterVisitElement(Element* el) {
}
private:
DISALLOW_COPY_AND_ASSIGN(Visitor);
friend class Element;
};
class ConstVisitor {
public:
virtual ~ConstVisitor() = default;
virtual void Visit(const Element* el) {
VisitChildren(el);
}
virtual void Visit(const Text* text) {
}
protected:
ConstVisitor() = default;
void VisitChildren(const Element* el) {
for (const auto& child : el->children) {
child->Accept(this);
}
}
virtual void BeforeVisitElement(const Element* el) {
}
virtual void AfterVisitElement(const Element* el) {
}
private:
DISALLOW_COPY_AND_ASSIGN(ConstVisitor);
friend class Element;
};
// An XML DOM visitor that will record the package name for a namespace prefix.
class PackageAwareVisitor : public Visitor, public IPackageDeclStack {
public:
using Visitor::Visit;
Maybe<ExtractedPackage> TransformPackageAlias(const android::StringPiece& alias) const override;
protected:
PackageAwareVisitor() = default;
void BeforeVisitElement(Element* el) override;
void AfterVisitElement(Element* el) override;
private:
DISALLOW_COPY_AND_ASSIGN(PackageAwareVisitor);
struct PackageDecl {
std::string prefix;
ExtractedPackage package;
};
std::vector<std::vector<PackageDecl>> package_decls_;
};
namespace internal {
// Base class that overrides the default behaviour and does not descend into child nodes.
class NodeCastBase : public ConstVisitor {
public:
void Visit(const Element* el) override {
}
void Visit(const Text* el) override {
}
protected:
NodeCastBase() = default;
void BeforeVisitElement(const Element* el) override {
}
void AfterVisitElement(const Element* el) override {
}
private:
DISALLOW_COPY_AND_ASSIGN(NodeCastBase);
};
template <typename T>
class NodeCastImpl : public NodeCastBase {
public:
using NodeCastBase::Visit;
NodeCastImpl() = default;
const T* value = nullptr;
void Visit(const T* v) override {
value = v;
}
private:
DISALLOW_COPY_AND_ASSIGN(NodeCastImpl);
};
} // namespace internal
template <typename T>
const T* NodeCast(const Node* node) {
internal::NodeCastImpl<T> visitor;
node->Accept(&visitor);
return visitor.value;
}
template <typename T>
T* NodeCast(Node* node) {
return const_cast<T*>(NodeCast<T>(static_cast<const T*>(node)));
}
} // namespace xml
} // namespace aapt
#endif // AAPT_XML_DOM_H