Label.js

module.exports = Label;

/**
 * A label represents the element(s) which further describe a link.
 * It encapsulates the property and its inverse property.
 * @param property the property; the inverse is inferred
 * @param link the link this label belongs to
 */
function Label( property, link ){
  this.link = function (){
    return link;
  };
  
  this.property = function (){
    return property;
  };
  
  // "Forward" the fixed value set on the property to avoid having to access this container
  Object.defineProperty(this, "fixed", {
    get: function (){
      var inverseFixed = property.inverse() ? property.inverse().fixed : false;
      return property.fixed || inverseFixed;
    },
    set: function ( v ){
      property.fixed = v;
      if ( property.inverse() ) property.inverse().fixed = v;
    }
  });
  this.frozen = property.frozen;
  this.locked = property.locked;
  this.pinned = property.pinned;
}

Label.prototype.actualRadius = function (){
  return this.property().actualRadius();
};

Label.prototype.draw = function ( container ){
  return this.property().draw(container);
};

Label.prototype.inverse = function (){
  return this.property().inverse();
};

Label.prototype.equals = function ( other ){
  if ( !other ) {
    return false;
  }
  
  var instance = other instanceof Label;
  var equalProperty = this.property().equals(other.property());
  
  var equalInverse = false;
  if ( this.inverse() ) {
    equalInverse = this.inverse().equals(other.inverse());
  } else if ( !other.inverse() ) {
    equalInverse = true;
  }
  
  return instance && equalProperty && equalInverse;
};