<Swing Dev> [13] RFR JDK-8213781:web page background renders blue in JEditorPane

[Prasanta Sadhukhan]

On 21-Feb-19 9:21 PM, Shashidhara Veerabhadraiah wrote:
> Hi Prashanta, Thank you for pointing that information. It was useful. But then again  what we actually use is CSS-1, not CSS-2 and here is the link per CSS.java: http://www.w3.org/TR/REC-CSS1. So for the color attribute, here is the link for it: https://www.w3.org/TR/REC-CSS1/#color-units.
>
> The comments for this function needs to be changed to "The three-digit RGB notation (#rgb) is converted into six-digit form (#rrggbb) by replicating digits, not by adding zeros." to be more clear.
The fn comment was generic "an attempt will be made to fix it up"..so I 
guess it is correct. I will add the above line to my comment where I add 
the code, when I push. Any other objection?

Regards
Prasanta
> Thanks and regards,
> Shashi
>
> -----Original Message-----
> From: Prasanta Sadhukhan
> Sent: Thursday, February 21, 2019 8:20 PM
> To: Shashidhara Veerabhadraiah <shashidhara.veerabhadraiah at oracle.com>; swing-dev at openjdk.java.net
> Subject: Re: <Swing Dev> [13] RFR JDK-8213781:web page background renders blue in JEditorPane
>
> Also, as per https://www.w3.org/TR/CSS2/syndata.html#value-def-color, we have
>
> The three-digit RGB notation (#rgb) is converted into six-digit form
> (#rrggbb) by replicating digits, not by adding zeros. For example, #fb0 expands to #ffbb00. This ensures that white (#ffffff) can be specified with the short notation (#fff) and removes any dependencies on the color depth of the display.
>
> Regards
> Prasanta
> On 21-Feb-19 7:45 PM, Prasanta Sadhukhan wrote:
>> Hi Shashi,
>>
>> As you can see, Color.decode() called from hexToColor() accepts an
>> opaque 24 bit integer which is what returns the actual color that will
>> be rendered. Normally, it's 2D api's (ie Color.java) job to use
>> ColorSpace/ColorModel to give back the correct color and hexToColor's
>> job is to give a 6 digit string. The basic premise of the issue is CSS
>> parser gets a 3-digit string #fff instead of 6digit string #ffffff.
>> Please do not get confused by r,g,b variable name, it can as well be
>> a, b, c variables.
>>
>> Regarding doing the logic at hexToColor(), it's because the comment of
>> that fn itself says "If the color specification is bad, an attempt
>> will be made to fix it up" so I made the attempt to fix it in that
>> function as expected by that comment.
>>
>> Hope this clarifies.
>>
>> Regards
>> Prasanta
>> On 21-Feb-19 3:46 PM, Shashidhara Veerabhadraiah wrote:
>>> Hi Prashanta, I have a question on the proposed solution. Shouldn’t
>>> one check for the color depth of the system like true color(24 bit)
>>> or high color system(12 bit or non-true color system) before applying
>>> this logic? Assuming 24 bit color system isn't the right thing to do
>>> I think but again that may be mostly default these days. I also think
>>> we should receive the expanded form at the hexToColor() rather than
>>> expanding at this function. We should simply apply the received color
>>> at this lower function level I think.
>>>
>>> Thanks and regards,
>>> Shashi
>>>
>>> -----Original Message-----
>>> From: Prasanta Sadhukhan
>>> Sent: Thursday, February 21, 2019 2:04 PM
>>> To: swing-dev at openjdk.java.net
>>> Subject: <Swing Dev> [13] RFR JDK-8213781:web page background renders
>>> blue in JEditorPane
>>>
>>> Hi All,
>>>
>>> Please review a fix for an issue where it is seen that some webpage
>>> shows wrong background color when displayed in JEditorPane.
>>>
>>> It seems that some webpage can have #rgb [as in #fff] as CSS
>>> attributes which when parsed and passed to hexToColor() it is decoded
>>> as 0x000fff resulting in primarily blue background instead of white
>>> as desired.
>>> Now, hexToColor() is only able to handle 24 bit hex string as in
>>> #FFFFFF but not 12bit hexstring. So, fix is to make it recognize #fff
>>> and use
>>> Color.decode() to decode it correctly to 0xffffff.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8213781
>>> webrev: http://cr.openjdk.java.net/~psadhukhan/8213781/webrev.0/
>>>
>>> Regards
>>> Prasanta