drm/java/android/drm/DrmManagerClient.java

/*
 * Copyright (C) 2010 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 android.drm;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteException;
import android.net.Uri;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.provider.MediaStore;
import android.util.Log;

import dalvik.system.CloseGuard;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.HashMap;

/**
 * The main programming interface for the DRM framework. An application must instantiate this class
 * to access DRM agents through the DRM framework.
 *
 */
public class DrmManagerClient {
    /**
     * Indicates that a request was successful or that no error occurred.
     */
    public static final int ERROR_NONE = 0;
    /**
     * Indicates that an error occurred and the reason is not known.
     */
    public static final int ERROR_UNKNOWN = -2000;

    /** {@hide} */
    public static final int INVALID_SESSION = -1;

    HandlerThread mInfoThread;
    HandlerThread mEventThread;
    private static final String TAG = "DrmManagerClient";

    private final CloseGuard mCloseGuard = CloseGuard.get();

    static {
        // Load the respective library
        System.loadLibrary("drmframework_jni");
    }

    /**
     * Interface definition for a callback that receives status messages and warnings
     * during registration and rights acquisition.
     */
    public interface OnInfoListener {
        /**
         * Called when the DRM framework sends status or warning information during registration
         * and rights acquisition.
         *
         * @param client The <code>DrmManagerClient</code> instance.
         * @param event The {@link DrmInfoEvent} instance that wraps the status information or 
         * warnings.
         */
        public void onInfo(DrmManagerClient client, DrmInfoEvent event);
    }

    /**
     * Interface definition for a callback that receives information
     * about DRM processing events.
     */
    public interface OnEventListener {
        /**
         * Called when the DRM framework sends information about a DRM processing request.
         *
         * @param client The <code>DrmManagerClient</code> instance.
         * @param event The {@link DrmEvent} instance that wraps the information being
         * conveyed, such as the information type and message.
         */
        public void onEvent(DrmManagerClient client, DrmEvent event);
    }

    /**
     * Interface definition for a callback that receives information about DRM framework errors.
     */
    public interface OnErrorListener {
        /**
         * Called when the DRM framework sends error information.
         *
         * @param client The <code>DrmManagerClient</code> instance.
         * @param event The {@link DrmErrorEvent} instance that wraps the error type and message.
         */
        public void onError(DrmManagerClient client, DrmErrorEvent event);
    }

    private static final int ACTION_REMOVE_ALL_RIGHTS = 1001;
    private static final int ACTION_PROCESS_DRM_INFO = 1002;

    private int mUniqueId;
    private long mNativeContext;
    private volatile boolean mReleased;
    private Context mContext;
    private InfoHandler mInfoHandler;
    private EventHandler mEventHandler;
    private OnInfoListener mOnInfoListener;
    private OnEventListener mOnEventListener;
    private OnErrorListener mOnErrorListener;

    private class EventHandler extends Handler {

        public EventHandler(Looper looper) {
            super(looper);
        }

        public void handleMessage(Message msg) {
            DrmEvent event = null;
            DrmErrorEvent error = null;
            HashMap<String, Object> attributes = new HashMap<String, Object>();

            switch(msg.what) {
            case ACTION_PROCESS_DRM_INFO: {
                final DrmInfo drmInfo = (DrmInfo) msg.obj;
                DrmInfoStatus status = _processDrmInfo(mUniqueId, drmInfo);

                attributes.put(DrmEvent.DRM_INFO_STATUS_OBJECT, status);
                attributes.put(DrmEvent.DRM_INFO_OBJECT, drmInfo);

                if (null != status && DrmInfoStatus.STATUS_OK == status.statusCode) {
                    event = new DrmEvent(mUniqueId,
                            getEventType(status.infoType), null, attributes);
                } else {
                    int infoType = (null != status) ? status.infoType : drmInfo.getInfoType();
                    error = new DrmErrorEvent(mUniqueId,
                            getErrorType(infoType), null, attributes);
                }
                break;
            }
            case ACTION_REMOVE_ALL_RIGHTS: {
                if (ERROR_NONE == _removeAllRights(mUniqueId)) {
                    event = new DrmEvent(mUniqueId, DrmEvent.TYPE_ALL_RIGHTS_REMOVED, null);
                } else {
                    error = new DrmErrorEvent(mUniqueId,
                            DrmErrorEvent.TYPE_REMOVE_ALL_RIGHTS_FAILED, null);
                }
                break;
            }
            default:
                Log.e(TAG, "Unknown message type " + msg.what);
                return;
            }
            if (null != mOnEventListener && null != event) {
                mOnEventListener.onEvent(DrmManagerClient.this, event);
            }
            if (null != mOnErrorListener && null != error) {
                mOnErrorListener.onError(DrmManagerClient.this, error);
            }
        }
    }

    /**
     * {@hide}
     */
    public static void notify(
            Object thisReference, int uniqueId, int infoType, String message) {
        DrmManagerClient instance = (DrmManagerClient)((WeakReference)thisReference).get();

        if (null != instance && null != instance.mInfoHandler) {
            Message m = instance.mInfoHandler.obtainMessage(
                InfoHandler.INFO_EVENT_TYPE, uniqueId, infoType, message);
            instance.mInfoHandler.sendMessage(m);
        }
    }

    private class InfoHandler extends Handler {
        public static final int INFO_EVENT_TYPE = 1;

        public InfoHandler(Looper looper) {
            super(looper);
        }

        public void handleMessage(Message msg) {
            DrmInfoEvent info = null;
            DrmErrorEvent error = null;

            switch (msg.what) {
            case InfoHandler.INFO_EVENT_TYPE:
                int uniqueId = msg.arg1;
                int infoType = msg.arg2;
                String message = msg.obj.toString();

                switch (infoType) {
                case DrmInfoEvent.TYPE_REMOVE_RIGHTS: {
                    try {
                        DrmUtils.removeFile(message);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    info = new DrmInfoEvent(uniqueId, infoType, message);
                    break;
                }
                case DrmInfoEvent.TYPE_ALREADY_REGISTERED_BY_ANOTHER_ACCOUNT:
                case DrmInfoEvent.TYPE_RIGHTS_INSTALLED:
                case DrmInfoEvent.TYPE_WAIT_FOR_RIGHTS:
                case DrmInfoEvent.TYPE_ACCOUNT_ALREADY_REGISTERED:
                case DrmInfoEvent.TYPE_RIGHTS_REMOVED: {
                    info = new DrmInfoEvent(uniqueId, infoType, message);
                    break;
                }
                default:
                    error = new DrmErrorEvent(uniqueId, infoType, message);
                    break;
                }

                if (null != mOnInfoListener && null != info) {
                    mOnInfoListener.onInfo(DrmManagerClient.this, info);
                }
                if (null != mOnErrorListener && null != error) {
                    mOnErrorListener.onError(DrmManagerClient.this, error);
                }
                return;
            default:
                Log.e(TAG, "Unknown message type " + msg.what);
                return;
            }
        }
    }

    /**
     * Creates a <code>DrmManagerClient</code>.
     *
     * @param context Context of the caller.
     */
    public DrmManagerClient(Context context) {
        mContext = context;
        createEventThreads();

        // save the unique id
        mUniqueId = _initialize();
        mCloseGuard.open("release");
    }

    @Override
    protected void finalize() throws Throwable {
        try {
            if (mCloseGuard != null) {
                mCloseGuard.warnIfOpen();
            }
            release();
        } finally {
            super.finalize();
        }
    }

    /**
     * Releases resources associated with the current session of DrmManagerClient.
     *
     * It is considered good practice to call this method when the {@link DrmManagerClient} object
     * is no longer needed in your application. After release() is called,
     * {@link DrmManagerClient} is no longer usable since it has lost all of its required resource.
     */
    public void release() {
        if (mReleased) return;
        mReleased = true;

        if (mEventHandler != null) {
            mEventThread.quit();
            mEventThread = null;
        }
        if (mInfoHandler != null) {
            mInfoThread.quit();
            mInfoThread = null;
        }
        mEventHandler = null;
        mInfoHandler = null;
        mOnEventListener = null;
        mOnInfoListener = null;
        mOnErrorListener = null;
        _release(mUniqueId);
        mCloseGuard.close();
    }

    /**
     * Registers an {@link DrmManagerClient.OnInfoListener} callback, which is invoked when the 
     * DRM framework sends status or warning information during registration or rights acquisition.
     *
     * @param infoListener Interface definition for the callback.
     */
    public synchronized void setOnInfoListener(OnInfoListener infoListener) {
        mOnInfoListener = infoListener;
        if (null != infoListener) {
            createListeners();
        }
    }

    /**
     * Registers an {@link DrmManagerClient.OnEventListener} callback, which is invoked when the 
     * DRM framework sends information about DRM processing.
     *
     * @param eventListener Interface definition for the callback.
     */
    public synchronized void setOnEventListener(OnEventListener eventListener) {
        mOnEventListener = eventListener;
        if (null != eventListener) {
            createListeners();
        }
    }

    /**
     * Registers an {@link DrmManagerClient.OnErrorListener} callback, which is invoked when 
     * the DRM framework sends error information.
     *
     * @param errorListener Interface definition for the callback.
     */
    public synchronized void setOnErrorListener(OnErrorListener errorListener) {
        mOnErrorListener = errorListener;
        if (null != errorListener) {
            createListeners();
        }
    }

    /**
     * Retrieves information about all the DRM plug-ins (agents) that are registered with
     * the DRM framework.
     *
     * @return A <code>String</code> array of DRM plug-in descriptions.
     */
    public String[] getAvailableDrmEngines() {
        DrmSupportInfo[] supportInfos = _getAllSupportInfo(mUniqueId);
        ArrayList<String> descriptions = new ArrayList<String>();

        for (int i = 0; i < supportInfos.length; i++) {
            descriptions.add(supportInfos[i].getDescriprition());
        }

        String[] drmEngines = new String[descriptions.size()];
        return descriptions.toArray(drmEngines);
    }

    /**
     * Retrieves constraint information for rights-protected content.
     *
     * @param path Path to the content from which you are retrieving DRM constraints.
     * @param action Action defined in {@link DrmStore.Action}.
     *
     * @return A {@link android.content.ContentValues} instance that contains
     * key-value pairs representing the constraints. Null in case of failure.
     * The keys are defined in {@link DrmStore.ConstraintsColumns}.
     */
    public ContentValues getConstraints(String path, int action) {
        if (null == path || path.equals("") || !DrmStore.Action.isValid(action)) {
            throw new IllegalArgumentException("Given usage or path is invalid/null");
        }
        return _getConstraints(mUniqueId, path, action);
    }

   /**
    * Retrieves metadata information for rights-protected content.
    *
    * @param path Path to the content from which you are retrieving metadata information.
    *
    * @return A {@link android.content.ContentValues} instance that contains
    * key-value pairs representing the metadata. Null in case of failure.
    */
    public ContentValues getMetadata(String path) {
        if (null == path || path.equals("")) {
            throw new IllegalArgumentException("Given path is invalid/null");
        }
        return _getMetadata(mUniqueId, path);
    }

    /**
     * Retrieves constraint information for rights-protected content.
     *
     * @param uri URI for the content from which you are retrieving DRM constraints.
     * @param action Action defined in {@link DrmStore.Action}.
     *
     * @return A {@link android.content.ContentValues} instance that contains
     * key-value pairs representing the constraints. Null in case of failure.
     */
    public ContentValues getConstraints(Uri uri, int action) {
        if (null == uri || Uri.EMPTY == uri) {
            throw new IllegalArgumentException("Uri should be non null");
        }
        return getConstraints(convertUriToPath(uri), action);
    }

   /**
    * Retrieves metadata information for rights-protected content.
    *
    * @param uri URI for the content from which you are retrieving metadata information.
    *
    * @return A {@link android.content.ContentValues} instance that contains
    * key-value pairs representing the constraints. Null in case of failure.
    */
    public ContentValues getMetadata(Uri uri) {
        if (null == uri || Uri.EMPTY == uri) {
            throw new IllegalArgumentException("Uri should be non null");
        }
        return getMetadata(convertUriToPath(uri));
    }

    /**
     * Saves rights to a specified path and associates that path with the content path.
     * 
     * <p class="note"><strong>Note:</strong> For OMA or WM-DRM, <code>rightsPath</code> and
     * <code>contentPath</code> can be null.</p>
     *
     * @param drmRights The {@link DrmRights} to be saved.
     * @param rightsPath File path where rights will be saved.
     * @param contentPath File path where content is saved.
     *
     * @return ERROR_NONE for success; ERROR_UNKNOWN for failure.
     *
     * @throws IOException If the call failed to save rights information at the given
     * <code>rightsPath</code>.
     */
    public int saveRights(
            DrmRights drmRights, String rightsPath, String contentPath) throws IOException {
        if (null == drmRights || !drmRights.isValid()) {
            throw new IllegalArgumentException("Given drmRights or contentPath is not valid");
        }
        if (null != rightsPath && !rightsPath.equals("")) {
            DrmUtils.writeToFile(rightsPath, drmRights.getData());
        }
        return _saveRights(mUniqueId, drmRights, rightsPath, contentPath);
    }

    /**
     * Installs a new DRM plug-in (agent) at runtime.
     *
     * @param engineFilePath File path to the plug-in file to be installed.
     *
     * {@hide}
     */
    public void installDrmEngine(String engineFilePath) {
        if (null == engineFilePath || engineFilePath.equals("")) {
            throw new IllegalArgumentException(
                "Given engineFilePath: "+ engineFilePath + "is not valid");
        }
        _installDrmEngine(mUniqueId, engineFilePath);
    }

    /**
     * Checks whether the given MIME type or path can be handled.
     *
     * @param path Path of the content to be handled.
     * @param mimeType MIME type of the object to be handled.
     *
     * @return True if the given MIME type or path can be handled; false if they cannot be handled.
     */
    public boolean canHandle(String path, String mimeType) {
        if ((null == path || path.equals("")) && (null == mimeType || mimeType.equals(""))) {
            throw new IllegalArgumentException("Path or the mimetype should be non null");
        }
        return _canHandle(mUniqueId, path, mimeType);
    }

    /**
     * Checks whether the given MIME type or URI can be handled.
     *
     * @param uri URI for the content to be handled.
     * @param mimeType MIME type of the object to be handled
     *
     * @return True if the given MIME type or URI can be handled; false if they cannot be handled.
     */
    public boolean canHandle(Uri uri, String mimeType) {
        if ((null == uri || Uri.EMPTY == uri) && (null == mimeType || mimeType.equals(""))) {
            throw new IllegalArgumentException("Uri or the mimetype should be non null");
        }
        return canHandle(convertUriToPath(uri), mimeType);
    }

    /**
     * Processes the given DRM information based on the information type.
     *
     * @param drmInfo The {@link DrmInfo} to be processed.
     * @return ERROR_NONE for success; ERROR_UNKNOWN for failure.
     */
    public int processDrmInfo(DrmInfo drmInfo) {
        if (null == drmInfo || !drmInfo.isValid()) {
            throw new IllegalArgumentException("Given drmInfo is invalid/null");
        }
        int result = ERROR_UNKNOWN;
        if (null != mEventHandler) {
            Message msg = mEventHandler.obtainMessage(ACTION_PROCESS_DRM_INFO, drmInfo);
            result = (mEventHandler.sendMessage(msg)) ? ERROR_NONE : result;
        }
        return result;
    }

    /**
     * Retrieves information for registering, unregistering, or acquiring rights.
     *
     * @param drmInfoRequest The {@link DrmInfoRequest} that specifies the type of DRM
     * information being retrieved.
     *
     * @return A {@link DrmInfo} instance.
     */
    public DrmInfo acquireDrmInfo(DrmInfoRequest drmInfoRequest) {
        if (null == drmInfoRequest || !drmInfoRequest.isValid()) {
            throw new IllegalArgumentException("Given drmInfoRequest is invalid/null");
        }
        return _acquireDrmInfo(mUniqueId, drmInfoRequest);
    }

    /**
     * Processes a given {@link DrmInfoRequest} and returns the rights information asynchronously.
     *<p>
     * This is a utility method that consists of an
     * {@link #acquireDrmInfo(DrmInfoRequest) acquireDrmInfo()} and a
     * {@link #processDrmInfo(DrmInfo) processDrmInfo()} method call. This utility method can be 
     * used only if the selected DRM plug-in (agent) supports this sequence of calls. Some DRM
     * agents, such as OMA, do not support this utility method, in which case an application must
     * invoke {@link #acquireDrmInfo(DrmInfoRequest) acquireDrmInfo()} and
     * {@link #processDrmInfo(DrmInfo) processDrmInfo()} separately.
     *
     * @param drmInfoRequest The {@link DrmInfoRequest} used to acquire the rights.
     * @return ERROR_NONE for success; ERROR_UNKNOWN for failure.
     */
    public int acquireRights(DrmInfoRequest drmInfoRequest) {
        DrmInfo drmInfo = acquireDrmInfo(drmInfoRequest);
        if (null == drmInfo) {
            return ERROR_UNKNOWN;
        }
        return processDrmInfo(drmInfo);
    }

    /**
     * Retrieves the type of rights-protected object (for example, content object, rights
     * object, and so on) using the specified path or MIME type. At least one parameter must
     * be specified to retrieve the DRM object type.
     *
     * @param path Path to the content or null.
     * @param mimeType MIME type of the content or null.
     * 
     * @return An <code>int</code> that corresponds to a {@link DrmStore.DrmObjectType}.
     */
    public int getDrmObjectType(String path, String mimeType) {
        if ((null == path || path.equals("")) && (null == mimeType || mimeType.equals(""))) {
            throw new IllegalArgumentException("Path or the mimetype should be non null");
        }
        return _getDrmObjectType(mUniqueId, path, mimeType);
    }

    /**
     * Retrieves the type of rights-protected object (for example, content object, rights
     * object, and so on) using the specified URI or MIME type. At least one parameter must
     * be specified to retrieve the DRM object type.
     *
     * @param uri URI for the content or null.
     * @param mimeType MIME type of the content or null.
     * 
     * @return An <code>int</code> that corresponds to a {@link DrmStore.DrmObjectType}.
     */
    public int getDrmObjectType(Uri uri, String mimeType) {
        if ((null == uri || Uri.EMPTY == uri) && (null == mimeType || mimeType.equals(""))) {
            throw new IllegalArgumentException("Uri or the mimetype should be non null");
        }
        String path = "";
        try {
            path = convertUriToPath(uri);
        } catch (Exception e) {
            // Even uri is invalid the mimetype shall be valid, so allow to proceed further.
            Log.w(TAG, "Given Uri could not be found in media store");
        }
        return getDrmObjectType(path, mimeType);
    }

    /**
     * Retrieves the MIME type embedded in the original content.
     *
     * @param path Path to the rights-protected content.
     *
     * @return The MIME type of the original content, such as <code>video/mpeg</code>.
     */
    public String getOriginalMimeType(String path) {
        if (null == path || path.equals("")) {
            throw new IllegalArgumentException("Given path should be non null");
        }

        String mime = null;

        FileInputStream is = null;
        try {
            FileDescriptor fd = null;
            File file = new File(path);
            if (file.exists()) {
                is = new FileInputStream(file);
                fd = is.getFD();
            }
            mime = _getOriginalMimeType(mUniqueId, path, fd);
        } catch (IOException ioe) {
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch(IOException e) {}
            }
        }

        return mime;
    }

    /**
     * Retrieves the MIME type embedded in the original content.
     *
     * @param uri URI of the rights-protected content.
     *
     * @return MIME type of the original content, such as <code>video/mpeg</code>.
     */
    public String getOriginalMimeType(Uri uri) {
        if (null == uri || Uri.EMPTY == uri) {
            throw new IllegalArgumentException("Given uri is not valid");
        }
        return getOriginalMimeType(convertUriToPath(uri));
    }

    /**
     * Checks whether the given content has valid rights.
     *
     * @param path Path to the rights-protected content.
     *
     * @return An <code>int</code> representing the {@link DrmStore.RightsStatus} of the content.
     */
    public int checkRightsStatus(String path) {
        return checkRightsStatus(path, DrmStore.Action.DEFAULT);
    }

    /**
     * Check whether the given content has valid rights.
     *
     * @param uri URI of the rights-protected content.
     *
     * @return An <code>int</code> representing the {@link DrmStore.RightsStatus} of the content.
     */
    public int checkRightsStatus(Uri uri) {
        if (null == uri || Uri.EMPTY == uri) {
            throw new IllegalArgumentException("Given uri is not valid");
        }
        return checkRightsStatus(convertUriToPath(uri));
    }

    /**
     * Checks whether the given rights-protected content has valid rights for the specified
     * {@link DrmStore.Action}.
     *
     * @param path Path to the rights-protected content.
     * @param action The {@link DrmStore.Action} to perform.
     *
     * @return An <code>int</code> representing the {@link DrmStore.RightsStatus} of the content.
     */
    public int checkRightsStatus(String path, int action) {
        if (null == path || path.equals("") || !DrmStore.Action.isValid(action)) {
            throw new IllegalArgumentException("Given path or action is not valid");
        }
        return _checkRightsStatus(mUniqueId, path, action);
    }

    /**
     * Checks whether the given rights-protected content has valid rights for the specified
     * {@link DrmStore.Action}.
     *
     * @param uri URI for the rights-protected content.
     * @param action The {@link DrmStore.Action} to perform.
     *
     * @return An <code>int</code> representing the {@link DrmStore.RightsStatus} of the content.
     */
    public int checkRightsStatus(Uri uri, int action) {
        if (null == uri || Uri.EMPTY == uri) {
            throw new IllegalArgumentException("Given uri is not valid");
        }
        return checkRightsStatus(convertUriToPath(uri), action);
    }

    /**
     * Removes the rights associated with the given rights-protected content.
     *
     * @param path Path to the rights-protected content.
     *
     * @return ERROR_NONE for success; ERROR_UNKNOWN for failure.
     */
    public int removeRights(String path) {
        if (null == path || path.equals("")) {
            throw new IllegalArgumentException("Given path should be non null");
        }
        return _removeRights(mUniqueId, path);
    }

    /**
     * Removes the rights associated with the given rights-protected content.
     *
     * @param uri URI for the rights-protected content.
     *
     * @return ERROR_NONE for success; ERROR_UNKNOWN for failure.
     */
    public int removeRights(Uri uri) {
        if (null == uri || Uri.EMPTY == uri) {
            throw new IllegalArgumentException("Given uri is not valid");
        }
        return removeRights(convertUriToPath(uri));
    }

    /**
     * Removes all the rights information of every DRM plug-in (agent) associated with
     * the DRM framework. Will be used during a master reset.
     *
     * @return ERROR_NONE for success; ERROR_UNKNOWN for failure.
     */
    public int removeAllRights() {
        int result = ERROR_UNKNOWN;
        if (null != mEventHandler) {
            Message msg = mEventHandler.obtainMessage(ACTION_REMOVE_ALL_RIGHTS);
            result = (mEventHandler.sendMessage(msg)) ? ERROR_NONE : result;
        }
        return result;
    }

    /**
     * Initiates a new conversion session. An application must initiate a conversion session
     * with this method each time it downloads a rights-protected file that needs to be converted.
     *<p>
     * This method applies only to forward-locking (copy protection) DRM schemes.
     *
     * @param mimeType MIME type of the input data packet.
     *
     * @return A convert ID that is used used to maintain the conversion session.
     */
    public int openConvertSession(String mimeType) {
        if (null == mimeType || mimeType.equals("")) {
            throw new IllegalArgumentException("Path or the mimeType should be non null");
        }
        return _openConvertSession(mUniqueId, mimeType);
    }

    /**
     * Converts the input data (content) that is part of a rights-protected file. The converted
     * data and status is returned in a {@link DrmConvertedStatus} object. This method should be
     * called each time there is a new block of data received by the application.
     *
     * @param convertId Handle for the conversion session.
     * @param inputData Input data that needs to be converted.
     *
     * @return A {@link DrmConvertedStatus} object that contains the status of the data conversion,
     * the converted data, and offset for the header and body signature. An application can 
     * ignore the offset because it is only relevant to the
     * {@link #closeConvertSession closeConvertSession()} method.
     */
    public DrmConvertedStatus convertData(int convertId, byte[] inputData) {
        if (null == inputData || 0 >= inputData.length) {
            throw new IllegalArgumentException("Given inputData should be non null");
        }
        return _convertData(mUniqueId, convertId, inputData);
    }

    /**
     * Informs the DRM plug-in (agent) that there is no more data to convert or that an error 
     * has occurred. Upon successful conversion of the data, the DRM agent will provide an offset
     * value indicating where the header and body signature should be added. Appending the 
     * signature is necessary to protect the integrity of the converted file.
     *
     * @param convertId Handle for the conversion session.
     *
     * @return A {@link DrmConvertedStatus} object that contains the status of the data conversion,
     * the converted data, and the offset for the header and body signature.
     */
    public DrmConvertedStatus closeConvertSession(int convertId) {
        return _closeConvertSession(mUniqueId, convertId);
    }

    private int getEventType(int infoType) {
        int eventType = -1;

        switch (infoType) {
        case DrmInfoRequest.TYPE_REGISTRATION_INFO:
        case DrmInfoRequest.TYPE_UNREGISTRATION_INFO:
        case DrmInfoRequest.TYPE_RIGHTS_ACQUISITION_INFO:
            eventType = DrmEvent.TYPE_DRM_INFO_PROCESSED;
            break;
        }
        return eventType;
    }

    private int getErrorType(int infoType) {
        int error = -1;

        switch (infoType) {
        case DrmInfoRequest.TYPE_REGISTRATION_INFO:
        case DrmInfoRequest.TYPE_UNREGISTRATION_INFO:
        case DrmInfoRequest.TYPE_RIGHTS_ACQUISITION_INFO:
            error = DrmErrorEvent.TYPE_PROCESS_DRM_INFO_FAILED;
            break;
        }
        return error;
    }

    /**
     * This method expects uri in the following format
     *     content://media/<table_name>/<row_index> (or)
     *     file://sdcard/test.mp4
     *     http://test.com/test.mp4
     *
     * Here <table_name> shall be "video" or "audio" or "images"
     * <row_index> the index of the content in given table
     */
    private String convertUriToPath(Uri uri) {
        String path = null;
        if (null != uri) {
            String scheme = uri.getScheme();
            if (null == scheme || scheme.equals("") ||
                    scheme.equals(ContentResolver.SCHEME_FILE)) {
                path = uri.getPath();

            } else if (scheme.equals("http")) {
                path = uri.toString();

            } else if (scheme.equals(ContentResolver.SCHEME_CONTENT)) {
                String[] projection = new String[] {MediaStore.MediaColumns.DATA};
                Cursor cursor = null;
                try {
                    cursor = mContext.getContentResolver().query(uri, projection, null,
                            null, null);
                    if (null == cursor || 0 == cursor.getCount() || !cursor.moveToFirst()) {
                        throw new IllegalArgumentException("Given Uri could not be found" +
                                " in media store");
                    }
                    int pathIndex = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
                    path = cursor.getString(pathIndex);
                } catch (SQLiteException e) {
                    throw new IllegalArgumentException("Given Uri is not formatted in a way " +
                            "so that it can be found in media store.");
                } finally {
                    if (null != cursor) {
                        cursor.close();
                    }
                }
            } else {
                throw new IllegalArgumentException("Given Uri scheme is not supported");
            }
        }
        return path;
    }

    // private native interfaces
    private native int _initialize();

    private native void _setListeners(int uniqueId, Object weak_this);

    private native void _release(int uniqueId);

    private native void _installDrmEngine(int uniqueId, String engineFilepath);

    private native ContentValues _getConstraints(int uniqueId, String path, int usage);

    private native ContentValues _getMetadata(int uniqueId, String path);

    private native boolean _canHandle(int uniqueId, String path, String mimeType);

    private native DrmInfoStatus _processDrmInfo(int uniqueId, DrmInfo drmInfo);

    private native DrmInfo _acquireDrmInfo(int uniqueId, DrmInfoRequest drmInfoRequest);

    private native int _saveRights(
            int uniqueId, DrmRights drmRights, String rightsPath, String contentPath);

    private native int _getDrmObjectType(int uniqueId, String path, String mimeType);

    private native String _getOriginalMimeType(int uniqueId, String path, FileDescriptor fd);

    private native int _checkRightsStatus(int uniqueId, String path, int action);

    private native int _removeRights(int uniqueId, String path);

    private native int _removeAllRights(int uniqueId);

    private native int _openConvertSession(int uniqueId, String mimeType);

    private native DrmConvertedStatus _convertData(
            int uniqueId, int convertId, byte[] inputData);

    private native DrmConvertedStatus _closeConvertSession(int uniqueId, int convertId);

    private native DrmSupportInfo[] _getAllSupportInfo(int uniqueId);

    private void createEventThreads() {
        if (mEventHandler == null && mInfoHandler == null) {
            mInfoThread = new HandlerThread("DrmManagerClient.InfoHandler");
            mInfoThread.start();
            mInfoHandler = new InfoHandler(mInfoThread.getLooper());

            mEventThread = new HandlerThread("DrmManagerClient.EventHandler");
            mEventThread.start();
            mEventHandler = new EventHandler(mEventThread.getLooper());
        }
    }

    private void createListeners() {
        _setListeners(mUniqueId, new WeakReference<DrmManagerClient>(this));
    }
}