Subversion Repositories SmartDukaan

/**

 * Copyright 2010-present Facebook.

 *

 * 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.facebook;

import android.content.ContentProvider;

import android.content.ContentValues;

import android.database.Cursor;

import android.net.Uri;

import android.os.ParcelFileDescriptor;

import android.util.Log;

import android.util.Pair;

import java.io.File;

import java.io.FileNotFoundException;

import java.util.UUID;

/**

 * <p>Implements a <a href="http://developer.android.com/reference/android/content/ContentProvider.html">

 * ContentProvider</a> that can be used to provide binary attachments (e.g., images) to calls made

 * via @link FacebookDialog}. The {@link NativeAppCallAttachmentStore} class provides methods to attach

 * and clean up the attachments.

 *

 * <p>Note that this ContentProvider is only necessary if an application wishes to attach images, etc., that are

 * stored in memory and do not have another way to be referenced by a content URI. For images obtained from,

 * e.g., the Camera or Gallery, that already have a content URI associated with them, use of this class is not

 * necessary.</p>

 *

 * <p>If an application wishes to attach images that are stored in-memory within the application, this content

 * provider must be listed in the application's AndroidManifest.xml, and it should be named according to the

 * pattern <code>"com.facebook.app.NativeAppCallContentProvider{FACEBOOK_APP_ID}"</code>. See the

 * {@link NativeAppCallContentProvider#getAttachmentUrl(String) getContentProviderName} method.</p>

 */

public class NativeAppCallContentProvider extends ContentProvider {

    private static final String TAG = NativeAppCallContentProvider.class.getName();

    private static final String ATTACHMENT_URL_BASE = "content://com.facebook.app.NativeAppCallContentProvider";

    private final AttachmentDataSource dataSource;

    public NativeAppCallContentProvider() {

        this(new NativeAppCallAttachmentStore());

    }

    NativeAppCallContentProvider(AttachmentDataSource dataSource) {

        this.dataSource = dataSource;

    }

    interface AttachmentDataSource {

        File openAttachment(UUID callId, String attachmentName) throws FileNotFoundException;

    }

    /**

     * Returns the name of the content provider formatted correctly for constructing URLs.

     * @param applicationId the Facebook application ID of the application

     * @return the String to use as the authority portion of a content URI.

     */

    public static String getAttachmentUrl(String applicationId, UUID callId, String attachmentName) {

        return String.format("%s%s/%s/%s", ATTACHMENT_URL_BASE, applicationId, callId.toString(), attachmentName);

    }

    @Override

    public boolean onCreate() {

        return true;

    }

    @Override

    public Cursor query(Uri uri, String[] strings, String s, String[] strings2, String s2) {

        return null;

    }

    @Override

    public String getType(Uri uri) {

        return null;

    }

    @Override

    public Uri insert(Uri uri, ContentValues contentValues) {

        return null;

    }

    @Override

    public int delete(Uri uri, String s, String[] strings) {

        return 0;

    }

    @Override

    public int update(Uri uri, ContentValues contentValues, String s, String[] strings) {

        return 0;

    }

    @Override

    public android.os.ParcelFileDescriptor openFile(android.net.Uri uri, java.lang.String mode)

            throws java.io.FileNotFoundException {

        Pair<UUID, String> callIdAndAttachmentName = parseCallIdAndAttachmentName(uri);

        if (callIdAndAttachmentName == null) {

            throw new FileNotFoundException();

        }

        try {

            File file = dataSource.openAttachment(callIdAndAttachmentName.first, callIdAndAttachmentName.second);

            return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);

        } catch (FileNotFoundException exception) {

            Log.e(TAG, "Got unexpected exception:" + exception);

            throw exception;

        }

    }

    Pair<UUID, String> parseCallIdAndAttachmentName(Uri uri) {

        try {

            // We don't do explicit format checking here. Malformed URIs may generate NullPointerExceptions or

            // array bounds exceptions, which we'll catch and return null. All of these will result in a

            // FileNotFoundException being thrown in openFile.

            String callIdAndAttachmentName = uri.getPath().substring(1);

            String [] parts = callIdAndAttachmentName.split("/");

            String callIdString = parts[0];

            String attachmentName = parts[1];

            UUID callId = UUID.fromString(callIdString);

            return new Pair<UUID, String>(callId, attachmentName);

        } catch (Exception exception) {

            return null;

        }

    }

}