/*
*
* This file is part of QMapControl,
* an open-source cross-platform map widget
*
* Copyright (C) 2007 - 2008 Kai Winter
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with QMapControl. If not, see <http://www.gnu.org/licenses/>.
*
* Contact e-mail: kaiwinter@gmx.de
* Program URL   : http://qmapcontrol.sourceforge.net/
*
*/

#ifndef IMAGEMANAGER_H
#define IMAGEMANAGER_H

#include <QObject>
#include <QPixmapCache>
#include <QDebug>
#include <QMutex>
#include <QFile>
#include <QBuffer>
#include <QDir>
#include "mapnetwork.h"

namespace qmapcontrol
{
	class MapNetwork;
	/**
	@author Kai Winter <kaiwinter@gmx.de>
	 */
	class ImageManager : public QObject
	{
		Q_OBJECT;
		public:
			static ImageManager* instance()
			{
				if(!m_Instance)
				{
					m_Instance = new ImageManager;
				}
				return m_Instance;
			}
		
			~ImageManager();

		//! returns a QPixmap of the asked image
		/*!
			 * If this component doesn´t have the image a network query gets started to load it.
			 * @param host the host of the image
			 * @param path the path to the image
			 * @return the pixmap of the asked image
		 */
			QPixmap getImage(const QString& host, const QString& path);
		
			QPixmap prefetchImage(const QString& host, const QString& path);
		
			void receivedImage(const QPixmap pixmap, const QString& url);
		
		/*!
			 * This method is called by MapNetwork, after all images in its queue were loaded.
			 * The ImageManager emits a signal, which is used in MapControl to remove the zoom image.
			 * The zoom image should be removed on Tile Images with transparency.
			 * Else the zoom image stay visible behind the newly loaded tiles.
		 */
			void loadingQueueEmpty();
		
		/*!
			 * Aborts all current loading threads.
			 * This is useful when changing the zoom-factor, though newly needed images loads faster
		 */
			void abortLoading();
		
		//! sets the proxy for HTTP connections
		/*!
			 * This method sets the proxy for HTTP connections.
			 * This is not provided by the current Qtopia version!
			 * @param host the proxy´s hostname or ip
			 * @param port the proxy´s port
		 */
			void setProxy(QString host, int port);
				
		//! sets the cache directory for persistently saving map tiles
		/*!
			* 
			* @param path the path where map tiles should be stored
			* @todo add maximum size
		*/
			void setCacheDir(const QDir& path);

		private:
			ImageManager(QObject* parent = 0);
			ImageManager(const ImageManager&);
			ImageManager& operator=(const ImageManager&);
			QPixmap emptyPixmap;
			MapNetwork* net;
			QVector<QString> prefetch;
			QDir cacheDir;
			bool doPersistentCaching;
	
			static ImageManager* m_Instance;
			
			bool saveTile(QString tileName,QPixmap tileData);
			bool loadTile(QString tileName,QPixmap &tileData);
			bool tileExist(QString tileName);
		
		signals:
			void imageReceived();
			void loadingFinished();
	};
}
#endif
