/**
* Adds bubbling and delegation support to DOM events focus and blur.
*
* @module event
* @submodule event-focus
*/
var Event = Y.Event,
YLang = Y.Lang,
isString = YLang.isString,
arrayIndex = Y.Array.indexOf,
useActivate = YLang.isFunction(
Y.DOM.create('<p onbeforeactivate=";"/>').onbeforeactivate);
function define(type, proxy, directEvent) {
var nodeDataKey = '_' + type + 'Notifiers';
Y.Event.define(type, {
_attach: function (el, notifier, delegate) {
if (Y.DOM.isWindow(el)) {
return Event._attach([type, function (e) {
notifier.fire(e);
}, el]);
} else {
return Event._attach(
[proxy, this._proxy, el, this, notifier, delegate],
{ capture: true });
}
},
_proxy: function (e, notifier, delegate) {
var target = e.target,
currentTarget = e.currentTarget,
notifiers = target.getData(nodeDataKey),
yuid = Y.stamp(currentTarget._node),
defer = (useActivate || target !== currentTarget),
directSub;
notifier.currentTarget = (delegate) ? target : currentTarget;
notifier.container = (delegate) ? currentTarget : null;
// Maintain a list to handle subscriptions from nested
// containers div#a>div#b>input #a.on(focus..) #b.on(focus..),
// use one focus or blur subscription that fires notifiers from
// #b then #a to emulate bubble sequence.
if (!notifiers) {
notifiers = {};
target.setData(nodeDataKey, notifiers);
// only subscribe to the element's focus if the target is
// not the current target (
if (defer) {
directSub = Event._attach(
[directEvent, this._notify, target._node]).sub;
directSub.once = true;
}
} else {
// In old IE, defer is always true. In capture-phase browsers,
// The delegate subscriptions will be encountered first, which
// will establish the notifiers data and direct subscription
// on the node. If there is also a direct subscription to the
// node's focus/blur, it should not call _notify because the
// direct subscription from the delegate sub(s) exists, which
// will call _notify. So this avoids _notify being called
// twice, unnecessarily.
defer = true;
}
if (!notifiers[yuid]) {
notifiers[yuid] = [];
}
notifiers[yuid].push(notifier);
if (!defer) {
this._notify(e);
}
},
_notify: function (e, container) {
var currentTarget = e.currentTarget,
notifierData = currentTarget.getData(nodeDataKey),
axisNodes = currentTarget.ancestors(),
doc = currentTarget.get('ownerDocument'),
delegates = [],
// Used to escape loops when there are no more
// notifiers to consider
count = notifierData ?
Y.Object.keys(notifierData).length :
0,
target, notifiers, notifier, yuid, match, tmp, i, len, sub, ret;
// clear the notifications list (mainly for delegation)
currentTarget.clearData(nodeDataKey);
// Order the delegate subs by their placement in the parent axis
axisNodes.push(currentTarget);
// document.get('ownerDocument') returns null
// which we'll use to prevent having duplicate Nodes in the list
if (doc) {
axisNodes.unshift(doc);
}
// ancestors() returns the Nodes from top to bottom
axisNodes._nodes.reverse();
// Store the count for step 2
tmp = count;
axisNodes.some(function (node) {
var yuid = Y.stamp(node),
notifiers = notifierData[yuid],
i, len;
if (notifiers) {
count--;
for (i = 0, len = notifiers.length; i < len; ++i) {
if (notifiers[i].handle.sub.filter) {
delegates.push(notifiers[i]);
}
}
}
return !count;
});
count = tmp;
// Walk up the parent axis, notifying direct subscriptions and
// testing delegate filters.
while (count && (target = axisNodes.shift())) {
yuid = Y.stamp(target);
notifiers = notifierData[yuid];
if (notifiers) {
for (i = 0, len = notifiers.length; i < len; ++i) {
notifier = notifiers[i];
sub = notifier.handle.sub;
match = true;
e.currentTarget = target;
if (sub.filter) {
match = sub.filter.apply(target,
[target, e].concat(sub.args || []));
// No longer necessary to test against this
// delegate subscription for the nodes along
// the parent axis.
delegates.splice(
arrayIndex(delegates, notifier), 1);
}
if (match) {
// undefined for direct subs
e.container = notifier.container;
ret = notifier.fire(e);
}
if (ret === false || e.stopped === 2) {
break;
}
}
delete notifiers[yuid];
count--;
}
if (e.stopped !== 2) {
// delegates come after subs targeting this specific node
// because they would not normally report until they'd
// bubbled to the container node.
for (i = 0, len = delegates.length; i < len; ++i) {
notifier = delegates[i];
sub = notifier.handle.sub;
if (sub.filter.apply(target,
[target, e].concat(sub.args || []))) {
e.container = notifier.container;
e.currentTarget = target;
ret = notifier.fire(e);
}
if (ret === false || e.stopped === 2) {
break;
}
}
}
if (e.stopped) {
break;
}
}
},
on: function (node, sub, notifier) {
sub.handle = this._attach(node._node, notifier);
},
detach: function (node, sub) {
sub.handle.detach();
},
delegate: function (node, sub, notifier, filter) {
if (isString(filter)) {
sub.filter = function (target) {
return Y.Selector.test(target._node, filter,
node === target ? null : node._node);
};
}
sub.handle = this._attach(node._node, notifier, true);
},
detachDelegate: function (node, sub) {
sub.handle.detach();
}
}, true);
}
// For IE, we need to defer to focusin rather than focus because
// `el.focus(); doSomething();` executes el.onbeforeactivate, el.onactivate,
// el.onfocusin, doSomething, then el.onfocus. All others support capture
// phase focus, which executes before doSomething. To guarantee consistent
// behavior for this use case, IE's direct subscriptions are made against
// focusin so subscribers will be notified before js following el.focus() is
// executed.
if (useActivate) {
// name capture phase direct subscription
define("focus", "beforeactivate", "focusin");
define("blur", "beforedeactivate", "focusout");
} else {
define("focus", "focus", "focus");
define("blur", "blur", "blur");
}