RFR: 8360070: AccessibleText.getBeforeIndex returns null for last character

[Abhishek Kumar]

On Wed, 25 Jun 2025 15:05:27 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

>>> > I think the check is to ensure the passed index parameter is to verify the boundary of text length.
>>> 
>>> Yes, but the index passed to the method is `an index within the text`, so it should be from 0 to length - 1. You can take a look at the opposite case when the index is outside the range, for example at the beginning of the text and getAfterIndex:
>>> 
>>> > result = at.getAfterIndex(AccessibleText.CHARACTER, -1);
>>> > verifyResult("T", result);
>>> 
>>> Is that expectation correct or not? I think we should first decide whether this is actually a bug or not.
>> 
>> I got your point now. The spec says that `index an index within the text` and that means the value should range from 0 to length - 1. And that means, `getBeforeIndex` won't be able to fetch the last character and `getAfterIndex` won't be able to fetch the first character.
>> 
>> So, if someone wants to retrieve the first or last character, they shouldn't rely on `getAfterIndex and getBeforeIndex` method respectively, rather use `getAtIndex` method to get the first and last character with index passed as 0 and length -1 respectively.
>> 
>> Right ?
>
>> The spec says
> 
> What spec in particular?

@aivanov-jdk @azuev-java As per the discussion with @mrserb [here](https://github.com/openjdk/jdk/pull/25941#issuecomment-3003204161), it seems this is not an issue with the code. I would like to know about your opinion ?

If this is not an issue to fix, **can we update the javadoc for the APIs for better understanding** ?

Something like  `getBeforeIndex shouldn't be used to retrieve the last character or word or sentence` and similar for getAfterIndex and getAtIndex APIs.

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PR Comment: https://git.openjdk.org/jdk/pull/25941#issuecomment-3045669182