/** @param {...string} types */

d3.dispatch = function(types) {

var dispatch = {},

type;

for (var i = 0, n = arguments.length; i < n; i++) {

type = arguments[i];

dispatch[type] = d3_dispatch(type);

}

return dispatch;

};

function d3_dispatch(type) {

var dispatch = {},

listeners = [];

dispatch.add = function(listener) {

for (var i = 0; i < listeners.length; i++) {

if (listeners[i].listener == listener) return dispatch; // already registered

}

listeners.push({listener: listener, on: true});

return dispatch;

};

dispatch.remove = function(listener) {

for (var i = 0; i < listeners.length; i++) {

var l = listeners[i];

if (l.listener == listener) {

l.on = false;

listeners = listeners.slice(0, i).concat(listeners.slice(i + 1));

break;

}

}

return dispatch;

};

dispatch.dispatch = function() {

var ls = listeners; // defensive reference

for (var i = 0, n = ls.length; i < n; i++) {

var l = ls[i];

if (l.on) l.listener.apply(this, arguments);

}

};

return dispatch;

};