draggable scroll + getvelocity

[gibo]

I'm not sure if this is a bug, or that I'm doing something slightly wrong.

 

      Draggable.create(".viewport", {type:"scroll",

        throwProps:true,

        onDragEnd:function() {

          console.log("velocity is: " + ThrowPropsPlugin.getVelocity(this.target, "scroll") + " and the duration is " + this.tween.duration() + " seconds.");

        }

      });

 

Using the property scroll always returns NaN, using another property such as rotation works as expected.

[GreenSock]

Well, the "scroll" type is a bit more tricky because Draggable has to create a special "scrollProxy" object that handles all the movement and velocity (due to the fact that browsers don't allow scrollTop or scrollLeft to overscroll - we have to use transforms or margins to accomplish that). You can get that ScrollProxy object directly on the Draggable instance itself (it's a property), and the ScrollProxy has "top" and "left" methods that get/set the vertical/horizontal scroll values. So to get the velocity of the vertical movement, for example, you could do this in your onDragEnd: 

console.log("velocity is: " + ThrowPropsPlugin.getVelocity(this.scrollProxy, "top") + " and the duration is " + this.tween.duration() + " seconds.");

Of course for the horizontal velocity, you'd check "left" instead of "top". 

 

Is that what you were looking for? 

[gibo]

Indeed it is, many thanks.

 

I couldn't find this in the docs, perhaps an example should be added to the Draggable documentation.

 

Thanks again.

[GreenSock]

Done. Added a note to the docs.