[Android] Nested RecyclerView 만들기

RecyclerView 에서 onCreateViewHolder 나 onBindViewHolder와 같은 VIew를 설정할 함수가 불러지지 않을 경우가 있다.

getItemCount 에서 0으로 설정되어 있지 않다면!

혹시 ScrollView 안이나 ListView,GridView,RecyclerView 같은 Scroll기능이 포함된 View에 들어있지 않은가??

이럴 경우, 수동적으로 View 높이를 지정해야 하는데 반나절을 열심히 찾아본 결과 좋은 소스가 있어 공유 한다.

public class CustomLinearLayoutManager extends LinearLayoutManager {

    private static final String TAG = CustomLinearLayoutManager.class.getSimpleName();

    public CustomLinearLayoutManager(Context context) {
        super(context);
    }

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

    private int[] mMeasuredDimension = new int[2];

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {

        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);

        int width = 0;
        int height = 0;
        for (int i = 0; i < getItemCount(); i++) {
            measureScrapChild(recycler, i, View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                mMeasuredDimension);


            if (getOrientation() == HORIZONTAL) {
                width = width + mMeasuredDimension[0];
                if (i == 0) {
                    height = mMeasuredDimension[1];
                }
            } else {
                height = height + mMeasuredDimension[1];
                if (i == 0) {
                    width = mMeasuredDimension[0];
                }
            }
        }
        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                               int heightSpec, int[] measuredDimension) {
        try {
            View view = recycler.getViewForPosition(0);//fix 动态添加时报IndexOutOfBoundsException

            if (view != null) {
                RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();

                int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight(), p.width);

                int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom(), p.height);

                view.measure(childWidthSpec, childHeightSpec);
                measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
                measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
                recycler.recycleView(view);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } 
    }
}

You can just copy and past the custom layout manager as above and in set up your recyclerview in the parent adapter like this:

RecyclerView.LayoutManager layoutManager = new CustomLinearLayoutManager(mContext);
holder.childRecyclerView.setLayoutManager(layoutManager);

Remember : Don't use same layoutManager as parent adapter, or error will occur.

자식RecyclerView에 위와 같이 커스텀화 된 LinearLayoutManager를 설정해주면 강제적으로 높이를 조절해 준다.

혹시 GridLayoutManager를 이용하고자 한다면, span 값을 지정 할 것이다.

For 문에 증가 값을 span으로 올리면 똑같이 동작으로 한다.

for (int i = 0; i < getItemCount(); i+=getSpanCount()) {
            measureScrapChild(recycler, i, View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                mMeasuredDimension);

위 소스 같이 말이다.

## 혹시 위 소스가 안되시는 분들은!! 아래 소스로 해보세요.

You can use RecyclerView inside NestedScrollView. First of all you should implement your own custom LinearLayoutManager, it makes your RecyclerView to wrap its content. For example:

public class WrappingLinearLayoutManager extends LinearLayoutManager
{

    public WrappingLinearLayoutManager(Context context) {
        super(context);
    }

    private int[] mMeasuredDimension = new int[2];

    @Override
    public boolean canScrollVertically() {
        return false;
    }

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
            int widthSpec, int heightSpec) {
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);

        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);

        int width = 0;
        int height = 0;
        for (int i = 0; i < getItemCount(); i++) {
            if (getOrientation() == HORIZONTAL) {
                measureScrapChild(recycler, i,
                        View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
                        heightSpec,
                        mMeasuredDimension);

                width = width + mMeasuredDimension[0];
                if (i == 0) {
                    height = mMeasuredDimension[1];
                }
            } else {
                measureScrapChild(recycler, i,
                        widthSpec,
                        View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
                        mMeasuredDimension);

                height = height + mMeasuredDimension[1];
                if (i == 0) {
                    width = mMeasuredDimension[0];
                }
            }
        }

        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
            int heightSpec, int[] measuredDimension) {

        View view = recycler.getViewForPosition(position);
        if (view.getVisibility() == View.GONE) {
            measuredDimension[0] = 0;
            measuredDimension[1] = 0;
            return;
        }
        // For adding Item Decor Insets to view
        super.measureChildWithMargins(view, 0, 0);
        RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
        int childWidthSpec = ViewGroup.getChildMeasureSpec(
                widthSpec,
                getPaddingLeft() + getPaddingRight() + getDecoratedLeft(view) + getDecoratedRight(view),
                p.width);
        int childHeightSpec = ViewGroup.getChildMeasureSpec(
                heightSpec,
                getPaddingTop() + getPaddingBottom() + getDecoratedTop(view) + getDecoratedBottom(view),
                p.height);
        view.measure(childWidthSpec, childHeightSpec);

        // Get decorated measurements
        measuredDimension[0] = getDecoratedMeasuredWidth(view) + p.leftMargin + p.rightMargin;
        measuredDimension[1] = getDecoratedMeasuredHeight(view) + p.bottomMargin + p.topMargin;
        recycler.recycleView(view);
    }
}

After that use this LayoutManager for your RecyclerView

recyclerView.setLayoutManager(new WrappingLinearLayoutManager(getContext()));

But you also should call those two methods:

recyclerView.setNestedScrollingEnabled(false);
recyclerView.setHasFixedSize(false);

Here setNestedScrollingEnabled(false) disable scrolling for RecyclerView, so it doesn't intercept scrolling event from NestedScrollView. And setHasFixedSize(false) determine that changes in adapter content can change the size of the RecyclerView

Hope it helps you

Update:

This solution is little buggy in some cases and has problems with perfomance, so if you have a lot of items in your RecyclerView I'd recommend to use custom LinearLayout-based implementation of list view, create analogue of Adapter for it and make it behave like ListView or RecyclerView

http://stackoverflow.com/a/32736113/3534559

도움이 되었길 바란다.

http://stackoverflow.com/questions/32011995/how-to-have-a-listview-recyclerview-inside-a-parent-recyclerview-i-have-a-pare/32086918#32086918

## 이블로그는 어디까지는 찾았던 부분을 잊지 않기 위해 올려놓은 것 입니다.

    내용이 부실해도 이해해 주시길 바랍니다.