1
1
forked from 0ad/0ad
0ad/source/tools/atlas/AtlasUI/General/Observable.h
Ykkrosh b6c1022566 # Improved actor-viewer tool (more viewing controls, support for random actor variations)
Also right-click-and-drag to rotate the camera vertically.
Fixed LookAt code (the algorithm in the gluLookAt man page seems to be
wrong).

This was SVN commit r4394.
2006-09-27 16:54:23 +00:00

100 lines
2.1 KiB
C++

#ifndef OBSERVABLE_H__
#define OBSERVABLE_H__
/*
Wrapper around Boost.Signals to make watching objects for changes more convenient.
General usage:
Observable<int> variable_to_be_watched;
...
class Thing {
ObservableScopedConnection m_Conn;
Thing() {
m_Conn = variable_to_be_watched.RegisterObserver(OnChange);
}
void OnChange(const int& var) {
do_something_with(var);
}
}
...
variable_to_be_watched.NotifyObservers();
*/
#include <boost/signals.hpp>
#include <boost/bind.hpp>
typedef boost::signals::connection ObservableConnection;
typedef boost::signals::scoped_connection ObservableScopedConnection;
template <typename T> class Observable : public T
{
public:
Observable() {}
template <typename T1>
explicit Observable(const T1& a1) : T(a1) {}
template <typename T1, typename T2>
explicit Observable(T1& a1, T2 a2) : T(a1, a2) {}
template<typename C> ObservableConnection RegisterObserver(int order, void (C::*callback) (const T&), C* obj)
{
return m_Signal.connect(order, boost::bind(std::mem_fun(callback), obj, _1));
}
ObservableConnection RegisterObserver(int order, void (*callback) (const T&))
{
return m_Signal.connect(order, callback);
}
void RemoveObserver(const ObservableConnection& conn)
{
conn.disconnect();
}
void NotifyObservers()
{
m_Signal(*this);
}
// Use when an object is changing something that it's also observing,
// because it already knows about the change and doesn't need to be notified
// again (particularly since that may cause infinite loops).
void NotifyObserversExcept(ObservableConnection& conn)
{
if (conn.blocked())
{
// conn is already blocked and won't see anything
NotifyObservers();
}
else
{
// Temporarily disable conn
conn.block();
NotifyObservers();
conn.unblock();
}
}
Observable<T>* operator=(const T& rhs)
{
*dynamic_cast<T*>(this) = rhs;
return this;
}
private:
boost::signal<void (const T&)> m_Signal;
};
class ObservableScopedConnections
{
public:
void Add(const ObservableConnection& conn);
~ObservableScopedConnections();
private:
std::vector<ObservableConnection> m_Conns;
};
#endif // OBSERVABLE_H__