Events in SOFA

Recovering the events from the keyboard or the mouse can be very useful for interactive simulation (ex: controlling surgical instruments) There is already implemented in SOFA a very easy way to access these so-called events during the simulation. To access the event within a SOFA component, you need:

• handleEvent() function: you need to define the inherited function handleEvent. A nice example is available in the component: BaseController.cpp (see at line 71).
• f_listening parameter: activate the boolean f_listening by the function handleEvent in order to listen to the events. This boolean is not activated by default.The best way to activate it is to specify it in the scene file that while writing "listening=1". You can otherwise "hard" code it in your C++ component as follows "myComponent.f_listening.setValue(true)".

Now, you will be able to recover the events and therefore to interact with your simulation. Have fun !

If you still don't receive events, it may be possible than you will need to press Ctrl key.

Mouse or Keyboard Events

template< class DataTypes>
void myComponent< datatypes >::handleEvent(core::objectmodel::Event *event)
{
    // Key pressed event
    if(KeypressedEvent* ev = dynamic_cast< keypressedevent *>(event))
    {
        switch(ev->getKey())
        {
            // The key M is pressed
            case 'M':
            case 'm':
            {
            ....
            }
        }
    }


    // Mouse Events
    if(MouseEvent* ev = dynamic_cast< mouseevent *>(event))
    {
        switch(ev->getState())
        {
            // The left key of the mouse is pressed
            case MouseEvent::LeftPressed:
            {
            ....
            }
        }
    }
}

Specific integration events

Similarly to Mouse or Keyboard events, you can detect specific events during the time integration. These events are managed and sent by the AnimationLoop you are using.

Events related to the mechanics/solving are:

• BeginAnimationStep: start of a time step
• EndAnimationStep: end of a time step
• IntegrationBeginEvent: start of the integration phase
• IntegrationEndEvent: end of the integration phase
• CollisionBeginEvent: start of the collision phase
• CollisionEndEvent: end of the collision phase

Interaction-related events are:

• KeypressedEvent
• KeyreleasedEvent
• MouseEvent
• HapticDeviceEvent
• PauseEvent
• IdleEvent

template< class DataTypes>
void myComponent< datatypes >::handleEvent(core::objectmodel::Event *event)
{
    // Begin of the animation step
    if (dynamic_cast< sofa::simulation::AnimateBeginEvent *>(event))
    {
            ...
    }


    // End of the animation step
    if (dynamic_cast< sofa::simulation::AnimateEndEvent *>(event))
    {
            ...
    }
}