Doubletap + Storyboard
Posted on Wed, 2012-01-25 03:28
Hello folks,
I've got a small problem. Let me describe what I want to do. I am doing a picture book using storyboard API. I have a couple of arrows to navigate between pages. I don't want to have a home button. Therefore I came up with an idea - if a user singel taps an arrow, next page is shown. But double tap would show the first page.
The issue is that there is no event "doubletap" only "tap". There is of cause numTaps. But if a user double taps an object the tap even is called 2 times: first where numTaps = 1 and second with numTaps = 2.
I thought I could manage this as follows (please note this is not a complete code)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | local numTaps local timerStash = {} local function goToScene() if numTaps > 1 then timer.cancel(timerStash[1]) storyboard.gotoScene(true, "firstPage", effect, 500) else storyboard.gotoScene(true, nextPage, effect, 500) end end local function turnPage(event) numTaps = event.numTaps table.insert(timerStash, timer.performWithDelay(350, goToScene, 1)) end |
But this thing just crashes.
Please help. Thanks in advance.
Replies
Posted on Mon, 2012-02-06 00:28
#2
Thank you. Unfortunately it's the same issue here. Your code is handeling only double tap. My problem is that I need to handle both single and double-tap. What happens is that both events are caught. So I need somehow to cancel an action of the first event if double-tap is detected. I just can'r figure out how to do that.
Posted on Mon, 2012-02-06 07:35
#3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | local function tapAbsorberHandler(event) print("event.phase", event.phase) -- -- in my app this is sitting on top of a scroll view (sv) and I want -- any movement gestures to go to the scroll view. -- the "ended" phase has the double tap code in it. -- if event.phase == "moved" then if math.abs(event.xStart - event.x) > 5 or math.abs(event.yStart - event.y) then sv:takeFocus(event) return true end elseif event.phase == "ended" then print("e.time - ptt", event.time - previousTapTime) if (event.time - previousTapTime) < 300 then -- double tap so close -- -- do what you need to on a double tap for example -- print("double tap") storyboard.gotoScene(previousScene) return true -- -- added this bit -- else -- -- do whatever you want to do on a single tap -- end previousTapTime = event.time end return true end |
Posted on Mon, 2012-02-06 11:01
#4
Well. I want to switch scenes both when i tap and double-tap. So this suggestion doesn't work. The reason is that if a switch begins during first tap, the second one never registeres. But I finally solved it. Here's how
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | local nextScene local timer1, timer2 local gfp = false -- go to next scene cancel all timers local function goToNextScen() storyboard.gotoScene(true, nextScene, effect, 500) if timer1 then timer.cancel(timer1) end if timer2 then timer.cancel(timer2) end return true end -- turn page local function turnPage(event) if event.phase == "ended" then -- if double-tap if event.time - previousTapTime < 300 then -- we can go to first page gfp = true -- fix what needed to be done to go to first page nextScene = "firstPage" else -- do not go to first page gfp = fale -- fix what needed to be done to go to next page nextScene = ... end -- now this event will be called twice for each tap. -- so we start to actually change to new scene first after 300 ms -- if during that time double-tap happens, we cancel the first call -- now we can go to first page if gfp then timer.cancel(timer1) timer2 = timer.performWithDelay(300, goToNextScen, 1) else timer1 = timer.performWithDelay(300, goToNextScen, 1) end previousTapTime = event.time end return true end |
Posted on Wed, 2012-03-21 07:24
#5
Yogamatta, does this incur a delay after the taps before there is a response (300 milliseconds)?
I'm trying to write a routine that detects doubletaps without a delay (that doesn't also trigger single tap response), if possible.
Thanks,
Eric
Posted on Wed, 2012-03-21 09:20
#6
Well, there is a delay of cause. But there was a major delay bug with storyboard and transitions. With Those 2 delays combining it was very noticible. But I haven't had a chance to test with the latest fix and see how it looks like only with 300ms delay.
I don't think there is a way to solve it without a delay. If you find one, please share the solution. Good luck.
Posted on Wed, 2012-03-21 09:44
#7
It's a dilemna (if you don't want a delay for a tap), because you have to wait to see if a double tap happens before you respond to the single tap!
Besides using tachyons that tunnel backward through time, I don't know what the solution would be. :)
But maybe I'm just not seeing it ...
I will keep you posted.
By the way, I used 200 milliseconds in my solution, and it seems fine. YMMV.
Thanks
Eric
Try this:
You have to use a touch handler, not a tap handler since I don't think the event.time is passed on tap.