This has hit me a few times over the last couple of days when viewing text in a textarea. 1) Load attachment 2 [review]) Click on scrollbar to move down (or right) Textarea becomes positioned at last character. Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9.3a6pre) Gecko/20100616 Minefield/3.7a6pre

Similarly context-clicking in the unfocussed textarea.

ehsan, you seem to have done a few changes in this area recently.

This happens because the textarea is focused when you click a scroll button, which causes us to scroll its selection into view, which causes this behavior (see bug 353539 where this behavior was added). I guess we could detect that we're getting the focus because of a click on the scrollbar, but I'm not sure how to do that.

I think we can distinguish click-to-focus from other kinds of focus. We shouldn't scroll into view when clicking to focus.

(In reply to comment #4) > I think we can distinguish click-to-focus from other kinds of focus. We > shouldn't scroll into view when clicking to focus. It may not only be click-to-focus 1) Load attachment. 2) Press tab key.

Neil, could you please answer comment 4?

You can detect what method was last used to focus with nsIFocusManager::GetLastFocusMethod But why do you want to special case this considering comment 5? Shouldn't the textarea already be scrolled to the caret to start with?

Hmm, I guess one solution would be to initialize the selection to the beginning of the textarea initially instead of its end, but I'm not sure if we want that. That's what Webkit does BTW.

In general, though, caret position can be outside of the visible area due to mousewheel scrolling.

(In reply to comment #9) > In general, though, caret position can be outside of the visible area due to > mousewheel scrolling. Hmm, yes. So, in that case, I'm not really sure how to address this problem.

We can make clicking in the scrollbar focus the textarea without scrolling anything into view. Ehsan, do you want this?

(In reply to comment #11) > We can make clicking in the scrollbar focus the textarea without scrolling > anything into view. What about comment 5? > Ehsan, do you want this? Sure.

It's not clear to me that scrolling the caret into view when we tab into the control is wrong, whereas it seems to clear to me that this bug as filed (comment #0) is a real bug.

Verified. [That makes my CMS usable again.] Mozilla/5.0 (Windows NT 5.0; rv:2.0b7pre) Gecko/20100922 Firefox/4.0b7pre