Libgdx - How to spawn particles only when I hold mouse button?

So I slowly got to know how to manipulate particle system and emitter in-game through the code, but there is one simple task I can't get to know how... How can I spawn particles ONLY when I hold the mouse button? I tried a work-around by setting the maxCount of emmiter to 0 when its not pressed but then it either doesnt emit particles at all, or just makes the existing ones disappear immidiately, which looks very unnatural and I don't want it. Is there a way to emit them "manually" in render method?