Programming Reference:Stimulus Class

Location

src/shared/modules/application/stimuli

Synopsis

The Stimulus class is a virtual base class which defines an event handling interface for stimuli. There, a "Stimulus" is defined as "an object that can present (and possibly conceal) itself."

The Stimulus class is purely virtual; descendant classes need to implement its OnPresent() and OnConceal() event handlers. An application uses the public Stimulus::Present() and Stimulus::Conceal() functions to control its behavior; these, in turn, call the virtual event handlers.

The SetOfStimuli class allows to define sets of stimuli, and to present or conceal all of the stimuli it contains.

Properties

int Tag (rw)

An arbitrary integer that may be used to encode information about a given stimulus (e.g., its corresponding row in a configuration matrix).

Methods

Present()

Prompts a stimulus to present itself by calling its OnPresent() event handler.

Conceal()

Prompts a stimulus to conceal itself by calling its OnConceal() event handler.

Events

OnPresent

In its OnPresent event handler, a stimulus is supposed to present itself, e.g., to make itself visible, play itself if it is a sound or a movie, or highlight itself if it is a P300 matrix element.

OnConceal

In its OnConceal event handler, a stimulus is supposed to conceal itself, e.g., make itself invisible, or switch back to normal mode. For non-visual stimuli, this handler is typically empty.

This event is called Conceal rather than Hide because "Hide" is already used as a name for a GraphObject's function that makes it invisible.

Descendants

The Stimulus class is parent to a class hierarchy containing a number of auditory and visual stimuli:

Stimulus |-> VisualStimulus |-> ImageStimulus
         |                  |-> TextStimulus
         |-> AudioStimulus
         |-> SpeechStimulus
         |-> SoundStimulus

See also

Programming Reference:Association Class, Programming Reference:Target Class, Programming Reference:StimulusTask Class

Programming Reference:AudioStimulus Class, Programming Reference:ImageStimulus Class, Programming Reference:TextStimulus Class, Programming Reference:VisualStimulus Class,

Programming Reference:GraphObject Class