HorizontalDividerItemDecoration.java 文件源码

@Override
protected Rect getDividerBound(int position, RecyclerView parent, View child) {
    Rect bounds = new Rect(0, 0, 0, 0);
    int transitionX = (int) ViewCompat.getTranslationX(child);
    int transitionY = (int) ViewCompat.getTranslationY(child);
    RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
    bounds.left = parent.getPaddingLeft() +
            mMarginProvider.dividerLeftMargin(position, parent) + transitionX;
    bounds.right = parent.getWidth() - parent.getPaddingRight() -
            mMarginProvider.dividerRightMargin(position, parent) + transitionX;

    int dividerSize = getDividerSize(position, parent);
    if (mDividerType == DividerType.DRAWABLE) {
        bounds.top = child.getBottom() + params.topMargin + transitionY;
        bounds.bottom = bounds.top + dividerSize;
    } else {
        bounds.top = child.getBottom() + params.topMargin + dividerSize / 2 + transitionY;
        bounds.bottom = bounds.top;
    }

    return bounds;
}