android - StaggeredGridLayoutManager left a gap before a full span element -

i have recyclerview staggeredgridlayoutmanager. problem before full span element there gap need fill, increasing/decreasing height of last 2 elements. picture of problem:

• just 2 columns required.
• the elements of grid can have different heights.

i'm trying calculate height of 2 columns using each element height, , @ end see column longer, , add height shortest, don't know safe place set new height. when know sure height of view 1 going draw.

i'm stuck days problem, suggestions welcome!

onbindviewholder

double positionheight = getpositionratio(position);   holder.img_event).setheightratio(positionheight);  private double getpositionratio(final int position) {         double ratio = spositionheightratios.get(position, 0.0);         // if not yet done generate , stash columns height         // in our real world scenario determined         // match based on known height , width of image         // , maybe helpful way column height!         if (ratio == 0) {             ratio = getrandomheightratio();             spositionheightratios.append(position, ratio);             log.d("'", "getpositionratio:" + position + " ratio:" + ratio);         }         return ratio;     } private final random mrandom = new random();      private double getrandomheightratio() {         return (mrandom.nextdouble() / 2.0) + 1.0; // height 1.0 - 1.5 width     }