Event System - Revision history

94.6.161.247 at 12:03, 5 May 2024

2024-05-05T12:03:52Z

← Older revision		Revision as of 12:03, 5 May 2024
Line 3:		Line 3:
	To create an event handler simply use a lambda expression thus:		To create an event handler simply use a lambda expression thus:

	<~~code~~>		<pre>
	button1.clicked([](){ /* ... code ... */ });		button1.clicked([](){ /* ... code ... */ });
	</~~code~~>		</pre>

	If automatic event handler de-registration (traditional role of a "slot") is wanted:		If automatic event handler de-registration (traditional role of a "slot") is wanted:

	<~~code~~>		<pre>
	neogfx::sink s;		neogfx::sink s;
	s += button1.clicked([](){ /* ... code ... */ });		s += button1.clicked([](){ /* ... code ... */ });
	</~~code~~>		</pre>

	When 's' is destroyed any associated event registrations are de-registered automatically. Sink objects can be on the stack, member variables or the more traditional slot-like base class sub-object.		When <code>s</code> is destroyed any associated event registrations are de-registered automatically. Sink objects can be on the stack, member variables or the more traditional slot-like base class sub-object.

	The event system is fully multi-threaded. If you want to handle the event in the same thread that is emitting the event rather than the thread that created the event handler then one simply uses the ''thread snake'', <nowiki>~~~~</nowiki>, which has the nice side effect of making it obvious that the lambda is being executed in a thread that may be different to that which is running the surrounding code:		The event system is fully multi-threaded. If you want to handle the event in the same thread that is emitting the event rather than the thread that created the event handler then one simply uses the ''thread snake'', <code><nowiki>~~~~</nowiki></code>, which has the nice side effect of making it obvious that the lambda is being executed in a thread that may be different to that which is running the surrounding code:

	<pre>		<pre>

Leigh at 21:53, 4 May 2024

2024-05-04T21:53:14Z

← Older revision		Revision as of 21:53, 4 May 2024
Line 53:		Line 53:
	public:		public:
	virtual void qux() = 0;		virtual void qux() = 0;
	/* ... ~~code~~ ... */		/* ... other interface methods or helper functions ... */
	};		};

94.6.161.247 at 19:09, 4 May 2024

2024-05-04T19:09:10Z

← Older revision		Revision as of 19:09, 4 May 2024
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	declare_event(our_event, int)		declare_event(our_event, int)
	public:		public:
	virtual ~~~i_frumple~~() = default;		virtual ~i_xyzzy() = default;
	public:		public:
	virtual void qux() = 0;		virtual void qux() = 0;

Leigh at 19:02, 4 May 2024

2024-05-04T19:02:32Z

← Older revision		Revision as of 19:02, 4 May 2024
Line 56:		Line 56:
	};		};

	class xyzzy : public i_xyzzy // a concrete class implementing the interface ~~i_frumple~~		class xyzzy : public i_xyzzy // a concrete class implementing the above interface
	{		{
	public:		public:

Leigh at 19:01, 4 May 2024

2024-05-04T19:01:50Z

← Older revision		Revision as of 19:01, 4 May 2024
Line 10:		Line 10:

	<code>		<code>
	~~neoGFX~~::sink s;		neogfx::sink s;
	s += button1.clicked([](){ /* ... code ... */ });		s += button1.clicked([](){ /* ... code ... */ });
	</code>		</code>

Leigh at 19:01, 4 May 2024

2024-05-04T19:01:38Z

← Older revision		Revision as of 19:01, 4 May 2024
Line 52:		Line 52:
	virtual ~i_frumple() = default;		virtual ~i_frumple() = default;
	public:		public:
			virtual void qux() = 0;
	/* ... code ... */		/* ... code ... */
	};		};
Line 60:		Line 61:
	define_declared_event(OurEvent, our_event, int)		define_declared_event(OurEvent, our_event, int)
	public:		public:
			void qux() final {}
	/* ... code ... */		/* ... code ... */
	};		};
	</pre>		</pre>

Leigh at 18:59, 4 May 2024

2024-05-04T18:59:34Z

← Older revision		Revision as of 18:59, 4 May 2024
Line 30:		Line 30:
	{		{
	public:		public:
	~~neoGFX::event<~~int~~> wibble;~~		define_event(OurEvent, our_event, int)
	public:		public:
	void something()		void something()
	{		{
	~~wibble~~.trigger(42); // by default a synchronous trigger		// Using event object directly
	~~wibble~~.sync_trigger(42); // synchronous trigger		OurEvent.trigger(42); // by default a synchronous trigger
	~~wibble~~.async_trigger(42); // asynchronous trigger		OurEvent.sync_trigger(42); // synchronous trigger
			OurEvent.async_trigger(42); // asynchronous trigger
			// Using event (virtual) function
			our_event().trigger(42); // by default a synchronous trigger
			our_event().sync_trigger(42); // synchronous trigger
			our_event().async_trigger(42); // asynchronous trigger
	}		}
			};

			class i_xyzzy // an interface (abstract base) class
			{
			public:
			declare_event(our_event, int)
			public:
			virtual ~i_frumple() = default;
			public:
			/* ... code ... */
			};

			class xyzzy : public i_xyzzy // a concrete class implementing the interface i_frumple
			{
			public:
			define_declared_event(OurEvent, our_event, int)
			public:
			/* ... code ... */
	};		};
	</pre>		</pre>

Leigh at 18:44, 4 May 2024

2024-05-04T18:44:12Z

← Older revision		Revision as of 18:44, 4 May 2024
Line 1:		Line 1:
	The ''neoGFX'' event system is a modern, simple, improvement over traditional signals and slots.		The ''neoGFX'' event system is a modern, simple improvement over traditional signals and slots.

	To create an event handler simply use a lambda expression thus:		To create an event handler simply use a lambda expression thus:

Leigh at 18:38, 4 May 2024

2024-05-04T18:38:55Z

← Older revision		Revision as of 18:38, 4 May 2024
Line 1:		Line 1:
	The ''neoGFX'' event system is a modern, simple improvement over traditional signals and slots.		The ''neoGFX'' event system is a modern, simple, improvement over traditional signals and slots.

	To create an event handler simply use a lambda expression thus:		To create an event handler simply use a lambda expression thus:

Leigh at 18:38, 4 May 2024

2024-05-04T18:38:36Z

← Older revision		Revision as of 18:38, 4 May 2024
Line 1:		Line 1:
	The ''neoGFX'' event system is ~~both~~ modern ~~and~~ simple ~~and is an~~ improvement over traditional signals and slots.		The ''neoGFX'' event system is a modern, simple improvement over traditional signals and slots.

	To create an event handler simply use a lambda expression thus:		To create an event handler simply use a lambda expression thus: