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RecyclerViewグリッドのフッターとして不確定なプログレスバーを配置する

グリッドのRecycleViewで「スクロールしてさらに読み込む」の不確定な円形インジケータを取得する方法は?

パターンはそこで説明されています。 http://www.google.com/design/spec/components/progress-activity.html#progress-activity-behavior 「2段階の負荷」と「例2:上にスクロールしてさらに読み込む」サンプル動画。

私は新しいRecyclerViewを使用してこれを達成しようとしていますが、それを行うには「あまりにもハックのない」方法を見つけることができません。最初にグリッドの行全体をカバーするフッターを追加する方法がないためです。助言がありますか?

54

それはとても簡単です。

解決策は、LinearLayoutManagerGridLayoutManagerと同じアプローチを使用し、次にsetSpanSizeLookupLayoutManagerメソッドを次のように使用することです。

mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            switch(myAdapter.getItemViewType(position)){
                case MyAdapter.VIEW_TYPES.Product:
                    return 1;
                case MyAdapter.VIEW_TYPES.Progress:
                    return 2; //number of columns of the grid
                default:
                    return -1;
            }
        }
    });

これにより、アイテムがグリッドの行全体に自動的に表示されます(行が完全に空でない場合、このアイテムは次の行に移動します)。

64
Bronx

以下のソリューションにはいくつかの潜在的な問題と制限があります。修正されたソリューションについてはこちらを確認してください下部のProgressBarでEndless Scroll RecyclerViewにアイテムを追加する

ここに私が最近思いついた解決策があります:2つのタイプのアイテムを備えたRecyclerViewを持ち、1つは通常のアイテム、2つ目はプログレスバーです。アイデアからコード例まで

progress_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
              Android:orientation="vertical"
              Android:layout_width="match_parent"
              Android:layout_height="match_parent">

    <ProgressBar
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:id="@+id/progressBar"
        Android:indeterminate="true"
        style="@Android:style/Widget.Holo.ProgressBar"
        Android:layout_gravity="center_horizontal"/>
</LinearLayout>

activity_main.xml

<RelativeLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
                xmlns:tools="http://schemas.Android.com/tools"
                xmlns:ring="http://schemas.Android.com/apk/res-auto"
                Android:layout_width="match_parent"
                Android:layout_height="match_parent"
                tools:context=".MainActivity">

    <Android.support.v7.widget.RecyclerView
        Android:id="@+id/my_recycler_view"
        Android:scrollbars="vertical"
        Android:layout_width="match_parent"
        Android:layout_height="match_parent"/>
</RelativeLayout>

EndlessRecyclerOnScrollListener.Java

public abstract class EndlessRecyclerOnScrollListener extends RecyclerView.OnScrollListener {
    public static String TAG = EndlessRecyclerOnScrollListener.class.getSimpleName();

    private int previousTotal = 0; // The total number of items in the dataset after the last load
    private boolean loading = true; // True if we are still waiting for the last set of data to load.
    private int visibleThreshold = 1; // The minimum amount of items to have below your current scroll position before loading more.
    int firstVisibleItem, visibleItemCount, totalItemCount;

    private int current_page = 1;

    private LinearLayoutManager mLinearLayoutManager;

    public EndlessRecyclerOnScrollListener(LinearLayoutManager linearLayoutManager) {
        this.mLinearLayoutManager = linearLayoutManager;
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);

        visibleItemCount = recyclerView.getChildCount();
        totalItemCount = mLinearLayoutManager.getItemCount();
        firstVisibleItem = mLinearLayoutManager.findFirstVisibleItemPosition();

        if (loading) {
            if (totalItemCount > previousTotal+1) {
                loading = false;
                previousTotal = totalItemCount;
            }
        }
        if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)) {
        // End has been reached
        // Do something
            current_page++;
            onLoadMore(current_page);
            loading = true;
        }
    }

    public abstract void onLoadMore(int current_page);
}

MyAdapter.Java

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private final int VIEW_ITEM = 1;
    private final int VIEW_PROG = 0;

    private List<String> mDataset;

    public static class TextViewHolder extends RecyclerView.ViewHolder {
        public TextView mTextView;
        public TextViewHolder(View v) {
            super(v);
            mTextView = (TextView)v.findViewById(Android.R.id.text1);
        }
    }
    public static class ProgressViewHolder extends RecyclerView.ViewHolder {
        public ProgressBar progressBar;
        public ProgressViewHolder(View v) {
            super(v);
            progressBar = (ProgressBar)v.findViewById(R.id.progressBar);
        }
    }

    public MyAdapter(List<String> myDataset) {
        mDataset = myDataset;
    }

    @Override
    public int getItemViewType(int position) {
        return mDataset.get(position)!=null? VIEW_ITEM: VIEW_PROG;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        RecyclerView.ViewHolder vh;
        if(viewType==VIEW_ITEM) {
            View v = LayoutInflater.from(parent.getContext())
                    .inflate(Android.R.layout.simple_list_item_1, parent, false);

            vh = new TextViewHolder(v);
        }else {
            View v = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.progress_item, parent, false);

            vh = new ProgressViewHolder(v);
        }
        return vh;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if(holder instanceof TextViewHolder){
            ((TextViewHolder)holder).mTextView.setText(mDataset.get(position));
        }else{
            ((ProgressViewHolder)holder).progressBar.setIndeterminate(true);
        }
    }

    @Override
    public int getItemCount() {
        return mDataset.size();
    }
}

そして最後にMainActivity.Java

package virtoos.com.testapps;

import Android.app.Activity;
import Android.os.Bundle;
import Android.os.Handler;
import Android.support.v7.widget.LinearLayoutManager;
import Android.support.v7.widget.RecyclerView;

import Java.util.ArrayList;
import Java.util.List;


public class MainActivity extends Activity {
    private RecyclerView mRecyclerView;
    private LinearLayoutManager mLayoutManager;
    private MyAdapter mAdapter;
    private final List<String> myDataset = new ArrayList<>();
    private Handler handler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        handler = new Handler();
        addItems(20);
        mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout size of the RecyclerView
        mRecyclerView.setHasFixedSize(true);

        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        mAdapter = new MyAdapter(myDataset);
        mRecyclerView.setAdapter(mAdapter);

        //mRecyclerView.setItemAnimator(new DefaultItemAnimator());

        mRecyclerView.setOnScrollListener(new EndlessRecyclerOnScrollListener(mLayoutManager) {
            @Override
            public void onLoadMore(int current_page) {
                //add progress item
                myDataset.add(null);
                mAdapter.notifyItemInserted(myDataset.size());
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        //remove progress item
                        myDataset.remove(myDataset.size() - 1);
                        mAdapter.notifyItemRemoved(myDataset.size());
                        //add items one by one
                        for (int i = 0; i < 15; i++) {
                            myDataset.add("Item"+(myDataset.size()+1));
                            mAdapter.notifyItemInserted(myDataset.size());
                        }
                        //or you can add all at once but do not forget to call mAdapter.notifyDataSetChanged();
                    }
                }, 2000);
                System.out.println("load");
            }
        });

    }
}
55
Vilen

以下は、_RecyclerView.Adapter_の@Vilen Melkumyanの回答を少し修正したものです。 EndlessRecyclerOnScrollListenerは、データの読み込みに任意の方法で使用できます。また、いつでもフッターを有効または無効にできます。

PS:GridLayoutManagerで機能しました。

_public class MyRecyclerViewAdapter  extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

private final int VIEW_TYPE_ITEM = 1;
private final int VIEW_TYPE_PROGRESSBAR = 0;
private boolean isFooterEnabled = true;

private List<String> items;

public static class TextViewHolder extends RecyclerView.ViewHolder {
    public TextView mTextView;
    public TextViewHolder(View v) {
        super(v);
        mTextView = (TextView)v.findViewById(Android.R.id.text1);
    }
}
public static class ProgressViewHolder extends RecyclerView.ViewHolder {
    public ProgressBar progressBar;
    public ProgressViewHolder(View v) {
        super(v);
        progressBar = (ProgressBar)v.findViewById(R.id.progressBar);
    }
}

public MyRecyclerViewAdapter(List<String> myDataset) {
    items = myDataset;
}

@Override
public int getItemCount() {
    return  (isFooterEnabled) ? items.size() + 1 : items.size();
}

@Override
public int getItemViewType(int position) {
    return (isFooterEnabled && position >= items.size() ) ? VIEW_TYPE_PROGRESSBAR : VIEW_TYPE_ITEM;
}

/**
 * Enable or disable footer (Default is true)
 *
 * @param isEnabled boolean to turn on or off footer.
 */
public void enableFooter(boolean isEnabled){
    this.isFooterEnabled = isEnabled;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    RecyclerView.ViewHolder vh;
    if(viewType== VIEW_TYPE_ITEM) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(Android.R.layout.simple_list_item_1, parent, false);
        vh = new TextViewHolder(v);
    }else {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.progressbar, parent, false);

        vh = new ProgressViewHolder(v);
    }
    return vh;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    if(holder instanceof ProgressViewHolder){
        ((ProgressViewHolder)holder).progressBar.setIndeterminate(true);
    } else if(items.size() > 0 && position < items.size()) {
        ((TextViewHolder)holder).mTextView.setText(items.get(position));            
    }
}
}
_

私の2セント、平和!

8
cass_

https://github.com/ramirodo/endless-recycler-view-adapter または https://bintray.com/ramiro/Android/endless-recycler-で解決策を確認してくださいview-adapter 。そこには例があり、プロジェクトにライブラリを設定する手順もあります。

必要なメソッドを実装するだけで、リサイクラビューアダプタを拡張する必要があります。また、進行状況フッターのレイアウトを設定できます。

1
Ramiro

アダプタ内にコードを挿入することにより、ブロンクスの答えを簡素化できます。

public class ArticleGridAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private final int VIEW_ITEM = 0;
    private final int VIEW_LOADING = 1;

    private Context mContext;
    private List<Article> mArticles = new ArrayList<>();
    private RecyclerView mRecyclerView;
    private GridLayoutManager mManager;

    public ArticleGridAdapter(Context context, List<Article> articles, RecyclerView recyclerView) {
        this.mContext = context;
        this.mArticles = articles;
        this.mRecyclerView = recyclerView;
        this.mManager = (GridLayoutManager) recyclerView.getLayoutManager();

        mManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
            @Override
            public int getSpanSize(int position) {
                return getItemViewType(position) == VIEW_LOADING ? mManager.getSpanCount() : 1;
            }
        });
    }
}
0
wonsuc