/* QtImage.java --
   Copyright (C)  2005, 2006  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath 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
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */

package gnu.java.awt.peer.qt;

import java.awt.Graphics;
import java.awt.Color;
import java.awt.Image;
import java.awt.image.ColorModel;
import java.awt.image.DirectColorModel;
import java.awt.image.MemoryImageSource;
import java.awt.image.ImageObserver;
import java.awt.image.ImageProducer;
import java.io.File;
import java.io.IOException;
import java.io.ByteArrayOutputStream;
import java.io.BufferedInputStream;
import java.net.URL;
import java.util.Hashtable;
import java.util.WeakHashMap;
import java.util.Vector;

/**
 * QtImage - wraps a QImage
 *
 */
public class QtImage extends Image
{
  int width = -1, height = -1;

  /**
   * Properties.
   */
  Hashtable props;

  /**
   * Loaded or not flag, for asynchronous compatibility.
   */
  boolean isLoaded;

  /**
   * Pointer to the QImage
   */
  long nativeObject;

  /**
   * Observer queue.
   */
  Vector observers;

  /**
   * Error flag for loading.
   */
  boolean errorLoading;

  /**
   * Original source, if created from an ImageProducer.
   */
  ImageProducer source;

  /*
   * The 32-bit AARRGGBB format the  uses.
   */
  static ColorModel nativeModel = new DirectColorModel(32, 
						       0x00FF0000,
						       0x0000FF00,
						       0x000000FF,
						       0xFF000000);
  /**
   * HashMap of Graphics objects painting on this Image.
   */
  WeakHashMap painters;

  /**
   * Flags if this image is to be destroyed.
   */
  boolean killFlag;

  /**
   * Clears the image to RGBA 0
   */
  public native void clear();

  /**
   * Returns a copy of the pixel data as a java array.
   */
  private native int[] getPixels();

  /**
   * Sets the pixel data from a java array.
   */
  private native void setPixels(int[] pixels);

  /**
   * Loads an image 
   */
  private native boolean loadImage(String name);

  /**
   * Loads an image from data.
   */
  private native boolean loadImageFromData(byte[] data);

  /**
   * Allocates a QImage
   */
  private native void createImage();

  /**
   * Frees the above.
   */
  private synchronized native void freeImage();

  /**
   * Sets the image to scaled copy of src image. hints are rendering hints.
   */
  private native void createScaledImage(QtImage src, int hints);

  /**
   * Draws the image optionally composited.
   */
  native void drawPixels (QtGraphics gc, 
			  int bg_red, int bg_green, int bg_blue, 
			  int x, int y, 
			  boolean composite);
  /**
   * Draws the image, optionally scaled and composited.
   */
  private native void drawPixelsScaled (QtGraphics gc, 
					int bg_red, int bg_green, int bg_blue, 
					int x, int y, int width, int height, 
					boolean composite);

  /**
   * Draws the image transformed.
   */
  private native void drawPixelsTransformed (QtGraphics gc, QMatrix transform);
  
  /**
   * Draws the image scaled flipped and optionally composited.
   */
  native void drawPixelsScaledFlipped (QtGraphics gc, 
				       int bg_red, int bg_green, 
				       int bg_blue, 
				       boolean flipX, boolean flipY,
				       int srcX, int srcY,
				       int srcWidth, int srcHeight,
				       int dstX, int dstY,
				       int dstWidth, int dstHeight,
				       boolean composite);

  /**
   * Creates the image from an ImageProducer. May result in an error image.
   */
  public QtImage (ImageProducer producer)
  {
    killFlag = false;
    isLoaded = false;
    observers = new Vector();
    source = producer;
    errorLoading = false;
    if( producer != null )
      source.startProduction(new QtImageConsumer(this, source));
  }

  /**
   * Creates the image from a URL. May result in an error image.
   */
  public QtImage (URL url)
  {
    killFlag = false;
    isLoaded = false;
    observers = new Vector();
    errorLoading = false;
    if( url == null)
      return;
    ByteArrayOutputStream baos = new ByteArrayOutputStream( 5000 );
    try
      {
        BufferedInputStream bis = new BufferedInputStream(url.openStream());

        byte[] buf = new byte[5000];
        int n = 0;

        while ( (n = bis.read( buf )) != -1 ) 
	  baos.write(buf, 0, n); 
        bis.close();
      }
    catch(IOException e)
      {
	throw new IllegalArgumentException("Couldn't load image.");
      }
    if ( loadImageFromData( baos.toByteArray() ) != true )
      throw new IllegalArgumentException("Couldn't load image.");

    isLoaded = true;
    observers = null;
    props = new Hashtable();
  }

  /**
   * Constructs a QtImage by loading a given file.
   *
   * @throws IllegalArgumentException if the image could not be loaded.
   */
  public QtImage (String filename)
  {
    killFlag = false;
    File f = new File(filename);
    observers = null;
    props = new Hashtable();
    try
      {
	String fn = f.getCanonicalPath();
	if (loadImage( fn ) != true)
	  {
	    errorLoading = true;
	    isLoaded = false;
	    return;
	  }
      } 
    catch(IOException e)
      {
	errorLoading = true;
	isLoaded = false;
	return;
      }
    errorLoading = false;
    isLoaded = true;
  }

  /**
   * Constructs a QtImage from a byte array of an image file.
   *
   * @throws IllegalArgumentException if the image could not be loaded.
   */
  public QtImage (byte[] data)
  {
    if (loadImageFromData(data) != true)
      throw new IllegalArgumentException("Couldn't load image.");

    killFlag = false;
    isLoaded = true;
    observers = null;
    errorLoading = false;
    props = new Hashtable();
  }

  /**
   * Constructs an empty QtImage.
   */
  public QtImage (int width, int height)
  {
    this.width = width;
    this.height = height;
    props = new Hashtable();
    isLoaded = true;
    killFlag = false;
    observers = null;
    errorLoading = false;
    createImage();
    clear();
  }

  /**
   * Constructs a scaled version of the src bitmap, using Qt
   */
  private QtImage (QtImage src, int width, int height, int hints)
  {
    this.width = width;
    this.height = height;
    props = new Hashtable();
    isLoaded = true;
    killFlag = false;
    observers = null;
    errorLoading = false;

    createScaledImage(src, hints);
  }

  /**
   * Callback from the image consumer.
   */
  public void setImage(int width, int height, 
		       int[] pixels, Hashtable properties)
  {
    this.width = width;
    this.height = height;
    props = (properties != null) ? properties : new Hashtable();

    if (width <= 0 || height <= 0 || pixels == null)
      {
	errorLoading = true;
	return;
      }

    isLoaded = true;
    deliver();
    createImage();
    setPixels(pixels);
  }

  // java.awt.Image methods ////////////////////////////////////////////////

  public int getWidth (ImageObserver observer)
  {
    if (addObserver(observer))
      return -1;

    return width;
  }
  
  public int getHeight (ImageObserver observer)
  {
    if (addObserver(observer))
      return -1;
    
    return height;
  }

  public Object getProperty (String name, ImageObserver observer)
  {
    if (addObserver(observer))
      return UndefinedProperty;
    
    Object value = props.get (name);
    return (value == null) ? UndefinedProperty : value;
  }

  /**
   * Returns the source of this image.
   */
  public ImageProducer getSource ()
  {
    if (!isLoaded)
      return null;
    return new MemoryImageSource(width, height, nativeModel, getPixels(), 
				 0, width);
  }

  void putPainter(QtImageGraphics g)
  {
    if( painters == null )
      painters = new WeakHashMap();
    painters.put( g, "dummy" );
  }

  void removePainter(QtImageGraphics g)
  {
    painters.remove( g );
    if( killFlag && painters.isEmpty() )
      freeImage();
  }

  /**
   * Creates a Graphics context for this image.
   */
  public Graphics getGraphics ()
  {
    if (!isLoaded || killFlag) 
      return null;

    return new QtImageGraphics(this);
  }

  /**
   * Creates a Graphics context for this image.
   */
  Graphics getDirectGraphics(QtComponentPeer peer)
  {
    if (!isLoaded) 
      return null;

    return new QtImageDirectGraphics(this, peer);
  }
  
  /**
   * Returns a scaled instance of this image.
   */
  public Image getScaledInstance(int width,
				 int height,
				 int hints)
  {
    if (width <= 0 || height <= 0)
      throw new IllegalArgumentException("Width and height of scaled bitmap"+
					 "must be >= 0");

    return new QtImage(this, width, height, hints);
  }

  /**
   * If the image is loaded and comes from an ImageProducer, 
   * regenerate the image from there.
   *
   * I have no idea if this is ever actually used. Since QtImage can't be
   * instantiated directly, how is the user to know if it was created from
   * an ImageProducer or not?
   */
  public synchronized void flush ()
  {
    if (isLoaded && source != null)
      {
	observers = new Vector();
	isLoaded = false;
	freeImage();
	source.startProduction(new QtImageConsumer(this, source));
      }
  }

  public void finalize()
  {
    dispose();
  }

  public void dispose()
  {
    if (isLoaded)
      {
	if( painters == null || painters.isEmpty() )
	  freeImage();
	else
	  killFlag = true; // can't destroy image yet. 
	// Do so when all painters are gone.
      }
  }

  /**
   * Returns the image status, used by QtToolkit
   */
  public int checkImage (ImageObserver observer)
  {
    if (addObserver(observer))
      {
	if (errorLoading == true)
	  return ImageObserver.ERROR;
	else
	  return 0;
      }
    
    return ImageObserver.ALLBITS | ImageObserver.WIDTH | ImageObserver.HEIGHT;
  }

  // Drawing methods ////////////////////////////////////////////////

  /**
   * Draws an image with eventual scaling/transforming.
   */
  public boolean drawImage (QtGraphics g, QMatrix matrix,
			    ImageObserver observer)
  {
    if (addObserver(observer))
      return false;

    drawPixelsTransformed (g, matrix);

    return true;
  }

  /**
   * Draws an image to the QtGraphics context, at (x,y) with optional
   * compositing with a background color.
   */
  public boolean drawImage (QtGraphics g, int x, int y,
			    Color bgcolor, ImageObserver observer)
  {
    if (addObserver(observer))
      return false;

    if(bgcolor != null)
      drawPixels(g, bgcolor.getRed (), bgcolor.getGreen (), 
		       bgcolor.getBlue (), x, y, true);
    else
      drawPixels(g, 0, 0, 0, x, y, false);

    return true;
  }

  /**
   * Draws an image to the QtGraphics context, at (x,y) scaled to 
   * width and height, with optional compositing with a background color.
   */
  public boolean drawImage (QtGraphics g, int x, int y, int width, int height,
			    Color bgcolor, ImageObserver observer)
  {
    if (addObserver(observer))
      return false;

    if(bgcolor != null)
      drawPixelsScaled(g, bgcolor.getRed (), bgcolor.getGreen (), 
		       bgcolor.getBlue (), x, y, width, height, true);
    else
      drawPixelsScaled(g, 0, 0, 0, x, y, width, height, false);

    return true;
  }

  /**
   * Draws an image with eventual scaling/transforming.
   */
  public boolean drawImage (QtGraphics g, int dx1, int dy1, int dx2, int dy2, 
			    int sx1, int sy1, int sx2, int sy2, 
			    Color bgcolor, ImageObserver observer)
  {
    if (addObserver(observer))
      return false;

    boolean flipX = (dx1 > dx2)^(sx1 > sx2);
    boolean flipY = (dy1 > dy2)^(sy1 > sy2);
    int dstWidth = Math.abs (dx2 - dx1);
    int dstHeight = Math.abs (dy2 - dy1);
    int srcWidth = Math.abs (sx2 - sx1);
    int srcHeight = Math.abs (sy2 - sy1);
    int srcX = (sx1 < sx2) ? sx1 : sx2;
    int srcY = (sy1 < sy2) ? sy1 : sy2;
    int dstX = (dx1 < dx2) ? dx1 : dx2;
    int dstY = (dy1 < dy2) ? dy1 : dy2;

    // Clipping. This requires the dst to be scaled as well, 
    if (srcWidth > width)
      {
	dstWidth = (int)((double)dstWidth*((double)width/(double)srcWidth));
	srcWidth = width - srcX;
      }

    if (srcHeight > height) 
      {
	dstHeight = (int)((double)dstHeight*((double)height/(double)srcHeight));
	srcHeight = height - srcY;
      }

    if (srcWidth + srcX > width)
      {
	dstWidth = (int)((double)dstWidth * (double)(width - srcX)/(double)srcWidth);
	srcWidth = width - srcX;
      }

    if (srcHeight + srcY > height)
      {
	dstHeight = (int)((double)dstHeight * (double)(width - srcY)/(double)srcHeight);
	srcHeight = height - srcY;
      }

    if ( srcWidth <= 0 || srcHeight <= 0 || dstWidth <= 0 || dstHeight <= 0)
      return true;

    if(bgcolor != null)
      drawPixelsScaledFlipped (g, bgcolor.getRed (), bgcolor.getGreen (), 
			       bgcolor.getBlue (), 
			       flipX, flipY,
			       srcX, srcY,
			       srcWidth, srcHeight,
			       dstX,  dstY,
			       dstWidth, dstHeight,
			       true);
    else
      drawPixelsScaledFlipped (g, 0, 0, 0, flipX, flipY,
			       srcX, srcY, srcWidth, srcHeight,
			       dstX,  dstY, dstWidth, dstHeight,
			       false);
    return true;
  }

  public native void copyArea(int x, int y, int width, int height, 
			      int dx, int dy);

  // Private methods ////////////////////////////////////////////////

  /**
   * Delivers notifications to all queued observers.
   */
  private void deliver()
  {
    int flags = ImageObserver.HEIGHT | 
      ImageObserver.WIDTH |
      ImageObserver.PROPERTIES |
      ImageObserver.ALLBITS;

    if (observers != null)
      for(int i=0; i < observers.size(); i++)
	((ImageObserver)observers.elementAt(i)).
	  imageUpdate(this, flags, 0, 0, width, height);

    observers = null;
  }
  
  /**
   * Adds an observer, if we need to.
   * @return true if an observer was added.
   */
  private boolean addObserver(ImageObserver observer)
  {
    if (!isLoaded)
      {
	if(observer != null)
	  if (!observers.contains (observer))
	    observers.addElement (observer);
	return true;
      }
    return false;
  }

  public String toString()
  {
    return "QtImage [isLoaded="+isLoaded+", width="+width+", height="+height
      +"]";
  }
}