JDK-8294090 : Aligns the CSS `<rgb()>` and `<rgba()>` function behaviours

The purpose of this issue is to align the `<rgb()>` and `<rgba()>` function behaviours in CSS.java.

This is referenced in Java Bug Database as

JDK-8294090 : Aligns the CSS <rgb()> and <rgba()> function behaviours

This is tracked in JBS as

JDK-8294090 : Aligns the CSS <rgb()> and <rgba()> function behaviours

Related Pull Request

Aligns the <rgb()> and <rgba()> function behaviours in CSS.java, as described in : CSS Color Module Level 4 W3C Candidate Recommendation Snapshot, 5 July 2022 4.1 The <Color> syntax 6.1. The RGB functions: rgb() and rgba()

In this recommendation there is no difference between the two function behaviours but this is not the case in the JDK present implementation.
Some other parts of the described syntax are not supported.
For example e-notation is not supported 5.3 Real Numbers: the <number> type

... a number is either an integer, or zero or more decimal digits followed by a dot (.) followed by one or more decimal digits; optionally, it can be concluded by the letter “e” or “E” followed by an integer indicating the base-ten exponent in scientific notation. ...

Status

~~This Enhancement Request is not yet accepted so it's internaly referenced in Java Bug Database as JI-9073933.~~

Basic test

In jshell type :

import java.awt.Color;
import javax.swing.text.html.StyleSheet;
StyleSheet styleSheet = new StyleSheet();

First test : Expected result, a value not an Exception.

styleSheet.stringToColor("rgba(12 23 17 50%)").getAlpha();
|  Exception java.lang.IllegalArgumentException: Color parameter outside of expected range: Alpha
|        at Color.testColorValueRange (Color.java:312)
|        at Color.<init> (Color.java:397)
|        at Color.<init> (Color.java:492)
|        at CSS.parseRGBA (CSS.java:1475)
|        at CSS.stringToColor (CSS.java:1404)
|        at StyleSheet.stringToColor (StyleSheet.java:1029)
|        at (#21:1)

Second test : Expected result, 240.

styleSheet.stringToColor("rgb(12 23 17 / 0.94)").getAlpha();
color ==> 255

Details :

Remind : (During the parsing process, before this method)
- Leading and trailing white-spaces (according to Java) in the argument string were removed.
- Inside () multiple white-space (according to Java) occurences are replaced by only one space character.
- white-spaces (according to Java) between rgb or rgba and ( are removed.
If / is not present, <rgb> functions need 3 values. Not verified.
Else functions need 4 values. Not verified.
To avoid later incompatibilies, other cases should return null.
A value can be percent or number. But the range is not the same according the component.
- r, g, b numbers in range 0 to 255 or percents in range 0% to 100%.
- a number in range 0 to 1 or percent in range 0% to 100%.
none keyword not scaned.
The format of number used as value is not defined in the specification. Then implementations should use the previous implementation format.
Add number e-notation support (see above).

Consequences

<rgba> accepts most of these functionalities excepted % for alpha value. According comments above, implementation doesn't respect the alpha range and treates this component like r, g, b. It's a bug.
<rgb> doesn't accept alpha value. It's an enhancement.
none keyword not supported. It's an enhancement.
number used as value is Java float $s \times m \times 2^{e-150}$.
- s is sign, 1 bit
- m is magnitude 23 bits
- e is exponent 8 bits

Syntax

`rgb()`
`rgb( [<percentage> \\| none]{3} [ / [<alpha-value> \\| none] ]? )`
`rgb( [<number> \\| none]{3} [ / [<alpha-value> \\| none] ]? )`
`rgb( <percentage>#{3} , <alpha-value>? )`
`rgb( <number>#{3} , <alpha-value>? )`
`number:= [+\\|-]? [0...9]* [[. [0...9]]]? [[e\\|E]! [0...9]]?`

Some tests

Value	Ret. Val. Before PR	Ret. Val. after PR
null	null	:green_circle:
#	null	null	:green_circle:
#f	java.awt.Color[r=0,g=0,b=15] + a=255	null	:white_circle:
#f0	java.awt.Color[r=0,g=0,b=240] + a=255	null	:white_circle:
#f0f	java.awt.Color[r=255,g=0,b=255] + a=255	java.awt.Color[r=255,g=0,b=255] + a=255	:green_circle:
#f0f1	java.awt.Color[r=0,g=240,b=241] + a=255	java.awt.Color[r=255,g=0,b=255] + a=17	:white_circle:
#f0f10	java.awt.Color[r=15,g=15,b=16] + a=255	null	:white_circle:
#f0f109	java.awt.Color[r=240,g=241,b=9] + a=255	java.awt.Color[r=240,g=241,b=9] + a=255	:green_circle:
#f0f1092	java.awt.Color[r=240,g=241,b=9] + a=255	null	:white_circle:
#f0f10928	java.awt.Color[r=240,g=241,b=9] + a=255	java.awt.Color[r=240,g=241,b=153] + a=40	:white_circle:
f0f10928	null	java.awt.Color[r=240,g=241,b=9] + a=40	:white_circle:
#f0f109289	java.awt.Color[r=240,g=241,b=9] + a=255	null	:white_circle:
f0f109289	null	null	:green_circle:
ppabcdef	null	null	:green_circle:
b52k	null	null	:green_circle:
#ppabcdef	null	null	:green_circle:
#b52k	null	null	:green_circle:
#ffffffff	java.awt.Color[r=255,g=255,b=255] + a=255	java.awt.Color[r=255,g=255,b=255] + a=255	:green_circle:
ffffffff	null	java.awt.Color[r=255,g=255,b=255] + a=255	:white_circle:
#ffffff	java.awt.Color[r=255,g=255,b=255] + a=255	java.awt.Color[r=255,g=255,b=255] + a=255	:green_circle:
ffffff	java.awt.Color[r=255,g=255,b=255] + a=255	java.awt.Color[r=255,g=255,b=255] + a=255	:green_circle:

Value	stringToColr Ret. Val.	Expected Val.
`rgb(12 24 200)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(-1 24 200%)`	`java.awt.Color[r=0,g=24,b=255] + a=255`	`rgba(0 24 255 1.0)`	:green_circle:	rgba(0 24 255 1.0)
`rgb(300 24 28)`	`java.awt.Color[r=255,g=24,b=28] + a=255`	`rgba(255 24 28 1.0)`	:green_circle:	rgba(255 24 28 1.0)
`rgb(12 24 200 / 82%)`	`java.awt.Color[r=12,g=24,b=200] + a=209`	`rgba(12 24 200 0.82)`	:green_circle:	rgba(12 24 200 0.82)
`rgb(12 24 200 / 0.82)`	`java.awt.Color[r=12,g=24,b=200] + a=209`	`rgba(12 24 200 0.82)`	:green_circle:	rgba(12 24 200 0.82)
`rgb(12 24 200 / -210)`	`java.awt.Color[r=12,g=24,b=200] + a=0`	`rgba(12 24 200 0.0)`	:green_circle:	rgba(12 24 200 0.0)
`rgb(12, 24, 200)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(12, 24, 200, 210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(12, 24, 200 , 210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(12 , 24 , 200 , 210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb( 12 , 24 , 200 , 210 )`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(12 ,24, 200 ,210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(12,24,200,210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(15% 60% 49%)`	`java.awt.Color[r=38,g=153,b=125] + a=255`	`rgba(38 153 125 1.0)`	:green_circle:	rgba(38 153 125 1.0)
`rgb(15% 60% 49% / 82%)`	`java.awt.Color[r=38,g=153,b=125] + a=209`	`rgba(38 153 125 0.82)`	:green_circle:	rgba(38 153 125 0.82)
`rgb(15%, 60%, 49% / 82%)`	`java.awt.Color[r=38,g=153,b=125] + a=209`	`rgba(38 153 125 0.82)`	:green_circle:	rgba(38 153 125 0.82)
`rgb(0.14 60% 52.3 / 0.98)`	`java.awt.Color[r=0,g=153,b=52] + a=250`	`rgba(0 153 52 0.98)`	:green_circle:	rgba(0 153 52 0.98)
`rgb(none none none)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)
`rgb(none none none / none)`	`java.awt.Color[r=0,g=0,b=0] + a=0`	`rgba(0 0 0 0.0)`	:green_circle:	rgba(0 0 0 0.0)
`rgb(none none none / none)`	`java.awt.Color[r=0,g=0,b=0] + a=0`	`rgba(0 0 0 0.0)`	:green_circle:	rgba(0 0 0 0.0)
`rgb(none none 30)`	`java.awt.Color[r=0,g=0,b=30] + a=255`	`rgba(0 0 30 1.0)`	:green_circle:	rgba(0 0 30 1.0)
`rgb(none 20 none)`	`java.awt.Color[r=0,g=20,b=0] + a=255`	`rgba(0 20 0 1.0)`	:green_circle:	rgba(0 20 0 1.0)
`rgb(10 none none)`	`java.awt.Color[r=10,g=0,b=0] + a=255`	`rgba(10 0 0 1.0)`	:green_circle:	rgba(10 0 0 1.0)
`rgb(none none none)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)
`rgb(10 50 13% / 50%)`	`java.awt.Color[r=10,g=50,b=33] + a=128`	`rgba(10 50 33 0.5)`	:green_circle:	rgba(10 50 33 0.5)
`rgb(10 50 13% // 50%)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)
`rgb(10 50,, 13% // 50%)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)
`rgb(10 50 ,, 13% // 50%)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)
`rgb(1.2e1 0.24e2 2e2)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)
`rgb(1200e-2 2400e-2 200000e-3)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)

Value	stringToColr Ret. Val.	Exp. Val. (R, G, B) comp.	Valid	Exp. Val. (R, G, B) comp.	Valid
`rgb(12 24 200)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(12 24 200%)`	`java.awt.Color[r=12,g=24,b=255] + a=255`	`rgba(12 24 255 1.0)`	:green_circle:	rgba(12 24 255 1.0)	:green_circle:
`rgb(-1 24 200%)`	`java.awt.Color[r=0,g=24,b=255] + a=255`	`rgba(0 24 255 1.0)`	:green_circle:	rgba(0 24 255 1.0)	:green_circle:
`rgb(300 24 28)`	`java.awt.Color[r=255,g=24,b=28] + a=255`	`rgba(255 24 28 1.0)`	:green_circle:	rgba(255 24 28 1.0)	:green_circle:
`rgb(12 24 200 / 82%)`	`java.awt.Color[r=12,g=24,b=200] + a=209`	`rgba(12 24 200 0.82)`	:green_circle:	rgba(12 24 200 0.82)	:green_circle:
`rgb(12 24 200 / 0.82)`	`java.awt.Color[r=12,g=24,b=200] + a=209`	`rgba(12 24 200 0.82)`	:green_circle:	rgba(12 24 200 0.82)	:green_circle:
`rgb(12 24 200 / -210)`	`java.awt.Color[r=12,g=24,b=200] + a=0`	`rgba(12 24 200 0.0)`	:green_circle:	rgba(12 24 200 0.0)	:green_circle:
`rgb(12, 24, 200)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(12, 24, 200, 210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(12, 24, 200 , 210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(12 , 24 , 200 , 210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb( 12 , 24 , 200 , 210 )`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(12 ,24, 200 ,210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(12,24,200,210)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(15% 60% 49%)`	`java.awt.Color[r=38,g=153,b=125] + a=255`	`rgba(38 153 125 1.0)`	:green_circle:	rgba(38 153 125 1.0)	:green_circle:
`rgb(15% 60% 49% / 82%)`	`java.awt.Color[r=38,g=153,b=125] + a=209`	`rgba(38 153 125 0.82)`	:green_circle:	rgba(38 153 125 0.82)	:green_circle:
`rgb(15%, 60%, 49% / 82%)`	`java.awt.Color[r=38,g=153,b=125] + a=209`	`rgba(38 153 125 0.82)`	:green_circle:	rgba(38 153 125 0.82)	:green_circle:
`rgb(0.14 60% 52.3 / 0.98)`	`java.awt.Color[r=0,g=153,b=52] + a=250`	`rgba(0 153 52 0.98)`	:green_circle:	rgba(0 153 52 0.98)	:green_circle:
`rgb(none none none)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)	:green_circle:
`rgb(none none none / none)`	`java.awt.Color[r=0,g=0,b=0] + a=0`	`rgba(0 0 0 0.0)`	:green_circle:	rgba(0 0 0 0.0)	:green_circle:
`rgb(none none none/none)`	`java.awt.Color[r=0,g=0,b=0] + a=0`	`rgba(0 0 0 0.0)`	:green_circle:	rgba(0 0 0 0.0)	:green_circle:
`rgb(none none 30)`	`java.awt.Color[r=0,g=0,b=30] + a=255`	`rgba(0 0 30 1.0)`	:green_circle:	rgba(0 0 30 1.0)	:green_circle:
`rgb(none 20 none)`	`java.awt.Color[r=0,g=20,b=0] + a=255`	`rgba(0 20 0 1.0)`	:green_circle:	rgba(0 20 0 1.0)	:green_circle:
`rgb(10 none none)`	`java.awt.Color[r=10,g=0,b=0] + a=255`	`rgba(10 0 0 1.0)`	:green_circle:	rgba(10 0 0 1.0)	:green_circle:
`rgb(none none none)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)	:green_circle:
`rgb(10 50 13% / 50%)`	`java.awt.Color[r=10,g=50,b=33] + a=128`	`rgba(10 50 33 0.5)`	:green_circle:	rgba(10 50 33 0.5)	:green_circle:
`rgb(10 50 13% // 50%)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)	:green_circle:
`rgb(10 50,, 13% // 50%)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)	:green_circle:
`rgb(10 50 ,, 13% // 50%)`	`java.awt.Color[r=0,g=0,b=0] + a=255`	`rgba(0 0 0 1.0)`	:green_circle:	rgba(0 0 0 1.0)	:green_circle:
`rgb(1.2e1 0.24e2 2e2)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(1200e-2 2400e-2 200000e-3)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:
`rgb(120560.64646464632469823160676064670646798706406464098706464097970906464067e-4 2400e-2 200000e-3)`	`java.awt.Color[r=12,g=24,b=200] + a=255`	`rgba(12 24 200 1.0)`	:green_circle:	rgba(12 24 200 1.0)	:green_circle:

About performances

[x] Performance test available. What is tested :
- 1 000 occurences of :
- a set of 1 650 valid color rgb rgba notations, equi-distributed (Not Real WWW).
- and wrong color notations except alpha percent values.
[x] Enhancements must be at least without performance cost.

Run	Nb Tests	Befor PR (ms)	First Ext Impl. (ms)	V1 Ext Impl. (ms)	V1 Ext Impl. optimised (ms)	V3 Ext Impl. (ms)
`<rgb>` alpha support	:heavy_check_mark:	:heavy_check_mark:	:heavy_check_mark:	:heavy_check_mark:
`<rgb>` `none` support	:heavy_check_mark:	:heavy_check_mark:	:heavy_check_mark:	:heavy_check_mark:
Number Gen Ext Impl.	:heavy_check_mark:	:heavy_check_mark:	:heavy_check_mark:
`<rgb>` base-ten floating-point notation support	:heavy_check_mark:
1	1 650 000	249	342	222	157	166
2	1 650 000	243	342	221	162
3	1 650 000	239	340	222	167
4	1 650 000	258	340	223	166
5	1 650 000	243	339	217	165

:heavy_check_mark:

scientificware / jdk

JDK-8294090 : Aligns the CSS `<rgb()>` and `<rgba()>` function behaviours #16

The purpose of this issue is to align the `<rgb()>` and `<rgba()>` function behaviours in CSS.java.

Status

Basic test

Details :

Consequences

Syntax

Some tests

About performances

scientificware / jdk

JDK-8294090 : Aligns the CSS `<rgb()>` and `<rgba()>` function behaviours #16

The purpose of this issue is to align the <rgb()> and <rgba()> function behaviours in CSS.java.

Status

Basic test

Details :

Consequences

Syntax

Some tests

About performances

The purpose of this issue is to align the `<rgb()>` and `<rgba()>` function behaviours in CSS.java.