[안드로이드] RecyclerView - Divider 생성

[ Step1 ] 선(Line)을 만들기 위한 ItemDecoration Class 생성

[java/SimpleDividerItemDecoration.java]

public class SimpleDividerItemDecoration extends RecyclerView.ItemDecoration {
    private Drawable mDivider;

    public SimpleDividerItemDecoration(Context context) {
        mDivider = context.getResources().getDrawable(R.drawable.line_divider);
    }

    @Override
    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();

        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = parent.getChildAt(i);

            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + mDivider.getIntrinsicHeight();

            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
}

[Step2] Divider 색상 지정

[res/drawable/line_divider.xml]

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <size
        android:width="1dp"
        android:height="1dp" />

    <solid android:color="#000000" />

</shape>

[Step3] RecyclerView에 Divider 지정

processingList.addItemDecoration(new SimpleDividerItemDecoration(getContext()));

※ Note: adapter를 Setting 전에 item decoration을 추가해줘야 합니다

※ 참고

[1] https://gist.github.com/polbins/e37206fbc444207c0e92