---
name: "SoTimerQueueSensor"
section: "3"
platform: "linux"
package: "coin"
version: "1:4.0.10-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/SoTimerQueueSensor"
---

# SoTimerQueueSensor(3)

The SoTimerQueueSensor class is the abstract base class for sensors triggering on certain timer events.

## NAME

SoTimerQueueSensor - The **SoTimerQueueSensor** class is the abstract base class for sensors triggering on certain timer events.

## SYNOPSIS

\#include \<Inventor/sensors/SoTimerQueueSensor.h\>

Inherits **SoSensor**.

Inherited by **SoAlarmSensor**, and **SoTimerSensor**.

### Public Member Functions

**SoTimerQueueSensor** (void)\
 **SoTimerQueueSensor** (SoSensorCB \***func**, void \*data)\
 virtual **~SoTimerQueueSensor** (void)\
 const **SbTime** & **getTriggerTime** (void) const\
 virtual void **schedule** (void)\
 virtual void **unschedule** (void)\
 virtual SbBool **isScheduled** (void) const\
 virtual void **trigger** (void)\

Public Member Functions inherited from **SoSensor** **SoSensor** (void)\
 **SoSensor** (SoSensorCB \***func**, void \*data)\
 virtual **~SoSensor** (void)\
 void **setFunction** (SoSensorCB \*callbackfunction)\
 SoSensorCBPtr **getFunction** (void) const\
 void **setData** (void \*callbackdata)\
 void \* **getData** (void) const\
 void **setNextInQueue** (**SoSensor** \*next)\
 **SoSensor** \* **getNextInQueue** (void) const\

### Protected Member Functions

void **setTriggerTime** (const **SbTime** &time)\

### Protected Attributes

SbBool **scheduled**\

Protected Attributes inherited from **SoSensor** SoSensorCB \* **func**\
 void \* **funcData**\

### Additional Inherited Members

Static Public Member Functions inherited from **SoSensor** static void **initClass** (void)\

## Detailed Description

The **SoTimerQueueSensor** class is the abstract base class for sensors triggering on certain timer events.

Timer sensors triggers upon specific points in time.

This class is an abstract superclass which collects the common interface of the various non-abstract timer sensor classes. See the documentation of the subclasses for information on what ways there are to specify base times, intervals, alarm-style single triggering, repeated triggers, etc.

Note that Coin timer sensors should in no way be considered "hardreal time". That is, you *cannot* expect a timer to always trigger at the exact moment it was set up for. Delays in triggering could be due to other activities in Coin, a task suspended, or heavy load from other applications on the system. These situations could all cause the processing of sensor queues (from SoQt / SoWin / SoXt / whatever) to be slightly delayed, thereby causing delays in timer sensor triggering.

On modern systems, a timer will usually trigger within a few milliseconds of its designated time, though.

If a timer sensor cannot trigger at the exact moment it has been scheduled, it will be triggered at the first opportunity after the scheduled time has passed.

Here's a simple usage example. It's a standalone example, which only demonstrates how to set up a repeating timer sensor with a callback:

```
#include <Inventor/Xt/SoXt.h>
#include <Inventor/sensors/SoTimerSensor.h>
#include <cstdio>
static void
timeSensorCallback(void * data, SoSensor * sensor)
{
  SbTime time = SbTime::getTimeOfDay();
  SbString string = time.format("%S.%i");
  (void)printf("%s\n", string.getString());
}
int
main(int argc, char ** argv)
{
  SoXt::init("test");
  SoTimerSensor * timeSensor = new SoTimerSensor;
  timeSensor->setFunction(timeSensorCallback);
  timeSensor->setBaseTime(SbTime::getTimeOfDay());
  timeSensor->setInterval(1.0f);
  timeSensor->schedule();
  SoXt::mainLoop();
  return 0;
}
```

## Constructor & Destructor Documentation

### SoTimerQueueSensor::SoTimerQueueSensor (void )

Default constructor.

### SoTimerQueueSensor::SoTimerQueueSensor (SoSensorCB \* func, void \* data)

Constructor taking as arguments the sensor callback function and the userdata which will be passed the callback.

**See also**

**setFunction()**, **setData()**

### SoTimerQueueSensor::~SoTimerQueueSensor (void ) \[virtual\]

Destructor.

## Member Function Documentation

### const SbTime & SoTimerQueueSensor::getTriggerTime (void ) const

Returns the time at which the sensor will trigger.

**See also**

**setTriggerTime()**

### void SoTimerQueueSensor::schedule (void ) \[virtual\]

Put the sensor in the global timer queue.

**See also**

**unschedule()**, **isScheduled()**

Implements **SoSensor**.

Reimplemented in **SoAlarmSensor**, and **SoTimerSensor**.

### void SoTimerQueueSensor::unschedule (void ) \[virtual\]

Remove sensor from the timer queue, without triggering it first.

**See also**

**schedule()**, **isScheduled()**

Implements **SoSensor**.

Reimplemented in **SoTimerSensor**.

### SbBool SoTimerQueueSensor::isScheduled (void ) const \[virtual\]

Check if this sensor is scheduled for triggering.

**See also**

**schedule()**, **unschedule()**

Implements **SoSensor**.

### void SoTimerQueueSensor::trigger (void ) \[virtual\]

Trigger the sensor's callback function.

Reimplemented from **SoSensor**.

### void SoTimerQueueSensor::setTriggerTime (const SbTime & time) \[protected\]

Set absolute time at which to trigger the sensor.

**See also**

**getTriggerTime()**

## Member Data Documentation

### SbBool SoTimerQueueSensor::scheduled \[protected\]

TRUE if the sensor is currently scheduled.

## Author

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