Android Recyclerview GridLayoutManager column spacing

Question

How do you set the column spacing with a RecyclerView using a GridLayoutManager? Setting the margin/padding inside my layout has no effect.

Answer 1

Following code works well, and each column has same width:

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {      private int spanCount;     private int spacing;     private boolean includeEdge;      public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {         this.spanCount = spanCount;         this.spacing = spacing;         this.includeEdge = includeEdge;     }      @Override     public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {         int position = parent.getChildAdapterPosition(view); // item position         int column = position % spanCount; // item column          if (includeEdge) {             outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)             outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)              if (position < spanCount) { // top edge                 outRect.top = spacing;             }             outRect.bottom = spacing; // item bottom         } else {             outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)             outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f /    spanCount) * spacing)             if (position >= spanCount) {                 outRect.top = spacing; // item top             }         }     } } 

Usage

1. no edge

int spanCount = 3; // 3 columns int spacing = 50; // 50px boolean includeEdge = false; recyclerView.addItemDecoration(new GridSpacingItemDecoration(spanCount, spacing, includeEdge)); 

2. with edge

int spanCount = 3; // 3 columns int spacing = 50; // 50px boolean includeEdge = true; recyclerView.addItemDecoration(new GridSpacingItemDecoration(spanCount, spacing, includeEdge)); 

Answer 2

RecyclerViews support the concept of ItemDecoration: special offsets and drawing around each element. As seen in this answer, you can use

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {   private int space;    public SpacesItemDecoration(int space) {     this.space = space;   }    @Override   public void getItemOffsets(Rect outRect, View view,        RecyclerView parent, RecyclerView.State state) {     outRect.left = space;     outRect.right = space;     outRect.bottom = space;      // Add top margin only for the first item to avoid double space between items     if (parent.getChildLayoutPosition(view) == 0) {         outRect.top = space;     } else {         outRect.top = 0;     }   } } 

Then add it via

mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view); int spacingInPixels = getResources().getDimensionPixelSize(R.dimen.spacing); mRecyclerView.addItemDecoration(new SpacesItemDecoration(spacingInPixels));