201322 - selection control's scrollbar does not work properly

Status: NEW

(Core :: Layout: Form Controls, defect)

Description

[Jan Zach]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4b) Gecko/20030408
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4b) Gecko/20030408

1. In the case that a list to be selected is longer than the select control:
When moving the vertical srollbar by mouse to the bottom of the list the last
item is not shown. Movement with keyboard arrows works.
2. Movement with arrows down from the top of the list causes causes crazy
jumping of the whole list. But maybe it is purposely as it occurs about in the
middle of the list.

Reproducible: Always

Steps to Reproduce:
1. create a selection with a selection list longer than the control
2. move bottom the vertical scroolbar


Actual Results:  
The last line of the list is not shown

Expected Results:  
Show the last line :-)

The definition of the select:

<select name="_ctl0:_ctl2:_ctl5" class="ListBox" size="10" multiple="multiple">
...

The style:

.ListBox
{
   width: 15em
}

Comment 1

[Robert O'Callahan (:roc) (email my personal email if necessary)]

OK, with some font sizes I can see that the bottom line of a listbox can't be
scrolled entirely into view using the scrollbar buttons.

However, I don't see any sort "jumping around". Can you be more specific?

Comment 2

[Jan Zach]

OK, for example: 
I  have a list box (with a view of size 10 items) with 5 items in it. When I
move the selection cursor down (with keyboard arrows) from the 1st item to the
3rd one, the whole view is scrolled up by 1 item. 
There is a very similar situation in the view with larger number of items than
the view size...