Action Hero
January 19, 1999
Action hero: once conditions are met the menu window is
prepped and popped.
function popIndex(topic,mouseX,mouseY)
{
if (popWin.closed)
{popIt();popWin.blur();}
if (popWin.setupComplete)
{popIndex2(topic,mouseX,mouseY)}
}
|
function popIndex2(topic,mouseX,mouseY)
{
if (clearPop!=0)
{popWin.clearTimeout(clearPop);
popWin.clearTimeout(popWin.clearPop2);}
clearPop=popWin.setTimeout
("self.resizeTo(0,0);
opener.focus()",5000);
//clear any open pop topic
if (opentopic!=null)
{ var oldobjName="['"+opentopic+"']";
eval(obj+oldobjName+visibility+invisible);}
var objName="['"+topic+"']";
//adjust window dimensions to match popup index
if (document.all)
// { popWin.resizeTo
(eval(obj+objName+posWidth)+30,eval(obj+objName+posHeight)+50) }
{popWin.resizeTo(250,popWin.document.all[topic].clientHeight+45);}
else { popWin.innerHeight=eval(obj+objName+posHeight); }
eval(obj+objName+visibility+visible);
opentopic=topic;
popWin.moveTo(mouseX+50,mouseY-25);
popWin.focus();
}
|
Inching ever closer to the action-packed center of these
scripts, popIndex() is the function called when
the user passes the mouse pointer over a topic link in the
table of contents. Ideally, this will lead to the pop-up
menu appearing; the popIndex() function, though, is
a "protection" function which ensures that
conditions are correct before actually launching the pop-up.
Specifically, popIndex() checks on two conditions:
first, is the pop-up menu window still open? This
protection serves to check user interference, in case
the user has manually closed the menu window (which they
shouldn't but we can't stop them). If the menu window has
been ruthlessly closed by the user then it is immediately
re-spawned. Second, it's vital that the menus inside the
menu window have all been setup -- remember the setup()
function in popups.html? The popups.html
script will set the variable setupComplete to true
when the menus are ready, and so we only continue on to
launching the menu if this is so.
The subsequent function popIndex2(), then, is the
real captain of the mission control center, doing the
dirty work, as they say. First things first, popIndex2()
sets up the timeouts which control disappearance
of the menu
(rule #1, seen earlier). If a
previous topic's menu has already been popped that
menu is cleared (set to invisible) within the menu window.
Turning the script's focus to the topic menu to be
popped, the menu window's size is adjusted to fit the size
of the menu. Within Internet Explorer both horizontal
and vertical dimensions of the menu window are adjusted;
within Navigator only the vertical height may change due
to a quirk wherein horizontal window adjustments cause the
menu window to reload with negative consequences.
All set for launch, the layer which contains the topic menu
is set to visible using the eval() technique
relying upon the common DHTML terms defined by crossBrowser().
The currently open topic is now registered
with opentopic and the window is moved into
correct position on the screen relative to the location of the
user's mouse when it originally passed over the table of
contents topic link.
The last line of popIndex2() is the final sparkle
on the shine, actually causing the pop-up menu window
to "appear":
popWin.focus();
Once the menu window gains focus then its own scripts,
within popups.html,
take over control.
Building the Imperfect Beast: Part 3 (embedded mission control)
DHTML Pop-Up Menus: A Parable of Triumph and Loss (Based on a True Story)
Create and Destroy
|
