Recursively check if Sprite is (literally) visible

totebo

Is there a way of checking if a Sprite is visible, taking all of its parents into account? Without being able check if the final Sprite has been added to "stage", I can't seem to figure it out.

I want to use this in my Button class to avoid it triggering if it has been added to a Sprite with setVisible(false), or if it hasn't been added to the stage at all.

totebo

This seems to work, but feels "dirty". Is there a better/simpler/more efficient way?

function isVisibleRecursive( sprite )   stage.__is_stage = true   local visible = false   repeat   visible = sprite:isVisible() and sprite:getParent() ~= nil sprite = sprite:getParent()   until sprite == nil or sprite.__is_stage   return visible   end   local sprite1 = Sprite.new() local sprite2 = Sprite.new() sprite2:addChild( sprite1 ) stage:addChild( sprite2 )   print( isVisibleRecursive(sprite1) )

totebo

.

pie

@totebo try this from GiderosCodingEasy by ar2rsawseen

function Sprite:isVisibleDeeply() -- Answer true only if the sprite and all it's a parents are visible. Normally, isVisible() will -- return true even if a sprite is actually not visible on screen by wont of one of it's parents -- being made invisible. -- local try=self while (try) do if not(try:isVisible() and try:getAlpha()>0) then return false end try = try:getParent() end return true end

https://github.com/ar2rsawseen/GiderosCodingEasy/blob/master/GiderosCodingEasy.lua#L687

totebo

Thanks @pie!

I think that solition only checks for isVisible, and would return true even if the Sprite is not added to the stage (and thus not actually visible)?

keszegh

for that part use
stage:contains(mysprite)

http://docs.giderosmobile.com/reference/gideros/Sprite/contains

totebo

Fantastic, thanks! Had missed that one.

totebo

This is the final method, for reference:

function isVisibleRecursive( sprite )   local visible = false   repeat   visible = sprite:isVisible() and stage:contains(sprite) sprite = sprite:getParent()   until sprite == nil or visible == false   return visible   end   local sprite1 = Sprite.new() local sprite2 = Sprite.new() sprite2:addChild( sprite1 ) stage:addChild( sprite2 )   print( isVisibleRecursive(sprite1) )

keszegh

i don't know if it would be faster to check at the beginning
local visible=false
if not stage:contains(sprite) then return visible end

as this is maybe native and so perhaps faster then checking one by one all levels of the hierarchy for containment.

totebo

Yeah, edited the post, check it out. It should break as soon as sprite is not visible, or stage does not contain it. If the first sprite isVisible() == false or not contained by stage, it's game over.

n1cke

function Sprite:isVisibleRecursive() if self.__parent then return self:isVisible() and self.__parent:isVisibleRecursive() else return self:isVisible() and stage:contains(self) end end

keszegh

yes, but contains needs to be called only for the initial sprite, like:

function isVisibleRecursive( sprite )   local visible = false if not stage:contains(sprite) then return visible end repeat   visible = sprite:isVisible() sprite = sprite:getParent()   until sprite == nil or visible == false   return visible   end   local sprite1 = Sprite.new() local sprite2 = Sprite.new() sprite2:addChild( sprite1 ) stage:addChild( sprite2 )   print( isVisibleRecursive(sprite1) )

totebo

Wow, that is neat. And beyond my level of efficient coding. Nice one @n1cke!

keszegh

@n1cke, that's neat, although my version still contains less calls to contains.

n1cke

@keszegh: only one "contains" call is performed here because it is last condition to check.

keszegh

@n1cke, you are right, my mistake. your code is most efficient.

at the end it depends also on if one tends to set sprites to not visible. if this is less likely (like in my case), then it still may be more efficient to start with a stage:contains and then proceed with the visibility checks.

hgy29

@totebo,
I don't know if it will work for you but you may want to try:

function isReallyVisible(sprite) local gx,gy=sprite:localToGlobal(0,0) --Assuming 0,0 is actually within the sprite return sprite:hitTestPoint(gx,gy,true) -- Check inside taking clip/visibility into account end

totebo

That's a cool and different solution!