Part of a polish tutorial

flickering_hearts_polish.js

// Have the heart container "pop" in
polish.popIn(this, bind(this, function () {
	// Wait a moment, then start to flicker away… then disappear
	var numFlashes = 20;
	this.numFlashes = 1;

	// Wait 1 second
	this.delayTween(1000);

	// Add flashes to the queue
	for (var i = 0; i < numFlashes; ++i) {
		this.delayTween((30 - i) * 6, bind(this, function () {
			// Toggle opacity
			this.opacity = this.opacity == 1 ? 0 : 1;

			// Gone through all the flashes? Then remove it
			if (++this.numFlashes == numFlashes) {
				this.remove();
			}
		}));
	}
}));

this.opacity ^= 1;

Yay XOR