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

[Prasanta Sadhukhan]

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