On Mon, 2 Mar 2026 16:09:33 GMT, Michael Strauß <[email protected]> wrote:
>> `CssParser.colorValueOfString()` parses a string into a `Color`. If this
>> fails by throwing an exception, `null` is returned from
>> `colorValueOfString()`, signalling to the caller that the color string might
>> be a lookup instead.
>>
>> Since color lookups can appear in many places in a CSS file, it is
>> preferable to use return values for flow control instead of exceptions. For
>> this purpose, we need non-throwing versions of methods that parse numbers
>> and colors.
>>
>> These are the changes in this PR:
>> 1. Move color parsing from the `Color` class to `CssColorParser`. This is
>> done so that we can access the new `tryParseColor(String)` method from
>> `CssParser`, and also to separate concerns between color representation and
>> parsing.
>> 2. Add a non-throwing `CssNumberParser.tryParseDouble()`, which returns
>> `NaN` to indicate a parsing failure. We can use `NaN` because it is not a
>> valid return value of the parser.
>> 3. Since color parsing also uses `Integer.parseInt()`, we need a
>> non-throwing version of this method: `CssNumberParser.tryParseInt()`. Since
>> we can't use any particular `int` as a return value that indicates failure,
>> I've decided to return a `long` value instead, where a value less than
>> `Integer.MIN_VALUE` indicates a parsing failure.
>
> modules/javafx.graphics/src/main/java/com/sun/javafx/css/parser/CssNumberParser.java
> line 42:
>
>> 40: * returns a long value less than {@link Integer#MIN_VALUE} to
>> indicate failure.
>> 41: */
>> 42: public static long tryParseInt(String s, int start, int end, int
>> radix) {
>
> This code is taken from `Integer.parseInt(String, int, int, int)` in the JDK,
> and modified to return `Long.MIN_VALUE` instead of throwing
> `NumberFormatException`.
I wonder if we really should do that. Whenever something in the JDK changes, we
may need to port it to our Integer parsing as well.
Can't we just do the same as we do with `Double`:
try {
return Double.parseDouble(s.substring(start, end));
} catch (NumberFormatException _) {
return Double.NaN;
}
But with `Integer`?
-------------
PR Review Comment: https://git.openjdk.org/jfx/pull/2093#discussion_r2874707231
