Is it possible to get the window object from the event in handleEvent?

问题

As in the question... how to get the window object from an event fired in the window scope for example:

handleEvent: function(event) {

  // is window object available here and can we get it from event
}

I can get the window object from other APIs. I was wondering if it was possible to get it from the fired event.

Reference:
handleEvent
Code Snippet using handleEvent

回答1:

I found out the answer ... any of these will get the window object from the event

event.view event.view
event.target.ownerDocument.defaultView event.target
event.originalTarget.ownerGlobal event.originalTarget (Non-standard)

回答2:

It depends on the event. But most usually yes you can. Do a console.log on the event then you might something like targetChromeWindow or something, this one I can't remember i came across it once though while doing something.

Most usually though, get event.target or relatedTarget or originalTarget (theres one more target i forgot what it is) and do ownerDocument.defaultView

If you want the chrome window from that you can get that by doing this:

var DOMWin = win.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIWebNavigation)
.QueryInterface(Ci.nsIDocShellTreeItem)
.rootTreeItem
.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIDOMWindow);

回答3:

The following will populate the window and document variables if they do not already exist. It should work from any scope/context:

if (typeof window === "undefined") {
    //If there is no window defined, get the most recent.
    var window = Components.classes["@mozilla.org/appshell/window-mediator;1"]
                           .getService(Components.interfaces.nsIWindowMediator)
                           .getMostRecentWindow("navigator:browser");
}

if (typeof document === "undefined") {
    //If there is no document defined, get it
    var document = window.content.document;
}

Here are some additional variables which might be useful to have available, depending on what you are doing:

if (typeof gBrowser === "undefined") {
    //If there is no gBrowser defined, get it
    var gBrowser = window.gBrowser;
}

var tab = gBrowser.selectedTab;
var browserForTab = gBrowser.getBrowserForTab( tab );
var notificationBox = gBrowser.getNotificationBox( browserForTab );
var ownerDocument = gBrowser.ownerDocument;

来源：https://stackoverflow.com/questions/25979154/is-it-possible-to-get-the-window-object-from-the-event-in-handleevent