Magnet

Position Helper for Corona SDK Graphics 2.0

A module to position display objects on different screen resolutions. This helper will only work with the newest version of Corona (aka 2.0). Anchors and screen orientations are internally managed to provide consistency.

Recent changes:

• Storyboard replaced with Composer API
• Refreshed build.settings with portrait orientation as a default
• Removed all print() logs

Positioning

To position you just call the function and pass the displayObject

magnet:topLeft( displayObject )

Margins

If you need to have a margin of 10px from the left this is how you do it:

magnet:topLeft( displayObject, 10 )

or same as before but with 20 px from the top:

magnet:topLeft( displayObject, 10, 20)

If you want to reposition after a screen rotation all you need to do is call the following function on the orientation event:

magnet:updateCurrentOrientation()

Basic Alignments

magnet:top(obj, marginY)
magnet:right(obj, marginX)
magnet:bottom(obj, marginY)
magnet:left(obj, marginX)
magnet:center(obj, marginX, marginY)

Composed Alignments

magnet:topLeft(obj, marginX, marginY)
magnet:topRight(obj, marginX, marginY)
magnet:bottomLeft(obj, marginX, marginY)
magnet:bottomRight(obj, marginX, marginY)
magnet:topCenter(obj, marginX, marginY)
magnet:centerRight(obj, marginX, marginY)
magnet:bottomCenter(obj, marginX, marginY)
magnet:centerLeft(obj, marginX, marginY)

Generic Call

Or a generic call with the align as a parameter:

magnet:alignTo(sAlign, obj, ...)

where sAlign is the method name in a string like:

magnet("bottomRight", myObject, xMargin, yMargin)

Other utilities

magnet:getPercentX( percent )
magnet:getPercentY( percent )

Gotchas

When positioning display objects inside snapshots you'll need to provide an additional parameter "parent" as the current snapshot that contains it. Otherwise it won't work!

local snapshot = display.newSnapshot(width, height)
local circle = display.newCircle(snapshot.group, 0, 0, 10)
magnet:center(circle, 0, 0, snapshot) --add the parent