source: trunk/src/org/expeditee/core/Image.java@ 1097

package org.expeditee.core;

import java.io.File;
import java.io.IOException;
import java.io.Serializable;
import java.net.HttpURLConnection;
import java.net.URL;

import org.expeditee.core.bounds.AxisAlignedBoxBounds;
import org.expeditee.gio.ImageManager;

import com.sun.pdfview.PDFPage;

/**
 * A handle to an internal-type image maintained by the ImageManager.
 * 
 * @author cts16
 */
public class Image implements Serializable {

        /** Auto-generated serialisation ID#; */
        private static final long serialVersionUID = -5716308599893528323L;
        
        /** Integer representing an invalid size for width or height. */
        public static final int INVALID_SIZE = -1;

        /** The ImageManager used to perform platform-specific image interactions. */
        private static ImageManager _manager = null;
        
        /** Sets the platform-specific ImageManager for all images. Can only be set once. */
        public static void setManager(ImageManager manager)
        {
                if (_manager == null) _manager = manager;
        }
        
        /** Gets a reference to the designated platform-specific image manager. */
        public static ImageManager getManager()
        {
                return _manager;
        }
        
        /** The handle ID# to use for the next-created image. */
        private static long nextHandle = 1;
        
        /** The handle ID# for this image. */
        private long _handle;
        
        /** Whether this image has a corresponding file on disk */
        private boolean _isStoredOnDisk;
        
        /** Whether or not this image is animated (e.g. a GIF). */
        private boolean _animated = false;
        
        /** The width of this image. */
        private int _width = INVALID_SIZE;
        /** The height of this image. */
        private int _height = INVALID_SIZE;
        
        /**
         * Controls creation of image handles. Will only return null until an ImageManager is provided
         * with Image.setManager(ImageManager). This should only be used by the ImageManager to
         * create a handle to associate with a real internal image. Handles created by anyone else
         * will not be accepted by the image manager.
         */
        public static Image get(boolean fromDisk)
        {
                // Return null until an image manager is available
                if (_manager == null) return null;
                
                return new Image(fromDisk);
        }
        
        /** Private constructor as instantiation handled through Image.get(boolean). */
        private Image(boolean fromDisk)
        {
                // Assign the next available handle ID number
                _handle = nextHandle;
                nextHandle++;
                
                // Remember if this image is stored on disk or not
                _isStoredOnDisk = fromDisk;
        }
        
        /** Returns the ID# for this handle. */
        public long getHandle()
        {
                return _handle;
        }
        
        /** Returns whether or not this image is stored on disk. */
        public boolean isStoredOnDisk()
        {
                return _isStoredOnDisk;
        }
        
        /** Sets the animated property of this image. */
        public void setIsAnimated(boolean isAnimated)
        {
                _animated = isAnimated;
        }
        
        /** Returns whether this image is animated. */
        public boolean isAnimated()
        {
                return _animated;
        }
        
        /** Convenience access to ImageManager.createImage(Dimension). */
        public static Image createImage(Dimension size)
        {
                return _manager.createImage(size);
        }
        
        /** Convenience access to ImageManager.createImage(int, int). */
        public static Image createImage(int width, int height)
        {
                return _manager.createImage(width, height);
        }
        
        /** Convenience access to ImageManager.createImage(Dimension, boolean). */
        public static Image createImage(Dimension size, boolean hintUseAcceleratedMemory)
        {
                return _manager.createImage(size, hintUseAcceleratedMemory);
        }
        
        /** Convenience access to ImageManager.createImage(int, int, boolean). */
        public static Image createImage(int width, int height, boolean hintUseAcceleratedMemory)
        {
                return _manager.createImage(width, height, hintUseAcceleratedMemory);
        }
        /** Convenience access to ImageManager.createImage(int, int, int[]). */
        public static Image createImage(int width, int height, int[] pixelData)
        {
                return _manager.createImage(width, height, pixelData);
        }
        
        /** Convenience access to ImageManager.createImage(int, int, PDFPage). */
        public static Image createImage(int width, int height, PDFPage page)
        {
                return _manager.createImage(width, height, page);
        }
        
        /** Convenience access to ImageManager.createImageAsCroppedCopy(Image, int, int, int, int). */
        public static Image createImageAsCroppedCopy(Image orig, int x, int y, int width, int height)
        {
                return _manager.createImageAsCroppedCopy(orig, x,  y, width, height);
        }
        
        /** Convenience access to ImageManager.getImage(URL). */
        public static Image getImage(URL url)
        {
                return _manager.getImage(url);
        }

        /** Convenience access to ImageManager.getImage(String). */
        public static Image getImage(String filename)
        {
                return _manager.getImage(filename);
        }

        /** Convenience access to ImageManager.getImage(HttpURLConnection). */
        public static Image getImage(HttpURLConnection connection) throws IOException
        {
                return _manager.getImage(connection);
        }

        /** Convenience access to ImageManager.releaseImage(Image). */
        public void releaseImage()
        {
                _manager.releaseImage(this);
        }

        /** Convenience access to ImageManager.isImageValid(Image). */
        public boolean isValid()
        {
                return _manager.isImageValid(this);
        }
        
        /** Gets the width of this image. */
        public int getWidth()
        {
                // Cache the width of the image if its isn't already 
                if (_width == INVALID_SIZE) _width = _manager.getWidth(this);
                
                return _width;
        }
        
        /** Gets the height of this image. */
        public int getHeight()
        {
                // Cache the height of the image if its isn't already 
                if (_height == INVALID_SIZE) _height = _manager.getHeight(this);
                
                return _height;
        }
        
        /** Gets the size of this image. */
        public Dimension getSize()
        {
                return new Dimension(getWidth(), getHeight());
        }
        
        /** Convenience access to ImageManager.getPixel(Image, int, int). */
        public Colour getPixel(int x, int y)
        {
                return _manager.getPixel(this, x, y);
        }

        /** Convenience access to ImageManager.setPixel(Image, int, int, Colour). */
        public void setPixel(int x, int y, Colour c)
        {
                _manager.setPixel(this, x, y, c);
        }

        /** Convenience access to ImageManager.writeToDisk(Image, String, File). */
        public boolean writeToDisk(String format, File file) throws IOException
        {
                return _manager.writeImageToDisk(this, format, file);
        }
        
        /** Returns the bounds of this image. */
        public AxisAlignedBoxBounds getBounds()
        {
                return new AxisAlignedBoxBounds(0, 0, getWidth(), getHeight());
        }
        
        @Override
        protected void finalize()
        {
                // Tell the image manager that nobody's using this image anymore
                releaseImage();
        }
}