[OpenJDK 2D-Dev] RFR: 8230672: Spec. for FontMetrics.getMaxAdvance is too prescriptive.

[Philip Race]

I am not 100% sure what you are getting at, but maybe
"render each such character" could be rephrased as
"query the advance of each such character".

But I would not point to charWidth() for this because
it is not adequate for all code points.

Does that clear it up ?

-phil.

On 4/23/20, 9:49 AM, Sergey Bylokhov wrote:
> On 4/23/20 9:34 am, Philip Race wrote:
>> No, I don't see the relationship.
>>
>> charWidth() is accurate if you use the FontMetrics from the render 
>> context.
>
> If it is always accurate why it is not recommended in the new 
> documentation? Why we suggest to "render each such character".
>
>  299      * None of these are exposed and they are all implementation 
> details,
>  300      * and there is no practical way to determine this. An 
> application
>  301      * which needs a better estimate of the maximum advance, and 
> knows
>  302      * the subset of characters it expects to display could render
>  303      * each such character to find the widest, but as discussed 
> above,
>  304      * since the displayed width of a {@code String} is not 
> necessarily
>  305      * the sum of the advances the value needs to be used with 
> caution.
>
>>
>> -phil.
>>
>> On 4/23/20, 9:19 AM, Sergey Bylokhov wrote:
>>> Hi, Phil.
>>>
>>> Isn't all/some of the new text in getMaxAdvance() is also applicable 
>>> to charWidth()?
>>> If I read the current doc properly then it looks like the 
>>> charWidth() should return "advance"
>>> of some specific "advance", and getMaxAdvance() is "just" maximum 
>>> value of any possible
>>> results from the charWidth().
>>>
>>> On 4/22/20 12:49 pm, Philip Race wrote:
>>>> bug : https://bugs.openjdk.java.net/browse/JDK-8230672
>>>> webrev : http://cr.openjdk.java.net/~prr/8230672/
>>>>
>>>> Loosen up the spec. a lot to reflect reality.
>>>>
>>>> I considered deprecating the method but there isn't any easy 
>>>> replacement,
>>>> so it would just be annoying to old code.
>>>>
>>>> This will clearly need a CSR which I will draft once we agree on 
>>>> the text here.
>>>>
>>>> -phil.
>>>
>>>
>
>