55868 - Cleanup of screen object

Status: RESOLVED INACTIVE

(Core :: DOM: Core & HTML, defect, P5)

Description

[Henrik Gemal]

The "screen" object needs a cleanup I think.
1) There two unknown properties (screen.top and screen.left)
What should these contain? I never seen a top or left property of the screen 
object...

2) There two empty properties (screen.availLeft and screen.availTop)
Shouldn't these be filed out?

Comment 1

[Johnny Stenback (:jst)]

Too late to do anything about this now, marking future.

Comment 2

[Gérard Talbot]

I agree with you that the "screen" object needs a cleanup.

1) Window.screen.left and window.screen.top are unknown to me as well. I've
checked documentations everywhere and tried use screen.left/top and couldn't
achieve/figure out anything. The screen object first appeared around the time
where javascript 1.2 and with NS 4.0 PR1 appeared.

http://developer.netscape.com/viewsource/davis_javascript.html

And there is no mention at all of what these left/top properties do. They seem
to only have the 0 value. You can only get the left/top properties, btw: you
can't set them.

2) screen.availLeft and screen.availTop are different though. And they might be
useful for rtl language users who place their window taskbar on the left or even
users having absolutely positioned applet on their monitor screen. Here's what
these properties mean and how to use them (availTop demonstrated here):

a) Go to this precise url:

http://www.bekkoame.ne.jp/~hamba/mozilla/screen/availTop.html

The availTop value should be 0... unless you already had your taskbar at
the top before opening your Netscape browser.

b) In windows XP Pro, right click on the task bar/Properties/Taskbar
appearance and then

"Lock the taskbar" should be unchecked
"Auto-hide the taskbar" should be unchecked
"Keep the taskbar on top of other windows" should be checked

The goal here is to be able to relocate the taskbar and keep it visible,
shouldering other active applications within the video monitor screen
display of the user.

c) Now move, drag the taskbar to the top of your screen.

d) Then close your browser totally, the application. Reopen your NS 6+
browser and

e) then go again to:

http://www.bekkoame.ne.jp/~hamba/mozilla/screen/availTop.html

and here the value of availTop should be different. Unless I'm wrong,
this whole sequence of steps will end showing a positive value for
availTop for NS 4.7x, NS 6.x, NS 7 PR1 and all Mozilla 0.9+ releases.
You can repeat the same whole process for screen.availLeft by putting
the taskbar at the left and by going at

http://www.bekkoame.ne.jp/~hamba/mozilla/screen/availLeft.html .

Here's the best definition I found about screen.availTop:

screen.availTop: Specifies the y-coordinate of the first pixel that is
not allocated to permanent or semipermanent user interface features.
coming from Client-Side JavaScript Reference v1.3 at
http://developer.netscape.com/docs/manuals/js/client/jsref/screen.htm#11
95107

Also,
"About the screen.availTop and screen.availLeft properties: Reader Robin
Berjon reports that in some instances, these properties are not zero, as
stated on page 706. In Windows, if you move the Taskbar to the top of
the screen, screen.availTop is 28, meaning that the first available top
coordinate of the screen is 28; likewise, if you move the Taskbar to the
left edge of the screen, screen.availLeft is 60. When the Taskbar is at
the right or bottom of the screen, the properties return zero, because
available space is flush with the top and left screen edges in those
cases."
can be found at the end of this page:
http://www.dannyg.com/update5.html

Now, let's say you suspect your users to have their window taskbar at the left
edge of their screen or at the top edge of their screen, and you need to open up
a popup. If you don't consider the window taskbar position (or even an
absolutely positioned applet), then a great part of the popup window will be
covered, masked by the window taskbar. In such cases, admittedly rare ones..but
possible ones, availTop and availLeft properties will be useful. I've tested all
this.

Conclusion: unless someone can come up with an explanation and a demo, I agree
that window.screen.left and window.screen.top should be removed.
Window.screen.availLeft and window.screen.availTop might be useful though (rare
but possible).

Comment 3

[Johnny Stenback (:jst)]

Mass-reassigning bugs to [e-mail]

Comment 4

[Boris Zbarsky [:bzbarsky]]

What exactly are availTop/availLeft supposed to indicate?

Comment 5

[Firefox Bug Husbandry Bot]

Bulk priority change, per :mdaly