HTML and CSS Reference
In-Depth Information
function references that the browser executes when the event occurs.
For example, a popular, albeit simple, use of the
onMouseOver
event
is to print a more descriptive explanation in the browser's status box
whenever the user passes the mouse pointer over a region of the image
map:
<area href="http://www.oreilly.com/kumquats/homecooking/recipes.html#quat5"
onMouseOver="self.status='A recipe for kumquat soup.';return true">
We should point out that the current versions of the popular browsers
automatically display the
alt
attribute's string value, ostensibly accom-
plishing the same task. So we recommend that you include the
alt
at-
tribute and value in lieu of hacking JavaScript. And, in context with a
text-based hyperlink, we argue that the contents of the tag itself should
explain the link. But images can be deceptive, so we urge you to take
advantage of both the
alt
attribute and event handlers to provide text
descriptions with your image maps.
6.5.4.7. The shape attribute
Use the
shape
attribute to define the shape of an image map's mouse-
sensitive region: a circle (
circ
or
circle
), polygon (
poly
or
polygon
), or
rectangle (
rect
or
rectangle
).
The value of the
shape
attribute affects how the browser interprets the
value of the
coords
attribute. If you don't include a
shape
attribute, the
value
default
is assumed. According to the standard,
default
means
that the area covers the entire image. In practice, the browsers default
to a rectangular area and expect to find four
coords
values. If you don't
specify a shape and don't include four coordinates with the tag, the
browsers ignore the area altogether.
