css.cpp

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/*******************************************************************************
Copyright (c) 2021, Jan Koester jan.koester@gmx.net
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      names of its contributors may be used to endorse or promote products
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#include "css.h"
#include "exception.h"
 
#include <algorithm>
#include <sstream>
 
namespace {
 
    bool isWhitespace(char c) {
        return c == ' ' || c == '\t' || c == '\n' || c == '\r';
    }
 
    std::string trim(const std::string &s) {
        size_t start = 0;
        while (start < s.size() && isWhitespace(s[start])) ++start;
        size_t end = s.size();
        while (end > start && isWhitespace(s[end - 1])) --end;
        return s.substr(start, end - start);
    }
 
}
 
// --- CSSProperty ---
 
libhtmlpp::CSSProperty::CSSProperty() {}
 
libhtmlpp::CSSProperty::CSSProperty(const std::string &name, const std::string &value)
    : _Name(name), _Value(value) {}
 
libhtmlpp::CSSProperty::CSSProperty(const CSSProperty &prop)
    : _Name(prop._Name), _Value(prop._Value) {}
 
libhtmlpp::CSSProperty::~CSSProperty() {}
 
libhtmlpp::CSSProperty& libhtmlpp::CSSProperty::operator=(const CSSProperty &prop) {
    if (this != &prop) {
        _Name  = prop._Name;
        _Value = prop._Value;
    }
    return *this;
}
 
const std::string& libhtmlpp::CSSProperty::getName() const { return _Name; }
void libhtmlpp::CSSProperty::setName(const std::string &name) { _Name = name; }
 
const std::string& libhtmlpp::CSSProperty::getValue() const { return _Value; }
void libhtmlpp::CSSProperty::setValue(const std::string &value) { _Value = value; }
 
// --- CSSDeclaration ---
 
libhtmlpp::CSSDeclaration::CSSDeclaration() {}
 
libhtmlpp::CSSDeclaration::CSSDeclaration(const CSSDeclaration &decl)
    : _Properties(decl._Properties) {}
 
libhtmlpp::CSSDeclaration::~CSSDeclaration() {}
 
libhtmlpp::CSSDeclaration& libhtmlpp::CSSDeclaration::operator=(const CSSDeclaration &decl) {
    if (this != &decl) {
        _Properties = decl._Properties;
    }
    return *this;
}
 
void libhtmlpp::CSSDeclaration::addProperty(const std::string &name, const std::string &value) {
    std::string tname  = trim(name);
    std::string tvalue = trim(value);
 
    if (tname.empty()) return;
 
    for (auto &prop : _Properties) {
        if (prop.getName() == tname) {
            prop.setValue(tvalue);
            return;
        }
    }
    _Properties.emplace_back(tname, tvalue);
}
 
void libhtmlpp::CSSDeclaration::removeProperty(const std::string &name) {
    std::string tname = trim(name);
    _Properties.erase(
        std::remove_if(_Properties.begin(), _Properties.end(),
            [&tname](const CSSProperty &p) { return p.getName() == tname; }),
        _Properties.end()
    );
}
 
const libhtmlpp::CSSProperty* libhtmlpp::CSSDeclaration::getProperty(const std::string &name) const {
    std::string tname = trim(name);
    for (const auto &prop : _Properties) {
        if (prop.getName() == tname) return &prop;
    }
    return nullptr;
}
 
const std::vector<libhtmlpp::CSSProperty>& libhtmlpp::CSSDeclaration::getProperties() const {
    return _Properties;
}
 
std::string libhtmlpp::CSSDeclaration::serialize() const {
    std::string result;
    for (size_t i = 0; i < _Properties.size(); ++i) {
        result += _Properties[i].getName();
        result += ": ";
        result += _Properties[i].getValue();
        result += ";";
        if (i + 1 < _Properties.size()) result += " ";
    }
    return result;
}
 
void libhtmlpp::CSSDeclaration::parse(const std::string &input) {
    _Properties.clear();
 
    size_t pos = 0;
    size_t len = input.size();
 
    while (pos < len) {
        // Skip whitespace
        while (pos < len && isWhitespace(input[pos])) ++pos;
        if (pos >= len) break;
 
        // Find the colon separating property name from value
        size_t colon = input.find(':', pos);
        if (colon == std::string::npos) break;
 
        std::string propName = trim(input.substr(pos, colon - pos));
 
        pos = colon + 1;
 
        // Find the semicolon ending this declaration
        // Handle parentheses for functions like rgb(), url()
        size_t valueStart = pos;
        int parenDepth = 0;
        bool inSingleQuote = false;
        bool inDoubleQuote = false;
 
        while (pos < len) {
            char c = input[pos];
 
            if (inSingleQuote) {
                if (c == '\'') inSingleQuote = false;
                ++pos;
                continue;
            }
            if (inDoubleQuote) {
                if (c == '"') inDoubleQuote = false;
                ++pos;
                continue;
            }
 
            if (c == '\'') { inSingleQuote = true; ++pos; continue; }
            if (c == '"')  { inDoubleQuote = true; ++pos; continue; }
            if (c == '(')  { ++parenDepth; ++pos; continue; }
            if (c == ')')  { if (parenDepth > 0) --parenDepth; ++pos; continue; }
 
            if (c == ';' && parenDepth == 0) {
                break;
            }
            ++pos;
        }
 
        std::string propValue = trim(input.substr(valueStart, pos - valueStart));
 
        if (!propName.empty()) {
            addProperty(propName, propValue);
        }
 
        if (pos < len && input[pos] == ';') ++pos;
    }
}
 
void libhtmlpp::CSSDeclaration::clear() {
    _Properties.clear();
}
 
// --- CSSRule ---
 
libhtmlpp::CSSRule::CSSRule() {}
 
libhtmlpp::CSSRule::CSSRule(const std::string &selector)
    : _Selector(trim(selector)) {}
 
libhtmlpp::CSSRule::CSSRule(const CSSRule &rule)
    : _Selector(rule._Selector), _Declaration(rule._Declaration) {}
 
libhtmlpp::CSSRule::~CSSRule() {}
 
libhtmlpp::CSSRule& libhtmlpp::CSSRule::operator=(const CSSRule &rule) {
    if (this != &rule) {
        _Selector    = rule._Selector;
        _Declaration = rule._Declaration;
    }
    return *this;
}
 
const std::string& libhtmlpp::CSSRule::getSelector() const { return _Selector; }
void libhtmlpp::CSSRule::setSelector(const std::string &selector) { _Selector = trim(selector); }
 
libhtmlpp::CSSDeclaration& libhtmlpp::CSSRule::getDeclaration() { return _Declaration; }
const libhtmlpp::CSSDeclaration& libhtmlpp::CSSRule::getDeclaration() const { return _Declaration; }
 
std::string libhtmlpp::CSSRule::serialize(bool formatted) const {
    std::string result;
    if (formatted) {
        result += _Selector + " {\n";
        for (const auto &prop : _Declaration.getProperties()) {
            result += "    " + prop.getName() + ": " + prop.getValue() + ";\n";
        }
        result += "}";
    } else {
        result += _Selector + "{";
        result += _Declaration.serialize();
        result += "}";
    }
    return result;
}
 
// --- CSSStyleSheet ---
 
libhtmlpp::CSSStyleSheet::CSSStyleSheet() {}
 
libhtmlpp::CSSStyleSheet::CSSStyleSheet(const CSSStyleSheet &sheet)
    : _Rules(sheet._Rules) {}
 
libhtmlpp::CSSStyleSheet::~CSSStyleSheet() {}
 
libhtmlpp::CSSStyleSheet& libhtmlpp::CSSStyleSheet::operator=(const CSSStyleSheet &sheet) {
    if (this != &sheet) {
        _Rules = sheet._Rules;
    }
    return *this;
}
 
void libhtmlpp::CSSStyleSheet::_skipWhitespace(const std::string &input, size_t &pos) const {
    while (pos < input.size() && isWhitespace(input[pos])) ++pos;
}
 
void libhtmlpp::CSSStyleSheet::_skipComment(const std::string &input, size_t &pos) const {
    if (pos + 1 < input.size() && input[pos] == '/' && input[pos + 1] == '*') {
        pos += 2;
        while (pos + 1 < input.size()) {
            if (input[pos] == '*' && input[pos + 1] == '/') {
                pos += 2;
                return;
            }
            ++pos;
        }
        pos = input.size();
    }
}
 
void libhtmlpp::CSSStyleSheet::parse(const std::string &input) {
    _Rules.clear();
 
    size_t pos = 0;
    size_t len = input.size();
 
    while (pos < len) {
        _skipWhitespace(input, pos);
        if (pos >= len) break;
 
        // Skip comments
        if (pos + 1 < len && input[pos] == '/' && input[pos + 1] == '*') {
            _skipComment(input, pos);
            continue;
        }
 
        // Handle @-rules
        if (input[pos] == '@') {
            size_t atStart = pos;
 
            // Check for @-rules with blocks like @media, @keyframes, @supports, @font-face
            // and simple @-rules like @import, @charset
            size_t semiPos = input.find(';', pos);
            size_t bracePos = input.find('{', pos);
 
            if (bracePos != std::string::npos && (semiPos == std::string::npos || bracePos < semiPos)) {
                // Block @-rule: find matching closing brace
                std::string atSelector = trim(input.substr(atStart, bracePos - atStart));
                pos = bracePos + 1;
 
                int depth = 1;
                size_t blockStart = pos;
                while (pos < len && depth > 0) {
                    if (input[pos] == '{') ++depth;
                    else if (input[pos] == '}') --depth;
                    if (depth > 0) ++pos;
                }
 
                std::string blockContent = input.substr(blockStart, pos - blockStart);
                pos = (pos < len) ? pos + 1 : pos;
 
                // Parse nested rules inside the @-block
                CSSStyleSheet nested;
                nested.parse(blockContent);
 
                // Wrap each nested rule with the @-selector
                for (const auto &nestedRule : nested.getRules()) {
                    CSSRule rule;
                    rule.setSelector(atSelector + " " + nestedRule.getSelector());
                    for (const auto &prop : nestedRule.getDeclaration().getProperties()) {
                        rule.getDeclaration().addProperty(prop.getName(), prop.getValue());
                    }
                    _Rules.push_back(rule);
                }
 
                // If no nested rules (e.g. @font-face), store as single rule
                if (nested.getRuleCount() == 0 && !blockContent.empty()) {
                    CSSRule rule(atSelector);
                    rule.getDeclaration().parse(blockContent);
                    _Rules.push_back(rule);
                }
            } else if (semiPos != std::string::npos) {
                // Simple @-rule ending with semicolon (e.g. @import, @charset)
                std::string atRule = trim(input.substr(atStart, semiPos - atStart));
                CSSRule rule(atRule);
                _Rules.push_back(rule);
                pos = semiPos + 1;
            } else {
                // Malformed @-rule, skip
                ++pos;
            }
            continue;
        }
 
        // Standard rule: find selector then { declarations }
        size_t braceOpen = input.find('{', pos);
        if (braceOpen == std::string::npos) break;
 
        std::string selector = trim(input.substr(pos, braceOpen - pos));
        pos = braceOpen + 1;
 
        // Find matching closing brace
        int depth = 1;
        size_t declStart = pos;
        while (pos < len && depth > 0) {
            if (pos + 1 < len && input[pos] == '/' && input[pos + 1] == '*') {
                _skipComment(input, pos);
                continue;
            }
            if (input[pos] == '{') ++depth;
            else if (input[pos] == '}') --depth;
            if (depth > 0) ++pos;
        }
 
        std::string declarations = input.substr(declStart, pos - declStart);
        pos = (pos < len) ? pos + 1 : pos;
 
        if (!selector.empty()) {
            CSSRule rule(selector);
            rule.getDeclaration().parse(declarations);
            _Rules.push_back(rule);
        }
    }
}
 
void libhtmlpp::CSSStyleSheet::addRule(const CSSRule &rule) {
    _Rules.push_back(rule);
}
 
void libhtmlpp::CSSStyleSheet::removeRule(size_t index) {
    if (index < _Rules.size()) {
        _Rules.erase(_Rules.begin() + static_cast<std::ptrdiff_t>(index));
    }
}
 
const libhtmlpp::CSSRule* libhtmlpp::CSSStyleSheet::getRule(size_t index) const {
    if (index < _Rules.size()) return &_Rules[index];
    return nullptr;
}
 
size_t libhtmlpp::CSSStyleSheet::getRuleCount() const {
    return _Rules.size();
}
 
const std::vector<libhtmlpp::CSSRule>& libhtmlpp::CSSStyleSheet::getRules() const {
    return _Rules;
}
 
std::string libhtmlpp::CSSStyleSheet::serialize(bool formatted) const {
    std::string result;
    for (size_t i = 0; i < _Rules.size(); ++i) {
        result += _Rules[i].serialize(formatted);
        if (formatted) result += "\n";
        if (i + 1 < _Rules.size() && formatted) result += "\n";
    }
    return result;
}
 
void libhtmlpp::CSSStyleSheet::clear() {
    _Rules.clear();
}
 
libhtmlpp::CSSDeclaration libhtmlpp::CSSStyleSheet::parseInlineStyle(const std::string &style) {
    CSSDeclaration decl;
    decl.parse(style);
    return decl;
}