How to detect if touch is outside of the object with a local touch listener?

Solar2D General Questions/Discussion
#1

Hey all,

   I’m trying to create a ‘turret’ which shoots as long as you keep touching it. I have this listener;

local function autoTurretTouchListener(e)     if(isGamePaused == false) then         local turret = e.target                  if (e.phase == "began") then                          if(turret.shootingTimer == nil) then                 turret.shootingTimer = timer.performWithDelay(turret.fireRate, function() turret:spawnBall() end, 0)             end                          timer.resume(turret.shootingTimer)                  elseif e.phase == "ended" then                          if(turret.shootingTimer ~= nil) then                 timer.pause(turret.shootingTimer)             end                          end              end end

It works as expected but if you press inside the ‘turret’ object and drag the touch out of the object it won’t stop shooting because it doesn’t get the “ended” event.phase. I couldn’t come up with a workaround for this. I tried with global touch listener but you can’t get event.target so it was no use.

And I have multiple turrents on-screen at once. I was thinking about adding a global touch listener and in the “ended” phase, loop thru all the turrets to make them stop shooting but I was  hoping there would be a better solution… Any help is appreciated.

#2

I think you are looking for cancelled :slight_smile:

elseif (e.phase == “ended” or e.phase == “cancelled”) then

#3

Nope, the “cancelled” never gets fired in my case, I think it is when system cancels the touch for some reason, not the user.

#4

Hmmm, I just tried your code above with the added cancelled and it worked fine for me. ie: I clicked in the middle and dragged outside of the object and let go it then triggered off the “cancelled” phase. (not the ended phase)

#5

From the Forum to the rescue! Check out this forum post for a bit of info on onscreen touch logic.

#6

“A lot of people encounter this issue and, just like almost every other dilemma, the Corona community has come up with a great solution…”

I’m on it!

I’m adding the event listener like this;

autoTurret:addEventListener("touch", autoTurretTouchListener)

And if I start the touch inside the object it fires “began”, and when I move out of the object while pressed I get a lot of “moved”. And once I’m out of the object bounds I get no more updates, if I release the touch I see nothing, the last time it entered the listener it was “moved”. What are we doing different?
 

#7

Setting bounding properties for the touch listener is the best way to accomplish what you’re looking for IMO. Check out that forum post for some sample code to get started.

#8

I copy pasted the exact code to my project and when I run it I get the same old results. e.phase never becomes “offTarget”

I tried the same method myself prior but as soon as the mouse leaves the content bounds, the listener stops getting further updates so it never knows the event.x is actually out. Is there any chance something else is interfering with touch listeners?

#9

Did you declare the object which should demonstrate the contentBounds properties? Can you post your own code so we can take a look?

#10

Here is the code that seems to work for some but not for me;

local button = display.newCircle(320,500, 150) button:setFillColor(255,0,0 ) local function buttonClick() &nbsp;&nbsp;&nbsp; button:setFillColor(55,10,0 ) end&nbsp;&nbsp; &nbsp; local function buttonRelease() &nbsp;&nbsp;&nbsp; button:setFillColor(255,0,0 ) end&nbsp;&nbsp; &nbsp; local function buttonPressed(e) &nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; if e.phase == "began" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; buttonClick(e.target) &nbsp;&nbsp;&nbsp; elseif e.phase == "moved" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if e.x \< e.target.contentBounds.xMin or &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; e.x \> e.target.contentBounds.xMax or &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; e.y \< e.target.contentBounds.yMin or &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; e.y \> e.target.contentBounds.yMax then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; print("Its out") &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; e.phase = "offTarget" &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; e.target:dispatchEvent(e) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp; elseif e.phase == "offTarget" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; buttonRelease() &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; print("It ran off the button") &nbsp;&nbsp;&nbsp; elseif e.phase == "ended" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; buttonRelease() &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; print("It ended") &nbsp;&nbsp;&nbsp; elseif e.phase == "cancelled" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; buttonRelease() &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; print("It canceled") &nbsp;&nbsp;&nbsp; end end button:addEventListener("touch",buttonPressed)
#11

Try putting the buttonRelease() function call inside the contentBounds logic call inside the touch listener.

That was a mouthful. Try this and let us know what happens:

 if e.x \< e.target.contentBounds.xMin or e.x \> e.target.contentBounds.xMax or e.y \< e.target.contentBounds.yMin or e.y \> e.target.contentBounds.yMax then print("Its out") buttonRelease() --e.phase = "offTarget" e.target:dispatchEvent(e) end
#12

You need to “return true” in your call as well otherwise it keeps going.

#13

@Panc software, I tried it and it is the same result, the last execution of ‘buttonPressed’ function gets “event.phase == moved” and nothing else once touch is outside.

@Christopher Bishop, I tried it with and without returning true after your post. The only difference I see is that if I return true, my global touch listener won’t fire if I press inside the object. Otherwise it’s the same issue.

#14

Ok so little confused here, you have a “global” touch handler and a local one attached to your button?

#15

Yes, I have a runtime touch listener but I tried removing it entirely, the result was the same.

Edit: I said yes earlier but I guess the correct answer should have been no. I don’t have them both on the same object. I have a touch listener for each turret, and a runtime touch listener.

local function onScreenTouch(event) &nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; if isGamePaused == true then return end &nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; if event.phase == "began" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; mouseX = event.x &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; mouseY = event.y &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; startShooting() &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; elseif ( event.phase == "ended" or event.phase == "cancelled" ) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; stopShooting() &nbsp;&nbsp;&nbsp; end &nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; if event.phase == "moved" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; mouseX = event.x &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; mouseY = event.y &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; end &nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; return true end

I also tried not returning true, the result was the same with my button touch listener.

#16

the code was meant for touch on objects not global but could be modified

#17

Okay, I just learned about setFocus() and it was just what I needed! This works like a charm, does exactly what I wanted;

local function autoTurretTouchListener(e) &nbsp; &nbsp;&nbsp;&nbsp; if(isGamePaused == false) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; local turret = e.target &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (e.phase == "began") then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; display.getCurrentStage():setFocus( e.target, e.id ) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(turret.shootingTimer == nil) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; turret.shootingTimer = timer.performWithDelay(turret.fireRate, function() turret:spawnBall() end, 0) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(isMainTurretShooting == false) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; timer.performWithDelay(1, function() stopShooting() end, 1) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; timer.resume(turret.shootingTimer) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; elseif e.phase == "ended" or e.phase == "cancelled" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; display.getCurrentStage():setFocus( nil, e.id ) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(turret.shootingTimer ~= nil) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; timer.pause(turret.shootingTimer) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; elseif e.phase == "cancelled" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(turret.shootingTimer ~= nil) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; timer.pause(turret.shootingTimer) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; turret.isShooting = false &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; display.getCurrentStage():setFocus( nil ) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; elseif e.phase == "moved" then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; --if touch is moved outside of turret &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if e.x \< e.target.x - e.target.width/2&nbsp; or e.x \> e.target.x + e.target.width/2 or e.y \< e.target.y - e.target.height/2 or e.y \> e.target.y + e.target.height/2 then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(turret.shootingTimer ~= nil) then &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; timer.pause(turret.shootingTimer) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; end end
#18

I think you are looking for cancelled :slight_smile:

elseif (e.phase == “ended” or e.phase == “cancelled”) then

#19

Nope, the “cancelled” never gets fired in my case, I think it is when system cancels the touch for some reason, not the user.

#20

Hmmm, I just tried your code above with the added cancelled and it worked fine for me. ie: I clicked in the middle and dragged outside of the object and let go it then triggered off the “cancelled” phase. (not the ended phase)