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#pragma once
#include "registry.h"
namespace registry
{
/**
* \brief Simple value caching class for a registry key.
*
* This can be used when a registry key needs to be read frequently but only
* written rarely. It stores a copy of the value converted to its given type,
* and uses the registry signal to update its copy when the value changes.
*/
template<typename T>
class CachedKey: public sigc::trackable
{
const std::string _key;
T _cachedValue;
private:
void updateCachedValue()
{
_cachedValue = registry::getValue<T>(_key);
}
public:
/// Construct a CachedKey to observe the given registry key
explicit CachedKey(const std::string& key)
: _key(key)
{
updateCachedValue();
GlobalRegistry().signalForKey(key).connect(
sigc::mem_fun(this, &CachedKey<T>::updateCachedValue)
);
}
/// Return the current value
T get() const
{
return _cachedValue;
}
};
}
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