contextMenuShowEvent

A BrowserSetting object which determines whether the browser's context menu is shown on the mouseup event or on the mousedown event.

Its underlying value is a string that may be either "mouseup" or "mousedown".

The default value is "mouseup" on Windows, and "mousedown" on macOS and Linux. Assigning to it on Windows has no effect - the setting is only designed to allow the context menu to be opened on mouseup instead of mousedown, not the inverse.

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Set the setting to "mouseup":

function logResult(result) {
  console.log(`Setting was modified: ${result}`);
}

browser.browserSettings.contextMenuShowEvent.set({value: "mouseup"}).
  then(logResult);