Touch events outside

Solar2D General Questions/Discussion
#1

Hi guys!

I am wondering… how do I know if a user has dragged his finger outside a touch area? It doesnt give me an event like: ‘ended’ or ‘draggedOutside’. 

And is there a way to find out if an area is touched, without listening to events from it? That would also suffice.

Thanks!

#2

you need to set focus on the touch object to continue receiving events once you drag beyond the bounds of the object.

https://docs.coronalabs.com/api/type/StageObject/setFocus.html#examples

#3

You will have to detect that yourself. For instance, if your object/area has a centre pivot, and event.x is greater than event.target.x + event.target.width/2, then the user moved their finger off the right side of the object. 

And as RG says above, the object will require focus…

#4

Note: While the examples at that link are perfectly suitable, you may find this easier to use as it is compatiable with multi-touch on or off:

local function onTouch( self, event ) local phase = event.phase if( phase == "began" ) then self.isFocus = true display.currentStage:setFocus( event.target, event.id ) -- YOUR CODE HERE elseif( self.isFocus ) then if( phase == "moved" ) then -- YOUR CODE HERE elseif( phase == "ended" or phase == "cancelled" ) then self.isFocus = false display.currentStage:setFocus( event.target, nil ) -- YOUR CODE HERE end end return false end

Then:

local obj = newRect( 100, 100, 100, 100 ) obj.touch = onTouch obj:addEventListener("touch")
#5

Tip: One question per post gets better answers I totally missed the second question and will let nick answer that.

Alternately, if you want to include a few related questions try prefacing it with, "these are my question"s and then use a numbered list of questions.

#6

OK, I lied I’ll answer the second question too.

First, SSK2 has this feature in it, but the concept  you’re describing is what I think of as ‘in bounds’.  Specifically, in bounds of an objec’ts axis-aligned bounding box:

local function isInBounds( obj, obj2 ) if(not obj2) then return false end local bounds = obj2.contentBounds if( obj.x \> bounds.xMax ) then return false end if( obj.x \< bounds.xMin ) then return false end if( obj.y \> bounds.yMax ) then return false end if( obj.y \< bounds.yMin ) then return false end return true end

With the above code, you can extend my original example as follows:

local function onTouch( self, event ) local phase = event.phase if( phase == "began" ) then self.isFocus = true display.currentStage:setFocus( event.target, event.id ) -- SET OBJECT TO GREEN FILL self:setFillColor(0,1,0) elseif( self.isFocus ) then -- Touch in bounds? local inBounds = isInBounds( event, self ) if( phase == "moved" ) then -- Highlight as green it touch in bounds else clear to white if(inBounds) then self:setFillColor(0,1,0) else self:setFillColor(1,1,1) end elseif( phase == "ended" or phase == "cancelled" ) then self.isFocus = false display.currentStage:setFocus( event.target, nil ) -- Clear to white, touch is done self:setFillColor(1,1,1) end end return false end
#7

Thank you very much!

#8

you need to set focus on the touch object to continue receiving events once you drag beyond the bounds of the object.

https://docs.coronalabs.com/api/type/StageObject/setFocus.html#examples

#9

You will have to detect that yourself. For instance, if your object/area has a centre pivot, and event.x is greater than event.target.x + event.target.width/2, then the user moved their finger off the right side of the object. 

And as RG says above, the object will require focus…

#10

Note: While the examples at that link are perfectly suitable, you may find this easier to use as it is compatiable with multi-touch on or off:

local function onTouch( self, event ) local phase = event.phase if( phase == "began" ) then self.isFocus = true display.currentStage:setFocus( event.target, event.id ) -- YOUR CODE HERE elseif( self.isFocus ) then if( phase == "moved" ) then -- YOUR CODE HERE elseif( phase == "ended" or phase == "cancelled" ) then self.isFocus = false display.currentStage:setFocus( event.target, nil ) -- YOUR CODE HERE end end return false end

Then:

local obj = newRect( 100, 100, 100, 100 ) obj.touch = onTouch obj:addEventListener("touch")
#11

Tip: One question per post gets better answers I totally missed the second question and will let nick answer that.

Alternately, if you want to include a few related questions try prefacing it with, "these are my question"s and then use a numbered list of questions.

#12

OK, I lied I’ll answer the second question too.

First, SSK2 has this feature in it, but the concept  you’re describing is what I think of as ‘in bounds’.  Specifically, in bounds of an objec’ts axis-aligned bounding box:

local function isInBounds( obj, obj2 ) if(not obj2) then return false end local bounds = obj2.contentBounds if( obj.x \> bounds.xMax ) then return false end if( obj.x \< bounds.xMin ) then return false end if( obj.y \> bounds.yMax ) then return false end if( obj.y \< bounds.yMin ) then return false end return true end

With the above code, you can extend my original example as follows:

local function onTouch( self, event ) local phase = event.phase if( phase == "began" ) then self.isFocus = true display.currentStage:setFocus( event.target, event.id ) -- SET OBJECT TO GREEN FILL self:setFillColor(0,1,0) elseif( self.isFocus ) then -- Touch in bounds? local inBounds = isInBounds( event, self ) if( phase == "moved" ) then -- Highlight as green it touch in bounds else clear to white if(inBounds) then self:setFillColor(0,1,0) else self:setFillColor(1,1,1) end elseif( phase == "ended" or phase == "cancelled" ) then self.isFocus = false display.currentStage:setFocus( event.target, nil ) -- Clear to white, touch is done self:setFillColor(1,1,1) end end return false end
#13

Thank you very much!