Re: Inclusion of :drag-over in CSS4 UI

On Fri, Sep 23, 2011 at 8:41 AM, Tantek Çelik <tantek@cs.stanford.edu>wrote:

> On Thu, Sep 22, 2011 at 18:33, Ojan Vafai <ojan@chromium.org> wrote:
> > On Thu, Sep 22, 2011 at 6:30 PM, David Chambers
> > <david.chambers.05@gmail.com> wrote:
> >>
> >> This would indeed be an excellent feature!
> >> David
> >>
> >>
> >> On 22 September 2011 18:20, Tab Atkins Jr. <jackalmage@gmail.com>
> wrote:
> >>>
> >>> On Thu, Sep 22, 2011 at 5:18 PM, Ryan Seddon <seddon.ryan@gmail.com>
> >>> wrote:
> >>> > Firefox has had the :-moz-drag-over[1] pseudo-class for sometime
> which
> >>> > allows you to style an element when the drag over event is called on
> >>> > it.
> >>> >
> >>> > I think this would be a useful inclusion to be considered for the
> CSS4
> >>> > UI
> >>> > module, albeit perhaps with a more descriptive name.
> >>> >
> >>> > [1] https://developer.mozilla.org/en/CSS/:-moz-drag-over
> >>>
> >>> Since this actually matches an element with @dropzone (and which is a
> >>> valid dropzone for the dragged element), I think it needs a better
> >>> name.  As an initial bad suggestion, :valid-dropzone.
> >
> > How about just :dropzone?
>
> This makes sense (suggestion, comments).
>
> >>> Other than the name thing, though, this is definitely useful.  It's
> >>> very useful for an author to indicate visually when the user is
> >>> hovering over a valid dropzone, and without this you can only achieve
> >>> that effect by adding/removing a class in the drag events (which isn't
> >>> reliable, iirc, because you could, for example, drag from the element
> >>> to outside the window).
> >
> > I agree. This is very useful. Would love to add this to WebKit.
>
> That's good to hear.
>

Just to be clear. I'm not representing the official WebKit opinion here. All
I can do is advocate for it. If another WebKit reviewer is opposed to it I
can't guarantee it'll get in. That said, I don't expect opposition for this
specific feature.


> Two (checkbox) choices:
>
> 1. :drop-zone - spec'd as Firefox implements
> https://developer.mozilla.org/en/CSS/:-moz-drag-over - added to
> *CSS3-UI*, since it sounds like a WebKit implementation would be
> imminent, thus being CR-ready in short order.
>
> 2. :valid-drop-zone, :invalid-drop-zone - spec'd as a :drop-zone that
> is valid/invalid per Tab's suggested text (edited), added to
> *CSS4-UI*, since there are zero implementations today.
>   :valid-drop-zone - a drop zone that accepts the type of data being
> dragged
>   :invalid-drop-zone - a drop zone that doesn't accept the type of
> data being dragged
>
> Thoughts?
>
> I'm fine with both options (thus adding all three).
>

Adding all three seems unnecessary and I don't think we should decide this
based of the CR-readyness. I don't see any disadvantages to option 2 and I
can see use-cases for caring about validness of drop zones.


>
> Tantek
>