From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: Gtk scrollbar: thumb too short Date: Tue, 01 Apr 2003 04:38:30 -0500 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: <20030325193739.ZGIN3924.fep01-svc.swip.net@gaffa.gaia.swipnet.se> <3E8345E8.4090509@swipnet.se> <1048872463.17161.132.camel@localhost.localdomain> <1049134327.3326.74.camel@localhost.localdomain> Reply-To: rms@gnu.org NNTP-Posting-Host: main.gmane.org X-Trace: main.gmane.org 1049659105 28837 80.91.224.249 (6 Apr 2003 19:58:25 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Sun, 6 Apr 2003 19:58:25 +0000 (UTC) Cc: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Sun Apr 06 21:58:23 2003 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 192GHX-0007Ut-00 for ; Sun, 06 Apr 2003 21:58:23 +0200 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian)) id 192GKh-0007Ry-00 for ; Sun, 06 Apr 2003 22:01:40 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 192GGz-0004Bl-03 for emacs-devel@quimby.gnus.org; Sun, 06 Apr 2003 15:57:49 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.10.13) id 192GGh-0004BJ-00 for emacs-devel@gnu.org; Sun, 06 Apr 2003 15:57:31 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.10.13) id 192GGg-0004AS-00 for emacs-devel@gnu.org; Sun, 06 Apr 2003 15:57:30 -0400 Original-Received: from fencepost.gnu.org ([199.232.76.164]) by monty-python.gnu.org with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.10.13) id 192GCN-0003b1-00 for emacs-devel@gnu.org; Sun, 06 Apr 2003 15:53:03 -0400 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.10) id 190IDu-0000K4-00; Tue, 01 Apr 2003 04:38:30 -0500 Original-To: Owen Taylor In-reply-to: <1049134327.3326.74.camel@localhost.localdomain> (message from Owen Taylor on 31 Mar 2003 13:12:07 -0500) Original-cc: jan.h.d@swipnet.se Original-cc: kai.grossjohann@uni-duisburg.de X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Emacs development discussions. List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:12933 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:12933 > That is unnecessarily complicated. I think the position value that > users see is thumb_start / trough_pixels. That is much simpler > and it is visually evident. For the normal case, these two approaches are the same. The two models are mathematically equivalent in the normal case, but I conjecture that the simple one is the way users really understand it. In unusual cases, where the two models disagree, preserving the simple model will seem natural. Preserving the complex model will seem unnatural. But in more complicated cases, your approach isn't possible. Of course it is possible. Emacs already does it, with some toolkits. You get a situation where the correct size of the thumb cannot fit into the trough with that starting position, which gives you two choices: - Make the thumb go out of the trough. I think there is a misnunderstanding here. Nobody proposed this. You said that some themes might do this, as a consequence of how the code works; I responded it is no problem if they do. - Shrink the thumb to a smaller size than it should be. While less of a problem than the previous approach, it strikes me as a little strange. Also, you still have to consider what happens when you reach some minimum size for the handlebar. This is what should happen. This is what Emacs already does on some platforms. (What is the "handlebar"?) I'm not sure that presenting this simple model to the user is compatible with allowing the user to drag the scrollbar thumb to overscroll. They must be compatible; they already work together on other platforms. It is somewhat hard to grab the thumb when most of the thumb is off-screen, but it should not be impossible. You have to decide whether dragging the scrollbar to the bottom: - Scrolls to last page of the document Dragging it to the bottom of the trough should scroll to the last full page. Dragging it beyond the bottom should show less than a full page. (Note that by allowing the user to drag the thumb to overscroll, no matter how you do it, you make the operation of scrolling to the last page of the document a precision operation rather That is true, but the amount of precision required is no more than for scrolling at any other place in the document. Emacs has worked this way for many years, and we have not heard a complaint.