/*
* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
* This component and the accompanying materials are made available
* under the terms of "Eclipse Public License v1.0"
* which accompanies this distribution, and is available
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description: FramePositioningControl
*
*/
package com.nokia.microedition.media.animation;

import javax.microedition.media.MediaException;
import javax.microedition.media.Player;

import org.eclipse.swt.graphics.ImageData;

import com.nokia.microedition.media.control.ControlImpl;
import com.nokia.mj.impl.utils.Logger;


public class FramePositioningControl extends ControlImpl implements
		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;
	}

}