Ecore event are a helper to create events are being notified of events.

Ecore events provide two main features that are of use to those using ecore: creating events and being notified of events. Those two are usually used in different contexts, creating events is mainly done by libraries wrapping some system functionality while being notified of events is mainly a necessity of applications.

For a program to be notified of events it's interested in, it needs to have a function to process the event and to register that function as the callback to the event, that's all:

 ecore_event_handler_add(EVENT_TYPE, _my_event_handler, some_data);
 ...
 static Eina_Bool
 _my_event_handler(void *data, int type, void *event)
 {
    //Data is some_data
    //Event is provided by whoever created the event
    //Do really cool stuff with the event
 }

One very important thing to note here is the EVENT_TYPE. To register a handler for an event, you must know its type before hand. Ecore provides the following events that are emitted in response to POSIX signals(https://en.wikipedia.org/wiki/Signal_%28computing%29):

ECORE_EVENT_SIGNAL_USER
ECORE_EVENT_SIGNAL_HUP
ECORE_EVENT_SIGNAL_POWER
ECORE_EVENT_SIGNAL_EXIT

Don't override these using the signal or sigaction calls. These, however, aren't the only signals one can handle. Many libraries(including ecore modules) have their own signals that can be listened to and handled. To do that one only needs to know the type of the event. This information can be found on the documentation of the library emitting the signal.

This usage can be divided into two parts, setup and adding events. The setup is very simple, all that needs to be done is getting a type ID for the event:

 int MY_EV_TYPE = ecore_event_type_new();

This variable should be declared in the header since it is needed by anyone wishing to register a handler to your event.

The complexity of adding an event to the queue depends on whether that event sends or uses event, if it doesn't it is a one-liner:

 ecore_event_add(MY_EV_TYPE, NULL, NULL, NULL);

The usage when an event is needed is not that complex and can be seen in ecore_event_add.

Functions
Ecore_Event_Handler *	ecore_event_handler_add (int type, Ecore_Event_Handler_Cb func, const void *data)
	Adds an event handler.
void *	ecore_event_handler_del (Ecore_Event_Handler *event_handler)
	Deletes an event handler.
Ecore_Event *	ecore_event_add (int type, void ev, Ecore_End_Cb func_free, void data)
	Adds an event to the event queue.
void *	ecore_event_del (Ecore_Event *event)
	Deletes an event from the queue.
void *	ecore_event_handler_data_get (Ecore_Event_Handler *eh)
	Gets the data associated with an Ecore_Event_Handler.
void *	ecore_event_handler_data_set (Ecore_Event_Handler eh, const void data)
	Sets the data associated with an Ecore_Event_Handler.
int	ecore_event_type_new (void)
	Allocates a new event type ID sensibly and returns the new ID.
Ecore_Event_Filter *	ecore_event_filter_add (Ecore_Data_Cb func_start, Ecore_Filter_Cb func_filter, Ecore_End_Cb func_end, const void *data)
	Adds a filter to the current event queue.
void *	ecore_event_filter_del (Ecore_Event_Filter *ef)
	Deletes an event filter.
int	ecore_event_current_type_get (void)
	Returns the current event type being handled.
void *	ecore_event_current_event_get (void)
	Returns the current event type pointer handled.
Typedefs
typedef struct _Ecore_Event_Handler	Ecore_Event_Handler
	A handle for an event handler.
typedef struct _Ecore_Event_Filter	Ecore_Event_Filter
	A handle for an event filter.
typedef struct _Ecore_Event	Ecore_Event
	A handle for an event.
typedef struct _Ecore_Event_Signal_User	Ecore_Event_Signal_User
	User signal event.
typedef struct _Ecore_Event_Signal_Hup	Ecore_Event_Signal_Hup
	Hup signal event.
typedef struct _Ecore_Event_Signal_Exit	Ecore_Event_Signal_Exit
	Exit signal event.
typedef struct _Ecore_Event_Signal_Power	Ecore_Event_Signal_Power
	Power signal event.
typedef struct _Ecore_Event_Signal_Realtime	Ecore_Event_Signal_Realtime
	Realtime signal event.
typedef Eina_Bool(*	Ecore_Filter_Cb )(void data, void loop_data, int type, void *event)
	The boolean type for a callback used for filtering events from the main loop.
typedef void(*	Ecore_End_Cb )(void user_data, void func_data)
	Called at the end of a function, usually for cleanup purposes.
typedef Eina_Bool(*	Ecore_Event_Handler_Cb )(void data, int type, void event)
	The boolean type used by the main loop to handle events of a specified type.
Defines
#define	ECORE_EVENT_SIGNAL_USER 1
#define	ECORE_EVENT_SIGNAL_HUP 2
#define	ECORE_EVENT_SIGNAL_EXIT 3
#define	ECORE_EVENT_SIGNAL_POWER 4
#define	ECORE_EVENT_SIGNAL_REALTIME 5

Define Documentation

#define ECORE_EVENT_SIGNAL_EXIT 3

Exit signal event

#define ECORE_EVENT_SIGNAL_HUP 2

Hup signal event

#define ECORE_EVENT_SIGNAL_POWER 4

Power signal event

#define ECORE_EVENT_SIGNAL_REALTIME 5

Realtime signal event

#define ECORE_EVENT_SIGNAL_USER 1

User signal event

Function Documentation

Ecore_Event* ecore_event_add	(	int	type,
		void *	ev,
		Ecore_End_Cb	func_free,
		void *	data
	)

Adds an event to the event queue.

Remarks:: If it succeeds, an event of type type is added to the queue for processing by event handlers added by ecore_event_handler_add(). The ev parameter is passed as the event parameter of the handler. When the event is no longer needed, func_free is called and it passes ev for cleaning up. If func_free is NULL, free() is called with the private structure pointer.

Since :: 2.3.1

Parameters:

[in]	type	The event type to add to the end of the event queue
[in]	ev	The data structure passed as event to event handlers
[in]	func_free	The function to be called to free ev
[in]	data	The data pointer to be passed to the free function

Returns:: A Handle for that event on success, otherwise NULL on failure

void* ecore_event_current_event_get ( void )

Returns the current event type pointer handled.

Since :: 2.3.1

Remarks:: If the program is currently inside an Ecore event handler callback this returns the pointer of the current event being processed.; This is useful when certain Ecore modules such as Ecore_Evas "swallow" events and not all the original information is passed on. In special cases, this extra information may be useful or needed and using this call can let the program access the event data if the type of the event is handled by the program.

Returns:: The current event pointer being handled if inside a handler callback, otherwise NULL

int ecore_event_current_type_get ( void )

Returns the current event type being handled.

Since :: 2.3.1

Remarks:: If the program is currently inside an Ecore event handler callback this returns the type of the current event being processed.

This is useful when certain Ecore modules such as Ecore_Evas "swallow" events and not all the original information is passed on. In special cases, this extra information may be useful or needed and using this call can let the program know if the event type being handled is the one about which it wants to get more information.

Returns:: The current event type being handled if inside a handler callback, otherwise ECORE_EVENT_NONE

void* ecore_event_del ( Ecore_Event * event )

Deletes an event from the queue.

This deletes the event event from the event queue, and returns the data parameter originally set when adding it using ecore_event_add(). This does not immediately call the free function, and it may be called later for cleanup, and so if the free function depends on the data pointer to work, you should defer cleaning of this till the free function is called later.

Since :: 2.3.1

Parameters:

[in] event The event handle to delete

Returns:: The data pointer originally set for the event free function

Ecore_Event_Filter* ecore_event_filter_add	(	Ecore_Data_Cb	func_start,
		Ecore_Filter_Cb	func_filter,
		Ecore_End_Cb	func_end,
		const void *	data
	)

Adds a filter to the current event queue.

This adds a callback to filter events from the event queue. Filters are called on the queue just before Event handler processing to try and remove redundant events. Just when processing is about to start func_start is called and passed the data pointer. The return value of this function is passed to func_filter as loop_data. func_filter is also passed data, the event type, and the event structure. If this func_filter returns EINA_FALSE, the event is removed from the queue. If it returns EINA_TRUE, the event is kept. When processing is finished func_end is called and is passed the loop_data(returned by func_start) and data pointer to clean up.

Since :: 2.3.1

Parameters:

[in]	func_start	The function to call just before filtering and returning data
[in]	func_filter	The function to call on each event
[in]	func_end	The function to call after the queue has been filtered
[in]	data	The data to pass to the filter functions

Returns:: A filter handle on success, otherwise NULL on failure

void* ecore_event_filter_del ( Ecore_Event_Filter * ef )

Deletes an event filter.

This deletes a filter that has been added by its ef handle.

Since :: 2.3.1

Parameters:

[in] ef The event filter handle

Returns:: The data set for the filter on success, otherwise NULL

Ecore_Event_Handler* ecore_event_handler_add	(	int	type,
		Ecore_Event_Handler_Cb	func,
		const void *	data
	)

Adds an event handler.

This adds an event handler to the list of handlers. This, on success, returns a handle to the event handler object that is created, that can be used later to remove the handler using ecore_event_handler_del(). The type parameter is the integer of the event type that triggers this callback to be called. The callback func is called when this event is processed and is passed the event type, a pointer to the private event structure that is specific to that event type, and a data pointer that is provided in this call as the data parameter.

Since :: 2.3.1

Remarks:: When the callback func is called, it must return 1 or 0. If it returns 1 (or ECORE_CALLBACK_PASS_ON), it keeps being called as per normal, for each handler set up for that event type. If it returns 0 (or ECORE_CALLBACK_DONE), it ceases processing handlers for that particular event, so all handlers set to handle that event type that have not already been called, are not called.

Parameters:

[in]	type	The type of the event that this handler gets called for
[in]	func	The function to call when the event is found in the queue
[in]	data	A data pointer to pass to the called function func

Returns:: A new Event handler, otherwise NULL on failure

void* ecore_event_handler_data_get ( Ecore_Event_Handler * eh )

Gets the data associated with an Ecore_Event_Handler.

This function returns the data previously associated with eh by ecore_event_handler_add().

Since :: 2.3.1

Parameters:

[in] eh The event handler

Returns:: The data

void* ecore_event_handler_data_set	(	Ecore_Event_Handler *	eh,
		const void *	data
	)

Sets the data associated with an Ecore_Event_Handler.

This function sets data to eh and returns the old data pointer that had been previously associated with eh by ecore_event_handler_add().

Since :: 2.3.1

Parameters:

[in]	eh	The event handler
[in]	data	The data to associate

Returns:: The previous data

void* ecore_event_handler_del ( Ecore_Event_Handler * event_handler )

Deletes an event handler.

This deletes a specified event handler from the handler list. On success, this deletes the event handler and returns the pointer passed as data when the handler is added by ecore_event_handler_add(). On failure, NULL is returned. Once a handler is deleted it is no longer called.

Since :: 2.3.1

Parameters:

[in] event_handler The event handler handle to delete

Returns:: The data passed to the handler

int ecore_event_type_new ( void )

Allocates a new event type ID sensibly and returns the new ID.

This function allocates a new event type ID and returns it. Once an event type has been allocated it can never be de-allocated during the life of the program. There is no guarantee of the contents of this event ID, or how it is calculated, except that the ID is unique to the current instance of the process.

Since :: 2.3.1

Returns:: A new event type ID

Functions

Typedefs

Defines

Define Documentation

Function Documentation