How to selectively decorate RecyclerView items

Question

I am creating a subclass of ItemDecoration from this gist: https://gist.github.com/alexfu/0f464fc3742f134ccd1e

How to make it only decorate items with

Answer 1

You need to call isDecorated on the draw method as well, because at the moment you don't put the offset on those items but you still draw over it.

The method loops over all the child views currently in the RecyclerView visible on the screen.

public void drawVertical(Canvas c, RecyclerView parent) {
    final int left = parent.getPaddingLeft();
    final int right = parent.getWidth() - parent.getPaddingRight();

    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = parent.getChildAt(i);
        if(isDecorated(child, parent))
        {
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
}

public void drawHorizontal(Canvas c, RecyclerView parent) {
    final int top = parent.getPaddingTop();
    final int bottom = parent.getHeight() - parent.getPaddingBottom();

    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = parent.getChildAt(i);
        if(isDecorated(child, parent))
        {
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
}