The following are event handlers (and their corresponding event handler event types) which must be supported, as event handler IDL attributes, by objects implementing the
|Event handler||Event handler event type|
|Feature||Android webview||Chrome for Android||Edge mobile||Firefox for Android||Opera Android||iOS Safari||Samsung Internet|
1. From version 51: this feature is behind the
dom.presentation.controller.enabled preference (needs to be set to
true). To change preferences in Firefox, visit about:config.