| Cause: | When attempting to set menus
with differing opacity levels, such as a permanently displayed menu with 80% opacity which
is supposed to display fully opaque child menus, remaining menus on the page are initially
displayed with the opacity setting of the other menu. Safari evidently displays an element
that appeara in a higher z-order with the opacity setting of the element beneath it
(in z-order). This seems to be true even if the items themselves do not actually
overlap (visually) on the page.
This is not a JavaScript issue; you can see the problem demonstrated yourself by
viewing this simple sample page. On the sample page, a
blue box and red box are defined. The blue box should have 60% opacity, while the
red box should be fully opaque. Yet, because the red box is defined with a higher
z-order than the blue box, it is also displayed with 60% opacity.
In HierMenus, we must display successive menus with higher z-order levels in order to
ensure they appear above their parent menus. Note that if a menu is set with a
specific opacity setting of less than 1.0, Safari will apply that opacity setting
properly even if it does differ from the opacity settings of menus beneath
them in z-order. To that end, one simple work around is to set all of
your menus to a high opacity setting (like .99) by default, and then specifically
set the appropriate menus to lower opacity settings. True, .99 opacity is not quite
the same as 100% opacity; but visually it would be awfully difficult (if possible
at all) to tell the difference; and the work around won't work with a value of
1.0 since Safari simply ignores that setting. Remember that you can set opacity
conditionally, so that other browsers needn't be effected:
MenuOpacity:(HM_IsSafari)?.99:null;
And of course if you simply set all your menus to the same opacity setting you
won't notice this problem in the first place.
This behavior was confirmed as a bug in Safari 1.1, and we'd like to thank
Safari Developer Dave Hyatt for suggesting the simple work
around. It was corrected in later Safari releases. |
