Tizen Native API
5.5
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Ecore events provide two main features that are of use to those using ecore: creating events and being notified of events. Those two will usually be 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 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 which are emitted in response to POSIX signals(https://en.wikipedia.org/wiki/Signal_%28computing%29):
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 for 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, so, for example, for events related to windowing one would look in Ecore_Evas wrapper/helper set of functions.Examples of libraries that integrate into ecore's main loop by providing events are Ecore_Con - Connection functions, Ecore_Evas wrapper/helper set of functions and Process Spawning Functions, amongst others. This usage can be divided into two parts, setup and adding events. The setup is very simple, all that needs doing is getting a type id for the event:
int MY_EV_TYPE = ecore_event_type_new();
The complexity of adding of an event to the queue depends on whether that event sends uses event
, if it doesn't it a one-liner:
ecore_event_add(MY_EV_TYPE, NULL, NULL, NULL);
The usage when an event
is needed is not that much more complex and can be seen in ecore_event_add.
Examples that deals with events:
Functions | |
Ecore_Event_Handler * | ecore_event_handler_add (int type, Ecore_Event_Handler_Cb func, const void *data) |
Adds an event handler. | |
Ecore_Event_Handler * | ecore_event_handler_prepend (int type, Ecore_Event_Handler_Cb func, const void *data) |
Adds an event handler to the beginning of the handler list. | |
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. | |
void | ecore_event_type_flush_internal (int type,...) |
Forcefully flush all pending type without processing them. | |
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 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_Win32_Handler | Ecore_Win32_Handler |
typedef struct _Ecore_Event_Handler | Ecore_Event_Handler |
typedef struct _Ecore_Event_Filter | Ecore_Event_Filter |
typedef struct _Ecore_Event | Ecore_Event |
typedef struct _Ecore_Event_Signal_User | Ecore_Event_Signal_User |
typedef struct _Ecore_Event_Signal_Hup | Ecore_Event_Signal_Hup |
typedef struct _Ecore_Event_Signal_Exit | Ecore_Event_Signal_Exit |
typedef struct _Ecore_Event_Signal_Power | Ecore_Event_Signal_Power |
typedef struct _Ecore_Event_Signal_Realtime | Ecore_Event_Signal_Realtime |
typedef Eina_Bool(* | Ecore_Filter_Cb )(void *data, void *loop_data, int type, void *event) |
typedef void(* | Ecore_End_Cb )(void *user_data, void *func_data) |
typedef Eina_Bool(* | Ecore_Event_Handler_Cb )(void *data, int type, void *event) |
Defines | |
#define | ECORE_EVENT_NONE 0 |
#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 | ECORE_EVENT_MEMORY_STATE 6 |
#define | ECORE_EVENT_POWER_STATE 7 |
#define | ECORE_EVENT_LOCALE_CHANGED 8 |
#define | ECORE_EVENT_HOSTNAME_CHANGED 9 |
#define | ECORE_EVENT_SYSTEM_TIMEDATE_CHANGED 10 |
#define | ECORE_EVENT_COUNT 11 |
#define | ecore_event_type_flush(...) ecore_event_type_flush_internal(__VA_ARGS__, ECORE_EVENT_NONE); |
Forcefully flush all pending type without processing them. |
#define ECORE_EVENT_COUNT 11 |
Number of events
#define ECORE_EVENT_HOSTNAME_CHANGED 9 |
Hostname changed
#define ECORE_EVENT_LOCALE_CHANGED 8 |
Locale changed
#define ECORE_EVENT_MEMORY_STATE 6 |
Memory state changed, see ecore_memory_state_get()
#define ECORE_EVENT_NONE 0 |
None event
#define ECORE_EVENT_POWER_STATE 7 |
Power state changed, see ecore_power_state_get()
#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
#define ECORE_EVENT_SYSTEM_TIMEDATE_CHANGED 10 |
Time or Date changed
#define ecore_event_type_flush | ( | ... | ) | ecore_event_type_flush_internal(__VA_ARGS__, ECORE_EVENT_NONE); |
Forcefully flush all pending type without processing them.
... | Serie of Ecore_Event. |
This function is to be called before calling ecore_shutdown() if any event has still a chance to be in the ecore event queue.
This is the callback which is called at the end of a function, usually for cleanup purposes.
typedef struct _Ecore_Event Ecore_Event |
A handle for an event
typedef struct _Ecore_Event_Filter Ecore_Event_Filter |
A handle for an event filter
typedef struct _Ecore_Event_Handler Ecore_Event_Handler |
A handle for an event handler
A callback used by the main loop to handle events of a specified type.
typedef struct _Ecore_Event_Signal_Exit Ecore_Event_Signal_Exit |
Exit signal event
typedef struct _Ecore_Event_Signal_Hup Ecore_Event_Signal_Hup |
Hup 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 struct _Ecore_Event_Signal_User Ecore_Event_Signal_User |
User signal event
A callback used for filtering events from the main loop.
typedef struct _Ecore_Win32_Handler Ecore_Win32_Handler |
A handle for HANDLE handlers on Windows
Ecore_Event* ecore_event_add | ( | int | type, |
void * | ev, | ||
Ecore_End_Cb | func_free, | ||
void * | data | ||
) |
Adds an event to the event queue.
type | The event type to add to the end of the event queue |
ev | The data structure passed as event to event handlers |
func_free | The function to be called to free ev |
data | The data pointer to be passed to the free function |
If it succeeds, an event of type type will be added to the queue for processing by event handlers added by ecore_event_handler_add(). The ev parameter will be passed as the event
parameter of the handler. When the event is no longer needed, func_free will be called and passed ev for cleaning up. If func_free
is NULL, free() will be called with the private structure pointer.
void* ecore_event_current_event_get | ( | void | ) |
Returns the current event type pointer handled.
NULL
otherwise.If the program is currently inside an Ecore event handler callback this will return 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.
int ecore_event_current_type_get | ( | void | ) |
Returns the current event type being handled.
ECORE_EVENT_NONE
otherwise.If the program is currently inside an Ecore event handler callback this will return 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 one it wants to get more information about.
void* ecore_event_del | ( | Ecore_Event * | event | ) |
Deletes an event from the queue.
event | The event handle to delete |
This deletes the event event
from the event queue, and returns the data
parameter originally set when adding it with ecore_event_add(). This does not immediately call the free function, and it may be called later on 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.
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 the current event queue.
func_start | Function to call just before filtering and return data |
func_filter | Function to call on each event |
func_end | Function to call after the queue has been filtered |
data | Data to pass to the filter functions |
NULL
otherwise.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 as processing is about to start func_start is called and passed the data pointer, the return value of this functions is passed to func_filter as loop_data. func_filter is also passed data and the event type and 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.
void* ecore_event_filter_del | ( | Ecore_Event_Filter * | ef | ) |
Deletes an event filter.
ef | The event filter handle |
NULL
otherwise.Delete a filter that has been added by its ef
handle.
Ecore_Event_Handler* ecore_event_handler_add | ( | int | type, |
Ecore_Event_Handler_Cb | func, | ||
const void * | data | ||
) |
Adds an event handler.
type | The type of the event this handler will get called for |
func | The function to call when the event is found in the queue |
data | A data pointer to pass to the called function func |
NULL
on failure.Add an event handler to the list of handlers. This will, on success, return a handle to the event handler object that was 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 will trigger this callback to be called. The callback func
is called when this event is processed and will be 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.
When the callback func
is called, it must return 1
or 0
. If it returns 1
(or ECORE_CALLBACK_PASS_ON
), It will keep being called as per normal, for each handler set up for that event type. If it returns 0
(or ECORE_CALLBACK_DONE
), it will cease processing handlers for that particular event, so all handler set to handle that event type that have not already been called, will not be.
void* ecore_event_handler_data_get | ( | Ecore_Event_Handler * | eh | ) |
Gets the data associated with an Ecore_Event_Handler.
eh | The event handler |
This function returns the data previously associated with eh
by ecore_event_handler_add().
void* ecore_event_handler_data_set | ( | Ecore_Event_Handler * | eh, |
const void * | data | ||
) |
Sets the data associated with an Ecore_Event_Handler.
eh | The event handler |
data | The data to associate |
This function sets data
to eh
and returns the old data pointer which was previously associated with eh
by ecore_event_handler_add().
void* ecore_event_handler_del | ( | Ecore_Event_Handler * | event_handler | ) |
Deletes an event handler.
event_handler | Event handler handle to delete |
Delete a specified event handler from the handler list. On success this will delete the event handler and return the pointer passed as data
when the handler was added by ecore_event_handler_add(). On failure NULL
will be returned. Once a handler is deleted it will no longer be called.
Ecore_Event_Handler* ecore_event_handler_prepend | ( | int | type, |
Ecore_Event_Handler_Cb | func, | ||
const void * | data | ||
) |
Adds an event handler to the beginning of the handler list.
type | The type of the event this handler will get called for |
func | The function to call when the event is found in the queue |
data | A data pointer to pass to the called function func |
NULL
on failure.This function is identical to ecore_event_handler_add() except that it creates the handler at the start of the list. Do not use this function.
void ecore_event_type_flush_internal | ( | int | type, |
... | |||
) |
Forcefully flush all pending type without processing them.
type | Ecore_Event. |
... | Serie of Ecore_Event finished by ECORE_EVENT_NONE. |
This function is to be called before calling ecore_shutdown() if any event has still a chance to be in the ecore event queue.
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 will be unique to the current instance of the process.