tdesktop/Telegram/SourceFiles/lang/lang_text_entity.cpp

76 lines
2.8 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "lang/lang_text_entity.h"
#include "lang/lang_tag.h"
namespace Lang {
TextWithEntities ReplaceTag<TextWithEntities>::Call(TextWithEntities &&original, ushort tag, const TextWithEntities &replacement) {
auto replacementPosition = FindTagReplacementPosition(original.text, tag);
if (replacementPosition < 0) {
return std::move(original);
}
return Replace(std::move(original), replacement, replacementPosition);
}
TextWithEntities ReplaceTag<TextWithEntities>::Replace(TextWithEntities &&original, const TextWithEntities &replacement, int start) {
auto result = TextWithEntities();
result.text = ReplaceTag<QString>::Replace(std::move(original.text), replacement.text, start);
auto originalEntitiesCount = original.entities.size();
auto replacementEntitiesCount = replacement.entities.size();
if (originalEntitiesCount != 0 || replacementEntitiesCount != 0) {
result.entities.reserve(originalEntitiesCount + replacementEntitiesCount);
auto replacementEnd = start + int(replacement.text.size());
auto replacementEntity = replacement.entities.cbegin();
auto addReplacementEntitiesUntil = [&](int untilPosition) {
while (replacementEntity != replacement.entities.cend()) {
auto newOffset = start + replacementEntity->offset();
if (newOffset >= untilPosition) {
return;
}
auto newEnd = newOffset + replacementEntity->length();
newOffset = std::clamp(newOffset, start, replacementEnd);
newEnd = std::clamp(newEnd, start, replacementEnd);
if (auto newLength = newEnd - newOffset) {
result.entities.push_back({ replacementEntity->type(), newOffset, newLength, replacementEntity->data() });
}
++replacementEntity;
}
};
for (const auto &entity : std::as_const(original.entities)) {
// Transform the entity by the replacement.
auto offset = entity.offset();
auto end = offset + entity.length();
if (offset > start) {
offset = offset + replacement.text.size() - kTagReplacementSize;
}
if (end > start) {
end = end + replacement.text.size() - kTagReplacementSize;
}
offset = std::clamp(offset, 0, int(result.text.size()));
end = std::clamp(end, 0, int(result.text.size()));
// Add all replacement entities that start before the current original entity.
addReplacementEntitiesUntil(offset);
// Add a modified original entity.
if (auto length = end - offset) {
result.entities.push_back({ entity.type(), offset, length, entity.data() });
}
}
// Add the remaining replacement entities.
addReplacementEntitiesUntil(result.text.size());
}
return result;
}
} // namespace Lang