mediawiki-extensions-Visual.../modules/ve2/ve.Node.js
Trevor Parscal c9ce7dbffe Added some basic coverage for ve.*Node classes
* prototype.canHaveChildren
* prototype.canHaveGrandchildren
* prototype.getType
* prototype.getParent
* prototype.getRoot
* prototype.setRoot
* prototype.attach
* prototype.detach

Change-Id: I920f7c9504e467f4818df537608760165c28d432
2012-04-19 14:43:58 -07:00

127 lines
2.7 KiB
JavaScript

/**
* Creates an ve.Node object.
*
* @class
* @abstract
* @constructor
* @extends {ve.EventEmitter}
* @param {String} type Symbolic name of node type
*/
ve.Node = function( type ) {
// Inheritance
ve.EventEmitter.call( this );
// Properties
this.type = type;
this.parent = null;
this.root = this;
// Convenience function for emitting update events
// Has this bound to the closure scope, so can be passed as a callback
var _this = this;
this.emitUpdate = function() {
_this.emit( 'update' );
};
};
/* Methods */
/**
* Checks if this node can have child nodes.
*
* @method
* @abstract
* @returns {Boolean} Whether this node can have children
*/
ve.Node.prototype.canHaveChildren = function() {
throw 've.Node.canHaveChildren not implemented in this subclass:' + this.constructor;
};
/**
* Checks if this node can have child nodes that can have child nodes.
*
* If this function returns false, only nodes that can't have children can be attached to this node.
* If canHaveChildren() returns false, this method must also return false.
*
* @method
* @abstract
* @returns {Boolean} Whether this node can have grandchildren
*/
ve.Node.prototype.canHaveGrandchildren = function() {
throw 've.Node.canHaveGrandchildren not implemented in this subclass:' + this.constructor;
};
/**
* Gets the symbolic node type name.
*
* @method
* @returns {String} Symbolic name of element type
*/
ve.Node.prototype.getType = function() {
return this.type;
};
/**
* Gets a reference to this node's parent.
*
* @method
* @returns {ve.Node} Reference to this node's parent
*/
ve.Node.prototype.getParent = function() {
return this.parent;
};
/**
* Gets the root node in the tree this node is currently attached to.
*
* @method
* @returns {ve.Node} Root node
*/
ve.Node.prototype.getRoot = function() {
return this.root;
};
/**
* Sets the root node to this and all of its children.
*
* This method is overridden by nodes with children.
*
* @method
* @param {ve.Node} root Node to use as root
*/
ve.Node.prototype.setRoot = function( root ) {
// TODO events?
this.root = root;
};
/**
* Attaches this node to another as a child.
*
* @method
* @param {ve.Node} parent Node to attach to
* @emits attach (parent)
*/
ve.Node.prototype.attach = function( parent ) {
this.emit( 'beforeAttach', parent );
this.parent = parent;
this.setRoot( parent.getRoot() );
this.emit( 'afterAttach', parent );
};
/**
* Detaches this node from its parent.
*
* @method
* @emits detach
*/
ve.Node.prototype.detach = function() {
this.emit( 'beforeDetach' );
this.parent = null;
this.setRoot( this );
this.emit( 'afterDetach' );
};
/* Inheritance */
ve.extendClass( ve.Node, ve.EventEmitter );