CSSParser Color.parse() for unexpected CSS properties

[David Grieve]

The parser doesn't have any concept of what the property is or value it 
might have. This allows the addition of new properties (such as an user 
might add for their own CSS styles) without having to modify the parser 
to handle them.


On 4/4/18 10:03 AM, Matthew Elliot wrote:
> Hi all, (first post).
>
> I was profiling our PROD JavaFX application recently I discovered something
> rather peculiar in the CSSParser. (jdk1.8.0_151)
>
> I noticed several hundred IllegalArgumentExceptions on the
> JavaApplicationThread where for various unrelated css properties the
> CSSParser is trying to parse a color. While the exception is subsequently
> caught and swallowed silently doing this hundred of times on this thread is
> rather ugly and caused *minor* delays in the application thread.
>
> This happened for alignment, shape, and a few other properties where
> no-lookup case was found and it ended on approx. line 900 of the CSSParser
> in
>
> colorValueOfString()
>
> with a value like 'center'; clearly no color.
>
> // if the property value is another property, then it needs to be looked up.
> boolean needsLookup = isIdent && properties.containsKey(text);
> if (needsLookup || ((value = colorValueOfString(str)) == null )) {
>      // If the value is a lookup, make sure to use the lower-case text
> so it matches the property
>      // in the Declaration. If the value is not a lookup, then use str
> since the value might
>      // be a string which could have some case sensitive meaning
>      //
>      // TODO: isIdent is needed here because of RT-38345. This
> effectively undoes RT-38201
>      value = new ParsedValueImpl<String,String>(needsLookup ? text :
> str, null, isIdent || needsLookup);
> }
>
> I had a look in the bug tracker https://bugs.openjdk.java.net/ but didn't
> find much in this regard so thought I would post in case it has come up
> before.
>
> I saw some of the css properties are from our application and some from
> e(fx)clipse which I can raise to Tom Schindl separately if it is a
> stylesheet issue, however it would appear that for example -fx-alignment in
> a layout VBOX/HBOX component should be valid according to JavaFX docs.
>
> More generally, is it expected that a property such as -fx-alignment should
> fall into this else {} catch all case, and why does JavaFX try to parse a
> Color by default?
>
> -fx-alignment: center;
>
> Any input much appreciated.
>
> Regards,
> Matt