1938623 - Support dynamically disabling main action button in PopupNotifications

Status: NEW

(Toolkit :: PopupNotifications and Notification Bars, enhancement)

Description

[Rob Wu [:robwu]]

The popupnotification element defines the mainactiondisabled attribute that mirrors to the disabled property of the primary button (e.g. "Allow" button in permissions prompts). I tried setting this property, but it disappeared because PopupNotifications._setNotificationUIState toggles the same attribute.

Ideally, PopupNotifications should offer first-class support for toggling the primary's button disabled status. It already has support for disabling a button (by setting mainAction.disabled), but there is no API to update its flag later.

More details:
PopupNotifications._setNotificationUIState removes the "mainactiondisabled" attribute by default, because PopupNotifications supports an optional checkbox option that is linked to the disabled state of the primary button. The only consumer is WebRTC prompt logic (source), which conditionally sets the checkbox option. Because the checkbox option is sometimes present and sometimes absent, PopupNotifications cannot tell for sure whether the button should be disabled, and clears the "mainactiondisabled" just to be safe.

When I added a (XUL) checkbox that toggles the mainactiondisabled attribute depending on the checkbox state (in bug 1931548), the main button's disabled state got out of sync. This is because toggling my custom checkbox dispatches a "command" event, that bubbles up and is captured by PopupNotifications._onCommand, which in turn calls _setNotificationUIState() that removes the mainactiondisabled attribute that I had just set. As a work-around for my use case (see patch of bug 1931548), I set the invalidselection attribute because I noticed that the PopupNotifications._setNotificationUIState method mirrors that attribute by default, and there is nothing else that sets this attribute in my popupnotification. This feels like a hack though.