prevent the uicollectionview cell form moving to the right when there is space -- SWIFT -

my problem uicollectionview cell moving left when next cell jumps second line , there space in first line (space didnt fit contain next cell), how prevent cell moving right, when there still space, need thing setmaximumspace between cells (which doesnt exist) ?

here code :

 func collectionview(collectionview: uicollectionview, cellforitematindexpath indexpath: nsindexpath) -> uicollectionviewcell {     let cell = mycollectionview.dequeuereusablecellwithreuseidentifier("charaktercell", forindexpath: indexpath) charaktercollectionviewcell      (var i=0 ; i<4 ; i++)     {         if (collectioncellindex[i] == nil)         {             collectioncellindex[i] = indexpath             println("\(collectioncellindex[i])")             println(i)             break         }     }      return cell }   func collectionview(collectionview: uicollectionview, layout collectionviewlayout:uicollectionviewlayout, sizeforitematindexpath indexpath: nsindexpath) -> cgsize {     var size = cgsize(width: 0, height: 0)     var label = uilabel()     if (selectedcharincollectionnames[indexpath.row] == "")     {         size = cgsize(width: 40, height: 30)      }     else     {         label.text = selectedcharincollectionnames[indexpath.row]         label.sizetofit()         var width = label.frame.width         size = cgsize(width: (width+25), height: 30)      }     label.sizetofit()     return size }  private let sectioninsets = uiedgeinsets(top: 10, left: 10, bottom: 10, right: 10)  func collectionview(collectionview: uicollectionview!,     layout collectionviewlayout: uicollectionviewlayout!,     insetforsectionatindex section: int) -> uiedgeinsets {           return sectioninsets } 

@kevin r answer here! solved question

class alignleftflowlayout: uicollectionviewflowlayout {  var maximumcellspacing = cgfloat(9.0)  override func layoutattributesforelementsinrect(rect: cgrect) -> [anyobject]? {     let attributestoreturn = super.layoutattributesforelementsinrect(rect) as? [uicollectionviewlayoutattributes]      attributes in attributestoreturn ?? [] {         if attributes.representedelementkind == nil {             attributes.frame = self.layoutattributesforitematindexpath(attributes.indexpath).frame         }     }      return attributestoreturn }  override func layoutattributesforitematindexpath(indexpath: nsindexpath) -> uicollectionviewlayoutattributes! {     let curattributes = super.layoutattributesforitematindexpath(indexpath)     let sectioninset = (self.collectionview?.collectionviewlayout uicollectionviewflowlayout).sectioninset      if indexpath.item == 0 {         let f = curattributes.frame         curattributes.frame = cgrectmake(sectioninset.left, f.origin.y, f.size.width, f.size.height)         return curattributes     }      let previndexpath = nsindexpath(foritem: indexpath.item-1, insection: indexpath.section)     let prevframe = self.layoutattributesforitematindexpath(previndexpath).frame     let prevframerightpoint = prevframe.origin.x + prevframe.size.width + maximumcellspacing      let curframe = curattributes.frame     let stretchedcurframe = cgrectmake(0, curframe.origin.y, self.collectionview!.frame.size.width, curframe.size.height)      if cgrectintersectsrect(prevframe, stretchedcurframe) {         curattributes.frame = cgrectmake(prevframerightpoint, curframe.origin.y, curframe.size.width, curframe.size.height)     } else {         curattributes.frame = cgrectmake(sectioninset.left, curframe.origin.y, curframe.size.width, curframe.size.height)     }      return curattributes } 

}