234 lines
10 KiB
C
234 lines
10 KiB
C
/*
|
|
* This file is subject to the terms of the GFX License. If a copy of
|
|
* the license was not distributed with this file, you can obtain one at:
|
|
*
|
|
* http://chibios-gfx.com/license.html
|
|
*/
|
|
|
|
/**
|
|
* @file include/gevent/gevent.h
|
|
* @brief GEVENT GFX User Event subsystem header file.
|
|
*
|
|
* @addtogroup GEVENT
|
|
*
|
|
* @details GEVENT provides a simple to use but yet powerful event
|
|
* system.
|
|
*
|
|
* @pre GFX_USE_GEVENT must be set to TRUE in your gfxconf.h
|
|
*
|
|
* @{
|
|
*/
|
|
#ifndef _GEVENT_H
|
|
#define _GEVENT_H
|
|
|
|
#include "gfx.h"
|
|
|
|
#if GFX_USE_GEVENT || defined(__DOXYGEN__)
|
|
|
|
/*===========================================================================*/
|
|
/* Type definitions */
|
|
/*===========================================================================*/
|
|
|
|
typedef uint16_t GEventType;
|
|
#define GEVENT_NULL 0x0000 // Null Event - Do nothing
|
|
#define GEVENT_EXIT 0x0001 // The listener is being forced to exit (someone is destroying the listener)
|
|
|
|
/* Other event types are allocated in ranges in their respective include files */
|
|
#define GEVENT_GINPUT_FIRST 0x0100 // GINPUT events range from 0x0100 to 0x01FF
|
|
#define GEVENT_GWIN_FIRST 0x0200 // GWIN events range from 0x0200 to 0x02FF
|
|
#define GEVENT_GADC_FIRST 0x0300 // GADC events range from 0x0300 to 0x033F
|
|
#define GEVENT_GAUDIN_FIRST 0x0340 // GAUDIN events range from 0x0340 to 0x037F
|
|
#define GEVENT_GAUDOUT_FIRST 0x0380 // GAUDOUT events range from 0x0380 to 0x03BF
|
|
#define GEVENT_USER_FIRST 0x8000 // Any application defined events start at 0x8000
|
|
|
|
// This object can be typecast to any GEventXxxxx type to allow any sub-system (or the application) to create events.
|
|
// The prerequisite is that the new status structure type starts with a field named 'type' of type 'GEventType'.
|
|
// The total status structure also must not exceed GEVENT_MAXIMUM_SIZE bytes.
|
|
// For example, this is used by GWIN button events, GINPUT data streams etc.
|
|
typedef union GEvent_u {
|
|
GEventType type; // The type of this event
|
|
char pad[GEVENT_MAXIMUM_SIZE]; // This is here to allow static initialisation of GEventObject's in the application.
|
|
} GEvent;
|
|
|
|
// A special callback function
|
|
typedef void (*GEventCallbackFn)(void *param, GEvent *pe);
|
|
|
|
// The Listener Object
|
|
typedef struct GListener {
|
|
gfxSem waitqueue; // Private: Semaphore for the listener to wait on.
|
|
gfxSem eventlock; // Private: Protect against more than one sources trying to use this event lock at the same time
|
|
GEventCallbackFn callback; // Private: Call back Function
|
|
void *param; // Private: Parameter for the callback function.
|
|
GEvent event; // Public: The event object into which the event information is stored.
|
|
} GListener;
|
|
|
|
// The Source Object
|
|
typedef struct GSource_t GSource, *GSourceHandle;
|
|
|
|
// This structure is passed to a source to describe a contender listener for sending the current event.
|
|
typedef struct GSourceListener_t {
|
|
GListener *pListener; // The listener
|
|
GSource *pSource; // The source
|
|
unsigned listenflags; // The flags the listener passed when the source was assigned to it.
|
|
unsigned srcflags; // For the source's exclusive use. Initialised as 0 for a new listener source assignment.
|
|
} GSourceListener;
|
|
|
|
/*===========================================================================*/
|
|
/* External declarations. */
|
|
/*===========================================================================*/
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/* How to listen for events (act as a Listener)...
|
|
1. Get handles for all the event sources you are interested in.
|
|
2. Initialise a listener
|
|
3. Attach sources to your listener.
|
|
- Sources can be attached or detached from a listener at any time.
|
|
- A source can be attached to more than one listener.
|
|
4. Loop on getting listener events
|
|
5. When finished detach all sources from the listener
|
|
|
|
How to create events (act as a Source)...
|
|
1. Provide a funtion to the application that returns a GSourceHandle (which can be a pointer to whatever the source wants)
|
|
2. Whenever a possible event occurs call geventGetSourceListener to get a pointer to a GSourceListener.
|
|
This will return NULL when there are no more listeners.
|
|
For each listener - check the flags to see if an event should be sent.
|
|
- use geventGetEvent() to get the event buffer supplied by the listener
|
|
and then call geventSendEvent to send the event.
|
|
- Note: geventGetEvent() may return FALSE to indicate the listener is currently not listening and
|
|
therefore no event should be sent. This situation enables the source to (optionally) flag
|
|
to the listener on its next wait that there have been missed events.
|
|
- Note: The GSourceListener pointer (and the GEvent buffer) are only valid between
|
|
the geventGetSourceListener call and either the geventSendEvent call or the next
|
|
geventGetSourceListener call.
|
|
- Note: All listeners must be processed for this event before anything else is processed.
|
|
*/
|
|
|
|
/*---------- Listener Functions --------------------------------------------*/
|
|
|
|
/**
|
|
* @brief Create a Listener
|
|
* @details If insufficient resources are available it will either assert or return NULL
|
|
* depending on the value of GEVENT_ASSERT_NO_RESOURCE.
|
|
*
|
|
* @param[in] pl A listener
|
|
*/
|
|
void geventListenerInit(GListener *pl);
|
|
|
|
/**
|
|
* @brief Attach a source to a listener
|
|
* @details Flags are interpreted by the source when generating events for each listener.
|
|
* If this source is already assigned to the listener it will update the flags.
|
|
* If insufficient resources are available it will either assert or return FALSE
|
|
* depending on the value of GEVENT_ASSERT_NO_RESOURCE.
|
|
*
|
|
* @param[in] pl The listener
|
|
* @param[in] gsh The source which has to be attached to the listener
|
|
* @param[in] flags The flags
|
|
*
|
|
* @return TRUE if succeeded, FALSE otherwise
|
|
*/
|
|
bool_t geventAttachSource(GListener *pl, GSourceHandle gsh, unsigned flags);
|
|
|
|
/**
|
|
* @brief Detach a source from a listener
|
|
* @details If gsh is NULL detach all sources from this listener and if there is still
|
|
* a thread waiting for events on this listener, it is sent the exit event.
|
|
*
|
|
* @param[in] pl The listener
|
|
* @param[in] gsh The source
|
|
*/
|
|
void geventDetachSource(GListener *pl, GSourceHandle gsh);
|
|
|
|
/**
|
|
* @brief Wait for an event on a listener from an assigned source.
|
|
* @details The type of the event should be checked (pevent->type) and then pevent should
|
|
* be typecast to the actual event type if it needs to be processed.
|
|
* timeout specifies the time to wait in system ticks.
|
|
* TIME_INFINITE means no timeout - wait forever for an event.
|
|
* TIME_IMMEDIATE means return immediately
|
|
* @note The GEvent buffer is staticly allocated within the GListener so the event does not
|
|
* need to be dynamicly freed however it will get overwritten by the next call to
|
|
* this routine.
|
|
*
|
|
* @param[in] pl The listener
|
|
* @param[in] timeout The timeout
|
|
*
|
|
* @return NULL on timeout
|
|
*/
|
|
GEvent *geventEventWait(GListener *pl, delaytime_t timeout);
|
|
|
|
/* @brief Register a callback for an event on a listener from an assigned source.
|
|
* @details The type of the event should be checked (pevent->type) and then pevent should be typecast to the
|
|
* actual event type if it needs to be processed.
|
|
*
|
|
* @params[in] pl The Listener
|
|
* @params[in] fn The function to call back
|
|
* @params[in] param A parameter to pass the callback function
|
|
*
|
|
* @note The GEvent buffer is valid only during the time of the callback. The callback MUST NOT save
|
|
* a pointer to the buffer for use outside the callback.
|
|
* @note An existing callback function is de-registered by passing a NULL for 'fn'. Any existing
|
|
* callback function is replaced. Any thread currently waiting using geventEventWait will be sent the exit event.
|
|
* @note Callbacks occur in a thread context but stack space must be kept to a minumum and
|
|
* the callback must process quickly as all other events are performed on a single thread.
|
|
* @note In the callback function you should never call ANY event functions using your own GListener handle
|
|
* as it WILL create a deadlock and lock the system up.
|
|
* @note Applications should not use this call - geventEventWait() is the preferred mechanism for an
|
|
* application. This call is provided for GUI objects that may not have their own thread.
|
|
*/
|
|
void geventRegisterCallback(GListener *pl, GEventCallbackFn fn, void *param);
|
|
|
|
/*---------- Source Functions --------------------------------------------*/
|
|
|
|
/**
|
|
* @brief Called by a source with a possible event to get a listener record.
|
|
* @details @p lastlr should be NULL on the first call and thereafter the result of the previous call.
|
|
*
|
|
* @param[in] gsh The source handler
|
|
* @param[in] lastlr The source listener
|
|
*
|
|
* @return NULL when there are no more listeners for this source
|
|
*/
|
|
GSourceListener *geventGetSourceListener(GSourceHandle gsh, GSourceListener *lastlr);
|
|
|
|
/**
|
|
* @brief Get the event buffer from the GSourceListener.
|
|
* @details A NULL return allows the source to record (perhaps in glr->scrflags) that the listener
|
|
* has missed events. This can then be notified as part of the next event for the listener.
|
|
* The buffer can only be accessed untill the next call to geventGetSourceListener
|
|
* or geventSendEvent
|
|
*
|
|
* @param[in] psl The source listener
|
|
*
|
|
* @return NULL if the listener is not currently listening.
|
|
*/
|
|
GEvent *geventGetEventBuffer(GSourceListener *psl);
|
|
|
|
/**
|
|
* @brief Called by a source to indicate the listener's event buffer has been filled.
|
|
* @details After calling this function the source must not reference in fields in the GSourceListener or the event buffer.
|
|
*
|
|
* @param[in] psl The source listener
|
|
*/
|
|
void geventSendEvent(GSourceListener *psl);
|
|
|
|
/**
|
|
* @brief Detach any listener that has this source attached
|
|
*
|
|
* @param[in] gsh The source handle
|
|
*/
|
|
void geventDetachSourceListeners(GSourceHandle gsh);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* GFX_USE_GEVENT */
|
|
|
|
#endif /* _GEVENT_H */
|
|
/** @} */
|
|
|