On Mon, 2 Mar 2026 16:04:12 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.
void f() {
if(lv() instanceof int v) {
bytecode:
void f();
Code:
0: aload_0
1: invokevirtual #7 // Method lv:()J
4: lstore_2
5: lload_2
6: lstore 4
8: lload 4
10: invokestatic #13 // Method
java/lang/runtime/ExactConversionsSupport.isLongToIntExact:(J)Z
13: ifeq 26
16: lload_2
17: l2i
18: istore_1
-------------
PR Comment: https://git.openjdk.org/jfx/pull/2093#issuecomment-3993721661
