function Toggler(button, toggleElement) {
  this.toggleElement = toggleElement;
  this.showing = true;
  button.addEventListener('click', this.onToggleButtonClick.bind(this), false);
}

Toggler.prototype.onToggleButtonClick = function(e) {
  this.toggle();
}

Toggle.prototype.toggle = function() {
  if(this.showing) {
    this.hide();
  } else {
    this.show();
  }
}

Toggle.prototype.show = function() {
  this.toggleElement.classList.remove('hide');
  this.showing = true;
}

Toggle.prototype.hide = function() {
  this.toggleElement.classList.add('hide');
  this.showing = false;
}