Add new views on a LinearLayout like you do on a ListView or RecycleView

LinearLayoutWrapper.java

import android.database.DataSetObserver;
import android.os.Handler;
import android.os.Looper;
import android.support.annotation.UiThread;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.LinearLayout;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by bruno on 27/06/16.
 */
public final class LinearLayoutWrapper {
    private static final String TAG = "LinearLayoutAdapter";

    private final LinearLayout layout;
    private final AdapterInterator interator;
    private Runnable register, unregister;
    private final Handler mainHandler = new Handler(Looper.getMainLooper());

    public LinearLayoutWrapper(LinearLayout layout, Adapter adapter) {
        this.layout = layout;
        removeBuiltViews();
        interator = new ListViewAdapterInterator(adapter);
        setupAdapter(adapter);
        register.run();
    }

    public LinearLayoutWrapper(LinearLayout layout, RecyclerView.Adapter adapter) {
        this.layout = layout;
        removeBuiltViews();
        interator = new RecyclerViewAdapterInterator(adapter);
        setupAdapter(adapter);
        register.run();
    }

    private void setupAdapter(Adapter adapter) {
        DataSetObserver observer = new ListViewAdapterObserver(this::cleanAndBuildViews);
        buildViews();
        register = () -> {
            try {
                adapter.registerDataSetObserver(observer);
            } catch (IllegalStateException e) {
            }
        };
        unregister = () -> {
            try {
                adapter.unregisterDataSetObserver(observer);
            } catch (IllegalStateException e) {
            }
        };
    }

    private void setupAdapter(RecyclerView.Adapter adapter) {
        RecyclerViewAdapterObserver observer = new RecyclerViewAdapterObserver(this::cleanAndBuildViews);
        buildViews();
        register = () -> {
            try {
                adapter.registerAdapterDataObserver(observer);
            } catch (IllegalStateException e) {
            }
        };
        unregister = () -> {
            try {
                adapter.unregisterAdapterDataObserver(observer);
            } catch (IllegalStateException e) {
            }
        };
    }

    private void cleanAndBuildViews() {
        mainHandler.post(() -> {
            removeBuiltViews();
            tryBuildViews();
        });
    }

    @UiThread
    private void tryBuildViews() {
        try {
            buildViews();
        } catch (Exception e) {
            Log.e(TAG, "tryBuildViews: Hey guys, looks like we got one exception when build a new view", e);
        }
    }

    @UiThread
    private void buildViews() {
        for (int i = 0; i < interator.getCount(); i++)
            addView(interator.getView(i, layout));
    }

    @UiThread
    private void addView(View view) {
        layout.addView(view);
    }


    @UiThread
    private synchronized void removeBuiltViews() {
        layout.removeAllViews();
    }

    public void register() {
        if (register != null) register.run();
    }

    public void unregister() {
        if (unregister != null) unregister.run();
    }

    private static interface AdapterInterator {
        int getCount();

        View getView(int index, ViewGroup container);
    }

    private static final class ListViewAdapterInterator implements AdapterInterator {
        private final Adapter adapter;

        public ListViewAdapterInterator(Adapter adapter) {
            this.adapter = adapter;
        }

        @Override
        public int getCount() {
            return adapter.getCount();
        }

        @Override
        public View getView(int index, ViewGroup container) {
            return adapter.getView(index, null, container);
        }
    }

    private static final class RecyclerViewAdapterInterator implements AdapterInterator {

        private final RecyclerView.Adapter adapter;

        public RecyclerViewAdapterInterator(RecyclerView.Adapter adapter) {
            this.adapter = adapter;
        }

        @Override
        public int getCount() {
            return adapter.getItemCount();
        }

        @Override
        public View getView(int index, ViewGroup container) {
            RecyclerView.ViewHolder viewHolder = adapter.onCreateViewHolder(container, adapter.getItemViewType(index));
            adapter.onBindViewHolder(viewHolder, index);
            return viewHolder.itemView;
        }
    }

    private static interface OnDataSetChanged {
        void onChanged();
    }

    private static final class ListViewAdapterObserver extends DataSetObserver {

        private final OnDataSetChanged listener;

        ListViewAdapterObserver(OnDataSetChanged listener) {
            this.listener = listener;
        }

        @Override
        public void onChanged() {
            listener.onChanged();
        }
    }

    private static final class RecyclerViewAdapterObserver extends RecyclerView.AdapterDataObserver {

        private final OnDataSetChanged listner;

        RecyclerViewAdapterObserver(OnDataSetChanged listner) {
            this.listner = listner;
        }

        @Override
        public void onChanged() {
            listner.onChanged();
        }

        @Override
        public void onItemRangeChanged(int positionStart, int itemCount) {
            onChanged();
        }

        @Override
        public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
            onChanged();
        }

        @Override
        public void onItemRangeInserted(int positionStart, int itemCount) {
            onChanged();
        }

        @Override
        public void onItemRangeRemoved(int positionStart, int itemCount) {
            onChanged();
        }
    }
}

SampleActivity.java

public class SampleActivity extends Activity {
  
  private LinearLayout linearLayout;
  private LinearLayoutWrapper wrapper;
  private RecyclerView.Adapter myAdapter;
  private List<Dto> data;
  
  public void onCreate(Bundler savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sample);
    linearLayout = (LinearLayout)findViewById(R.id.myLinearLayout); 
    // Here the wrapper will try to find the data from the adapter and build the views.
    // The wrapper will be registered as an observer of the myAdapter
    wrapper = new LinearLayoutWrapper(linearLayout, myAdapter);
  }
  
  public void onStart() {
    super.onStart();
//     data = getDataFromSomewhere();
  }
  
  public void onResume() {
    super.onResume();
    // you can instatiate the wrapper here. 
    // If you choose to instantiate it on the `onCreate`, call `wrapper.register()`, just for sure.
    wrapper.register();
  
    // Beware: when you change the adapter the whole LinearLayout will be recreated.
    myAdapter.setList(data);
    myAdapter.notifyDataSetChanged();
  }
  
  public void onPause() {
    super.onPause();
    // unregister the wrapper 
    if (wrapper != null) wrapper.unregister();
  }
  
}