Can I set I get a display group to determine its bounds AFTER I have inserted a number of display objects?

Solar2D General Questions/Discussion
#1

I have a dispay group (DG) which contains 25 display objects (DO) arranged in a grid. The player can tap on any DO to select it at which itthey animates to the top of the screen to show that it is selected. I want to be able to manipulate the selected DOs so I decided to put each selected DO into a new DG which I could then use to manipulate them in a group.

The problem is that the new DG’s bounds seem to be defined by the selected DO’s orginal position NOT their final positions  after being animated to the top of the screen. This means that the bounding box does not actually reflect the selected DO’s boundaries accurately.

How can I get the new DG to update its bounds after the selected DO animates up to its new position?

#2

Actually groups have no bounds.  They only have an origin which starts at 0,0.  If you put things in a group, then you can use display.contentBounds to find the bounding box around the objects.

Using this code:

local g = display.newGroup() local r = display.newRect(display.contentCenterX - 100, display.contentCenterY, 100, 100) g:insert(r) local r1 = display.newRect(display.contentCenterX, display.contentCenterY, 100, 100) g:insert(r1) local r2 = display.newRect(display.contentCenterX + 100, display.contentCenterY, 100, 100) g:insert(r2) local bounds = g.contentBounds print( "xMin: ".. bounds.xMin ) -- xMin: 100 print( "yMin: ".. bounds.yMin ) -- yMin: 100 print( "xMax: ".. bounds.xMax ) -- xMax: 150 print( "yMax: ".. bounds.yMax ) -- yMax: 150

It seems to measure the bounds correctly and when I move the group’s origin from 0, 0, the values in the second set of prints, updates accordingly.

Rob

#3

Thanks Rob… My code was actually being problematic from another angle but I have fixed it now. The info supplied was useful regardless!

#4

Actually groups have no bounds.  They only have an origin which starts at 0,0.  If you put things in a group, then you can use display.contentBounds to find the bounding box around the objects.

Using this code:

local g = display.newGroup() local r = display.newRect(display.contentCenterX - 100, display.contentCenterY, 100, 100) g:insert(r) local r1 = display.newRect(display.contentCenterX, display.contentCenterY, 100, 100) g:insert(r1) local r2 = display.newRect(display.contentCenterX + 100, display.contentCenterY, 100, 100) g:insert(r2) local bounds = g.contentBounds print( "xMin: ".. bounds.xMin ) -- xMin: 100 print( "yMin: ".. bounds.yMin ) -- yMin: 100 print( "xMax: ".. bounds.xMax ) -- xMax: 150 print( "yMax: ".. bounds.yMax ) -- yMax: 150

It seems to measure the bounds correctly and when I move the group’s origin from 0, 0, the values in the second set of prints, updates accordingly.

Rob

#5

Thanks Rob… My code was actually being problematic from another angle but I have fixed it now. The info supplied was useful regardless!