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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.
*/
#include "BindingXmlPullParser.h"
#include "Util.h"
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
namespace aapt {
constexpr const char16_t* kBindingNamespaceUri = u"http://schemas.android.com/apk/binding";
constexpr const char16_t* kAndroidNamespaceUri = u"http://schemas.android.com/apk/res/android";
constexpr const char16_t* kVariableTagName = u"variable";
constexpr const char* kBindingTagPrefix = "android:binding_";
BindingXmlPullParser::BindingXmlPullParser(const std::shared_ptr<XmlPullParser>& parser) :
mParser(parser), mOverride(false), mNextTagId(0) {
}
bool BindingXmlPullParser::readVariableDeclaration() {
VarDecl var;
const auto endAttrIter = mParser->endAttributes();
for (auto attrIter = mParser->beginAttributes(); attrIter != endAttrIter; ++attrIter) {
if (!attrIter->namespaceUri.empty()) {
continue;
}
if (attrIter->name == u"name") {
var.name = util::utf16ToUtf8(attrIter->value);
} else if (attrIter->name == u"type") {
var.type = util::utf16ToUtf8(attrIter->value);
}
}
XmlPullParser::skipCurrentElement(mParser.get());
if (var.name.empty()) {
mLastError = "variable declaration missing name";
return false;
}
if (var.type.empty()) {
mLastError = "variable declaration missing type";
return false;
}
mVarDecls.push_back(std::move(var));
return true;
}
bool BindingXmlPullParser::readExpressions() {
mOverride = true;
std::vector<XmlPullParser::Attribute> expressions;
std::string idValue;
const auto endAttrIter = mParser->endAttributes();
for (auto attr = mParser->beginAttributes(); attr != endAttrIter; ++attr) {
if (attr->namespaceUri == kAndroidNamespaceUri && attr->name == u"id") {
idValue = util::utf16ToUtf8(attr->value);
} else {
StringPiece16 value = util::trimWhitespace(attr->value);
if (util::stringStartsWith<char16_t>(value, u"@{") &&
util::stringEndsWith<char16_t>(value, u"}")) {
// This is attribute's value is an expression of the form
// @{expression}. We need to capture the expression inside.
expressions.push_back(XmlPullParser::Attribute{
attr->namespaceUri,
attr->name,
value.substr(2, value.size() - 3).toString()
});
} else {
// This is a normal attribute, use as is.
mAttributes.emplace_back(*attr);
}
}
}
// Check if we have any expressions.
if (!expressions.empty()) {
// We have expressions, so let's assign the target a tag number
// and add it to our targets list.
int32_t targetId = mNextTagId++;
mTargets.push_back(Target{
util::utf16ToUtf8(mParser->getElementName()),
idValue,
targetId,
std::move(expressions)
});
std::stringstream numGen;
numGen << kBindingTagPrefix << targetId;
mAttributes.push_back(XmlPullParser::Attribute{
std::u16string(kAndroidNamespaceUri),
std::u16string(u"tag"),
util::utf8ToUtf16(numGen.str())
});
}
return true;
}
XmlPullParser::Event BindingXmlPullParser::next() {
// Clear old state in preparation for the next event.
mOverride = false;
mAttributes.clear();
while (true) {
Event event = mParser->next();
if (event == Event::kStartElement) {
if (mParser->getElementNamespace().empty() &&
mParser->getElementName() == kVariableTagName) {
// This is a variable tag. Record data from it, and
// then discard the entire element.
if (!readVariableDeclaration()) {
// mLastError is set, so getEvent will return kBadDocument.
return getEvent();
}
continue;
} else {
// Check for expressions of the form @{} in attribute text.
const auto endAttrIter = mParser->endAttributes();
for (auto attr = mParser->beginAttributes(); attr != endAttrIter; ++attr) {
StringPiece16 value = util::trimWhitespace(attr->value);
if (util::stringStartsWith<char16_t>(value, u"@{") &&
util::stringEndsWith<char16_t>(value, u"}")) {
if (!readExpressions()) {
return getEvent();
}
break;
}
}
}
} else if (event == Event::kStartNamespace || event == Event::kEndNamespace) {
if (mParser->getNamespaceUri() == kBindingNamespaceUri) {
// Skip binding namespace tags.
continue;
}
}
return event;
}
return Event::kBadDocument;
}
bool BindingXmlPullParser::writeToFile(std::ostream& out) const {
out << "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
out << "<Layout directory=\"\" layout=\"\" layoutId=\"\">\n";
// Write the variables.
out << " <Variables>\n";
for (const VarDecl& v : mVarDecls) {
out << " <entries name=\"" << v.name << "\" type=\"" << v.type << "\"/>\n";
}
out << " </Variables>\n";
// Write the imports.
std::stringstream tagGen;
// Write the targets.
out << " <Targets>\n";
for (const Target& t : mTargets) {
tagGen.str({});
tagGen << kBindingTagPrefix << t.tagId;
out << " <Target boundClass=\"" << t.className << "\" id=\"" << t.id
<< "\" tag=\"" << tagGen.str() << "\">\n";
out << " <Expressions>\n";
for (const XmlPullParser::Attribute& a : t.expressions) {
out << " <Expression attribute=\"" << a.namespaceUri << ":" << a.name
<< "\" text=\"" << a.value << "\"/>\n";
}
out << " </Expressions>\n";
out << " </Target>\n";
}
out << " </Targets>\n";
out << "</Layout>\n";
return bool(out);
}
XmlPullParser::const_iterator BindingXmlPullParser::beginAttributes() const {
if (mOverride) {
return mAttributes.begin();
}
return mParser->beginAttributes();
}
XmlPullParser::const_iterator BindingXmlPullParser::endAttributes() const {
if (mOverride) {
return mAttributes.end();
}
return mParser->endAttributes();
}
size_t BindingXmlPullParser::getAttributeCount() const {
if (mOverride) {
return mAttributes.size();
}
return mParser->getAttributeCount();
}
XmlPullParser::Event BindingXmlPullParser::getEvent() const {
if (!mLastError.empty()) {
return Event::kBadDocument;
}
return mParser->getEvent();
}
const std::string& BindingXmlPullParser::getLastError() const {
if (!mLastError.empty()) {
return mLastError;
}
return mParser->getLastError();
}
const std::u16string& BindingXmlPullParser::getComment() const {
return mParser->getComment();
}
size_t BindingXmlPullParser::getLineNumber() const {
return mParser->getLineNumber();
}
size_t BindingXmlPullParser::getDepth() const {
return mParser->getDepth();
}
const std::u16string& BindingXmlPullParser::getText() const {
return mParser->getText();
}
const std::u16string& BindingXmlPullParser::getNamespacePrefix() const {
return mParser->getNamespacePrefix();
}
const std::u16string& BindingXmlPullParser::getNamespaceUri() const {
return mParser->getNamespaceUri();
}
bool BindingXmlPullParser::applyPackageAlias(std::u16string* package,
const std::u16string& defaultPackage) const {
return mParser->applyPackageAlias(package, defaultPackage);
}
const std::u16string& BindingXmlPullParser::getElementNamespace() const {
return mParser->getElementNamespace();
}
const std::u16string& BindingXmlPullParser::getElementName() const {
return mParser->getElementName();
}
} // namespace aapt