A ListAdapter (and a StickyListHeaders version) that merges multiple ListAdapters.

MergeListAdapter.java

/*
 * Copyright (c) 2014 Zhang Hai
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.yourapplication;

import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListAdapter;

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

/**
 * A ListAdapter that merges multiple ListAdapters.
 * Initially it propagates data set observer notifications from each of its children to it's view.
 */
public class MergeListAdapter extends BaseAdapter {

    private final DataSetObserver dataSetObserver = new DataSetObserver() {
        @Override
        public void onChanged() {
            if (dataSetObserverSuppressed) {
                notifyDataSetChanged();
            }
        }
        @Override
        public void onInvalidated() {
            if (dataSetObserverSuppressed) {
                notifyDataSetInvalidated();
            }
        }
    };

    protected List<ListAdapter> adapterList = new ArrayList<>();

    private boolean dataSetObserverSuppressed = false;

    // NOTE: No no-args constructor provided so that users get to know the observer issue.
    public MergeListAdapter(boolean dataSetObserverSuppressed) {
        this.dataSetObserverSuppressed = dataSetObserverSuppressed;
    }

    @Override
    public int getCount() {
        int count = 0;
        for (ListAdapter adapter : adapterList) {
            count += adapter.getCount();
        }
        return count;
    }

    @Override
    public Object getItem(int position) {
        for (ListAdapter adapter : adapterList) {
            int count = adapter.getCount();
            if (position < count) {
                return adapter.getItem(position);
            } else {
                position -= count;
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }

    @Override
    public long getItemId(int position) {
        int i = 0;
        for (ListAdapter adapter : adapterList) {
            int count = adapter.getCount();
            if (position < count) {
                return 31 * i + adapter.getItemId(position);
            } else {
                position -= count;
                ++i;
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        for (ListAdapter adapter : adapterList) {
            int count = adapter.getCount();
            if (position < count) {
                return adapter.getView(position, convertView, parent);
            } else {
                position -= count;
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }

    @Override
    public boolean isEnabled(int position) {
        for (ListAdapter adapter : adapterList) {
            int count = adapter.getCount();
            if (position < count) {
                return adapter.isEnabled(position);
            } else {
                position -= count;
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }

    @Override
    public boolean areAllItemsEnabled() {
        for (ListAdapter adapter : adapterList) {
            if (!adapter.areAllItemsEnabled()) {
                return false;
            }
        }
        return true;
    }

    @Override
    public boolean hasStableIds() {
        for (ListAdapter adapter : adapterList) {
            if (!adapter.hasStableIds()) {
                return false;
            }
        }
        return true;
    }

    @Override
    public int getViewTypeCount() {
        int count = 0;
        for (ListAdapter adapter : adapterList) {
            count += adapter.getViewTypeCount();
        }
        return count;
    }

    // NOTICE: Assumes that view type of each adapter starts at 0 and increments by 1.
    @Override
    public int getItemViewType(int position) {
        int type = 0;
        for (ListAdapter adapter : adapterList) {
            int count = adapter.getCount();
            if (position < count) {
                return type + adapter.getItemViewType(position);
            } else {
                position -= count;
                type += adapter.getViewTypeCount();
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }

    public void addAdapter(ListAdapter adapter) {
        adapterList.add(adapter);
        adapter.registerDataSetObserver(dataSetObserver);
    }

    public void addView(View view, boolean enabled) {
        addAdapter(new SingleViewAdapter(view, enabled));
    }

    public void addView(View view) {
        addView(view, true);
    }

    public boolean isDataSetObserverSuppressed() {
        return dataSetObserverSuppressed;
    }

    public void setDataSetObserverSuppressed(boolean dataSetObserverSuppressed) {
        this.dataSetObserverSuppressed = dataSetObserverSuppressed;
    }
}

MergeStickyHeaderListAdapter.java

/*
 * Copyright (c) 2014 Zhang Hai
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.yourapplication;

import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;

import se.emilsjolander.stickylistheaders.StickyListHeadersAdapter;

public class MergeStickyHeaderListAdapter extends MergeListAdapter
        implements StickyListHeadersAdapter {

    public interface HeaderViewAdapter {
        public View getHeaderView(View convertView, ViewGroup parent);
    }

    public MergeStickyHeaderListAdapter(boolean dataSetObserverSuppressed) {
        super(dataSetObserverSuppressed);
    }

    @Override
    public View getHeaderView(int position, View convertView, ViewGroup parent) {
        for (ListAdapter adapter : adapterList) {
             int count = adapter.getCount();
            if (position < count) {
                return ((HeaderViewAdapter)adapter).getHeaderView(convertView, parent);
            } else {
                position -= count;
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }

    @Override
    public long getHeaderId(int position) {
        int i = 0;
        for (ListAdapter adapter : adapterList) {
            int count = adapter.getCount();
            if (position < count) {
                return i;
            } else {
                position -= count;
                ++i;
            }
        }
        throw new IllegalStateException("Unknown position: " + position);
    }
}

SingleViewAdapter.java

/*
 * Copyright (c) 2014 Zhang Hai
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.yourapplication;

import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

public class SingleViewAdapter extends BaseAdapter {

    private View view;

    private boolean enabled;


    public SingleViewAdapter() {
        this(true);
    }

    public SingleViewAdapter(boolean enabled) {
        this.enabled = enabled;
    }

    public SingleViewAdapter(View view) {
        this(view, true);
    }

    public SingleViewAdapter(View view, boolean enabled) {
        this.view = view;
        this.enabled = enabled;
    }

    public View getView() {
        return view;
    }

    public void setView(View view) {
        this.view = view;
    }

    public boolean isEnabled() {
        return enabled;
    }

    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }

    protected View createView(ViewGroup parent) {
        // Returns null by default.
        return null;
    }

    @Override
    public int getCount() {
        return 1;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (view == null) {
            setView(createView(parent));
        }
        return view;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public boolean areAllItemsEnabled() {
        return enabled;
    }

    @Override
    public boolean isEnabled(int position) {
        return enabled;
    }
}