JavaScript: The Definitive Guide, Fourth Edition

Name

HTMLElement.onmousemove — the handler invoked when the mouse moves within an element

Availability

JavaScript 1.2; HTML 4.0

Synopsis

<element onmousemove="handler" ... > element.onmousemove

Description

The onmousemove property of an HTMLElement object specifies an event handler function that is invoked when the user moves the mouse pointer within the element.

The initial value of this property is a function that contains the JavaScript statements specified by the onmousemove attribute of the HTML tag that defined the object. When an event handler function is defined by an HTML attribute, it is executed in the scope of element rather than in the scope of the containing window.

In the Netscape 4 event model, the onmousemove handler function is passed an Event object as an argument. In the IE event model, no argument is passed, but the applicable Event object is available as the event property of the Window object that contains the element.

If you define an onmousemove event handler, mouse motion events are generated and reported in huge quantities when the mouse is moved within element. Keep this in mind when writing the function to be invoked by the event handler.

In Netscape 4, you cannot define this event handler on individual elements; instead, you must explicitly register your interest in mouse motion events by capturing them with the captureEvents( ) method of a Window, Document, or Layer object.

See Also

Event, Window.captureEvents( ); Chapter 19; EventListener, EventTarget ...