ShareActionProvider that allows intent filtering based on package name and the ability to turn off history.

ActivityChooserModel.java

package com.your.package;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.database.DataSetObservable;
import android.os.AsyncTask;
import android.os.Build;
import android.text.TextUtils;
import android.util.Log;
import android.util.Xml;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlSerializer;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * <p>
 * This class represents a data model for choosing a component for handing a
 * given {@link Intent}. The model is responsible for querying the system for
 * activities that can handle the given intent and order found activities
 * based on historical data of previous choices. The historical data is stored
 * in an application private file. If a client does not want to have persistent
 * choice history the file can be omitted, thus the activities will be ordered
 * based on historical usage for the current session.
 * <p>
 * </p>
 * For each backing history file there is a singleton instance of this class. Thus,
 * several clients that specify the same history file will share the same model. Note
 * that if multiple clients are sharing the same model they should implement semantically
 * equivalent functionality since setting the model intent will change the found
 * activities and they may be inconsistent with the functionality of some of the clients.
 * For example, choosing a share activity can be implemented by a single backing
 * model and two different views for performing the selection. If however, one of the
 * views is used for sharing but the other for importing, for example, then each
 * view should be backed by a separate model.
 * </p>
 * <p>
 * The way clients interact with this class is as follows:
 * </p>
 * <p>
 * <pre>
 * <code>
 *  // Get a model and set it to a couple of clients with semantically similar function.
 *  ActivityChooserModel dataModel =
 *      ActivityChooserModel.get(context, "task_specific_history_file_name.xml");
 *
 *  ActivityChooserModelClient modelClient1 = getActivityChooserModelClient1();
 *  modelClient1.setActivityChooserModel(dataModel);
 *
 *  ActivityChooserModelClient modelClient2 = getActivityChooserModelClient2();
 *  modelClient2.setActivityChooserModel(dataModel);
 *
 *  // Set an intent to choose a an activity for.
 *  dataModel.setIntent(intent);
 * <pre>
 * <code>
 * </p>
 * <p>
 * <strong>Note:</strong> This class is thread safe.
 * </p>
 *
 * @hide
 */
public class ActivityChooserModel extends DataSetObservable {

    /**
     * Client that utilizes an {@link ActivityChooserModel}.
     */
    public interface ActivityChooserModelClient {

        /**
         * Sets the {@link ActivityChooserModel}.
         *
         * @param dataModel The model.
         */
        public void setActivityChooserModel(ActivityChooserModel dataModel);
    }

    /**
     * Defines a sorter that is responsible for sorting the activities
     * based on the provided historical choices and an intent.
     */
    public interface ActivitySorter {

        /**
         * Sorts the <code>activities</code> in descending order of relevance
         * based on previous history and an intent.
         *
         * @param intent The {@link Intent}.
         * @param activities Activities to be sorted.
         * @param historicalRecords Historical records.
         */
        // This cannot be done by a simple comparator since an Activity weight
        // is computed from history. Note that Activity implements Comparable.
        public void sort(Intent intent, List<ActivityResolveInfo> activities,
                         List<HistoricalRecord> historicalRecords);
    }

    /**
     * Listener for choosing an activity.
     */
    public interface OnChooseActivityListener {

        /**
         * Called when an activity has been chosen. The client can decide whether
         * an activity can be chosen and if so the caller of
         * {@link ActivityChooserModel#chooseActivity(int)} will receive and {@link Intent}
         * for launching it.
         * <p>
         * <strong>Note:</strong> Modifying the intent is not permitted and
         *     any changes to the latter will be ignored.
         * </p>
         *
         * @param host The listener's host model.
         * @param intent The intent for launching the chosen activity.
         * @return Whether the intent is handled and should not be delivered to clients.
         *
         * @see ActivityChooserModel#chooseActivity(int)
         */
        public boolean onChooseActivity(ActivityChooserModel host, Intent intent);
    }

    /**
     * Flag for selecting debug mode.
     */
    private static final boolean DEBUG = false;

    /**
     * Tag used for logging.
     */
    private static final String LOG_TAG = ActivityChooserModel.class.getSimpleName();

    /**
     * The root tag in the history file.
     */
    private static final String TAG_HISTORICAL_RECORDS = "historical-records";

    /**
     * The tag for a record in the history file.
     */
    private static final String TAG_HISTORICAL_RECORD = "historical-record";

    /**
     * Attribute for the activity.
     */
    private static final String ATTRIBUTE_ACTIVITY = "activity";

    /**
     * Attribute for the choice time.
     */
    private static final String ATTRIBUTE_TIME = "time";

    /**
     * Attribute for the choice weight.
     */
    private static final String ATTRIBUTE_WEIGHT = "weight";

    /**
     * The default name of the choice history file.
     */
    public static final String DEFAULT_HISTORY_FILE_NAME =
            "activity_choser_model_history.xml";

    /**
     * The default maximal length of the choice history.
     */
    public static final int DEFAULT_HISTORY_MAX_LENGTH = 50;

    /**
     * The amount with which to inflate a chosen activity when set as default.
     */
    private static final int DEFAULT_ACTIVITY_INFLATION = 5;

    /**
     * Default weight for a choice record.
     */
    private static final float DEFAULT_HISTORICAL_RECORD_WEIGHT = 1.0f;

    /**
     * The extension of the history file.
     */
    private static final String HISTORY_FILE_EXTENSION = ".xml";

    /**
     * An invalid item index.
     */
    private static final int INVALID_INDEX = -1;

    /**
     * Lock to guard the model registry.
     */
    private static final Object sRegistryLock = new Object();

    /**
     * This the registry for data models.
     */
    private static final Map<String, ActivityChooserModel> sDataModelRegistry =
            new HashMap<String, ActivityChooserModel>();

    /**
     * Lock for synchronizing on this instance.
     */
    private final Object mInstanceLock = new Object();

    /**
     * List of activities that can handle the current intent.
     */
    private final List<ActivityResolveInfo> mActivities = new ArrayList<ActivityResolveInfo>();

    /**
     * List with historical choice records.
     */
    private final List<HistoricalRecord> mHistoricalRecords = new ArrayList<HistoricalRecord>();

    /**
     * Context for accessing resources.
     */
    private final Context mContext;

    /**
     * The name of the history file that backs this model.
     */
    private final String mHistoryFileName;

    /**
     * The intent for which a activity is being chosen.
     */
    private Intent mIntent;

    /**
     * The sorter for ordering activities based on intent and past choices.
     */
    private ActivitySorter mActivitySorter = new DefaultSorter();

    /**
     * The maximal length of the choice history.
     */
    private int mHistoryMaxSize = DEFAULT_HISTORY_MAX_LENGTH;

    private List<String> mIntentFilter = new ArrayList<String>();

    private boolean mShowHistory = true;

    /**
     * Flag whether choice history can be read. In general many clients can
     * share the same data model and {@link #readHistoricalDataIfNeeded()} may be called
     * by arbitrary of them any number of times. Therefore, this class guarantees
     * that the very first read succeeds and subsequent reads can be performed
     * only after a call to {@link #persistHistoricalDataIfNeeded()} followed by change
     * of the share records.
     */
    private boolean mCanReadHistoricalData = true;

    /**
     * Flag whether the choice history was read. This is used to enforce that
     * before calling {@link #persistHistoricalDataIfNeeded()} a call to
     * {@link #persistHistoricalDataIfNeeded()} has been made. This aims to avoid a
     * scenario in which a choice history file exits, it is not read yet and
     * it is overwritten. Note that always all historical records are read in
     * full and the file is rewritten. This is necessary since we need to
     * purge old records that are outside of the sliding window of past choices.
     */
    private boolean mReadShareHistoryCalled = false;

    /**
     * Flag whether the choice records have changed. In general many clients can
     * share the same data model and {@link #persistHistoricalDataIfNeeded()} may be called
     * by arbitrary of them any number of times. Therefore, this class guarantees
     * that choice history will be persisted only if it has changed.
     */
    private boolean mHistoricalRecordsChanged = true;

    /**
     * Flag whether to reload the activities for the current intent.
     */
    private boolean mReloadActivities = false;

    /**
     * Policy for controlling how the model handles chosen activities.
     */
    private OnChooseActivityListener mActivityChoserModelPolicy;

    /**
     * Gets the data model backed by the contents of the provided file with historical data.
     * Note that only one data model is backed by a given file, thus multiple calls with
     * the same file name will return the same model instance. If no such instance is present
     * it is created.
     * <p>
     * <strong>Note:</strong> To use the default historical data file clients should explicitly
     * pass as file name {@link #DEFAULT_HISTORY_FILE_NAME}. If no persistence of the choice
     * history is desired clients should pass <code>null</code> for the file name. In such
     * case a new model is returned for each invocation.
     * </p>
     *
     * <p>
     * <strong>Always use difference historical data files for semantically different actions.
     * For example, sharing is different from importing.</strong>
     * </p>
     *
     * @param context Context for loading resources.
     * @param historyFileName File name with choice history, <code>null</code>
     *        if the model should not be backed by a file. In this case the activities
     *        will be ordered only by data from the current session.
     *
     * @return The model.
     */
    public static ActivityChooserModel get(Context context, String historyFileName) {
        synchronized (sRegistryLock) {
            ActivityChooserModel dataModel = sDataModelRegistry.get(historyFileName);
            if (dataModel == null) {
                dataModel = new ActivityChooserModel(context, historyFileName);
                sDataModelRegistry.put(historyFileName, dataModel);
            }
            return dataModel;
        }
    }

    /**
     * Creates a new instance.
     *
     * @param context Context for loading resources.
     * @param historyFileName The history XML file.
     */
    private ActivityChooserModel(Context context, String historyFileName) {
        mContext = context.getApplicationContext();
        if (!TextUtils.isEmpty(historyFileName)
                && !historyFileName.endsWith(HISTORY_FILE_EXTENSION)) {
            mHistoryFileName = historyFileName + HISTORY_FILE_EXTENSION;
        } else {
            mHistoryFileName = historyFileName;
        }
    }

    /**
     * Sets an intent for which to choose a activity.
     * <p>
     * <strong>Note:</strong> Clients must set only semantically similar
     * intents for each data model.
     * <p>
     *
     * @param intent The intent.
     */
    public void setIntent(Intent intent) {
        synchronized (mInstanceLock) {
            if (mIntent == intent) {
                return;
            }
            mIntent = intent;
            mReloadActivities = true;
            ensureConsistentState();
        }
    }

    /**
     * Gets the intent for which a activity is being chosen.
     *
     * @return The intent.
     */
    public Intent getIntent() {
        synchronized (mInstanceLock) {
            return mIntent;
        }
    }

    public List<String> getIntentFilter() {
        synchronized (mInstanceLock) {
            return mIntentFilter;
        }
    }

    public void setIntentFilter(List<String> intentFilter) {
        synchronized (mInstanceLock) {
            if (mIntentFilter == intentFilter) {
                return;
            }
            mIntentFilter = intentFilter;
            mReloadActivities = true;
            ensureConsistentState();
        }
    }

    public void setShowHistory(boolean showHistory) {
        synchronized (mInstanceLock) {
            if (mShowHistory == showHistory) {
                return;
            }
            mShowHistory = showHistory;
            notifyChanged();
        }
    }

    public boolean getShowHistory() {
        synchronized (mInstanceLock) {
            return mShowHistory;
        }
    }

    /**
     * Gets the number of activities that can handle the intent.
     *
     * @return The activity count.
     *
     * @see #setIntent(Intent)
     */
    public int getActivityCount() {
        synchronized (mInstanceLock) {
            ensureConsistentState();
            return mActivities.size();
        }
    }

    /**
     * Gets an activity at a given index.
     *
     * @return The activity.
     *
     * @see ActivityResolveInfo
     * @see #setIntent(Intent)
     */
    public ResolveInfo getActivity(int index) {
        synchronized (mInstanceLock) {
            ensureConsistentState();
            return mActivities.get(index).resolveInfo;
        }
    }

    /**
     * Gets the index of a the given activity.
     *
     * @param activity The activity index.
     *
     * @return The index if found, -1 otherwise.
     */
    public int getActivityIndex(ResolveInfo activity) {
        synchronized (mInstanceLock) {
            ensureConsistentState();
            List<ActivityResolveInfo> activities = mActivities;
            final int activityCount = activities.size();
            for (int i = 0; i < activityCount; i++) {
                ActivityResolveInfo currentActivity = activities.get(i);
                if (currentActivity.resolveInfo == activity) {
                    return i;
                }
            }
            return INVALID_INDEX;
        }
    }

    /**
     * Chooses a activity to handle the current intent. This will result in
     * adding a historical record for that action and construct intent with
     * its component name set such that it can be immediately started by the
     * client.
     * <p>
     * <strong>Note:</strong> By calling this method the client guarantees
     * that the returned intent will be started. This intent is returned to
     * the client solely to let additional customization before the start.
     * </p>
     *
     * @return An {@link Intent} for launching the activity or null if the
     *         policy has consumed the intent or there is not current intent
     *         set via {@link #setIntent(Intent)}.
     *
     * @see HistoricalRecord
     * @see OnChooseActivityListener
     */
    public Intent chooseActivity(int index) {
        synchronized (mInstanceLock) {
            if (mIntent == null) {
                return null;
            }

            ensureConsistentState();

            ActivityResolveInfo chosenActivity = mActivities.get(index);

            ComponentName chosenName = new ComponentName(
                    chosenActivity.resolveInfo.activityInfo.packageName,
                    chosenActivity.resolveInfo.activityInfo.name);

            Intent choiceIntent = new Intent(mIntent);
            choiceIntent.setComponent(chosenName);

            if (mActivityChoserModelPolicy != null) {
                // Do not allow the policy to change the intent.
                Intent choiceIntentCopy = new Intent(choiceIntent);
                final boolean handled = mActivityChoserModelPolicy.onChooseActivity(this,
                        choiceIntentCopy);
                if (handled) {
                    return null;
                }
            }

            HistoricalRecord historicalRecord = new HistoricalRecord(chosenName,
                    System.currentTimeMillis(), DEFAULT_HISTORICAL_RECORD_WEIGHT);
            addHistoricalRecord(historicalRecord);

            return choiceIntent;
        }
    }

    /**
     * Sets the listener for choosing an activity.
     *
     * @param listener The listener.
     */
    public void setOnChooseActivityListener(OnChooseActivityListener listener) {
        synchronized (mInstanceLock) {
            mActivityChoserModelPolicy = listener;
        }
    }

    /**
     * Gets the default activity, The default activity is defined as the one
     * with highest rank i.e. the first one in the list of activities that can
     * handle the intent.
     *
     * @return The default activity, <code>null</code> id not activities.
     *
     * @see #getActivity(int)
     */
    public ResolveInfo getDefaultActivity() {
        synchronized (mInstanceLock) {
            ensureConsistentState();
            if (!mActivities.isEmpty()) {
                return mActivities.get(0).resolveInfo;
            }
        }
        return null;
    }

    /**
     * Sets the default activity. The default activity is set by adding a
     * historical record with weight high enough that this activity will
     * become the highest ranked. Such a strategy guarantees that the default
     * will eventually change if not used. Also the weight of the record for
     * setting a default is inflated with a constant amount to guarantee that
     * it will stay as default for awhile.
     *
     * @param index The index of the activity to set as default.
     */
    public void setDefaultActivity(int index) {
        synchronized (mInstanceLock) {
            ensureConsistentState();

            ActivityResolveInfo newDefaultActivity = mActivities.get(index);
            ActivityResolveInfo oldDefaultActivity = mActivities.get(0);

            final float weight;
            if (oldDefaultActivity != null) {
                // Add a record with weight enough to boost the chosen at the top.
                weight = oldDefaultActivity.weight - newDefaultActivity.weight
                        + DEFAULT_ACTIVITY_INFLATION;
            } else {
                weight = DEFAULT_HISTORICAL_RECORD_WEIGHT;
            }

            ComponentName defaultName = new ComponentName(
                    newDefaultActivity.resolveInfo.activityInfo.packageName,
                    newDefaultActivity.resolveInfo.activityInfo.name);
            HistoricalRecord historicalRecord = new HistoricalRecord(defaultName,
                    System.currentTimeMillis(), weight);
            addHistoricalRecord(historicalRecord);
        }
    }

    /**
     * Persists the history data to the backing file if the latter
     * was provided. Calling this method before a call to {@link #readHistoricalDataIfNeeded()}
     * throws an exception. Calling this method more than one without choosing an
     * activity has not effect.
     *
     * @throws IllegalStateException If this method is called before a call to
     *         {@link #readHistoricalDataIfNeeded()}.
     */
    private void persistHistoricalDataIfNeeded() {
        if (!mReadShareHistoryCalled) {
            throw new IllegalStateException("No preceding call to #readHistoricalData");
        }
        if (!mHistoricalRecordsChanged) {
            return;
        }
        mHistoricalRecordsChanged = false;
        if (!TextUtils.isEmpty(mHistoryFileName)) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
                executePersistHistoryAsyncTaskSDK11();
            } else {
                executePersistHistoryAsyncTaskBase();
            }
        }
    }

    private void executePersistHistoryAsyncTaskBase() {
        new PersistHistoryAsyncTask().execute(new ArrayList<HistoricalRecord>(mHistoricalRecords),
                mHistoryFileName);
    }

    private void executePersistHistoryAsyncTaskSDK11() {
        new PersistHistoryAsyncTask().executeOnExecutor(AsyncTask.SERIAL_EXECUTOR,
                new ArrayList<HistoricalRecord>(mHistoricalRecords), mHistoryFileName);
    }

    /**
     * Sets the sorter for ordering activities based on historical data and an intent.
     *
     * @param activitySorter The sorter.
     *
     * @see ActivitySorter
     */
    public void setActivitySorter(ActivitySorter activitySorter) {
        synchronized (mInstanceLock) {
            if (mActivitySorter == activitySorter) {
                return;
            }
            mActivitySorter = activitySorter;
            if (sortActivitiesIfNeeded()) {
                notifyChanged();
            }
        }
    }

    /**
     * Sets the maximal size of the historical data. Defaults to
     * {@link #DEFAULT_HISTORY_MAX_LENGTH}
     * <p>
     *   <strong>Note:</strong> Setting this property will immediately
     *   enforce the specified max history size by dropping enough old
     *   historical records to enforce the desired size. Thus, any
     *   records that exceed the history size will be discarded and
     *   irreversibly lost.
     * </p>
     *
     * @param historyMaxSize The max history size.
     */
    public void setHistoryMaxSize(int historyMaxSize) {
        synchronized (mInstanceLock) {
            if (mHistoryMaxSize == historyMaxSize) {
                return;
            }
            mHistoryMaxSize = historyMaxSize;
            pruneExcessiveHistoricalRecordsIfNeeded();
            if (sortActivitiesIfNeeded()) {
                notifyChanged();
            }
        }
    }

    /**
     * Gets the history max size.
     *
     * @return The history max size.
     */
    public int getHistoryMaxSize() {
        synchronized (mInstanceLock) {
            return mHistoryMaxSize;
        }
    }

    /**
     * Gets the history size.
     *
     * @return The history size.
     */
    public int getHistorySize() {
        synchronized (mInstanceLock) {
            ensureConsistentState();
            return mHistoricalRecords.size();
        }
    }

    /**
     * Ensures the model is in a consistent state which is the
     * activities for the current intent have been loaded, the
     * most recent history has been read, and the activities
     * are sorted.
     */
    private void ensureConsistentState() {
        boolean stateChanged = loadActivitiesIfNeeded();
        stateChanged |= readHistoricalDataIfNeeded();
        pruneExcessiveHistoricalRecordsIfNeeded();
        if (stateChanged) {
            sortActivitiesIfNeeded();
            notifyChanged();
        }
    }

    /**
     * Sorts the activities if necessary which is if there is a
     * sorter, there are some activities to sort, and there is some
     * historical data.
     *
     * @return Whether sorting was performed.
     */
    private boolean sortActivitiesIfNeeded() {
        if (mActivitySorter != null && mIntent != null
                && !mActivities.isEmpty() && !mHistoricalRecords.isEmpty()) {
            mActivitySorter.sort(mIntent, mActivities,
                    Collections.unmodifiableList(mHistoricalRecords));
            return true;
        }
        return false;
    }

    /**
     * Loads the activities for the current intent if needed which is
     * if they are not already loaded for the current intent.
     *
     * @return Whether loading was performed.
     */
    private boolean loadActivitiesIfNeeded() {
        if (mReloadActivities && mIntent != null) {
            mReloadActivities = false;
            mActivities.clear();
            List<ResolveInfo> resolveInfos = mContext.getPackageManager()
                    .queryIntentActivities(mIntent, 0);
            final int resolveInfoCount = resolveInfos.size();
            for (int i = 0; i < resolveInfoCount; i++) {
                ResolveInfo resolveInfo = resolveInfos.get(i);
                if (mIntentFilter.size() == 0 || mIntentFilter.contains(resolveInfo.activityInfo.packageName.toLowerCase())) {
                    mActivities.add(new ActivityResolveInfo(resolveInfo));
                }
            }
            return true;
        }
        return false;
    }

    /**
     * Reads the historical data if necessary which is it has
     * changed, there is a history file, and there is not persist
     * in progress.
     *
     * @return Whether reading was performed.
     */
    private boolean readHistoricalDataIfNeeded() {
        if (mCanReadHistoricalData && mHistoricalRecordsChanged &&
                !TextUtils.isEmpty(mHistoryFileName)) {
            mCanReadHistoricalData = false;
            mReadShareHistoryCalled = true;
            readHistoricalDataImpl();
            return true;
        }
        return false;
    }

    /**
     * Adds a historical record.
     *
     * @param historicalRecord The record to add.
     * @return True if the record was added.
     */
    private boolean addHistoricalRecord(HistoricalRecord historicalRecord) {
        final boolean added = mHistoricalRecords.add(historicalRecord);
        if (added) {
            mHistoricalRecordsChanged = true;
            pruneExcessiveHistoricalRecordsIfNeeded();
            persistHistoricalDataIfNeeded();
            sortActivitiesIfNeeded();
            notifyChanged();
        }
        return added;
    }

    /**
     * Prunes older excessive records to guarantee maxHistorySize.
     */
    private void pruneExcessiveHistoricalRecordsIfNeeded() {
        final int pruneCount = mHistoricalRecords.size() - mHistoryMaxSize;
        if (pruneCount <= 0) {
            return;
        }
        mHistoricalRecordsChanged = true;
        for (int i = 0; i < pruneCount; i++) {
            HistoricalRecord prunedRecord = mHistoricalRecords.remove(0);
            if (DEBUG) {
                Log.i(LOG_TAG, "Pruned: " + prunedRecord);
            }
        }
    }

    /**
     * Represents a record in the history.
     */
    public final static class HistoricalRecord {

        /**
         * The activity name.
         */
        public final ComponentName activity;

        /**
         * The choice time.
         */
        public final long time;

        /**
         * The record weight.
         */
        public final float weight;

        /**
         * Creates a new instance.
         *
         * @param activityName The activity component name flattened to string.
         * @param time The time the activity was chosen.
         * @param weight The weight of the record.
         */
        public HistoricalRecord(String activityName, long time, float weight) {
            this(ComponentName.unflattenFromString(activityName), time, weight);
        }

        /**
         * Creates a new instance.
         *
         * @param activityName The activity name.
         * @param time The time the activity was chosen.
         * @param weight The weight of the record.
         */
        public HistoricalRecord(ComponentName activityName, long time, float weight) {
            this.activity = activityName;
            this.time = time;
            this.weight = weight;
        }

        @Override
        public int hashCode() {
            final int prime = 31;
            int result = 1;
            result = prime * result + ((activity == null) ? 0 : activity.hashCode());
            result = prime * result + (int) (time ^ (time >>> 32));
            result = prime * result + Float.floatToIntBits(weight);
            return result;
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            HistoricalRecord other = (HistoricalRecord) obj;
            if (activity == null) {
                if (other.activity != null) {
                    return false;
                }
            } else if (!activity.equals(other.activity)) {
                return false;
            }
            if (time != other.time) {
                return false;
            }
            if (Float.floatToIntBits(weight) != Float.floatToIntBits(other.weight)) {
                return false;
            }
            return true;
        }

        @Override
        public String toString() {
            StringBuilder builder = new StringBuilder();
            builder.append("[");
            builder.append("; activity:").append(activity);
            builder.append("; time:").append(time);
            builder.append("; weight:").append(new BigDecimal(weight));
            builder.append("]");
            return builder.toString();
        }
    }

    /**
     * Represents an activity.
     */
    public final class ActivityResolveInfo implements Comparable<ActivityResolveInfo> {

        /**
         * The {@link ResolveInfo} of the activity.
         */
        public final ResolveInfo resolveInfo;

        /**
         * Weight of the activity. Useful for sorting.
         */
        public float weight;

        /**
         * Creates a new instance.
         *
         * @param resolveInfo activity {@link ResolveInfo}.
         */
        public ActivityResolveInfo(ResolveInfo resolveInfo) {
            this.resolveInfo = resolveInfo;
        }

        @Override
        public int hashCode() {
            return 31 + Float.floatToIntBits(weight);
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            ActivityResolveInfo other = (ActivityResolveInfo) obj;
            if (Float.floatToIntBits(weight) != Float.floatToIntBits(other.weight)) {
                return false;
            }
            return true;
        }

        public int compareTo(ActivityResolveInfo another) {
            return  Float.floatToIntBits(another.weight) - Float.floatToIntBits(weight);
        }

        @Override
        public String toString() {
            StringBuilder builder = new StringBuilder();
            builder.append("[");
            builder.append("resolveInfo:").append(resolveInfo.toString());
            builder.append("; weight:").append(new BigDecimal(weight));
            builder.append("]");
            return builder.toString();
        }
    }

    /**
     * Default activity sorter implementation.
     */
    private final class DefaultSorter implements ActivitySorter {
        private static final float WEIGHT_DECAY_COEFFICIENT = 0.95f;

        private final Map<String, ActivityResolveInfo> mPackageNameToActivityMap =
                new HashMap<String, ActivityResolveInfo>();

        public void sort(Intent intent, List<ActivityResolveInfo> activities,
                         List<HistoricalRecord> historicalRecords) {
            Map<String, ActivityResolveInfo> packageNameToActivityMap =
                    mPackageNameToActivityMap;
            packageNameToActivityMap.clear();

            final int activityCount = activities.size();
            for (int i = 0; i < activityCount; i++) {
                ActivityResolveInfo activity = activities.get(i);
                activity.weight = 0.0f;
                String packageName = activity.resolveInfo.activityInfo.packageName;
                packageNameToActivityMap.put(packageName, activity);
            }

            final int lastShareIndex = historicalRecords.size() - 1;
            float nextRecordWeight = 1;
            for (int i = lastShareIndex; i >= 0; i--) {
                HistoricalRecord historicalRecord = historicalRecords.get(i);
                String packageName = historicalRecord.activity.getPackageName();
                ActivityResolveInfo activity = packageNameToActivityMap.get(packageName);
                if (activity != null) {
                    activity.weight += historicalRecord.weight * nextRecordWeight;
                    nextRecordWeight = nextRecordWeight * WEIGHT_DECAY_COEFFICIENT;
                }
            }

            Collections.sort(activities);

            if (DEBUG) {
                for (int i = 0; i < activityCount; i++) {
                    Log.i(LOG_TAG, "Sorted: " + activities.get(i));
                }
            }
        }
    }

    /**
     * Command for reading the historical records from a file off the UI thread.
     */
    private void readHistoricalDataImpl() {
        FileInputStream fis = null;
        try {
            fis = mContext.openFileInput(mHistoryFileName);
        } catch (FileNotFoundException fnfe) {
            if (DEBUG) {
                Log.i(LOG_TAG, "Could not open historical records file: " + mHistoryFileName);
            }
            return;
        }
        try {
            XmlPullParser parser = Xml.newPullParser();
            parser.setInput(fis, null);

            int type = XmlPullParser.START_DOCUMENT;
            while (type != XmlPullParser.END_DOCUMENT && type != XmlPullParser.START_TAG) {
                type = parser.next();
            }

            if (!TAG_HISTORICAL_RECORDS.equals(parser.getName())) {
                throw new XmlPullParserException("Share records file does not start with "
                        + TAG_HISTORICAL_RECORDS + " tag.");
            }

            List<HistoricalRecord> historicalRecords = mHistoricalRecords;
            historicalRecords.clear();

            while (true) {
                type = parser.next();
                if (type == XmlPullParser.END_DOCUMENT) {
                    break;
                }
                if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                    continue;
                }
                String nodeName = parser.getName();
                if (!TAG_HISTORICAL_RECORD.equals(nodeName)) {
                    throw new XmlPullParserException("Share records file not well-formed.");
                }

                String activity = parser.getAttributeValue(null, ATTRIBUTE_ACTIVITY);
                final long time =
                        Long.parseLong(parser.getAttributeValue(null, ATTRIBUTE_TIME));
                final float weight =
                        Float.parseFloat(parser.getAttributeValue(null, ATTRIBUTE_WEIGHT));
                HistoricalRecord readRecord = new HistoricalRecord(activity, time, weight);
                historicalRecords.add(readRecord);

                if (DEBUG) {
                    Log.i(LOG_TAG, "Read " + readRecord.toString());
                }
            }

            if (DEBUG) {
                Log.i(LOG_TAG, "Read " + historicalRecords.size() + " historical records.");
            }
        } catch (XmlPullParserException xppe) {
            Log.e(LOG_TAG, "Error reading historical recrod file: " + mHistoryFileName, xppe);
        } catch (IOException ioe) {
            Log.e(LOG_TAG, "Error reading historical recrod file: " + mHistoryFileName, ioe);
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException ioe) {
                    /* ignore */
                }
            }
        }
    }

    /**
     * Command for persisting the historical records to a file off the UI thread.
     */
    private final class PersistHistoryAsyncTask extends AsyncTask<Object, Void, Void> {

        @Override
        @SuppressWarnings("unchecked")
        public Void doInBackground(Object... args) {
            List<HistoricalRecord> historicalRecords = (List<HistoricalRecord>) args[0];
            String hostoryFileName = (String) args[1];

            FileOutputStream fos = null;

            try {
                fos = mContext.openFileOutput(hostoryFileName, Context.MODE_PRIVATE);
            } catch (FileNotFoundException fnfe) {
                Log.e(LOG_TAG, "Error writing historical recrod file: " + hostoryFileName, fnfe);
                return null;
            }

            XmlSerializer serializer = Xml.newSerializer();

            try {
                serializer.setOutput(fos, null);
                serializer.startDocument("UTF-8", true);
                serializer.startTag(null, TAG_HISTORICAL_RECORDS);

                final int recordCount = historicalRecords.size();
                for (int i = 0; i < recordCount; i++) {
                    HistoricalRecord record = historicalRecords.remove(0);
                    serializer.startTag(null, TAG_HISTORICAL_RECORD);
                    serializer.attribute(null, ATTRIBUTE_ACTIVITY,
                            record.activity.flattenToString());
                    serializer.attribute(null, ATTRIBUTE_TIME, String.valueOf(record.time));
                    serializer.attribute(null, ATTRIBUTE_WEIGHT, String.valueOf(record.weight));
                    serializer.endTag(null, TAG_HISTORICAL_RECORD);
                    if (DEBUG) {
                        Log.i(LOG_TAG, "Wrote " + record.toString());
                    }
                }

                serializer.endTag(null, TAG_HISTORICAL_RECORDS);
                serializer.endDocument();

                if (DEBUG) {
                    Log.i(LOG_TAG, "Wrote " + recordCount + " historical records.");
                }
            } catch (IllegalArgumentException iae) {
                Log.e(LOG_TAG, "Error writing historical recrod file: " + mHistoryFileName, iae);
            } catch (IllegalStateException ise) {
                Log.e(LOG_TAG, "Error writing historical recrod file: " + mHistoryFileName, ise);
            } catch (IOException ioe) {
                Log.e(LOG_TAG, "Error writing historical recrod file: " + mHistoryFileName, ioe);
            } finally {
                mCanReadHistoricalData = true;
                if (fos != null) {
                    try {
                        fos.close();
                    } catch (IOException e) {
                        /* ignore */
                    }
                }
            }
            return null;
        }
    }
}

ActivityChooserView.java

package com.your.package;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.database.DataSetObserver;
import android.graphics.drawable.Drawable;
import android.support.v4.view.ActionProvider;
import android.support.v7.appcompat.R;
import android.support.v7.internal.widget.ListPopupWindow;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.PopupWindow;
import android.widget.TextView;

/**
 * This class is a view for choosing an activity for handling a given {@link Intent}.
 * <p>
 * The view is composed of two adjacent buttons:
 * <ul>
 * <li>
 * The left button is an immediate action and allows one click activity choosing.
 * Tapping this button immediately executes the intent without requiring any further
 * user input. Long press on this button shows a popup for changing the default
 * activity.
 * </li>
 * <li>
 * The right button is an overflow action and provides an optimized menu
 * of additional activities. Tapping this button shows a popup anchored to this
 * view, listing the most frequently used activities. This list is initially
 * limited to a small number of items in frequency used order. The last item,
 * "Show all..." serves as an affordance to display all available activities.
 * </li>
 * </ul>
 * </p>
 *
 * @hide
 */
public class ActivityChooserView extends ViewGroup implements
        ActivityChooserModel.ActivityChooserModelClient {

    /**
     * An adapter for displaying the activities in an {@link android.widget.AdapterView}.
     */
    private final ActivityChooserViewAdapter mAdapter;

    /**
     * Implementation of various interfaces to avoid publishing them in the APIs.
     */
    private final Callbacks mCallbacks;

    /**
     * The content of this view.
     */
    private final LinearLayout mActivityChooserContent;

    /**
     * Stores the background drawable to allow hiding and latter showing.
     */
    private final Drawable mActivityChooserContentBackground;

    /**
     * The expand activities action button;
     */
    private final FrameLayout mExpandActivityOverflowButton;

    /**
     * The image for the expand activities action button;
     */
    private final ImageView mExpandActivityOverflowButtonImage;

    /**
     * The default activities action button;
     */
    private final FrameLayout mDefaultActivityButton;

    /**
     * The image for the default activities action button;
     */
    private final ImageView mDefaultActivityButtonImage;

    /**
     * The maximal width of the list popup.
     */
    private final int mListPopupMaxWidth;

    /**
     * The ActionProvider hosting this view, if applicable.
     */
    ActionProvider mProvider;

    /**
     * Observer for the model data.
     */
    private final DataSetObserver mModelDataSetOberver = new DataSetObserver() {

        @Override
        public void onChanged() {
            super.onChanged();
            mAdapter.notifyDataSetChanged();
        }
        @Override
        public void onInvalidated() {
            super.onInvalidated();
            mAdapter.notifyDataSetInvalidated();
        }
    };

    private final OnGlobalLayoutListener mOnGlobalLayoutListener = new OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            if (isShowingPopup()) {
                if (!isShown()) {
                    getListPopupWindow().dismiss();
                } else {
                    getListPopupWindow().show();
                    if (mProvider != null) {
                        mProvider.subUiVisibilityChanged(true);
                    }
                }
            }
        }
    };

    /**
     * Popup window for showing the activity overflow list.
     */
    private ListPopupWindow mListPopupWindow;

    /**
     * Listener for the dismissal of the popup/alert.
     */
    private PopupWindow.OnDismissListener mOnDismissListener;

    /**
     * Flag whether a default activity currently being selected.
     */
    private boolean mIsSelectingDefaultActivity;

    /**
     * The count of activities in the popup.
     */
    private int mInitialActivityCount = ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_DEFAULT;

    /**
     * Flag whether this view is attached to a window.
     */
    private boolean mIsAttachedToWindow;

    /**
     * String resource for formatting content description of the default target.
     */
    private int mDefaultActionButtonContentDescription;

    /**
     * Create a new instance.
     *
     * @param context The application environment.
     */
    public ActivityChooserView(Context context) {
        this(context, null);
    }

    /**
     * Create a new instance.
     *
     * @param context The application environment.
     * @param attrs A collection of attributes.
     */
    public ActivityChooserView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    /**
     * Create a new instance.
     *
     * @param context The application environment.
     * @param attrs A collection of attributes.
     * @param defStyle The default style to apply to this view.
     */
    public ActivityChooserView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        TypedArray attributesArray = context.obtainStyledAttributes(attrs,
                R.styleable.ActivityChooserView, defStyle, 0);

        mInitialActivityCount = attributesArray.getInt(
                R.styleable.ActivityChooserView_initialActivityCount,
                ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_DEFAULT);

        Drawable expandActivityOverflowButtonDrawable = attributesArray.getDrawable(
                R.styleable.ActivityChooserView_expandActivityOverflowButtonDrawable);

        attributesArray.recycle();

        LayoutInflater inflater = LayoutInflater.from(getContext());
        inflater.inflate(R.layout.abc_activity_chooser_view, this, true);

        mCallbacks = new Callbacks();

        mActivityChooserContent = (LinearLayout) findViewById(R.id.activity_chooser_view_content);
        mActivityChooserContentBackground = mActivityChooserContent.getBackground();

        mDefaultActivityButton = (FrameLayout) findViewById(R.id.default_activity_button);
        mDefaultActivityButton.setOnClickListener(mCallbacks);
        mDefaultActivityButton.setOnLongClickListener(mCallbacks);
        mDefaultActivityButtonImage = (ImageView) mDefaultActivityButton.findViewById(R.id.image);

        mExpandActivityOverflowButton = (FrameLayout) findViewById(R.id.expand_activities_button);
        mExpandActivityOverflowButton.setOnClickListener(mCallbacks);
        mExpandActivityOverflowButtonImage =
                (ImageView) mExpandActivityOverflowButton.findViewById(R.id.image);
        mExpandActivityOverflowButtonImage.setImageDrawable(expandActivityOverflowButtonDrawable);

        mAdapter = new ActivityChooserViewAdapter();
        mAdapter.registerDataSetObserver(new DataSetObserver() {
            @Override
            public void onChanged() {
                super.onChanged();
                updateAppearance();
            }
        });

        Resources resources = context.getResources();
        mListPopupMaxWidth = Math.max(resources.getDisplayMetrics().widthPixels / 2,
                resources.getDimensionPixelSize(R.dimen.abc_config_prefDialogWidth));
    }

    /**
     * {@inheritDoc}
     */
    public void setActivityChooserModel(ActivityChooserModel dataModel) {
        mAdapter.setDataModel(dataModel);
        if (isShowingPopup()) {
            dismissPopup();
            showPopup();
        }
    }

    /**
     * Sets the background for the button that expands the activity
     * overflow list.
     *
     * <strong>Note:</strong> Clients would like to set this drawable
     * as a clue about the action the chosen activity will perform. For
     * example, if a share activity is to be chosen the drawable should
     * give a clue that sharing is to be performed.
     *
     * @param drawable The drawable.
     */
    public void setExpandActivityOverflowButtonDrawable(Drawable drawable) {
        mExpandActivityOverflowButtonImage.setImageDrawable(drawable);
    }

    /**
     * Sets the content description for the button that expands the activity
     * overflow list.
     *
     * description as a clue about the action performed by the button.
     * For example, if a share activity is to be chosen the content
     * description should be something like "Share with".
     *
     * @param resourceId The content description resource id.
     */
    public void setExpandActivityOverflowButtonContentDescription(int resourceId) {
        CharSequence contentDescription = getContext().getString(resourceId);
        mExpandActivityOverflowButtonImage.setContentDescription(contentDescription);
    }

    /**
     * Set the provider hosting this view, if applicable.
     * @hide Internal use only
     */
    public void setProvider(ActionProvider provider) {
        mProvider = provider;
    }

    /**
     * Shows the popup window with activities.
     *
     * @return True if the popup was shown, false if already showing.
     */
    public boolean showPopup() {
        if (isShowingPopup() || !mIsAttachedToWindow) {
            return false;
        }
        mIsSelectingDefaultActivity = false;
        showPopupUnchecked(mInitialActivityCount);
        return true;
    }

    /**
     * Shows the popup no matter if it was already showing.
     *
     * @param maxActivityCount The max number of activities to display.
     */
    private void showPopupUnchecked(int maxActivityCount) {
        if (mAdapter.getDataModel() == null) {
            throw new IllegalStateException("No data model. Did you call #setDataModel?");
        }

        getViewTreeObserver().addOnGlobalLayoutListener(mOnGlobalLayoutListener);

        final boolean defaultActivityButtonShown =
                mDefaultActivityButton.getVisibility() == VISIBLE;

        final int activityCount = mAdapter.getActivityCount();
        final int maxActivityCountOffset = defaultActivityButtonShown ? 1 : 0;
        if (maxActivityCount != ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_UNLIMITED
                && activityCount > maxActivityCount + maxActivityCountOffset) {
            mAdapter.setShowFooterView(true);
            mAdapter.setMaxActivityCount(maxActivityCount - 1);
        } else {
            mAdapter.setShowFooterView(false);
            mAdapter.setMaxActivityCount(maxActivityCount);
        }

        ListPopupWindow popupWindow = getListPopupWindow();
        if (!popupWindow.isShowing()) {
            if (mIsSelectingDefaultActivity || !defaultActivityButtonShown) {
                mAdapter.setShowDefaultActivity(true, defaultActivityButtonShown);
            } else {
                mAdapter.setShowDefaultActivity(false, false);
            }
            final int contentWidth = Math.min(mAdapter.measureContentWidth(), mListPopupMaxWidth);
            popupWindow.setContentWidth(contentWidth);
            popupWindow.show();
            if (mProvider != null) {
                mProvider.subUiVisibilityChanged(true);
            }
            popupWindow.getListView().setContentDescription(getContext().getString(
                    R.string.abc_activitychooserview_choose_application));
        }
    }

    /**
     * Dismisses the popup window with activities.
     *
     * @return True if dismissed, false if already dismissed.
     */
    public boolean dismissPopup() {
        if (isShowingPopup()) {
            getListPopupWindow().dismiss();
            ViewTreeObserver viewTreeObserver = getViewTreeObserver();
            if (viewTreeObserver.isAlive()) {
                viewTreeObserver.removeGlobalOnLayoutListener(mOnGlobalLayoutListener);
            }
        }
        return true;
    }

    /**
     * Gets whether the popup window with activities is shown.
     *
     * @return True if the popup is shown.
     */
    public boolean isShowingPopup() {
        return getListPopupWindow().isShowing();
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        ActivityChooserModel dataModel = mAdapter.getDataModel();
        if (dataModel != null) {
            dataModel.registerObserver(mModelDataSetOberver);
        }
        mIsAttachedToWindow = true;
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        ActivityChooserModel dataModel = mAdapter.getDataModel();
        if (dataModel != null) {
            dataModel.unregisterObserver(mModelDataSetOberver);
        }
        ViewTreeObserver viewTreeObserver = getViewTreeObserver();
        if (viewTreeObserver.isAlive()) {
            viewTreeObserver.removeGlobalOnLayoutListener(mOnGlobalLayoutListener);
        }
        if (isShowingPopup()) {
            dismissPopup();
        }
        mIsAttachedToWindow = false;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        View child = mActivityChooserContent;
        // If the default action is not visible we want to be as tall as the
        // ActionBar so if this widget is used in the latter it will look as
        // a normal action button.
        if (mDefaultActivityButton.getVisibility() != VISIBLE) {
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec),
                    MeasureSpec.EXACTLY);
        }
        measureChild(child, widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(child.getMeasuredWidth(), child.getMeasuredHeight());
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        mActivityChooserContent.layout(0, 0, right - left, bottom - top);
        if (!isShowingPopup()) {
            dismissPopup();
        }
    }

    public ActivityChooserModel getDataModel() {
        return mAdapter.getDataModel();
    }

    /**
     * Sets a listener to receive a callback when the popup is dismissed.
     *
     * @param listener The listener to be notified.
     */
    public void setOnDismissListener(PopupWindow.OnDismissListener listener) {
        mOnDismissListener = listener;
    }

    /**
     * Sets the initial count of items shown in the activities popup
     * i.e. the items before the popup is expanded. This is an upper
     * bound since it is not guaranteed that such number of intent
     * handlers exist.
     *
     * @param itemCount The initial popup item count.
     */
    public void setInitialActivityCount(int itemCount) {
        mInitialActivityCount = itemCount;
    }

    /**
     * Sets a content description of the default action button. This
     * resource should be a string taking one formatting argument and
     * will be used for formatting the content description of the button
     * dynamically as the default target changes. For example, a resource
     * pointing to the string "share with %1$s" will result in a content
     * description "share with Bluetooth" for the Bluetooth activity.
     *
     * @param resourceId The resource id.
     */
    public void setDefaultActionButtonContentDescription(int resourceId) {
        mDefaultActionButtonContentDescription = resourceId;
    }

    /**
     * Gets the list popup window which is lazily initialized.
     *
     * @return The popup.
     */
    private ListPopupWindow getListPopupWindow() {
        if (mListPopupWindow == null) {
            mListPopupWindow = new ListPopupWindow(getContext());
            mListPopupWindow.setAdapter(mAdapter);
            mListPopupWindow.setAnchorView(ActivityChooserView.this);
            mListPopupWindow.setModal(true);
            mListPopupWindow.setOnItemClickListener(mCallbacks);
            mListPopupWindow.setOnDismissListener(mCallbacks);
        }
        return mListPopupWindow;
    }

    /**
     * Updates the buttons state.
     */
    private void updateAppearance() {
        // Expand overflow button.
        if (mAdapter.getCount() > 0) {
            mExpandActivityOverflowButton.setEnabled(true);
        } else {
            mExpandActivityOverflowButton.setEnabled(false);
        }
        // Default activity button.
        final int activityCount = mAdapter.getActivityCount();
        final int historySize = mAdapter.getHistorySize();
        final boolean showHistory = mAdapter.getShowHistory();
        if (showHistory && (activityCount==1 || activityCount > 1 && historySize > 0)) {
            mDefaultActivityButton.setVisibility(VISIBLE);
            ResolveInfo activity = mAdapter.getDefaultActivity();
            PackageManager packageManager = getContext().getPackageManager();
            mDefaultActivityButtonImage.setImageDrawable(activity.loadIcon(packageManager));
            if (mDefaultActionButtonContentDescription != 0) {
                CharSequence label = activity.loadLabel(packageManager);
                String contentDescription = getContext().getString(
                        mDefaultActionButtonContentDescription, label);
                mDefaultActivityButton.setContentDescription(contentDescription);
            }
        } else {
            mDefaultActivityButton.setVisibility(View.GONE);
        }
        // Activity chooser content.
        if (mDefaultActivityButton.getVisibility() == VISIBLE) {
            mActivityChooserContent.setBackgroundDrawable(mActivityChooserContentBackground);
        } else {
            mActivityChooserContent.setBackgroundDrawable(null);
        }
    }

    /**
     * Interface implementation to avoid publishing them in the APIs.
     */
    private class Callbacks implements AdapterView.OnItemClickListener,
            View.OnClickListener, View.OnLongClickListener, PopupWindow.OnDismissListener {

        // AdapterView#OnItemClickListener
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            ActivityChooserViewAdapter adapter = (ActivityChooserViewAdapter) parent.getAdapter();
            final int itemViewType = adapter.getItemViewType(position);
            switch (itemViewType) {
                case ActivityChooserViewAdapter.ITEM_VIEW_TYPE_FOOTER: {
                    showPopupUnchecked(ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_UNLIMITED);
                } break;
                case ActivityChooserViewAdapter.ITEM_VIEW_TYPE_ACTIVITY: {
                    dismissPopup();
                    if (mIsSelectingDefaultActivity) {
                        // The item at position zero is the default already.
                        if (position > 0) {
                            mAdapter.getDataModel().setDefaultActivity(position);
                        }
                    } else {
                        // If the default target is not shown in the list, the first
                        // item in the model is default action => adjust index
                        position = mAdapter.getShowDefaultActivity() ? position : position + 1;
                        Intent launchIntent = mAdapter.getDataModel().chooseActivity(position);
                        if (launchIntent != null) {
                            launchIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
                            getContext().startActivity(launchIntent);
                        }
                    }
                } break;
                default:
                    throw new IllegalArgumentException();
            }
        }

        // View.OnClickListener
        public void onClick(View view) {
            if (view == mDefaultActivityButton) {
                dismissPopup();
                ResolveInfo defaultActivity = mAdapter.getDefaultActivity();
                final int index = mAdapter.getDataModel().getActivityIndex(defaultActivity);
                Intent launchIntent = mAdapter.getDataModel().chooseActivity(index);
                if (launchIntent != null) {
                    launchIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
                    getContext().startActivity(launchIntent);
                }
            } else if (view == mExpandActivityOverflowButton) {
                mIsSelectingDefaultActivity = false;
                showPopupUnchecked(mInitialActivityCount);
            } else {
                throw new IllegalArgumentException();
            }
        }

        // OnLongClickListener#onLongClick
        @Override
        public boolean onLongClick(View view) {
            if (view == mDefaultActivityButton) {
                if (mAdapter.getCount() > 0) {
                    mIsSelectingDefaultActivity = true;
                    showPopupUnchecked(mInitialActivityCount);
                }
            } else {
                throw new IllegalArgumentException();
            }
            return true;
        }

        // PopUpWindow.OnDismissListener#onDismiss
        public void onDismiss() {
            notifyOnDismissListener();
            if (mProvider != null) {
                mProvider.subUiVisibilityChanged(false);
            }
        }

        private void notifyOnDismissListener() {
            if (mOnDismissListener != null) {
                mOnDismissListener.onDismiss();
            }
        }
    }

    /**
     * Adapter for backing the list of activities shown in the popup.
     */
    private class ActivityChooserViewAdapter extends BaseAdapter {

        public static final int MAX_ACTIVITY_COUNT_UNLIMITED = Integer.MAX_VALUE;

        public static final int MAX_ACTIVITY_COUNT_DEFAULT = 4;

        private static final int ITEM_VIEW_TYPE_ACTIVITY = 0;

        private static final int ITEM_VIEW_TYPE_FOOTER = 1;

        private static final int ITEM_VIEW_TYPE_COUNT = 3;

        private ActivityChooserModel mDataModel;

        private int mMaxActivityCount = MAX_ACTIVITY_COUNT_DEFAULT;

        private boolean mShowDefaultActivity;

        private boolean mHighlightDefaultActivity;

        private boolean mShowFooterView;

        public void setDataModel(ActivityChooserModel dataModel) {
            ActivityChooserModel oldDataModel = mAdapter.getDataModel();
            if (oldDataModel != null && isShown()) {
                oldDataModel.unregisterObserver(mModelDataSetOberver);
            }
            mDataModel = dataModel;
            if (dataModel != null && isShown()) {
                dataModel.registerObserver(mModelDataSetOberver);
            }
            notifyDataSetChanged();
        }

        @Override
        public int getItemViewType(int position) {
            if (mShowFooterView && position == getCount() - 1) {
                return ITEM_VIEW_TYPE_FOOTER;
            } else {
                return ITEM_VIEW_TYPE_ACTIVITY;
            }
        }

        @Override
        public int getViewTypeCount() {
            return ITEM_VIEW_TYPE_COUNT;
        }

        public int getCount() {
            int count = 0;
            int activityCount = mDataModel.getActivityCount();
            if (!mShowDefaultActivity && mDataModel.getDefaultActivity() != null) {
                activityCount--;
            }
            count = Math.min(activityCount, mMaxActivityCount);
            if (mShowFooterView) {
                count++;
            }
            return count;
        }

        public Object getItem(int position) {
            final int itemViewType = getItemViewType(position);
            switch (itemViewType) {
                case ITEM_VIEW_TYPE_FOOTER:
                    return null;
                case ITEM_VIEW_TYPE_ACTIVITY:
                    if (!mShowDefaultActivity && mDataModel.getDefaultActivity() != null) {
                        position++;
                    }
                    return mDataModel.getActivity(position);
                default:
                    throw new IllegalArgumentException();
            }
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            final int itemViewType = getItemViewType(position);
            switch (itemViewType) {
                case ITEM_VIEW_TYPE_FOOTER:
                    if (convertView == null || convertView.getId() != ITEM_VIEW_TYPE_FOOTER) {
                        convertView = LayoutInflater.from(getContext()).inflate(
                                R.layout.abc_activity_chooser_view_list_item, parent, false);
                        convertView.setId(ITEM_VIEW_TYPE_FOOTER);
                        TextView titleView = (TextView) convertView.findViewById(R.id.title);
                        titleView.setText(getContext().getString(
                                R.string.abc_activity_chooser_view_see_all));
                    }
                    return convertView;
                case ITEM_VIEW_TYPE_ACTIVITY:
                    if (convertView == null || convertView.getId() != R.id.list_item) {
                        convertView = LayoutInflater.from(getContext()).inflate(
                                R.layout.abc_activity_chooser_view_list_item, parent, false);
                    }
                    PackageManager packageManager = getContext().getPackageManager();
                    // Set the icon
                    ImageView iconView = (ImageView) convertView.findViewById(R.id.icon);
                    ResolveInfo activity = (ResolveInfo) getItem(position);
                    iconView.setImageDrawable(activity.loadIcon(packageManager));
                    // Set the title.
                    TextView titleView = (TextView) convertView.findViewById(R.id.title);
                    titleView.setText(activity.loadLabel(packageManager));
                    // Highlight the default.
                    if (mShowDefaultActivity && position == 0 && mHighlightDefaultActivity) {
                        //TODO convertView.setActivated(true);
                    } else {
                        //TODO convertView.setActivated(false);
                    }
                    return convertView;
                default:
                    throw new IllegalArgumentException();
            }
        }

        public int measureContentWidth() {
            // The user may have specified some of the target not to be shown but we
            // want to measure all of them since after expansion they should fit.
            final int oldMaxActivityCount = mMaxActivityCount;
            mMaxActivityCount = MAX_ACTIVITY_COUNT_UNLIMITED;

            int contentWidth = 0;
            View itemView = null;

            final int widthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
            final int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
            final int count = getCount();

            for (int i = 0; i < count; i++) {
                itemView = getView(i, itemView, null);
                itemView.measure(widthMeasureSpec, heightMeasureSpec);
                contentWidth = Math.max(contentWidth, itemView.getMeasuredWidth());
            }

            mMaxActivityCount = oldMaxActivityCount;

            return contentWidth;
        }

        public void setMaxActivityCount(int maxActivityCount) {
            if (mMaxActivityCount != maxActivityCount) {
                mMaxActivityCount = maxActivityCount;
                notifyDataSetChanged();
            }
        }

        public ResolveInfo getDefaultActivity() {
            return mDataModel.getDefaultActivity();
        }

        public void setShowFooterView(boolean showFooterView) {
            if (mShowFooterView != showFooterView) {
                mShowFooterView = showFooterView;
                notifyDataSetChanged();
            }
        }

        public int getActivityCount() {
            return mDataModel.getActivityCount();
        }

        public int getHistorySize() {
            return mDataModel.getHistorySize();
        }

        public boolean getShowHistory() {
            return mDataModel.getShowHistory();
        }

        public int getMaxActivityCount() {
            return mMaxActivityCount;
        }

        public ActivityChooserModel getDataModel() {
            return mDataModel;
        }

        public void setShowDefaultActivity(boolean showDefaultActivity,
                                           boolean highlightDefaultActivity) {
            if (mShowDefaultActivity != showDefaultActivity
                    || mHighlightDefaultActivity != highlightDefaultActivity) {
                mShowDefaultActivity = showDefaultActivity;
                mHighlightDefaultActivity = highlightDefaultActivity;
                notifyDataSetChanged();
            }
        }

        public boolean getShowDefaultActivity() {
            return mShowDefaultActivity;
        }
    }
}

ExampleActivity.java

public class JournalEntryActivity extends ActionBarActivity {
  
  private final String[] INTENT_FILTER = new String[] {
          "com.twitter.android",
          "com.facebook.katana"
  };

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
      MenuInflater inflater = getMenuInflater();
      inflater.inflate(R.menu.journal_entry_menu, menu);

      // Set up ShareActionProvider's default share intent
      MenuItem shareItem = menu.findItem(R.id.action_share);

      if (shareItem instanceof SupportMenuItem) {
          mShareActionProvider = new ShareActionProvider(this);
          mShareActionProvider.setShareIntent(ShareUtils.share(mJournalEntry));
          mShareActionProvider.setIntentFilter(Arrays.asList(INTENT_FILTER));
          mShareActionProvider.setShowHistory(false);
          ((SupportMenuItem) shareItem).setSupportActionProvider(mShareActionProvider);
      }

      return super.onCreateOptionsMenu(menu);
  }
}

ShareActionProvider.java

package com.your.package;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.drawable.Drawable;
import android.support.v4.view.ActionProvider;
import android.support.v7.appcompat.R;
import android.util.TypedValue;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuItem.OnMenuItemClickListener;
import android.view.SubMenu;
import android.view.View;

import java.util.List;

/**
 * This is a provider for a share action. It is responsible for creating views
 * that enable data sharing and also to show a sub menu with sharing activities
 * if the hosting item is placed on the overflow menu.
 *
 * <p class="note"><strong>Note:</strong> This class is included in the <a
 * href="{@docRoot}tools/extras/support-library.html">support library</a> for compatibility
 * with API level 7 and higher. If you're developing your app for API level 14 and higher
 * <em>only</em>, you should instead use the framework {@link android.widget.ShareActionProvider}
 * class.</p>
 *
 * <p>
 * Here is how to use the action provider with custom backing file in a {@link MenuItem}:
 * </p>
 * <pre><code>
 *  // In {@link android.app.Activity#onCreateOptionsMenu Activity.onCreateOptionsMenu()}
 *  public boolean onCreateOptionsMenu(Menu menu) {
 *      // Get the menu item.
 *      MenuItem menuItem = menu.findItem(R.id.my_menu_item);
 *      // Get the provider and hold onto it to set/change the share intent.
 *      mShareActionProvider = (ShareActionProvider) MenuItemCompat.getActionProvider(menuItem);
 *      // Set history different from the default before getting the action
 *      // view since a call to {@link android.support.v4.view.MenuItemCompat#getActionView(android.view.MenuItem) MenuItemCompat.getActionView()} calls
 *      // {@link ActionProvider#onCreateActionView()} which uses the backing file name. Omit this
 *      // line if using the default share history file is desired.
 *      mShareActionProvider.setShareHistoryFileName("custom_share_history.xml");
 *      . . .
 *  }
 *
 *  // Somewhere in the application.
 *  public void doShare(Intent shareIntent) {
 *      // When you want to share set the share intent.
 *      mShareActionProvider.setShareIntent(shareIntent);
 *  }
 * </code></pre>
 * <p>
 * <strong>Note:</strong> While the sample snippet demonstrates how to use this provider
 * in the context of a menu item, the use of the provider is not limited to menu items.
 * </p>
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 *
 * <p>For information about how to use {@link ShareActionProvider}, see the
 * <a href="{@docRoot}guide/topics/ui/actionbar.html#ActionProvider">Action Bar</a> API guide.</p>
 * </div>
 *
 * @see ActionProvider
 */
public class ShareActionProvider extends ActionProvider {

    /**
     * Listener for the event of selecting a share target.
     */
    public interface OnShareTargetSelectedListener {

        /**
         * Called when a share target has been selected. The client can
         * decide whether to perform some action before the sharing is
         * actually performed.
         * <p>
         * <strong>Note:</strong> Modifying the intent is not permitted and
         *     any changes to the latter will be ignored.
         * </p>
         * <p>
         * <strong>Note:</strong> You should <strong>not</strong> handle the
         *     intent here. This callback aims to notify the client that a
         *     sharing is being performed, so the client can update the UI
         *     if necessary.
         * </p>
         *
         * @param source The source of the notification.
         * @param intent The intent for launching the chosen share target.
         * @return The return result is ignored. Always return false for consistency.
         */
        public boolean onShareTargetSelected(ShareActionProvider source, Intent intent);
    }

    /**
     * The default for the maximal number of activities shown in the sub-menu.
     */
    private static final int DEFAULT_INITIAL_ACTIVITY_COUNT = 4;

    /**
     * The the maximum number activities shown in the sub-menu.
     */
    private int mMaxShownActivityCount = DEFAULT_INITIAL_ACTIVITY_COUNT;

    /**
     * Listener for handling menu item clicks.
     */
    private final ShareMenuItemOnMenuItemClickListener mOnMenuItemClickListener =
            new ShareMenuItemOnMenuItemClickListener();

    /**
     * The default name for storing share history.
     */
    public static final String DEFAULT_SHARE_HISTORY_FILE_NAME = "share_history.xml";

    /**
     * Context for accessing resources.
     */
    private final Context mContext;

    /**
     * The name of the file with share history data.
     */
    private String mShareHistoryFileName = DEFAULT_SHARE_HISTORY_FILE_NAME;

    private OnShareTargetSelectedListener mOnShareTargetSelectedListener;

    private ActivityChooserModel.OnChooseActivityListener mOnChooseActivityListener;

    /**
     * Creates a new instance.
     *
     * @param context Context for accessing resources.
     */
    public ShareActionProvider(Context context) {
        super(context);
        mContext = context;
    }

    /**
     * Sets a listener to be notified when a share target has been selected.
     * The listener can optionally decide to handle the selection and
     * not rely on the default behavior which is to launch the activity.
     * <p>
     * <strong>Note:</strong> If you choose the backing share history file
     *     you will still be notified in this callback.
     * </p>
     * @param listener The listener.
     */
    public void setOnShareTargetSelectedListener(OnShareTargetSelectedListener listener) {
        mOnShareTargetSelectedListener = listener;
        setActivityChooserPolicyIfNeeded();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public View onCreateActionView() {
        // Create the view and set its data model.
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext, mShareHistoryFileName);
        ActivityChooserView activityChooserView = new ActivityChooserView(mContext);
        activityChooserView.setActivityChooserModel(dataModel);

        // Lookup and set the expand action icon.
        TypedValue outTypedValue = new TypedValue();
        mContext.getTheme().resolveAttribute(R.attr.actionModeShareDrawable, outTypedValue, true);
        Drawable drawable = mContext.getResources().getDrawable(outTypedValue.resourceId);
        activityChooserView.setExpandActivityOverflowButtonDrawable(drawable);
        activityChooserView.setProvider(this);

        // Set content description.
        activityChooserView.setDefaultActionButtonContentDescription(
                R.string.abc_shareactionprovider_share_with_application);
        activityChooserView.setExpandActivityOverflowButtonContentDescription(
                R.string.abc_shareactionprovider_share_with);

        return activityChooserView;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean hasSubMenu() {
        return true;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void onPrepareSubMenu(SubMenu subMenu) {
        // Clear since the order of items may change.
        subMenu.clear();

        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext, mShareHistoryFileName);
        PackageManager packageManager = mContext.getPackageManager();

        final int expandedActivityCount = dataModel.getActivityCount();
        final int collapsedActivityCount = Math.min(expandedActivityCount, mMaxShownActivityCount);

        // Populate the sub-menu with a sub set of the activities.
        for (int i = 0; i < collapsedActivityCount; i++) {
            ResolveInfo activity = dataModel.getActivity(i);
            subMenu.add(0, i, i, activity.loadLabel(packageManager))
                    .setIcon(activity.loadIcon(packageManager))
                    .setOnMenuItemClickListener(mOnMenuItemClickListener);
        }

        if (collapsedActivityCount < expandedActivityCount) {
            // Add a sub-menu for showing all activities as a list item.
            SubMenu expandedSubMenu = subMenu.addSubMenu(Menu.NONE, collapsedActivityCount,
                    collapsedActivityCount,
                    mContext.getString(R.string.abc_activity_chooser_view_see_all));
            for (int i = 0; i < expandedActivityCount; i++) {
                ResolveInfo activity = dataModel.getActivity(i);
                expandedSubMenu.add(0, i, i, activity.loadLabel(packageManager))
                        .setIcon(activity.loadIcon(packageManager))
                        .setOnMenuItemClickListener(mOnMenuItemClickListener);
            }
        }
    }

    /**
     * Sets the file name of a file for persisting the share history which
     * history will be used for ordering share targets. This file will be used
     * for all view created by {@link #onCreateActionView()}. Defaults to
     * {@link #DEFAULT_SHARE_HISTORY_FILE_NAME}. Set to <code>null</code>
     * if share history should not be persisted between sessions.
     * <p>
     * <strong>Note:</strong> The history file name can be set any time, however
     * only the action views created by {@link #onCreateActionView()} after setting
     * the file name will be backed by the provided file. Therefore, if you want to
     * use different history files for sharing specific types of content, every time
     * you change the history file {@link #setShareHistoryFileName(String)} you must
     * call {@link android.app.Activity#invalidateOptionsMenu()} to recreate the
     * action view. You should <strong>not</strong> call
     * {@link android.app.Activity#invalidateOptionsMenu()} from
     * {@link android.app.Activity#onCreateOptionsMenu(Menu)}."
     * <p>
     * <code>
     * private void doShare(Intent intent) {
     *     if (IMAGE.equals(intent.getMimeType())) {
     *         mShareActionProvider.setHistoryFileName(SHARE_IMAGE_HISTORY_FILE_NAME);
     *     } else if (TEXT.equals(intent.getMimeType())) {
     *         mShareActionProvider.setHistoryFileName(SHARE_TEXT_HISTORY_FILE_NAME);
     *     }
     *     mShareActionProvider.setIntent(intent);
     *     invalidateOptionsMenu();
     * }
     * <code>
     *
     * @param shareHistoryFile The share history file name.
     */
    public void setShareHistoryFileName(String shareHistoryFile) {
        mShareHistoryFileName = shareHistoryFile;
        setActivityChooserPolicyIfNeeded();
    }

    /**
     * Sets an intent with information about the share action. Here is a
     * sample for constructing a share intent:
     * <p>
     * <pre>
     * <code>
     *  Intent shareIntent = new Intent(Intent.ACTION_SEND);
     *  shareIntent.setType("image/*");
     *  Uri uri = Uri.fromFile(new File(getFilesDir(), "foo.jpg"));
     *  shareIntent.putExtra(Intent.EXTRA_STREAM, uri.toString());
     * </pre>
     * </code>
     * </p>
     *
     * @param shareIntent The share intent.
     *
     * @see Intent#ACTION_SEND
     * @see Intent#ACTION_SEND_MULTIPLE
     */
    public void setShareIntent(Intent shareIntent) {
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
                mShareHistoryFileName);
        dataModel.setIntent(shareIntent);
    }

    public void setIntentFilter(List<String> intentFilter) {
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
                mShareHistoryFileName);
        dataModel.setIntentFilter(intentFilter);
    }

    public void setShowHistory(boolean showHistory) {
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
                mShareHistoryFileName);
        dataModel.setShowHistory(showHistory);
    }

    /**
     * Reusable listener for handling share item clicks.
     */
    private class ShareMenuItemOnMenuItemClickListener implements OnMenuItemClickListener {
        @Override
        public boolean onMenuItemClick(MenuItem item) {
            ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
                    mShareHistoryFileName);
            final int itemId = item.getItemId();
            Intent launchIntent = dataModel.chooseActivity(itemId);
            if (launchIntent != null) {
                launchIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
                mContext.startActivity(launchIntent);
            }
            return true;
        }
    }

    /**
     * Set the activity chooser policy of the model backed by the current
     * share history file if needed which is if there is a registered callback.
     */
    private void setActivityChooserPolicyIfNeeded() {
        if (mOnShareTargetSelectedListener == null) {
            return;
        }
        if (mOnChooseActivityListener == null) {
            mOnChooseActivityListener = new ShareActivityChooserModelPolicy();
        }
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext, mShareHistoryFileName);
        dataModel.setOnChooseActivityListener(mOnChooseActivityListener);
    }

    /**
     * Policy that delegates to the {@link OnShareTargetSelectedListener}, if such.
     */
    private class ShareActivityChooserModelPolicy implements ActivityChooserModel.OnChooseActivityListener {
        @Override
        public boolean onChooseActivity(ActivityChooserModel host, Intent intent) {
            if (mOnShareTargetSelectedListener != null) {
                mOnShareTargetSelectedListener.onShareTargetSelected(
                        ShareActionProvider.this, intent);
            }
            return false;
        }
    }
}

Hey, got here through (http://stackoverflow.com/a/23036439), thanks for the helpful implementation!

There seems to be a bug where the text color of the app share list (and footer) that shows when the share button is pressed does not get set correctly.

In my app i use the Theme.AppCompat.Light and everything works fine if i get the default ShareActionProvider ((ShareActionProvider) MenuItemCompat.getActionProvider(item)). If i switch to your implementation however, the text color is black rather than white, which means that at some point it does not account for the theme properly.

I have worked around this for the moment by adding

titleView.setTextAppearance(getContext(), R.style.TextAppearance_AppCompat_Widget_ActionBar_Title_Inverse);

to the getView() method of the Adapter, but cannot for the life of me figure out why the style is not traversed when the titleViews are generated. If you have any suggestions I'd be grateful.

Aaaaaad 5 minutes later (after spending almost an hour)...

I was trying to see what I was doing differently, apparently passing the Activity context messes the theme traversal up. Instead, you need to pass the MenuItem context (which I'm guessing is what the MenuItemCompat.getActionProvider(item) does). (EDIT: Apparently it is handled inside the SupportMenuItem)

To do that, instead of this:

shareActionProvider = new ShareActionProvider(this);

do this:

shareActionProvider = new ShareActionProvider(MenuItemCompat.getActionView(item).getContext());

And magically everything is fine again...!

EDIT: And to be really correct (whatever this means), you should also replace this

((SupportMenuItem) item).setSupportActionProvider(shareActionProvider);

with this

MenuItemCompat.setActionProvider(item, shareActionProvider);

Which does inherent checking (source: MenuItemCompat).

This won't work with API 21

how do Iuse it on v7 support library?

There is an error with new code.

mShareActionProvider = new MyShareActionProvider(getApplicationContext());
With this code, click event does not have any effect.

mShareActionProvider = new MyShareActionProvider(MenuItemCompat.getActionView(shareItem).getContext());
Error "Successfully bound to service but never got onServiceConnected callback"

Is there any way to use these classes without adding the menu item?
i.e. As a replacement for otherwise calling: startActivity(Intent.createChooser(intent, title));