152 lines
4.3 KiB
C++
152 lines
4.3 KiB
C++
#include "./tag.h"
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using namespace std;
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namespace TagParser {
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/*!
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* \class TagParser::Tag
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* \brief The Tag class is used to store, read and write tag information.
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*
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* The Tag class only provides the interface and common functionality. It
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* is meant to be subclassed.This interface does not include parse/make
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* methods to read/write a tag from/to a stream because the availability
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* and signature of these methods may differ between the individual
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* implementations (eg. an Mp4Tag is read from the "meta" Mp4Atom).
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*/
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/*!
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* \brief Constructs a new Tag.
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*/
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Tag::Tag()
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: m_size(0)
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{
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}
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/*!
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* \brief Destroys the Tag.
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*/
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Tag::~Tag()
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{
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}
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/*!
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* \brief Returns a string representation of the tag.
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*/
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string Tag::toString() const
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{
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string res;
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res += typeName();
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if (supportsTarget()) {
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res += " targeting ";
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res += targetString();
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}
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return res;
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}
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/*!
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* \brief Returns the values of the specified \a field.
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* \remarks
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* - There might me more than one value assigned to a \a field. Whereas value()
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* returns only the first value, this method returns all values.
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* - However, the default implementation just returns the first value assuming
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* multiple values per field are not supported by the tag.
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*/
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std::vector<const TagValue *> Tag::values(KnownField field) const
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{
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std::vector<const TagValue *> values;
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const TagValue &v = value(field);
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if (!v.isEmpty()) {
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values.push_back(&v);
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}
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return values;
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}
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/*!
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* \brief Assigns the given \a values to the specified \a field.
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* \remarks
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* - There might me more than one value assigned to a \a field. Whereas setValue() only alters the first value, this
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* method will replace all currently assigned values with the specified \a values.
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* - However, the default implementation just sets the first value and discards additional values assuming
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* multiple values per field are not supported by the tag.
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*/
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bool Tag::setValues(KnownField field, const std::vector<TagValue> &values)
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{
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return setValue(field, values.size() ? values.front() : TagValue());
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}
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/*!
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* \fn Tag::value()
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* \brief Returns the value of the specified \a field.
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* \remarks
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* - If the specified \a field is not present an empty TagValue will be returned.
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* - Some tags support more than just one value per field. If there are multiple values
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* this method just returns the first one.
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* \sa setValue(), hasField()
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*/
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/*!
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* \fn Tag::setValue()
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* \brief Assigns the given \a value to the specified \a field.
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* \remarks
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* - If an empty \a value is given, the field will be be removed.
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* - Some tags support more than just one value per field. This method will only
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* alter the first value.
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* \sa value(), hasField()
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*/
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/*!
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* \fn Tag::hasField()
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* \brief Returns an indication whether the specified \a field is present.
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*
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* \sa value(), setValue()
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*/
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/*!
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* \fn Tag::removeAllFields()
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* \brief Removes all fields from the tag.
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*/
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/*!
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* \fn Tag::fieldCount()
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* \brief Returns the number of present fields.
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*/
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/*!
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* \fn Tag::supportsField()
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* \brief Returns an indication whether the specified \a field
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* is supported by the tag.
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*/
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/*!
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* \brief Inserts all compatible values \a from another Tag.
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* \param from Specifies the Tag the values should be inserted from.
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* \param overwrite Indicates whether existing values should be overwritten.
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* \return Returns the number of values that have been inserted.
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* \remarks The encoding of the inserted text values might not be supported by the tag.
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* To fix this, call ensureTextValuesAreProperlyEncoded() after insertion.
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*/
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unsigned int Tag::insertValues(const Tag &from, bool overwrite)
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{
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unsigned int count = 0;
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for (int i = static_cast<int>(KnownField::Invalid) + 1, last = static_cast<int>(KnownField::Description); i <= last; ++i) {
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KnownField field = static_cast<KnownField>(i);
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const TagValue &ownValue = value(field);
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if (overwrite || ownValue.isEmpty()) {
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const TagValue &otherValue = from.value(field);
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if (!otherValue.isEmpty() && setValue(field, otherValue)) {
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++count;
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}
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}
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}
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return count;
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}
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/*!
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* \fn Tag::ensureTextValuesAreProperlyEncoded()
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* \brief Ensures the encoding of all assigned text values is supported by the tag by
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* converting the character set if neccessary.
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*/
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} // namespace TagParser
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