Return-Path: X-Original-To: apmail-xmlgraphics-fop-dev-archive@www.apache.org Delivered-To: apmail-xmlgraphics-fop-dev-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id EF9567F4F for ; Tue, 6 Sep 2011 13:49:36 +0000 (UTC) Received: (qmail 27692 invoked by uid 500); 6 Sep 2011 13:49:36 -0000 Delivered-To: apmail-xmlgraphics-fop-dev-archive@xmlgraphics.apache.org Received: (qmail 27570 invoked by uid 500); 6 Sep 2011 13:49:35 -0000 Mailing-List: contact fop-dev-help@xmlgraphics.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: fop-dev@xmlgraphics.apache.org Delivered-To: mailing list fop-dev@xmlgraphics.apache.org Received: (qmail 27563 invoked by uid 99); 6 Sep 2011 13:49:35 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 06 Sep 2011 13:49:35 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of vhennebert@gmail.com designates 209.85.215.54 as permitted sender) Received: from [209.85.215.54] (HELO mail-ew0-f54.google.com) (209.85.215.54) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 06 Sep 2011 13:49:28 +0000 Received: by ewy1 with SMTP id 1so4183368ewy.27 for ; Tue, 06 Sep 2011 06:49:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject :x-enigmail-version:content-type:content-transfer-encoding; bh=w+X2heIk0BM3eScXNCcdWExEaFb9UJV5XFDRC2XaUTM=; b=sLmfO/d99QoMd8nv0rV/Xq9c3pbB5pZ/UegMGl2NDHl+vcBy6b1/cRlyckLh2T4UJJ jgeSZzgoVuGur3V24sdWKQRulEG26N59Dwc9/TBLXo0o96xJNDN9hinoijjecOKJg+aZ OjFIKYHc9ZY4op5ZQFUNxy0w5cQaSnRI+oQ0o= Received: by 10.213.7.10 with SMTP id b10mr731672ebb.55.1315316947121; Tue, 06 Sep 2011 06:49:07 -0700 (PDT) Received: from [192.168.3.73] (spc3-bagu2-0-0-cust872.bagu.broadband.ntl.com [81.104.63.105]) by mx.google.com with ESMTPS id i6sm345899eeb.11.2011.09.06.06.49.03 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 06 Sep 2011 06:49:04 -0700 (PDT) Message-ID: <4E6624CE.1030703@gmail.com> Date: Tue, 06 Sep 2011 14:49:02 +0100 From: Vincent Hennebert User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.21) Gecko/20110831 Lightning/1.0b2 Thunderbird/3.1.13 MIME-Version: 1.0 To: "fop-dev@xmlgraphics.apache.org" Subject: Re-architecturing Tagged PDF X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi All, As can be seen in Bugzilla #50852 [1], the current implementation of tagged PDF has fundamental limitations that prevent some features from working. Among others, an empty table cell will not show up in the structure tree, such that a screen reader will effectively shift other cells by one column. Also, building a structure tree using a preliminary XSLT does not scale well, and is not even necessary since the structure tree is almost readily available in form of the FO tree. Of course it’s possible to warp the current code into something that more or less does the job, but besides not solving the performance issue that would make it too difficult to understand and maintain. I’d like to work with Peter on re-architecturing the tagged PDF code. The broad idea is to integrate the construction of the structure tree into the current processing pipeline (XSL-FO -> FO tree -> Layout Managers -> Area Tree -> Rendering etc.). We will work on a temporary branch forked off Trunk so that interested parties can follow our progress. Once the work is done we will call for a vote to merge it back to Trunk. Any comments or suggestions are welcome. Thanks, Vincent [1] https://issues.apache.org/bugzilla/show_bug.cgi?id=50852 See also comment #21 https://issues.apache.org/bugzilla/show_bug.cgi?id=50852#c21 And mailing list: http://markmail.org/message/mn7jdbxmjdq7ey52