118799 - Page Up/Down twice in a text area does not keep caret visible, then arrow keys revert scroll

Status: RESOLVED DUPLICATE of bug 4302

(Core :: Layout: Form Controls, defect)

Description

[Jesse Glick]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.7) Gecko/20011221
BuildID:    2001122108

Scrolling up and down in HTML textareas does not reliably move the caret to keep
it visible in the screen area.

Reproducible: Always
Steps to Reproduce:
If you have an HTML <textarea> and have a lot of text in it (so that the
scrollbar is visible and there are several pages worth of stuff), moving around
with the arrow keys works fine: the caret is moved and the scrollbars move as
needed to keep the caret visible. Now press Page Up or Page Down to move to a
new screenful of text. The textarea is scrolled, and in most cases correctly
shows the caret at the trailing edge of the new area as you would expect; though
in some cases the caret is not moved at all (not clear what determines this).
Press the same Page Up/Down again (or several times). The textarea continues to
scroll as expected. However the caret is no longer visible. In fact it does not
seem to have moved again: if you then press one of the arrow keys, it will move
from the last position it was left in (after the first Page Up/Down) and the
textarea will be scrolled back to a window which shows that caret position. The
net effect is this: you have a long textarea full of text. You are at the
bottom. You wish to make some edit at the top. So you press Page Up several
times. The textarea scrolls and you finally see the top of the message. Press
e.g. Right arrow, thinking that you will begin moving in the first line of text.
No! The textarea suddenly flips back to near the bottom and you are moving
around about one screenful up from the bottom. In fact to get to the top of the
textarea with the keyboard you need to use the arrow keys only, which is
counterintuitive and of course much slower.

Actual Results:  Caret goes "off-screen" (outside visible scroll area) and is
only made visible again with arrow keys (moving scroll area back to where it was
originally).

Expected Results:  I would expect that when the caret is visible in a textarea,
pressing either Page Up or Page Down would scroll up or down by a screenful
(unless the caret is already within one screenful of the top resp. bottom of the
entered text) and would ensure that the caret continues to be visible, and then
subsequent arrow movements begin from that location.

I see this problem in HTML textareas generally, including this Mozilla bug
submission form, so I don't think it is specific to particular HTML pages.

Comment 1

[TucsonTester3]

confirmed on build 2002010803, win 98
Using Page Up to scroll through a lengthy document in a textarea, caret remained
at bottom of document.  Tested it in msie 5.5 to compare, caret moved up each
time Page Up was used, although the caret did sometimes shift up a line within
the textarea.  

Comment 2

[rods (gone)]

over to kin

Comment 3

[Kathleen :Brade]

dup of 4302 (page up/down doesn't move caret)

*** This bug has been marked as a duplicate of 4302 ***