UI Button problem...

6 replies [Last post]
Posted on Thu, 2010-03-11 14:00
menace690
User offline. Last seen 1 year 4 weeks ago. Offline
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Joined: 10 Mar 2010

Having an issue I can't resolve.

I have a function we will call MakeButtons

MakeButtons creates some buttons using UI Library and puts them in a table we will call buttonTable that is called at the top of the app and is Global

Each UIButton calls another function doWhenPressed.

While within MakeButtons everything works as expected. buttonTable[x].isVisible works for example.

doWhenPressed takes the event.id (which is verified to have same value as x). ie buttonTable[x] =buttonTable[event.id]

However buttonTable[event.id].isVisible does not work. In fact buttonTable[x] when x is forced also does not work.

Any clues anyone?

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Replies

Posted on Thu, 2010-03-11 14:07
#1
menace690
User offline. Last seen 1 year 4 weeks ago. Offline
Test Driver
Joined: 10 Mar 2010

I cleaned up the code so I could post an example
At the top of the program:

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 buttonTable={}

MakeButtons:

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        function MakeButtons (numOfCans)
        
                numOfCanNumber=tonumber(numOfCans);
                canToPop=5;
        
                
                local i=1;
 
 
 
        
                while i <= numOfCanNumber do
                        newButton=ui.newButton{
                                                default = "up.png",
                                                over = "down.png",
                                                onEvent = doWhenPressed,
                                                text = " ",
                                                id = i,
                                                emboss = true
                                        }
                        buttonTable[i]=newButton;
                        buttonTable[i].y=(math.floor((i-1)/3)+1) * StageHeight/5;
                        buttonTable[i].x=((i-1) % 3 + 1) * StageWidth/4;
                        i=i+1;
 
                end;
        
 
 
  
        end;
</code
 
doWhenPressed:
<code>
        function doWhenPressed(event)
                        if(event.id==canToPop) then
                                winscenario=true;
                        else 
                                buttonTable[event.id].isVisible=false;
                        end;
 
                end

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Posted on Mon, 2010-03-15 21:00
#2
slgilley
User offline. Last seen 16 weeks 6 days ago. Offline
Pro Developer
Joined: 19 Feb 2010

I'm no expert in Lua, but I believe at least part of the problem is in doWhenPressed(event).

The event.id is not the same as the id you set in the button above. What you want, I think, is something like:

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function doWhenPressed(event)
        local t = event.target
        if(t.id == canToPop) then
                winscenario = true;
        else
                buttonTable[t.id].isVisible=false;
        end
end

You need to get the target of the event, which is your button, then you can look at its id.

Sean.

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Posted on Wed, 2010-03-17 05:09
#3
menace690
User offline. Last seen 1 year 4 weeks ago. Offline
Test Driver
Joined: 10 Mar 2010

If I print(event.id), I have it correct index. Verified the type is number as well.

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Posted on Wed, 2010-03-17 07:01
#4
menace690
User offline. Last seen 1 year 4 weeks ago. Offline
Test Driver
Joined: 10 Mar 2010

Solved: Bug maybe???

The uiButtons get called multiple times on a single button press. Maybe I am just not following the code well enough. I made a checker to ensure the button only gets pressed once and now everything is fine.

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Posted on Wed, 2010-03-17 09:09
#5
slgilley
User offline. Last seen 16 weeks 6 days ago. Offline
Pro Developer
Joined: 19 Feb 2010

Remember, multiple events get generated each time a button is tapped.

For buttons, I always check that the event type (or "phase") is "ended", which means that the user lifted a finger from the button. But there are others, like "began" and "moved" as well. If you look at the sample code, you often see something like

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function dosomethingwithbutton(event)
        local phase = event.phase
        if "ended" == phase then

so that the code is only called when the user lifts the finger from the button.

Sean.

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