GridLayoutManager with variable number of columns calculated based on the measured view width

VarColumnGridLayoutManager

final VarColumnGridLayoutManager layoutManager
      = new VarColumnGridLayoutManager(getContext(), OrientationHelper.VERTICAL, false);
VarColumnGridLayoutManager.ColumnCountProvider columnProvider
      = new VarColumnGridLayoutManager.DefaultColumnCountProvider(getContext());
layoutManager.setColumnCountProvider(columnProvider);

mRecyclerView.setLayoutManager(layoutManager);

VarColumnGridLayoutManager.java

public class VarColumnGridLayoutManager extends GridLayoutManager {

    // Dummy column count just to supply some value to the super constructor
    private static final int FAKE_COUNT = 1;

    @Nullable
    private ColumnCountProvider columnCountProvider;

    public interface ColumnCountProvider {
        int getColumnCount(int recyclerViewWidth);
    }

    public static class DefaultColumnCountProvider implements ColumnCountProvider {
        @NonNull
        private final Context context;

        public DefaultColumnCountProvider(@NonNull Context context) {
            this.context = context;
        }

        @Override
        public int getColumnCount(int recyclerViewWidth) {
            return columnsForWidth(recyclerViewWidth);
        }
        
        public static int columnsForWidth(int widthPx) {
    		int widthDp = dpFromPx(widthPx);
    		if (widthDp >= 900) {
    			return 5;
    		} else if (widthDp >= 720) {
    			return 4;
    		} else if (widthDp >= 600) {
    			return 3;
    		} else if (widthDp >= 480) {
    			return 2;
    		} else if (widthDp >= 320) {
    			return 2;
    		} else {
    			return 2;
    		}
    	}
    	
    	public static int dpFromPx(float px) {
    		return (int)(px / context.getResources().getDisplayMetrics().density + 0.5f);
    	}
    }

    public VarColumnGridLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    public VarColumnGridLayoutManager(Context context) {
        super(context, FAKE_COUNT);
    }

    public VarColumnGridLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, FAKE_COUNT, orientation, reverseLayout);
    }

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler,
                                 RecyclerView.State state) {
        updateSpanCount(getWidth());
        super.onLayoutChildren(recycler, state);
    }

    private void updateSpanCount(int width) {
        if (columnCountProvider != null) {
            int spanCount = columnCountProvider.getColumnCount(width);
            setSpanCount(spanCount > 0 ? spanCount : 1);
        }
    }

    public void setColumnCountProvider(@Nullable ColumnCountProvider provider) {
        this.columnCountProvider = provider;
    }
}