Callback API Reference (libobs/callback)
Calldata
The calldata_t object is used to pass parameters from signal
handlers or to procedure handlers.
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type calldata_t
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void calldata_init(calldata_t *data)
Initializes a calldata structure (zeroes it).
- Parameters
data – Calldata structure
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void calldata_free(calldata_t *data)
Frees a calldata structure.
- Parameters
data – Calldata structure
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void calldata_set_int(calldata_t *data, const char *name, long long val)
Sets an integer parameter.
- Parameters
data – Calldata structure
name – Parameter name
val – Integer value
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void calldata_set_float(calldata_t *data, const char *name, double val)
Sets a floating point parameter.
- Parameters
data – Calldata structure
name – Parameter name
val – Floating point value
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void calldata_set_bool(calldata_t *data, const char *name, bool val)
Sets a boolean parameter.
- Parameters
data – Calldata structure
name – Parameter name
val – Boolean value
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void calldata_set_ptr(calldata_t *data, const char *name, void *ptr)
Sets a pointer parameter.
- Parameters
data – Calldata structure
name – Parameter name
val – Pointer value
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void calldata_set_string(calldata_t *data, const char *name, const char *str)
Sets a string parameter.
- Parameters
data – Calldata structure
name – Parameter name
val – String
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long long calldata_int(const calldata_t *data, const char *name)
Gets an integer parameter.
- Parameters
data – Calldata structure
name – Parameter name
- Returns
Integer value
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double calldata_float(const calldata_t *data, const char *name)
Gets a floating point parameter.
- Parameters
data – Calldata structure
name – Parameter name
- Returns
Floating point value
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bool calldata_bool(const calldata_t *data, const char *name)
Gets a boolean parameter.
- Parameters
data – Calldata structure
name – Parameter name
- Returns
Boolean value
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void *calldata_ptr(const calldata_t *data, const char *name)
Gets a pointer parameter.
- Parameters
data – Calldata structure
name – Parameter name
- Returns
Pointer value
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const char *calldata_string(const calldata_t *data, const char *name)
Gets a string parameter.
- Parameters
data – Calldata structure
name – Parameter name
- Returns
String value
Signals
Signals are used for all event-based callbacks.
#include <callback/signal.h>
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type signal_handler_t
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typedef void (*signal_callback_t)(void *data, calldata_t *cd)
Signal callback.
- Param data
Private data passed to this callback
- Param cd
Calldata object
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signal_handler_t *signal_handler_create(void)
Creates a new signal handler object.
- Returns
A new signal handler object
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void signal_handler_destroy(signal_handler_t *handler)
Destroys a signal handler.
- Parameters
handler – Signal handler object
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bool signal_handler_add(signal_handler_t *handler, const char *signal_decl)
Adds a signal to a signal handler.
- Parameters
handler – Signal handler object
signal_decl – Signal declaration string
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bool signal_handler_add_array(signal_handler_t *handler, const char **signal_decls)
Adds multiple signals to a signal handler.
- Parameters
handler – Signal handler object
signal_decls – An array of signal declaration strings, terminated by NULL
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void signal_handler_connect(signal_handler_t *handler, const char *signal, signal_callback_t callback, void *data)
Connect a callback to a signal on a signal handler.
- Parameters
handler – Signal handler object
callback – Signal callback
data – Private data passed the callback
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void signal_handler_connect_ref(signal_handler_t *handler, const char *signal, signal_callback_t callback, void *data)
Connect a callback to a signal on a signal handler, and increments the handler’s internal reference counter, preventing it from being destroyed until the signal has been disconnected.
- Parameters
handler – Signal handler object
callback – Signal callback
data – Private data passed the callback
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void signal_handler_disconnect(signal_handler_t *handler, const char *signal, signal_callback_t callback, void *data)
Disconnects a callback from a signal on a signal handler.
- Parameters
handler – Signal handler object
callback – Signal callback
data – Private data passed the callback
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void signal_handler_signal(signal_handler_t *handler, const char *signal, calldata_t *params)
Triggers a signal, calling all connected callbacks.
- Parameters
handler – Signal handler object
signal – Name of signal to trigger
params – Parameters to pass to the signal
Procedure Handlers
Procedure handlers are used to call functions without having to have direct access to declarations or callback pointers.
#include <callback/proc.h>
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type proc_handler_t
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typedef void (*proc_handler_proc_t)(void *data, calldata_t *cd)
Procedure handler callback.
- Param data
Private data passed to this callback
- Param cd
Calldata object
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proc_handler_t *proc_handler_create(void)
Creates a new procedure handler.
- Returns
A new procedure handler object
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void proc_handler_destroy(proc_handler_t *handler)
Destroys a procedure handler object.
- Parameters
handler – Procedure handler object
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void proc_handler_add(proc_handler_t *handler, const char *decl_string, proc_handler_proc_t proc, void *data)
Adds a procedure to a procedure handler.
- Parameters
handler – Procedure handler object
decl_string – Procedure declaration string
proc – Procedure callback
data – Private data to pass to the callback
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bool proc_handler_call(proc_handler_t *handler, const char *name, calldata_t *params)
Calls a procedure within the procedure handler.
- Parameters
handler – Procedure handler object
name – Name of procedure to call
params – Calldata structure to pass to the procedure