[OpenJDK 2D-Dev] <AWT Dev> [10] Review Request: 8182410, 8183508, 8181289

Kevin Rushforth kevin.rushforth at oracle.com
Wed Nov 22 23:47:29 UTC 2017

I can confirm the same behavior that Jon sees with Firefox 57 on Windows 7.

The link scrolls to the right place with the <a id="..."> link and does 
not with the <h1 id="..."> link.

-- Kevin

Jonathan Gibbons wrote:
> Semyon,
> Using the files I previously posted, I confirm that I see the same 
> display problem on a Mac, using the latest OS (High Sierra) and 
> Safari. I also see the problem on the same Mac, with Firefox 55.0.2
> -- Jon
> On 11/22/2017 02:53 PM, Jonathan Gibbons wrote:
>> Semyon,
>> I have reconstructed a very simple, very artificial example to demo 
>> the bug.   This example uses lots of filler text, but while that is 
>> artificial, for sake of recreating a demo,  note that the problem 
>> first appeared, for real, in real JDK 9 API documentation with 
>> extended doc comments, and that as a result, we followed the advice I 
>> have been trying to give you.
>> See the toy API bundle here:
>> http://cr.openjdk.java.net/~jjg/semyon/api/overview-summary.html
>> There are two modules, modA and modB.  Both have huge long doc 
>> comments, with a heading at the top and a link at the bottom.
>> In modA, the anchor is of the form <h1 id="head">.  In modB, the 
>> anchor is of the form <a id="head">.
>> In each of these files, scroll to the end of the comment, and look 
>> for a link, called "link", at the bottom of the page.  In both cases, 
>> the page scrolls so that the heading is near the top of the browser 
>> window, but in one case it is hidden under the javadoc navbar, and in 
>> the other case, it is clearly visible, below the javadoc navbar.
>> This is the difference in behavior that I can been trying to describe 
>> to you. I'm using Ubuntu 14.04 with Firefox 38, but I'm not the only 
>> one to have seen this effect.  I don't know whether you will get the 
>> same effect in your browser, but the fact that there is a reasonable 
>> OS/browser combo that demonstrates the problem is enough of a reason 
>> to avoid provoking the problem unnecessarily.   If you don't see the 
>> problem on your browser, but want to see it in mine, I see you are in 
>> SCA22, so drop by my office for a demo.
>> I'll leave it to the AWT team to decide what to do about this 
>> bug/review. I still recommend updating what is necessary to fix 
>> issues, and not otherwise changing the doc comments unnecessarily, 
>> and not changing them in a way to provoke this bad behavior.
>> -- Jon
>> On 11/22/2017 12:10 PM, Semyon Sadetsky wrote:
>>> Hi Jon,
>>> This is not only about HTML5 spec, I also hardly can find resources 
>>> that follow your "<a id=" rule. And I doubt that cross-browser 
>>> compatibility is important for Javadoc only and others do not care 
>>> about their readers. So, I asked you for an examples of such 
>>> workaround or a reference to a bug filed against any browser. 
>>> Fragment identifiers is too important functionality to let this 
>>> issue be unnoticeable.
>>> You are correct that there is no bug here. But a bug was absent  
>>> before this fix as well. This bug is about following to the HTML5 
>>> standards, so let's follow them in full and not to return to this 
>>> once again. We have a good chance to provide documentation in clean 
>>> HTML5 after the fix without any workarounds.
>>> --Semyon
>>> On 11/14/2017 09:16 AM, Jonathan Gibbons wrote:
>>>> Semyon,
>>>> I read the HTML 5 spec the same as you, and we (on the Javadoc 
>>>> team) started using id on other elements, as well as <a> to provide 
>>>> a target that could be linked to.
>>>> However, the pragmatic experience was that the scrolling in some 
>>>> browsers did not completely reveal the element when there was a 
>>>> layered z component involved: the target element sometimes ended up 
>>>> under that layered component. Our experience was that the behavior 
>>>> was fixed when the target identifier was in an <a> element.
>>>> So, yes, you can follow the rules, and suggest that it is OK to put 
>>>> id on any element, and use it as a fragment identifier in a link, 
>>>> as given in the spec. Or you can be nice to your readers, and 
>>>> workaround what is probably a display bug in some browsers.
>>>> In the case of this review, you were suggesting additional 
>>>> "cleanup" on code that worked. Since there was no bug involved, and 
>>>> thus no inherent need to fix the code, my review feedback is to 
>>>> leave the code alone.  You may choose to insist differently, and I 
>>>> cannot say that what you are suggesting is against the spec; I can 
>>>> just say that we can seen cases where such changes leads to bad 
>>>> visual effects.
>>>> -- Jon
>>>> On 10/25/17 6:31 PM, Semyon Sadetsky wrote:
>>>>> Hi Jonathan,
>>>>> On 10/24/2017 03:20 PM, Jonathan Gibbons wrote:
>>>>>> Semyon,
>>>>>> Although id is a global attribute and can be used to identify any 
>>>>>> node, some browsers do better navigation/scrolling when the id is 
>>>>>> in an <a> tag.  We have seen poor autoscrolling behavior when the 
>>>>>> id is an a header tag, such that the header ends up obscured 
>>>>>> under the navigation bar at the top of the page.
>>>>> You probably meant heading elements, because "header tag" is 
>>>>> something different. Do you have any references those issues 
>>>>> reports? Because in html5 the fragment identifiers are the only 
>>>>> correct way to have internal document bookmarks [1] [2]. If some 
>>>>> browsers do not navigate to fragment identifiers except for <a> 
>>>>> element there must be bugs reported that  which will be fixed soon.
>>>>> The html5 specification is very specific about navigating to the 
>>>>> fragment identifier [3]. So, there should no be difference between 
>>>>> navigating to "<a id=" or to any other element having id 
>>>>> attribute. If you just need an extra vertical space above header 
>>>>> you could use css style or <p>, but usage of <a> as an upper 
>>>>> margin seems odd since it is a special tag.
>>>>> --Semyon
>>>>> [1] https://www.w3schools.com/html/html_links.asp
>>>>> [2] http://www.html5-tutorials.org/html-basics/links/
>>>>> [3] https://www.w3.org/TR/html5/browsers.html#scroll-to-fragid
>>>>>> -- Jon
>>>>>> On 10/23/2017 10:08 PM, Semyon Sadetsky wrote:
>>>>>>> Hi Sergey,
>>>>>>> I see no reason to have an extra empty anchor tag to set a 
>>>>>>> bookmark. The id attribute works with any element.
>>>>>>> For example:
>>>>>>>     <a id="Definitions"></a>
>>>>>>>     <h3>Definitions</h3>
>>>>>>> should be
>>>>>>>     <h3 id="Definitions">Definitions</h3>
>>>>>>> --Semyon
>>>>>>> On 10/23/2017 02:42 PM, Sergey Bylokhov wrote:
>>>>>>>> Hello,
>>>>>>>> Please review the fix for.
>>>>>>>> 8182410: missing 'title' in 
>>>>>>>> api/javax/swing/plaf/synth/doc-files/componentProperties.html
>>>>>>>> 8183508: multi_tsc.html should be updated
>>>>>>>> 8181289: Invalid HTML 5 in AWT/Swing docs
>>>>>>>> Description:
>>>>>>>>  - Illegal characters were removed.
>>>>>>>>  - Unsupported tags/properties were removed -like <tt>, 
>>>>>>>> <center>, font, etc.(except the tags related to tables which 
>>>>>>>> I'll fix later).
>>>>>>>>  - HTML5 doctype is set for all files.
>>>>>>>>  - The <title> is set for all files.
>>>>>>>>  - <a name="" is replaced by <a id=""
>>>>>>> Why you replace
>>>>>>>>  - Copyrights were added to some files.
>>>>>>>> Note that I placed a <head> tag before copyright to solve 
>>>>>>>> errors like:
>>>>>>>> "A charset attribute on a meta element found after the first 
>>>>>>>> 1024 bytes. Fatal Error: Changing encoding at this point would 
>>>>>>>> need non-streamable behavior"
>>>>>>>> specdiff: 
>>>>>>>> http://cr.openjdk.java.net/~serb/8181289/specdiff/overview-summary.html 
>>>>>>>> Bugs:
>>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8182410
>>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8183508
>>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8181289
>>>>>>>> Webrev can be found at: 
>>>>>>>> http://cr.openjdk.java.net/~serb/8181289/webrev.00
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