Open layer, then close layer by clicking document.

layerOpen.js

// TODO: Add complete HTML document.

$layer: $('.layer'),
$button: $('.button'),

_initialize: function() {
	$(document).on('click', this._onClick.bind(this));
},

_onClick: function(event) {
	var $target = $(event.target),
		isLayer = $target.is(this.$layer) || $target.parents().is(this.$layer),
		isButton = ($target.is(this.$button) || $target.parents().is(this.$button));

	if (isLayer) {
		return;
	}

	if (isButton && !this.$layer.is(':visible')) {
		this.$layer.show();
	} else {
		this.$layer.hide();
	}
}