How to detect swipe direction?

[Scott Rossi]

Hi Roger:

Might be wrong, but I don't believe there's a built-in swipe
monitor/property.  I put together the following to detect course swipe
direction and added the ability to track the swipe angle.  You can set the
swipe distance threshold to control when an event is triggered from a
swipe.  The code is written to place direction output in a field.


-- 50 PIXEL SWIPE THRESHOLD

local hStart, vStart, theSwipeData
local theThreshold = 50

on touchStart theID
   put item 1 of mouseLoc() into hStart
   put item 2 of mouseLoc() into vStart
end touchStart

on touchmove theID, X, Y
   put empty into theSwipeData
   if Y > vStart and abs(vStart - Y) > theThreshold  then put "down,"
after theSwipeData
   if Y < vStart and abs(vStart - Y) > theThreshold  then put "up," after
theSwipeData
   if X > hStart and abs(hStart - X) > theThreshold  then put "right,"
after theSwipeData
   if X < hStart and abs(hStart - X) > theThreshold  then put "left,"
after theSwipeData
   if theSwipeData is not empty then put locToAngle(X,Y,hStart,vStart)
after theSwipeData
end touchmove

on touchEnd theID
   put "swipe: " into theResult
   if theSwipeData is not empty then put theSwipeData after theResult
   set text of fld 1 to theResult
end touchEnd

function locToAngle pX,pY,pXorigin,pYorigin
   put atan2(pY - pYorigin,pXorigin - pX) into R
   return round(180+(R*(180/pi)))
end locToAngle





Hope this helps.

Regards,

Scott Rossi
Creative Director
Tactile Media, UX/UI Design




On 10/6/13 2:09 PM, "Roger Eller" <roger.e.eller at sealedair.com> wrote:

>I want a different action to occur based on the direction the user swipes
>a
>control.  For example:
>
>   on swipeLeft
>        set the backgroundColor of me to red
>   end swipeLeft
>
>   on swipeRight
>        set the backgroundColor of me to green
>   end swipeRight
>
>Is there a one liner on mobile that can give me the direction, or
>true/false, or l/r/u/d?
>
>~Roger
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