javax.microedition.media.control.FramePositioningControl

{

    private ImageData[] iImagedata;

    /**

     * Constructor of this Control

     * This constructor should be accessible only in this package, that's why it is being

     * declared as package protected.

     */

    FramePositioningControl(Player aPlayer)

    {

        iPlayer=aPlayer;

        iImagedata=((AnimationPlayer)iPlayer).getImageData();

    }

    /**

     * Converts the given frame number to the corresponding media time.

     * The method only performs the calculations. It does not position the media to the given frame.

     */

    public long mapFrameToTime(int aFrameNumber)

    {

        checkState();

        long time=0;

        int totalNoOfFrames=iImagedata.length;

        // if invalid parameter is passed

        if (aFrameNumber<0 || aFrameNumber>totalNoOfFrames)

            return -1;

        for (int i=0; i<totalNoOfFrames; i++)

        {

            if (i==aFrameNumber)

                break;

            time+=iImagedata[i].delayTime;

        }

        return time*10000;

    }

    /**

     * Converts the given media time to the corresponding frame number.

     * The method only performs the calculations. It does not position the media to the given media time.

     * The frame returned is the nearest frame that has a media time less than or equal to the given media time.

     * mapTimeToFrame(0) must not fail and must return the frame number of the first frame.

     * @param the input media time for the conversion in microseconds.

     * @return the converted frame number for the given media time. If the conversion fails, -1 is returned.

     */

    public int mapTimeToFrame(long aMediaTime)

    {

        checkState();

        int frameNumber=-1;

        int totalNoOfFrames=iImagedata.length;

        long time=0;

        for (int i=0; i<totalNoOfFrames; i++)

        {

            if (time > aMediaTime)

            {

                frameNumber=i-1;

                break;

            }

            time+=iImagedata[i].delayTime*10000;

        }

        return frameNumber;

    }

    /**

     * Seek to a given video frame. The media time of the Player will be updated to reflect

     * the new position set.

     * This method can be called on a stopped or started Player. If the Player is in the Started state,

     * this method may cause the Player to change states. If that happens, the appropriate transition

     *  events will be posted by the Player when its state changes.

     * If the given frame number is less than the first or larger than the last frame number in the media,

     * seek will jump to either the first or the last frame respectively.

     * @param aFrameNumber the frame to seek to.

     * @return the actual number of frames skipped.

     */

    public int seek(int aFrameNumber)

    {

        final String DEBUG_STR = "FramePositionControl::seek";

        // Check the state of the player, it shouldn't be in closed state

        Logger.LOG(Logger.EJavaMMAPI, Logger.EInfo,DEBUG_STR + "+");

        checkState();

        int frameNumber = aFrameNumber;

        int totalNoOfFrames = iImagedata.length;

        if (aFrameNumber < 0)

        {

            frameNumber = 0;

        }

        else

        {

            if (aFrameNumber > totalNoOfFrames)

            {

                frameNumber = totalNoOfFrames;

            }

        }

        long mediaTime = mapFrameToTime(frameNumber);

        //if the frame number is equal to total number of frames, we will seek to last frame

        // because it's array index, so last index will be total length -1

        frameNumber=(frameNumber == totalNoOfFrames) ? (frameNumber-1) : frameNumber;

        try

        {

            long mediaTime1 = iPlayer.setMediaTime(mediaTime);

        }

        catch (MediaException e)

        {

            // Just ignore the exception

            e.printStackTrace();

        }

        Logger.LOG(Logger.EJavaMMAPI, Logger.EInfo,DEBUG_STR + "- seeked to "+frameNumber);

        return frameNumber;

    }

    /**

     *  Skip a given number of frames from the current position. The media time of the Player will be

     *  updated to reflect the new position set.

     *  This method can be called on a stopped or started Player. If the Player is in the Started state,

     *  the current position is changing. Hence, the frame actually skipped to will not be exact.

     *  If the Player is in the Started state, this method may cause the Player to change states.

     *  If that happens, the appropriate transition events will be posted.

     *  If the given framesToSkip will cause the position to extend beyond the first or last frame,

     *  skip will jump to the first or last frame respectively.

     *  @param framesToSkip - the number of frames to skip from the current position.

     *  If framesToSkip is positive, it will seek forward by framesToSkip number of frames.

     *  If framesToSkip is negative, it will seek backward by framesToSkip number of frames.

     *  e.g. skip(-1) will seek backward one frame.

     *

     *  @return the actual number of frames skipped.

     */

    public int skip(int aFramesToSkip)

    {

        final String DEBUG_STR = "FramePositionControl::skip";

        Logger.LOG(Logger.EJavaMMAPI, Logger.EInfo,DEBUG_STR+"+");

        // check the state of the player, if it closed throw exception

        checkState();

        int frameNumberToJump;

        if (aFramesToSkip < 0)

        {

            frameNumberToJump = 0;

        }

        // storing it in local variable, so that current frame index variable will be

        // consistent throughout this function, calling to getiFrameIndex(), each time

        // may return the different value.

        int currentFrameIndex=((AnimationPlayer) iPlayer).getiFrameIndex();

        // we are going to utilize the seek function here

        // just get the current frame index from player and

        // add it to the number of frame to skip

        frameNumberToJump = currentFrameIndex + aFramesToSkip;

        //if the frameNumberToJump > total no of frames, then skip to the last frame only

        frameNumberToJump =frameNumberToJump > iImagedata.length ? iImagedata.length-1 : frameNumberToJump;

        seek(frameNumberToJump);

        Logger.LOG(Logger.EJavaMMAPI, Logger.EInfo,DEBUG_STR+"-");

        return frameNumberToJump - currentFrameIndex;

    }