Add equal spacing to RecyclerView items automatically. Can handle horizontal, vertical, and grid display modes

 EqualSpacingItemDecoration.java

	import android.graphics.Rect;
	import android.support.v7.widget.GridLayoutManager;
	import android.support.v7.widget.RecyclerView;
	import android.view.View;
	public class EqualSpacingItemDecoration extends RecyclerView.ItemDecoration {
	private final int spacing;
	private int displayMode;
	public static final int HORIZONTAL = 0;
	public static final int VERTICAL = 1;
	public static final int GRID = 2;
	public EqualSpacingItemDecoration(int spacing) {
	this(spacing, -1);
	}
	public EqualSpacingItemDecoration(int spacing, int displayMode) {
	this.spacing = spacing;
	this.displayMode = displayMode;
	}
	@Override
	public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
	int position = parent.getChildViewHolder(view).getAdapterPosition();
	int itemCount = state.getItemCount();
	RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
	setSpacingForDirection(outRect, layoutManager, position, itemCount);
	}
	private void setSpacingForDirection(Rect outRect,
	RecyclerView.LayoutManager layoutManager,
	int position,
	int itemCount) {
	// Resolve display mode automatically
	if (displayMode == -1) {
	displayMode = resolveDisplayMode(layoutManager);
	}
	switch (displayMode) {
	case HORIZONTAL:
	outRect.left = spacing;
	outRect.right = position == itemCount - 1 ? spacing : 0;
	outRect.top = spacing;
	outRect.bottom = spacing;
	break;
	case VERTICAL:
	outRect.left = spacing;
	outRect.right = spacing;
	outRect.top = spacing;
	outRect.bottom = position == itemCount - 1 ? spacing : 0;
	break;
	case GRID:
	if (layoutManager instanceof GridLayoutManager) {
	GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
	int cols = gridLayoutManager.getSpanCount();
	int rows = itemCount / cols;
	outRect.left = spacing;
	outRect.right = position % cols == cols - 1 ? spacing : 0;
	outRect.top = spacing;
	outRect.bottom = position / cols == rows - 1 ? spacing : 0;
	}
	break;
	}
	}
	private int resolveDisplayMode(RecyclerView.LayoutManager layoutManager) {
	if (layoutManager instanceof GridLayoutManager) return GRID;
	if (layoutManager.canScrollHorizontally()) return HORIZONTAL;
	return VERTICAL;
	}
	}

Raw

 example.java

	// Automatically infer display orientation of items
	RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
	recyclerView.addItemDecoration(new EqualSpacingItemDecoration(16)); // 16px. In practice, you'll want to use getDimensionPixelSize
	// Explicitly specify display orientation of items.
	// Available display modes:
	// - HORIZONTAL
	// - VERTICAL
	// - GRID
	RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
	recyclerView.addItemDecoration(new EqualSpacingItemDecoration(16, EqualSpacingItemDecoration.HORIZONTAL)); // 16px. In practice, you'll want to use getDimensionPixelSize

Raw

 results.md

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