Manipulating lines in Corona

Question

I've created a line in Corona using display.newLine() thanks to tutorials online. I'm still learning, so I have a few questions.

Is it possible to create touch events for the drawn line? Like once I have the line on my scene, if I touch that line, something should happen.

If it is possible, how do I do this? I tried what I would do with other objects and used something like line:addEventListener("touch", something) but it did not work.

Also, is it possible to create some sort of animation for the drawn line? Like draw the line, the after a few frames, erase it and draw a new one? (I'm talking about automatically instead of drawing it through touch events)

Lastly, is it possible to draw a curved line using only 1 line? I'm trying to avoid having to use so many lines if I'm going to create some sort of animation using the line drawn.

hjpotter92 hjpotter92 · Accepted Answer · 2013-04-02T12:02:37

Is it possible to create touch events for the drawn line?

Yes, according to Corona Labs API for LineObjects, the methods and properties are inherited from DisplayObject and one of those methods include EventListeners. You can try it like this:

local line = display.newLine( ... )
line:addEventListener( "tap", myFunc )

Is it possible to create some sort of animation for the drawn line? Like draw the line, the after a few frames, erase it and draw a new one?

Once again, yes. You can use the performWithDelay method from the timer table. An example would be like this:

i, line = 30, display.newLine( 20, 50, 200, 300 )
changeText = function()
  line.x1 = 20 + (i % 80)
  line.x2 = 50 + (i % 100)
  i = i * 2
end
timer.performWithDelay( 1000, changeText )

Is it possible to draw a curved line using only 1 line?

You need to read a bit about geometry. A line can not be curved. Otherwise a circle wouldn't be a polygon.

Manipulating lines in Corona

1 Answers