discussion about touch events
pavel.safrata at oracle.com
Thu Dec 12 12:29:09 PST 2013
I'm sorry for the long delay on my side.
Daniel, the only remaining point of our discussion that I feel deserves
>>> We could reasonably limit the algorithm to dealing with convex shapes.
>> Can we? What about paths, polygons etc?
> I realize that it is possible to describe touch sensitive concave
> shapes, but I am not sure they matter for this. If developers are
> going to go to the trouble of defining a concave shape that they want
> to be touch sensitive within its area but not in all of its bounding
> box, are they really then going to want that area to be extended? I’d
> consider a concave touch shape with extended capture zone to be
> sufficiently unlikely that we could treat it as concave. Which, I
> realize is not quite what my proposed algorithm does.
I can imagine, for instance, an application showing a graph - a set of
vertices connected by edges. The edges are not straight lines, but are
e.g. QuadCurves. I can touch an edge and drag it to change its shape
(the control point). Now to be able to touch the curve, I certainly want
it to have the extended capture zone (it's thin). But if an edge circles
around the graph, I don't want it to be picked everywhere in between.
I'm not sure if this is compelling enough, but to me it sounds like a
reasonable use-case that needs concave extended capture zones..
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