SemanticScuttle/includes/js/dojo/_base/connect.js

285 lines
10 KiB
JavaScript

if(!dojo._hasResource["dojo._base.connect"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo._base.connect"] = true;
dojo.provide("dojo._base.connect");
dojo.require("dojo._base.lang");
// this file courtesy of the TurboAjax Group, licensed under a Dojo CLA
// low-level delegation machinery
dojo._listener = {
// create a dispatcher function
getDispatcher: function(){
// following comments pulled out-of-line to prevent cloning them
// in the returned function.
// - indices (i) that are really in the array of listeners (ls) will
// not be in Array.prototype. This is the 'sparse array' trick
// that keeps us safe from libs that take liberties with built-in
// objects
// - listener is invoked with current scope (this)
return function(){
var ap=Array.prototype, c=arguments.callee, ls=c._listeners, t=c.target;
// return value comes from original target function
var r=t && t.apply(this, arguments);
// invoke listeners after target function
for(var i in ls){
if(!(i in ap)){
ls[i].apply(this, arguments);
}
}
// return value comes from original target function
return r;
}
},
// add a listener to an object
add: function(/*Object*/ source, /*String*/ method, /*Function*/ listener){
// Whenever 'method' is invoked, 'listener' will have the same scope.
// Trying to supporting a context object for the listener led to
// complexity.
// Non trivial to provide 'once' functionality here
// because listener could be the result of a dojo.hitch call,
// in which case two references to the same hitch target would not
// be equivalent.
source = source || dojo.global;
// The source method is either null, a dispatcher, or some other function
var f = source[method];
// Ensure a dispatcher
if(!f||!f._listeners){
var d = dojo._listener.getDispatcher();
// original target function is special
d.target = f;
// dispatcher holds a list of listeners
d._listeners = [];
// redirect source to dispatcher
f = source[method] = d;
}
// The contract is that a handle is returned that can
// identify this listener for disconnect.
//
// The type of the handle is private. Here is it implemented as Integer.
// DOM event code has this same contract but handle is Function
// in non-IE browsers.
//
// We could have separate lists of before and after listeners.
return f._listeners.push(listener) ; /*Handle*/
},
// remove a listener from an object
remove: function(/*Object*/ source, /*String*/ method, /*Handle*/ handle){
var f = (source||dojo.global)[method];
// remember that handle is the index+1 (0 is not a valid handle)
if(f && f._listeners && handle--){
delete f._listeners[handle];
}
}
};
// Multiple delegation for arbitrary methods.
// This unit knows nothing about DOM,
// but we include DOM aware
// documentation and dontFix
// argument here to help the autodocs.
// Actual DOM aware code is in event.js.
dojo.connect = function(/*Object|null*/ obj,
/*String*/ event,
/*Object|null*/ context,
/*String|Function*/ method,
/*Boolean*/ dontFix){
// summary:
// Create a link that calls one function when another executes.
//
// description:
// Connects method to event, so that after event fires, method
// does too. All connected functions are passed the same arguments as
// the event function was initially called with. You may connect as
// many methods to event as needed.
//
// event must be a string. If obj is null, dojo.global is used.
//
// null arguments may simply be omitted.
//
// obj[event] can resolve to a function or undefined (null).
// If obj[event] is null, it is assigned a function.
//
// The return value is a handle that is needed to
// remove this connection with dojo.disconnect.
//
// obj:
// The source object for the event function.
// Defaults to dojo.global if null.
// If obj is a DOM node, the connection is delegated
// to the DOM event manager (unless dontFix is true).
//
// event:
// String name of the event function in obj.
// I.e. identifies a property obj[event].
//
// context:
// The object that method will receive as "this".
//
// If context is null and method is a function, then method
// inherits the context of event.
//
// If method is a string then context must be the source
// object object for method (context[method]). If context is null,
// dojo.global is used.
//
// method:
// A function reference, or name of a function in context.
// The function identified by method fires after event does.
// method receives the same arguments as the event.
// See context argument comments for information on method's scope.
//
// dontFix:
// If obj is a DOM node, set dontFix to true to prevent delegation
// of this connection to the DOM event manager.
//
// example:
// When obj.onchange(), do ui.update():
// | dojo.connect(obj, "onchange", ui, "update");
// | dojo.connect(obj, "onchange", ui, ui.update); // same
//
// example:
// Using return value for disconnect:
// | var link = dojo.connect(obj, "onchange", ui, "update");
// | ...
// | dojo.disconnect(link);
//
// example:
// When onglobalevent executes, watcher.handler is invoked:
// | dojo.connect(null, "onglobalevent", watcher, "handler");
//
// example:
// When ob.onCustomEvent executes, customEventHandler is invoked:
// | dojo.connect(ob, "onCustomEvent", null, "customEventHandler");
// | dojo.connect(ob, "onCustomEvent", "customEventHandler"); // same
//
// example:
// When ob.onCustomEvent executes, customEventHandler is invoked
// with the same scope (this):
// | dojo.connect(ob, "onCustomEvent", null, customEventHandler);
// | dojo.connect(ob, "onCustomEvent", customEventHandler); // same
//
// example:
// When globalEvent executes, globalHandler is invoked
// with the same scope (this):
// | dojo.connect(null, "globalEvent", null, globalHandler);
// | dojo.connect("globalEvent", globalHandler); // same
// normalize arguments
var a=arguments, args=[], i=0;
// if a[0] is a String, obj was ommited
args.push(dojo.isString(a[0]) ? null : a[i++], a[i++]);
// if the arg-after-next is a String or Function, context was NOT omitted
var a1 = a[i+1];
args.push(dojo.isString(a1)||dojo.isFunction(a1) ? a[i++] : null, a[i++]);
// absorb any additional arguments
for(var l=a.length; i<l; i++){ args.push(a[i]); }
// do the actual work
return dojo._connect.apply(this, args); /*Handle*/
}
// used by non-browser hostenvs. always overriden by event.js
dojo._connect = function(obj, event, context, method){
var l=dojo._listener, h=l.add(obj, event, dojo.hitch(context, method));
return [obj, event, h, l]; // Handle
}
dojo.disconnect = function(/*Handle*/ handle){
// summary:
// Remove a link created by dojo.connect.
// description:
// Removes the connection between event and the method referenced by handle.
// handle:
// the return value of the dojo.connect call that created the connection.
if(handle && handle[0] !== undefined){
dojo._disconnect.apply(this, handle);
// let's not keep this reference
delete handle[0];
}
}
dojo._disconnect = function(obj, event, handle, listener){
listener.remove(obj, event, handle);
}
// topic publish/subscribe
dojo._topics = {};
dojo.subscribe = function(/*String*/ topic, /*Object|null*/ context, /*String|Function*/ method){
// summary:
// Attach a listener to a named topic. The listener function is invoked whenever the
// named topic is published (see: dojo.publish).
// Returns a handle which is needed to unsubscribe this listener.
// context:
// Scope in which method will be invoked, or null for default scope.
// method:
// The name of a function in context, or a function reference. This is the function that
// is invoked when topic is published.
// example:
// | dojo.subscribe("alerts", null, function(caption, message){ alert(caption + "\n" + message); };
// | dojo.publish("alerts", [ "read this", "hello world" ]);
// support for 2 argument invocation (omitting context) depends on hitch
return [topic, dojo._listener.add(dojo._topics, topic, dojo.hitch(context, method))]; /*Handle*/
}
dojo.unsubscribe = function(/*Handle*/ handle){
// summary:
// Remove a topic listener.
// handle:
// The handle returned from a call to subscribe.
// example:
// | var alerter = dojo.subscribe("alerts", null, function(caption, message){ alert(caption + "\n" + message); };
// | ...
// | dojo.unsubscribe(alerter);
if(handle){
dojo._listener.remove(dojo._topics, handle[0], handle[1]);
}
}
dojo.publish = function(/*String*/ topic, /*Array*/ args){
// summary:
// Invoke all listener method subscribed to topic.
// topic:
// The name of the topic to publish.
// args:
// An array of arguments. The arguments will be applied
// to each topic subscriber (as first class parameters, via apply).
// example:
// | dojo.subscribe("alerts", null, function(caption, message){ alert(caption + "\n" + message); };
// | dojo.publish("alerts", [ "read this", "hello world" ]);
// Note that args is an array, which is more efficient vs variable length
// argument list. Ideally, var args would be implemented via Array
// throughout the APIs.
var f = dojo._topics[topic];
if(f){
f.apply(this, args||[]);
}
}
dojo.connectPublisher = function( /*String*/ topic,
/*Object|null*/ obj,
/*String*/ event){
// summary:
// Ensure that everytime obj.event() is called, a message is published
// on the topic. Returns a handle which can be passed to
// dojo.disconnect() to disable subsequent automatic publication on
// the topic.
// topic:
// The name of the topic to publish.
// obj:
// The source object for the event function. Defaults to dojo.global
// if null.
// event:
// The name of the event function in obj.
// I.e. identifies a property obj[event].
// example:
// | dojo.connectPublisher("/ajax/start", dojo, "xhrGet"};
var pf = function(){ dojo.publish(topic, arguments); }
return (event) ? dojo.connect(obj, event, pf) : dojo.connect(obj, pf); //Handle
};
}