This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Detect browser close event

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by FredMcD

more options

We are working with Firefox Portable ESR 78.6.0 on windows 10 OS We need to detect the close event to override it, or disable it when the user try to close the browser from the taskbar.

With an older version of Firefox Portable ESR (52.2.0), we used the following code to detect browser closure:

var observerService = Components.classes ["@ mozilla.org/observer-service;1"OUND.getService(Components.interfaces.nsIObserverService); observerService.addObserver (this, "quit-application-granted", false); observerService.addObserver (this, "quit-application-requested", false); observerService.addObserver (this, "browser-lastwindow-close-requested", false);


This code is no longer compatible with the version 78.6.0.

When the user close the browser from the taskbar we need to check:

if (user can close) close browser else do not close the browser

So, is there a way or an add-on to install to disable the closing of the browser from the taskbar? Or if possible how can we override the browser's code to prevent the user's click on "close window" ?

We are working with Firefox Portable ESR 78.6.0 on windows 10 OS We need to detect the close event to override it, or disable it when the user try to close the browser from the taskbar. With an older version of Firefox Portable ESR (52.2.0), we used the following code to detect browser closure: var observerService = Components.classes ["@ mozilla.org/observer-service;1"OUND.getService(Components.interfaces.nsIObserverService); observerService.addObserver (this, "quit-application-granted", false); observerService.addObserver (this, "quit-application-requested", false); observerService.addObserver (this, "browser-lastwindow-close-requested", false); This code is no longer compatible with the version 78.6.0. When the user close the browser from the taskbar we need to check: if (user can close) close browser else do not close the browser So, is there a way or an add-on to install to disable the closing of the browser from the taskbar? Or if possible how can we override the browser's code to prevent the user's click on "close window" ?
Attached screenshots

All Replies (1)

more options

Firefox Portable is a 3rd-party build. Support is available here: http://portableapps.com/forums/support/firefox_portable