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SoSensorManager Class Reference
[Sensor classes]

The SoSensorManager class handles the sensor queues. More...

#include <Inventor/sensors/SoSensorManager.h>

List of all members.

Public Member Functions

 SoSensorManager (void)
 ~SoSensorManager ()
void insertDelaySensor (SoDelayQueueSensor *s)
void insertTimerSensor (SoTimerQueueSensor *s)
void removeDelaySensor (SoDelayQueueSensor *s)
void removeTimerSensor (SoTimerQueueSensor *s)
void setChangedCallback (void(*func)(void *), void *data)
void rescheduleTimer (SoTimerSensor *s)
void removeRescheduledTimer (SoTimerQueueSensor *s)
void processDelayQueue (SbBool isidle)
void processImmediateQueue (void)
void processTimerQueue (void)
SbBool isDelaySensorPending (void)
SbBool isTimerSensorPending (SbTime &tm)
void setDelaySensorTimeout (const SbTime &t)
const SbTimegetDelaySensorTimeout (void)
int doSelect (int nfds, void *readfds, void *writefds, void *exceptfds, struct timeval *userTimeOut)


Detailed Description

The SoSensorManager class handles the sensor queues.

There are two major sensor types in Coin, "delay" sensors and "timer" sensors:

Each of these two types has its own queue, which is handled by the SoSensorManager. The queues are kept in sorted order by SoSensorManager, either according to trigger-time (for timer sensors) or by priority (for delay sensors).

The SoSensorManager provides methods for managing these queues, by insertion and removal of sensors, and processing (emptying) of the queues.

The sensor mechanism is crucial in Coin for a number of important features, most notably automatic scheduling redrawal upon changes, and for making it possible to set up animations in the scenegraph which does not need any additional book-keeping from the application code.

SoSensorManager should usually be considered as an internal class in the Coin API. It is only interesting for application programmers when implementing new windowsystem-specific libraries (like Systems in Motion's SoQt, SoXt, SoGtk or SoWin) or wrappers. Then one has to set up code to empty the queues at the correct intervals. For detailed information on how to do that, we would advise you to look at the implementation of said mechanisms in the So*-libraries which SIM provides.

See also:
SoSensor SoTimerQueueSensor SoDelayQueueSensor

SoTimerSensor SoAlarmSensor

SoIdleSensor SoDataSensor SoOneShotSensor

SoPathSensor SoFieldSensor SoNodeSensor


Constructor & Destructor Documentation

SoSensorManager::SoSensorManager void   ) 
 

Constructor.

SoSensorManager::~SoSensorManager  ) 
 

Destructor.


Member Function Documentation

void SoSensorManager::insertDelaySensor SoDelayQueueSensor newentry  ) 
 

Add a new entry to the queue of delay sensors.

See also:
removeFromQueue()

void SoSensorManager::insertTimerSensor SoTimerQueueSensor newentry  ) 
 

Add a new entry to the timer queue of sensors. The queue will be sorted in order of supposed trigger time.

See also:
removeFromQueue()

void SoSensorManager::removeDelaySensor SoDelayQueueSensor entry  ) 
 

Remove an entry from the queue of prioritized sensors.

See also:
addToQueue()

void SoSensorManager::removeTimerSensor SoTimerQueueSensor entry  ) 
 

Remove an entry from the queue of timer sensors.

void SoSensorManager::setChangedCallback void(*  func)(void *),
void *  data
 

For setting up a callback function to be invoked whenever any of the sensor queues are changed.

This callback should typically be responsible for updating the client-side mechanism which is used for processing the queues.

void SoSensorManager::rescheduleTimer SoTimerSensor s  ) 
 

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

void SoSensorManager::removeRescheduledTimer SoTimerQueueSensor s  ) 
 

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

void SoSensorManager::processDelayQueue SbBool  isidle  ) 
 

Trigger all delay queue entries in priority order.

The isidle flag indicates whether or not the processing happens because the application is idle or because the delay queue timeout was reached.

See also:
SoDB::setDelaySensorTimeout()

void SoSensorManager::processImmediateQueue void   ) 
 

Process all immediate sensors (delay sensors with priority 0).

Be aware that you might risk an infinite loop using immediate sensors. Unlike delay queue sensors, immediate sensors can be rescheduled and triggered multiple times during immediate queue processing.

See also:
SoDelayQueueSensor::setPriority()

void SoSensorManager::processTimerQueue void   ) 
 

Trigger all the timers which has expired.

SbBool SoSensorManager::isDelaySensorPending void   ) 
 

Returns TRUE if at least one delay sensor or immediate sensor is present in the respective queue, otherwise FALSE.

SbBool SoSensorManager::isTimerSensorPending SbTime tm  ) 
 

Returns TRUE if at least one timer sensor is present in the queue, otherwise FALSE.

If sensors are pending, the time interval until the next one should be triggered will be put in the tm variable.

void SoSensorManager::setDelaySensorTimeout const SbTime t  ) 
 

Delay sensors are usually triggered only when the system is idle. But when there are continuous updates to the scene graph, there's a possibility that the delay queue will starve and sensors are never triggered. To make sure this won't happen, this is a timeout value for the delay queue. When this timeout has been reached, the sensors in the delay queue gets processed before other sensors and events. This method will let the user set this timeout value.

The default value is 1/12 of a second.

See also:
getDelaySensorTimeout(), SoDelayQueueSensor

const SbTime & SoSensorManager::getDelaySensorTimeout void   ) 
 

Returns the timeout value for sensors in the delay queue.

See also:
setDelaySensorTimeout(), SoDelayQueueSensor

int SoSensorManager::doSelect int  nfds,
void *  readfds,
void *  writefds,
void *  exceptfds,
struct timeval *  usertimeout
 

This is a wrapper around the standard select(2) call, which will make sure the sensor queues are updated while waiting for any action to happen on the given file descriptors.

The void* arguments must be valid pointers to fd_set structures. We've changed this from the original SGI Inventor API to avoid messing up the header file with system-specific includes.


The documentation for this class was generated from the following files:
Generated on Tue Jul 27 23:53:07 2004 for Coin by doxygen 1.3.7