Move variable files to to variables folder

lib/variables/variable-string.cpp

@@ -0,0 +1,81 @@
+#include "variable-string.hpp"
+#include "utility.hpp"
+
+namespace advss {
+
+void StringVariable::Resolve() const
+{
+	if (GetVariables().empty()) {
+		_resolvedValue = _value;
+		return;
+	}
+	if (_lastResolve == GetLastVariableChangeTime()) {
+		return;
+	}
+	_resolvedValue = SubstitueVariables(_value);
+	_lastResolve = GetLastVariableChangeTime();
+}
+
+StringVariable::operator std::string() const
+{
+	Resolve();
+	return _resolvedValue;
+}
+
+StringVariable::operator QVariant() const
+{
+	return QVariant::fromValue<StringVariable>(*this);
+}
+
+void StringVariable::operator=(std::string value)
+{
+	_value = value;
+	_lastResolve = {};
+}
+
+void StringVariable::operator=(const char *value)
+{
+	_value = value;
+	_lastResolve = {};
+}
+
+void StringVariable::Load(obs_data_t *obj, const char *name)
+{
+	_value = obs_data_get_string(obj, name);
+	Resolve();
+}
+
+void StringVariable::Save(obs_data_t *obj, const char *name) const
+{
+	obs_data_set_string(obj, name, _value.c_str());
+}
+
+const char *StringVariable::c_str()
+{
+	Resolve();
+	return _resolvedValue.c_str();
+}
+
+const char *StringVariable::c_str() const
+{
+	Resolve();
+	return _resolvedValue.c_str();
+}
+
+bool StringVariable::empty() const
+{
+	Resolve();
+	return _resolvedValue.empty();
+}
+
+std::string SubstitueVariables(std::string str)
+{
+	for (const auto &v : GetVariables()) {
+		const auto &variable = std::dynamic_pointer_cast<Variable>(v);
+		const std::string pattern = "${" + variable->Name() + "}";
+		ReplaceAll(str, pattern, variable->Value());
+	}
+	return str;
+}
+
+} // namespace advss