<AWT Dev> [8] Review request for 8011059 [macosx] Make JDK demos look perfect on retina displays

[Sergey Bylokhov]

Hello, Jim.
On 13.11.2013 22:49, Jim Graham wrote:
> That's could be a problem. Is it possible to wrap imageObserver, which
>> was passed to the drawImage, and replace one image to another in the
>> WrapperImageObserver.imageUpdate()?
>
> It's possible - the things to watch out for:
>
> - they could hand the same IO in for multiple drawImage calls to 
> multiple images
>
> - they could hand the same IO in repeatedly for the same image while 
> it is loading if the loading takes a while or the image is animated; 
> you don't want to necessarily create an infinite number of wrappers 
> for the same observer and register them all with the image loading 
> mechanism
>
> - the image that you report to them should probably be the original 
> image, not the resolution-specific underlying images
>
> - we need to deal with making sure that the information flowing to the 
> IO does not report complete until all resolution variants that we plan 
> to load are done
>
> - given Mike's answer to my previous questions, it looks like @2x is 
> not a retina-specific issue, all images do that even non non-retina 
> apparently so maybe we do want to load all variants up front?
>
> - we don't want to pass ERROR conditions to the IO unless all 
> resolution variants are errored, we should silently swallow any ERROR 
> conditions for just some of the resolution variants and make do with 
> what we have
Well, it is necessary to decide that it is simpler to bypass all these 
problems or to move them to the user. As ScalableToolkitImage 
implementation is trivial.
>
>             ...jim


-- 
Best regards, Sergey.