3 buttons using classes not working

Harrison · April 2014

Button = Core.class(Sprite)
 
function Button:onMouseUp(event)
if self:hitTestPoint(event.x,event.y) then
print("you clicked me!!")
end
end
function Button:init(sprite)
print("initializing button")
self:addEventListener(Event.MOUSE_UP, self.onMouseUp, self)
self:addChild(sprite) 
 
end

I make 3 buttons in main.lua using

local bitmap = Bitmap.new(Texture.new("abuttonimage",true))
x=Button.new(bitmap) 
x:setPosition(0,0)
stage:addChild(x)

repeat with y and z, but change position.
now, only z is visible and running. The others initialise the button, but they do not appear or respond.
it works with 1 button, but not 3.
any ideas on why/how to fix it?

hgvyas123 · April 2014

you should have to do like this

local bitmap = Bitmap.new(Texture.new("abuttonimage",true))
x=Button.new(bitmap) 
x:setPosition(0,0)
stage:addChild(x)
 
local bitmap = Bitmap.new(Texture.new("abuttonimage",true))
y=Button.new(bitmap) 
y:setPosition(0,0)
stage:addChild(y)
 
local bitmap = Bitmap.new(Texture.new("abuttonimage",true))
z=Button.new(bitmap) 
z:setPosition(0,0)
stage:addChild(z)

as every bitmap can have only one parent and if you try to add them again in different paren then it will first remove from previous parent and then added in new parent and hence visible only one time

OZApps · April 2014

@hgvyas123,
but if you set the position of all the buttons to (0,0) they will all sit on top of each other.

@Harrison,
you are passing the function a child that is moved from parent to parent (same instance) as @hgvyas explained. you can try this code as

 function Button:init(theSpriteName)
  local bitmap = Bitmap.new(Texture.new(theSpriteName, true))
  self:addChild(sprite)
  self:addEventListener(... the rest of the code ...)
 end

and then call it easily as

 x = Button.new("abuttonimage.png")
 y = Button.new("bbuttonimage.png")
 z = Button.new("cbuttonimage.png")
 
 stage:addChild( add the x, the y and the z)

Or you can as I suggested in my book create a more generic code that looks like

 function Button:init(theSpriteName, xPos, yPos, parent)
  local parent = parent or stage
  local bitmap = Bitmap.new(Texture.new(theSpriteName, true))
  local xPos, yPos = xPos or 0, yPos or 0
  self:addChild(sprite)
  self:addEventListener(... the rest of the code ...)
  self:setPosition(xPos, yPos)
  parent:addChild(self)
 end

so you can call it all in one go as

 x = Button.new("abuttonimage.png", 0, 0)
 y = Button.new("bbuttonimage.png", 100, 100)
 z = Button.new("cbuttonimage.png", 0, 200)

hgvyas123 · April 2014

ohhh yes Copy Paste error

Harrison · April 2014

@OZApps
i am trying to make it work, but when i do
local start = Button.new("images/button.png", 10, 0)
in main.lua
and
self:addEventListener(Event.MOUSE_UP, self.onMouseUp, self)
in button.lua it dosent seem to work.. what am i doing wrong?

OZApps · April 2014

@harrison,
it would help to post your actual code, because there might be something in it that is the issue.

Secondly, there is no function called self.onMouseUp, so you will have to pass it Button.onMouseUp instead. The rest should be all the same.

Harrison · April 2014

It works now, i misspelled some variables and got mixed up. thanks!

Harrison · April 2014

Currently attempting to make unique code run based on the
function Button:init(sprite, xPos, yPos, parent) by adding a new variable "name".
the problem is.. i am not sure how to get the name from init to onmousedown without using global variables.
my new onmousedown code would look something like :

unction Button:onMouseDown(event)
--check if button is on click coordinates
if self:hitTestPoint(event.x,event.y) then
if name == "startbutton" then
--display pressed button
elseif name == "exit" then 
--display different pressed button
 end
end

My current code:

--make a sprite class "Button"
Button = Core.class(Sprite)
 
--check if button is pressed
function Button:onMouseDown(event)
--check if button is on click coordinates
if self:hitTestPoint(event.x,event.y) then
print("hi!")
 
end
end
 
--check if button is released
function Button:onMouseUp(event)
--check if the button is on click coordinates
if self:hitTestPoint(event.x,event.y) then
--debug print
print("you clicked me!!")
--make a click noise
local click= Sound.new("sounds/sfx/clickbutton.wav")
click:play()
end
end
 
function Button:init(sprite, xPos, yPos, parent)
  local parent = parent or stage
  --load the bitmap
  local bitmap = Bitmap.new(Texture.new(sprite, true))
  --load x any y position or set it to 0
  local xPos, yPos = xPos or 0, yPos or 0
  self:addChild(bitmap)
  self:addEventListener(Event.MOUSE_UP, Button.onMouseUp , self)
  self:addEventListener(Event.MOUSE_DOWN, Button.onMouseDown,self)
  --put the button at the specified x and y
  self:setPosition(xPos, yPos)
  parent:addChild(self)
 end

OZApps · April 2014

@harrison,
have you tried the

self.name

x = Button.new("exitImage.png", 10,10)
x.name = "exit"

and then in your code of

onMouseDown

just check for

self.name == "exit"

Hope that helps,

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3 buttons using classes not working

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