[webkit-gtk] WK2: WebKitWebViel scrolling

[Julian Scheel]

Am 30.07.2012 um 12:13 schrieb Carlos Garcia Campos <cgarcia at igalia.com>:

> El lun, 30-07-2012 a las 10:08 +0200, Julian Scheel escribió:
> [...]
>> 
>> Ok, thanks for the details. I agree with you that it probably would the
>> bigger hassle to deal with the gtk issues than having an own kinetic
>> scrolling implementation.
>> So is anyone already working on this? Otherwise I might take a look at
>> it. Although it will probably take some time before I am enough into the
>> WebKitGTK structure to really do it.
> 
> There's a cross-platform scroll animator implementation in WebCore. I
> don't know the details, I think it implements smooth scrolling by
> default, but you can take a look at that code as a start point. 
> 
> Source/WebCore/platform/ScrollAnimatorNone.cpp

Thanks. Actually the animation is the one part which seems to be handled by the ScrollableArea through ScrollAnimator. But when talking about kinetic-scrolling I was mainly thinking of touch based input. Which means, that before any scroll action can be executed we need some entry point for drag-and-drop style movement. I am unsure where this should be handled at? At a first glance I couldn't spot an obvious point that would deal with this.
Actually as there are several things to think of like preventing normal dnd events, text selection, etc. so that they don't interfere with the scrolling. I guess this forces an entry-point that is in a quite high level, where it can interrupt the normal input-event chain, which would lead to the mentioned behaviours.
Obviously one has to think of a way to allow dnd, text selection, etc. when dnd-scrolling is enabled - most likely some approach with longer touch times will be a good choice.
Any more thoughts?

-Julian