android/vcard/VCardComposer.java

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * 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.android.vcard;

import com.android.vcard.exception.VCardException;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.Entity;
import android.content.Entity.NamedContentValues;
import android.content.EntityIterator;
import android.database.Cursor;
import android.database.sqlite.SQLiteException;
import android.net.Uri;
import android.provider.ContactsContract.CommonDataKinds.Email;
import android.provider.ContactsContract.CommonDataKinds.Event;
import android.provider.ContactsContract.CommonDataKinds.Im;
import android.provider.ContactsContract.CommonDataKinds.Nickname;
import android.provider.ContactsContract.CommonDataKinds.Note;
import android.provider.ContactsContract.CommonDataKinds.Organization;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.provider.ContactsContract.CommonDataKinds.Photo;
import android.provider.ContactsContract.CommonDataKinds.Relation;
import android.provider.ContactsContract.CommonDataKinds.SipAddress;
import android.provider.ContactsContract.CommonDataKinds.StructuredName;
import android.provider.ContactsContract.CommonDataKinds.StructuredPostal;
import android.provider.ContactsContract.CommonDataKinds.Website;
import android.provider.ContactsContract.Contacts;
import android.provider.ContactsContract.Data;
import android.provider.ContactsContract.RawContacts;
import android.provider.ContactsContract.RawContactsEntity;
import android.text.TextUtils;
import android.util.Log;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * <p>
 * The class for composing vCard from Contacts information.
 * </p>
 * <p>
 * Usually, this class should be used like this.
 * </p>
 * <pre class="prettyprint">VCardComposer composer = null;
 * try {
 *     composer = new VCardComposer(context);
 *     composer.addHandler(
 *             composer.new HandlerForOutputStream(outputStream));
 *     if (!composer.init()) {
 *         // Do something handling the situation.
 *         return;
 *     }
 *     while (!composer.isAfterLast()) {
 *         if (mCanceled) {
 *             // Assume a user may cancel this operation during the export.
 *             return;
 *         }
 *         if (!composer.createOneEntry()) {
 *             // Do something handling the error situation.
 *             return;
 *         }
 *     }
 * } finally {
 *     if (composer != null) {
 *         composer.terminate();
 *     }
 * }</pre>
 * <p>
 * Users have to manually take care of memory efficiency. Even one vCard may contain
 * image of non-trivial size for mobile devices.
 * </p>
 * <p>
 * {@link VCardBuilder} is used to build each vCard.
 * </p>
 */
public class VCardComposer {
    private static final String LOG_TAG = "VCardComposer";
    private static final boolean DEBUG = false;

    public static final String FAILURE_REASON_FAILED_TO_GET_DATABASE_INFO =
        "Failed to get database information";

    public static final String FAILURE_REASON_NO_ENTRY =
        "There's no exportable in the database";

    public static final String FAILURE_REASON_NOT_INITIALIZED =
        "The vCard composer object is not correctly initialized";

    /** Should be visible only from developers... (no need to translate, hopefully) */
    public static final String FAILURE_REASON_UNSUPPORTED_URI =
        "The Uri vCard composer received is not supported by the composer.";

    public static final String NO_ERROR = "No error";

    // Strictly speaking, "Shift_JIS" is the most appropriate, but we use upper version here,
    // since usual vCard devices for Japanese devices already use it.
    private static final String SHIFT_JIS = "SHIFT_JIS";
    private static final String UTF_8 = "UTF-8";

    private static final Map<Integer, String> sImMap;

    static {
        sImMap = new HashMap<Integer, String>();
        sImMap.put(Im.PROTOCOL_AIM, VCardConstants.PROPERTY_X_AIM);
        sImMap.put(Im.PROTOCOL_MSN, VCardConstants.PROPERTY_X_MSN);
        sImMap.put(Im.PROTOCOL_YAHOO, VCardConstants.PROPERTY_X_YAHOO);
        sImMap.put(Im.PROTOCOL_ICQ, VCardConstants.PROPERTY_X_ICQ);
        sImMap.put(Im.PROTOCOL_JABBER, VCardConstants.PROPERTY_X_JABBER);
        sImMap.put(Im.PROTOCOL_SKYPE, VCardConstants.PROPERTY_X_SKYPE_USERNAME);
        // We don't add Google talk here since it has to be handled separately.
    }

    public static interface OneEntryHandler {
        public boolean onInit(Context context);
        public boolean onEntryCreated(String vcard);
        public void onTerminate();
    }

    /**
     * <p>
     * An useful handler for emitting vCard String to an OutputStream object one by one.
     * </p>
     * <p>
     * The input OutputStream object is closed() on {@link #onTerminate()}.
     * Must not close the stream outside this class.
     * </p>
     */
    public final class HandlerForOutputStream implements OneEntryHandler {
        private final OutputStream mOutputStream; // mWriter will close this.
        private Writer mWriter;

        /**
         * Input stream will be closed on the detruction of this object.
         */
        public HandlerForOutputStream(final OutputStream outputStream) {
            mOutputStream = outputStream;
        }

        @Override
        public boolean onInit(final Context context) {
            try {
                mWriter = new BufferedWriter(new OutputStreamWriter(
                        mOutputStream, mCharset));
            } catch (UnsupportedEncodingException e1) {
                Log.e(LOG_TAG, "Unsupported charset: " + mCharset);
                mErrorReason = "Encoding is not supported (usually this does not happen!): "
                        + mCharset;
                return false;
            }

            if (mIsDoCoMo) {
                try {
                    // Create one empty entry.
                    mWriter.write(createOneEntryInternal("-1", null));
                } catch (VCardException e) {
                    Log.e(LOG_TAG, "VCardException has been thrown during on Init(): " +
                            e.getMessage());
                    return false;
                } catch (IOException e) {
                    Log.e(LOG_TAG,
                            "IOException occurred during exportOneContactData: "
                                    + e.getMessage());
                    mErrorReason = "IOException occurred: " + e.getMessage();
                    return false;
                }
            }
            return true;
        }

        @Override
        public boolean onEntryCreated(String vcard) {
            try {
                mWriter.write(vcard);
            } catch (IOException e) {
                Log.e(LOG_TAG,
                        "IOException occurred during exportOneContactData: "
                                + e.getMessage());
                mErrorReason = "IOException occurred: " + e.getMessage();
                return false;
            }
            return true;
        }

        @Override
        public void onTerminate() {
            if (mWriter != null) {
                try {
                    mWriter.close();
                } catch (IOException e) {
                    Log.w(LOG_TAG, "IOException is thrown during close(). Ignored.", e);
                }
            }
        }
    }

    private final Context mContext;
    private final int mVCardType;
    private final boolean mCareHandlerErrors;
    private final ContentResolver mContentResolver;

    private final boolean mIsDoCoMo;
    private Cursor mCursor;
    private boolean mCursorSuppliedFromOutside;
    private int mIdColumn;
    private Uri mContentUriForRawContactsEntity = RawContactsEntity.CONTENT_URI;

    private final String mCharset;
    private final List<OneEntryHandler> mHandlerList;

    private boolean mInitDone;
    private String mErrorReason = NO_ERROR;

    /**
     * Set to false when one of {@link #init()} variants is called, and set to true when
     * {@link #terminate()} is called. Initially set to true.
     */
    private boolean mTerminateCalled = true;

    private static final String[] sContactsProjection = new String[] {
        Contacts._ID,
    };

    public VCardComposer(Context context) {
        this(context, VCardConfig.VCARD_TYPE_DEFAULT, null, true);
    }

    /**
     * The variant which sets charset to null and sets careHandlerErrors to true.
     */
    public VCardComposer(Context context, int vcardType) {
        this(context, vcardType, null, true);
    }

    public VCardComposer(Context context, int vcardType, String charset) {
        this(context, vcardType, charset, true);
    }

    /**
     * The variant which sets charset to null.
     */
    public VCardComposer(final Context context, final int vcardType,
            final boolean careHandlerErrors) {
        this(context, vcardType, null, careHandlerErrors);
    }

    /**
     * Constructs for supporting call log entry vCard composing.
     *
     * @param context Context to be used during the composition.
     * @param vcardType The type of vCard, typically available via {@link VCardConfig}.
     * @param charset The charset to be used. Use null when you don't need the charset.
     * @param careHandlerErrors If true, This object returns false everytime
     * a Handler object given via {{@link #addHandler(OneEntryHandler)} returns false.
     * If false, this ignores those errors.
     */
    public VCardComposer(final Context context, final int vcardType, String charset,
            final boolean careHandlerErrors) {
        this(context, context.getContentResolver(), vcardType, charset, careHandlerErrors);
    }

    /**
     * Just for testing for now.
     * @param resolver {@link ContentResolver} which used by this object.
     * @hide
     */
    public VCardComposer(final Context context, ContentResolver resolver,
            final int vcardType, String charset, final boolean careHandlerErrors) {
        mContext = context;
        mVCardType = vcardType;
        mCareHandlerErrors = careHandlerErrors;
        mContentResolver = resolver;

        mIsDoCoMo = VCardConfig.isDoCoMo(vcardType);
        mHandlerList = new ArrayList<OneEntryHandler>();

        charset = (TextUtils.isEmpty(charset) ? VCardConfig.DEFAULT_EXPORT_CHARSET : charset);
        final boolean shouldAppendCharsetParam = !(
                VCardConfig.isVersion30(vcardType) && UTF_8.equalsIgnoreCase(charset));

        if (mIsDoCoMo || shouldAppendCharsetParam) {
            // TODO: clean up once we're sure CharsetUtils are really unnecessary any more.
            if (SHIFT_JIS.equalsIgnoreCase(charset)) {
                /*if (mIsDoCoMo) {
                    try {
                        charset = CharsetUtils.charsetForVendor(SHIFT_JIS, "docomo").name();
                    } catch (UnsupportedCharsetException e) {
                        Log.e(LOG_TAG,
                                "DoCoMo-specific SHIFT_JIS was not found. "
                                + "Use SHIFT_JIS as is.");
                        charset = SHIFT_JIS;
                    }
                } else {
                    try {
                        charset = CharsetUtils.charsetForVendor(SHIFT_JIS).name();
                    } catch (UnsupportedCharsetException e) {
                        // Log.e(LOG_TAG,
                        // "Career-specific SHIFT_JIS was not found. "
                        // + "Use SHIFT_JIS as is.");
                        charset = SHIFT_JIS;
                    }
                }*/
                mCharset = charset;
            } else {
                /* Log.w(LOG_TAG,
                        "The charset \"" + charset + "\" is used while "
                        + SHIFT_JIS + " is needed to be used."); */
                if (TextUtils.isEmpty(charset)) {
                    mCharset = SHIFT_JIS;
                } else {
                    /*
                    try {
                        charset = CharsetUtils.charsetForVendor(charset).name();
                    } catch (UnsupportedCharsetException e) {
                        Log.i(LOG_TAG,
                                "Career-specific \"" + charset + "\" was not found (as usual). "
                                + "Use it as is.");
                    }*/
                    mCharset = charset;
                }
            }
        } else {
            if (TextUtils.isEmpty(charset)) {
                mCharset = UTF_8;
            } else {
                /*try {
                    charset = CharsetUtils.charsetForVendor(charset).name();
                } catch (UnsupportedCharsetException e) {
                    Log.i(LOG_TAG,
                            "Career-specific \"" + charset + "\" was not found (as usual). "
                            + "Use it as is.");
                }*/
                mCharset = charset;
            }
        }

        Log.d(LOG_TAG, "Use the charset \"" + mCharset + "\"");
    }

    /**
     * Must be called before {@link #init()}.
     */
    public void addHandler(OneEntryHandler handler) {
        if (handler != null) {
            mHandlerList.add(handler);
        }
    }

    /**
     * Initializes this object using default {@link Contacts#CONTENT_URI}.
     *
     * You can call this method or a variant of this method just once. In other words, you cannot
     * reuse this object.
     *
     * @return Returns true when initialization is successful and all the other
     *          methods are available. Returns false otherwise.
     */
    public boolean init() {
        return init(null, null);
    }

    /**
     * Special variant of init(), which accepts a Uri for obtaining {@link RawContactsEntity} from
     * {@link ContentResolver} with {@link Contacts#_ID}.
     * <code>
     * String selection = Data.CONTACT_ID + "=?";
     * String[] selectionArgs = new String[] {contactId};
     * Cursor cursor = mContentResolver.query(
     *         contentUriForRawContactsEntity, null, selection, selectionArgs, null)
     * </code>
     *
     * You can call this method or a variant of this method just once. In other words, you cannot
     * reuse this object.
     */
    public boolean initWithRawContactsEntityUri(Uri contentUriForRawContactsEntity) {
        mContentUriForRawContactsEntity = contentUriForRawContactsEntity;
        return init(null, null);
    }

    /**
     * Initializes this object using default {@link Contacts#CONTENT_URI} and given selection
     * arguments.
     */
    public boolean init(final String selection, final String[] selectionArgs) {
        return init(Contacts.CONTENT_URI, sContactsProjection, selection, selectionArgs, null);
    }

    /**
     * Note that this is unstable interface, may be deleted in the future.
     */
    public boolean init(final Uri contentUri, final String selection,
            final String[] selectionArgs, final String sortOrder) {
        return init(contentUri, sContactsProjection, selection, selectionArgs, sortOrder);
    }

    private boolean init(final Uri contentUri, final String[] projection,
            final String selection, final String[] selectionArgs, final String sortOrder) {
        if (!Contacts.CONTENT_URI.equals(contentUri)) {
            if (DEBUG) Log.d(LOG_TAG, "Unexpected contentUri: " + contentUri);
            mErrorReason = FAILURE_REASON_UNSUPPORTED_URI;
            return false;
        }
        if (!initInterFirstPart()) {
            return false;
        }
        if (!initInterCursorCreationPart(contentUri, projection, selection, selectionArgs,
                sortOrder)) {
            return false;
        }
        if (!initInterMainPart()) {
            return false;
        }
        return initInterLastPart();
    }

    /**
     * Just for testing for now. Do not use.
     * @hide
     */
    public boolean init(Cursor cursor) {
        if (!initInterFirstPart()) {
            return false;
        }
        mCursorSuppliedFromOutside = true;
        mCursor = cursor;
        if (!initInterMainPart()) {
            return false;
        }
        return initInterLastPart();
    }

    private boolean initInterFirstPart() {
        if (mInitDone) {
            Log.e(LOG_TAG, "init() is already called");
            return false;
        }

        if (mCareHandlerErrors) {
            final List<OneEntryHandler> finishedList = new ArrayList<OneEntryHandler>(
                    mHandlerList.size());
            for (OneEntryHandler handler : mHandlerList) {
                if (!handler.onInit(mContext)) {
                    if (DEBUG) {
                        Log.d(LOG_TAG,
                                String.format("One of OneEntryHandler (%s) return false on init.",
                                        handler.toString()));
                    }
                    for (OneEntryHandler finished : finishedList) {
                        finished.onTerminate();
                    }
                    return false;
                }
            }
        } else {
            // Just ignore the false returned from onInit().
            for (OneEntryHandler handler : mHandlerList) {
                handler.onInit(mContext);
            }
        }

        return true;
    }

    private boolean initInterCursorCreationPart(
            final Uri contentUri, final String[] projection,
            final String selection, final String[] selectionArgs, final String sortOrder) {
        mCursorSuppliedFromOutside = false;
        mCursor = mContentResolver.query(
                contentUri, projection, selection, selectionArgs, sortOrder);

        if (mCursor == null) {
            Log.e(LOG_TAG, String.format("Cursor became null unexpectedly"));
            mErrorReason = FAILURE_REASON_FAILED_TO_GET_DATABASE_INFO;
            return false;
        }
        return true;
    }

    private boolean initInterMainPart() {
        if (mCursor.getCount() == 0 || !mCursor.moveToFirst()) {
            if (DEBUG) {
                Log.d(LOG_TAG,
                    String.format("mCursor has an error (getCount: %d): ", mCursor.getCount()));
            }
            closeCursorIfAppropriate();
            return false;
        }
        mIdColumn = mCursor.getColumnIndex(Contacts._ID);
        return true;
    }

    private boolean initInterLastPart() {
        mInitDone = true;
        mTerminateCalled = false;
        return true;
    }

    public boolean createOneEntry() {
        return createOneEntry(null);
    }

    /**
     * @param getEntityIteratorMethod For Dependency Injection.
     * @hide just for testing.
     */
    public boolean createOneEntry(Method getEntityIteratorMethod) {
        if (!mInitDone) {
            mErrorReason = FAILURE_REASON_NOT_INITIALIZED;
            return false;
        }
        final String vcard;
        try {
            if (mIdColumn >= 0) {
                vcard = createOneEntryInternal(mCursor.getString(mIdColumn),
                        getEntityIteratorMethod);
            } else {
                Log.e(LOG_TAG, "Incorrect mIdColumn: " + mIdColumn);
                return true;
            }
        } catch (VCardException e) {
            Log.e(LOG_TAG, "VCardException has been thrown: " + e.getMessage());
            return false;
        } catch (OutOfMemoryError error) {
            // Maybe some data (e.g. photo) is too big to have in memory. But it
            // should be rare.
            Log.e(LOG_TAG, "OutOfMemoryError occured. Ignore the entry.");
            System.gc();
            // TODO: should tell users what happened?
            return true;
        } finally {
            mCursor.moveToNext();
        }

        // This function does not care the OutOfMemoryError on the handler side :-P
        if (mCareHandlerErrors) {
            List<OneEntryHandler> finishedList = new ArrayList<OneEntryHandler>(
                    mHandlerList.size());
            for (OneEntryHandler handler : mHandlerList) {
                if (!handler.onEntryCreated(vcard)) {
                    return false;
                }
            }
        } else {
            for (OneEntryHandler handler : mHandlerList) {
                handler.onEntryCreated(vcard);
            }
        }

        return true;
    }

    private String createOneEntryInternal(final String contactId,
            final Method getEntityIteratorMethod) throws VCardException {
        final Map<String, List<ContentValues>> contentValuesListMap =
                new HashMap<String, List<ContentValues>>();
        // The resolver may return the entity iterator with no data. It is possible.
        // e.g. If all the data in the contact of the given contact id are not exportable ones,
        //      they are hidden from the view of this method, though contact id itself exists.
        EntityIterator entityIterator = null;
        try {
            final Uri uri = mContentUriForRawContactsEntity;
            final String selection = Data.CONTACT_ID + "=?";
            final String[] selectionArgs = new String[] {contactId};
            if (getEntityIteratorMethod != null) {
                // Please note that this branch is executed by unit tests only
                try {
                    entityIterator = (EntityIterator)getEntityIteratorMethod.invoke(null,
                            mContentResolver, uri, selection, selectionArgs, null);
                } catch (IllegalArgumentException e) {
                    Log.e(LOG_TAG, "IllegalArgumentException has been thrown: " +
                            e.getMessage());
                } catch (IllegalAccessException e) {
                    Log.e(LOG_TAG, "IllegalAccessException has been thrown: " +
                            e.getMessage());
                } catch (InvocationTargetException e) {
                    Log.e(LOG_TAG, "InvocationTargetException has been thrown: ");
                    StackTraceElement[] stackTraceElements = e.getCause().getStackTrace();
                    for (StackTraceElement element : stackTraceElements) {
                        Log.e(LOG_TAG, "    at " + element.toString());
                    }
                    throw new VCardException("InvocationTargetException has been thrown: " +
                            e.getCause().getMessage());
                }
            } else {
                entityIterator = RawContacts.newEntityIterator(mContentResolver.query(
                        uri, null, selection, selectionArgs, null));
            }

            if (entityIterator == null) {
                Log.e(LOG_TAG, "EntityIterator is null");
                return "";
            }

            if (!entityIterator.hasNext()) {
                Log.w(LOG_TAG, "Data does not exist. contactId: " + contactId);
                return "";
            }

            while (entityIterator.hasNext()) {
                Entity entity = entityIterator.next();
                for (NamedContentValues namedContentValues : entity.getSubValues()) {
                    ContentValues contentValues = namedContentValues.values;
                    String key = contentValues.getAsString(Data.MIMETYPE);
                    if (key != null) {
                        List<ContentValues> contentValuesList =
                                contentValuesListMap.get(key);
                        if (contentValuesList == null) {
                            contentValuesList = new ArrayList<ContentValues>();
                            contentValuesListMap.put(key, contentValuesList);
                        }
                        contentValuesList.add(contentValues);
                    }
                }
            }
        } finally {
            if (entityIterator != null) {
                entityIterator.close();
            }
        }

        return buildVCard(contentValuesListMap);
    }

    /**
     * Builds and returns vCard using given map, whose key is CONTENT_ITEM_TYPE defined in
     * {ContactsContract}. Developers can override this method to customize the output.
     */
    public String buildVCard(final Map<String, List<ContentValues>> contentValuesListMap) {
        if (contentValuesListMap == null) {
            Log.e(LOG_TAG, "The given map is null. Ignore and return empty String");
            return "";
        } else {
            final VCardBuilder builder = new VCardBuilder(mVCardType, mCharset);
            builder.appendNameProperties(contentValuesListMap.get(StructuredName.CONTENT_ITEM_TYPE))
                    .appendNickNames(contentValuesListMap.get(Nickname.CONTENT_ITEM_TYPE))
                    .appendPhones(contentValuesListMap.get(Phone.CONTENT_ITEM_TYPE))
                    .appendEmails(contentValuesListMap.get(Email.CONTENT_ITEM_TYPE))
                    .appendPostals(contentValuesListMap.get(StructuredPostal.CONTENT_ITEM_TYPE))
                    .appendOrganizations(contentValuesListMap.get(Organization.CONTENT_ITEM_TYPE))
                    .appendWebsites(contentValuesListMap.get(Website.CONTENT_ITEM_TYPE));
            if ((mVCardType & VCardConfig.FLAG_REFRAIN_IMAGE_EXPORT) == 0) {
                builder.appendPhotos(contentValuesListMap.get(Photo.CONTENT_ITEM_TYPE));
            }
            builder.appendNotes(contentValuesListMap.get(Note.CONTENT_ITEM_TYPE))
                    .appendEvents(contentValuesListMap.get(Event.CONTENT_ITEM_TYPE))
                    .appendIms(contentValuesListMap.get(Im.CONTENT_ITEM_TYPE))
                    .appendSipAddresses(contentValuesListMap.get(SipAddress.CONTENT_ITEM_TYPE))
                    .appendRelation(contentValuesListMap.get(Relation.CONTENT_ITEM_TYPE));
            return builder.toString();
        }
    }

    public void terminate() {
        for (OneEntryHandler handler : mHandlerList) {
            handler.onTerminate();
        }

        closeCursorIfAppropriate();
        mTerminateCalled = true;
    }

    private void closeCursorIfAppropriate() {
        if (!mCursorSuppliedFromOutside && mCursor != null) {
            try {
                mCursor.close();
            } catch (SQLiteException e) {
                Log.e(LOG_TAG, "SQLiteException on Cursor#close(): " + e.getMessage());
            }
            mCursor = null;
        }
    }

    @Override
    protected void finalize() throws Throwable {
        try {
            if (!mTerminateCalled) {
                Log.e(LOG_TAG, "finalized() is called before terminate() being called");
            }
        } finally {
            super.finalize();
        }
    }

    /**
     * @return returns the number of available entities. The return value is undefined
     * when this object is not ready yet (typically when {{@link #init()} is not called
     * or when {@link #terminate()} is already called).
     */
    public int getCount() {
        if (mCursor == null) {
            Log.w(LOG_TAG, "This object is not ready yet.");
            return 0;
        }
        return mCursor.getCount();
    }

    /**
     * @return true when there's no entity to be built. The return value is undefined
     * when this object is not ready yet.
     */
    public boolean isAfterLast() {
        if (mCursor == null) {
            Log.w(LOG_TAG, "This object is not ready yet.");
            return false;
        }
        return mCursor.isAfterLast();
    }

    /**
     * @return Returns the error reason.
     */
    public String getErrorReason() {
        return mErrorReason;
    }
}