Re: Question about implementing DataTransfer.addElement

On 10/10/2011 3:26 PM, Ian Hickson wrote:
> On Fri, 7 Oct 2011, Daniel Cheng wrote:
>> What's the difference between addElement and setDragImage()?
>>
>> The spec says:
>>
>>> The difference between setDragImage() and addElement() is that the
>>> latter automatically generates the image based on the current
>>> rendering of the elements added (potentially keeping it updated as the
>>> drag continues, e.g. if the elements include an actively playing
>>> video), whereas the former uses the exact specified image at the time
>>> the method is invoked.
>> For technical reasons, animating the drag image is non-trivial and not
>> likely to be implemented in the near future, if it is ever implemented.

What are the technical reasons? Is this something to do with OS level 
handling?

Seems that on an OS level, an animated drag image might be something 
that the OS does not support. But for all intents, the OS does not need 
to support a drag image either.

Should this kind of fallback be specified?

I'd imagine that current OS X and Windows systems do support more 
dynamic dragging. If they don't, well, what about the next round?

It does seem to me to be fundamentally different than images that are 
shown within the browser, where things can be animated by the UA. Once 
you're outside of the UA, it's really up to the OS capabilities.

But, again, show me the proof: What are the technical reasons? There's 
no magic box here, the major OS APIs are open to all of us.

-Charles

Received on Monday, 10 October 2011 22:38:38 UTC