Event
Basic Callbacks
main.cpp
#include <Core/Core.h>
using namespace Upp;
struct Foo {
int x;
void Action() { Cout() << "Action: " << x << '\n'; }
void ActionWithParam(int y) { Cout() << "ActionWithParam: " << x + y << '\n'; }
Event<> WhenDo;
void Do() { WhenDo(); }
Foo(int x = 0) : x(x) {}
};
void Fn()
{
Cout() << "Fn!" << '\n';
}
struct Bar {
Foo foo;
Bar() {
foo.WhenDo = [=] { Cout() << "foo's Do called\n"; };
}
};
struct Safe : Pte<Safe> {
void Action() { Cout() << "safe action!\n"; }
};
CONSOLE_APP_MAIN
{
Foo a(10);
Event<> ev1, ev2, ev4;
Event<int> ev3;
ev1 << [&] { a.Action(); };
ev2 << [] { Fn(); };
ev3 << [&](int x) { a.ActionWithParam(x); };
ev4 << [&] { a.ActionWithParam(30); };
ev1();
ev2();
ev3(10);
ev4();
Cout() << "---------\n";
ev4 << ev2;
ev4();
Cout() << "---------\n";
Bar b;
b.foo.Do();
Cout() << "---------\n";
{
Safe f;
Ptr<Safe> p = &f;
ev4 = [=] { if(p) p->Action(); };
Cout() << "callback valid: " << (bool)ev4 << '\n';
ev4();
} // Safe f gets destroyed here, which makes capture 'p' NULL
ev4(); // captured 'p' is now NULL, so no Action is called
}
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