/* ComponentGraphics.java --
   Copyright (C) 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.gtk;

import gnu.classpath.Pointer;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.Toolkit;
import java.awt.font.GlyphVector;
import java.awt.geom.AffineTransform;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.ImageObserver;
import java.awt.image.ImageProducer;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import java.util.Hashtable;

/**
 * ComponentGraphics - context for drawing directly to a component,
 * as this is an X drawable, it requires that we use GTK locks.
 *
 * This context draws directly to the drawable and requires xrender.
 */
public class ComponentGraphics extends CairoGraphics2D
{
  private static final boolean hasXRenderExtension = hasXRender();

  private GtkComponentPeer component;
  protected long cairo_t;
  private BufferedImage buffer, componentBuffer;

  private static ThreadLocal hasLock = new ThreadLocal();
  private static Integer ONE = Integer.valueOf(1);

  ComponentGraphics()
  {
  }
  
  private ComponentGraphics(GtkComponentPeer component)
  {
    this.component = component;
    cairo_t = initState(component);
    setup( cairo_t );
    Rectangle bounds = component.awtComponent.getBounds();
    setClip( new Rectangle( 0, 0, bounds.width, bounds.height) );
    setBackground(component.awtComponent.getBackground());
    setColor(component.awtComponent.getForeground());
  }

  private ComponentGraphics(ComponentGraphics cg)
  {
    component = cg.component;
    cairo_t = initState(component);
    copy( cg, cairo_t );
    Rectangle bounds = component.awtComponent.getBounds();
    setClip( new Rectangle( 0, 0, bounds.width, bounds.height) );
    setBackground(component.awtComponent.getBackground());
    setColor(component.awtComponent.getForeground());
  }

  /**
   * Creates a cairo_t for the component surface and return it.
   */
  private native long initState(GtkComponentPeer component);

  private void lock()
  {
    Integer i = (Integer) hasLock.get();
    if (i == null)
      {
	start_gdk_drawing();
	hasLock.set(ONE);
      }
    else
      hasLock.set(Integer.valueOf(i.intValue() + 1));
  }

  private void unlock()
  {
    Integer i = (Integer) hasLock.get();
    if (i == null)
      throw new IllegalStateException();
    if (i == ONE)
      {
	hasLock.set(null);
	end_gdk_drawing();
      }
    else
      hasLock.set(Integer.valueOf(i.intValue() - 1));
  }

  /**
   * Destroys the component surface and calls dispose on the cairo
   * graphics2d to destroy any super class resources.
   */
  public void dispose()
  {
    super.dispose();
    disposeSurface(nativePointer);
  }

  /**
   * Destroys the component surface.
   */
  private native void disposeSurface(long nativePointer);

  /**
   * Creates a cairo_t for a volatile image
   */
  protected native long initFromVolatile( long pixmapPtr, int width, int height);

  /**
   * Grab lock
   */
  private native void start_gdk_drawing();

  /**
   * Release lock
   */
  private native void end_gdk_drawing();

  /**
   * Query if the system has the XRender extension.
   */
  public static native boolean hasXRender();

  /**
   * This is a utility method (used by GtkComponentPeer) for grabbing the
   * image of a component.
   */
  private static native Pointer nativeGrab(GtkComponentPeer component);

  private native void copyAreaNative(GtkComponentPeer component, int x, int y, 
				     int width, int height, int dx, int dy);

  private native void drawVolatile(GtkComponentPeer component,
				   long vimg, int x, int y, 
				   int width, int height, int cx, int cy,
                                   int cw, int ch);

  /**
   * Not really related (moveme?). Utility method used by GtkComponent.
   */
  public static GtkImage grab( GtkComponentPeer component )
  {
    return new GtkImage( nativeGrab( component ) );
  }

  /**
   * Returns a Graphics2D object for a component, either an instance of this 
   * class (if xrender is supported), or a context which copies.
   */
  public static Graphics2D getComponentGraphics(GtkComponentPeer component)
  {
    if( hasXRenderExtension )
      return new ComponentGraphics(component);

    Rectangle r = component.awtComponent.getBounds();
    return new ComponentGraphicsCopy(r.width, r.height, component);
  }

  public GraphicsConfiguration getDeviceConfiguration()
  {
    return component.getGraphicsConfiguration();
  }

  public Graphics create()
  {
    return new ComponentGraphics(this);
  }
  
  protected Rectangle2D getRealBounds()
  {
    return component.awtComponent.getBounds();
  }

  public void copyAreaImpl(int x, int y, int width, int height, int dx, int dy)
  {
    copyAreaNative(component, x, y, width, height, dx, dy);
  }

  /**
   * Overloaded methods that do actual drawing need to enter the gdk threads 
   * and also do certain things before and after.
   */
  public void draw(Shape s)
  {
    lock();
    try
      {
        if (comp == null || comp instanceof AlphaComposite)
          super.draw(s);
        
        else
          {
            createBuffer();
            
            Graphics2D g2d = (Graphics2D)buffer.getGraphics();
            g2d.setStroke(this.getStroke());
            g2d.setColor(this.getColor());
            g2d.draw(s);
            
            drawComposite(s.getBounds2D(), null);
          }
      }
    finally
      {
	unlock();
      }
  }

  public void fill(Shape s)
  {
    lock();
    try
      {
        if (comp == null || comp instanceof AlphaComposite)
          super.fill(s);
        
        else
          {
            createBuffer();
            
            Graphics2D g2d = (Graphics2D)buffer.getGraphics();
            g2d.setPaint(this.getPaint());
            g2d.setColor(this.getColor());
            g2d.fill(s);
            
            drawComposite(s.getBounds2D(), null);
          }
      }
    finally
      {
	unlock();
      }
  }

  public void drawRenderedImage(RenderedImage image, AffineTransform xform)
  {
    lock();
    try
      {
        if (comp == null || comp instanceof AlphaComposite)
          super.drawRenderedImage(image, xform);
        
        else
          {
            createBuffer();

            Graphics2D g2d = (Graphics2D)buffer.getGraphics();
            g2d.setRenderingHints(this.getRenderingHints());
            g2d.drawRenderedImage(image, xform);
            
            drawComposite(buffer.getRaster().getBounds(), null);
          }
      }
    finally
      {
	unlock();
      }
  }

  protected boolean drawImage(Image img, AffineTransform xform,
			      Color bgcolor, ImageObserver obs)
  {
    boolean rv;
    lock();
    try
      {
        if (comp == null || comp instanceof AlphaComposite)
          rv = super.drawImage(img, xform, bgcolor, obs);
        
        else
          {
            // Get buffered image of source
            if( !(img instanceof BufferedImage) )
              {
                ImageProducer source = img.getSource();
                if (source == null)
                  return false;
                img = Toolkit.getDefaultToolkit().createImage(source);
              }
            BufferedImage bImg = (BufferedImage) img;
            
            // Find translated bounds
            Point2D origin = new Point2D.Double(bImg.getMinX(), bImg.getMinY());
            Point2D pt = new Point2D.Double(bImg.getWidth() + bImg.getMinX(),
                                            bImg.getHeight() + bImg.getMinY());
            if (xform != null)
              {
                origin = xform.transform(origin, origin);
                pt = xform.transform(pt, pt);
              }
            
            // Create buffer and draw image
            createBuffer();
            
            Graphics2D g2d = (Graphics2D)buffer.getGraphics();
            g2d.setRenderingHints(this.getRenderingHints());
            g2d.drawImage(img, xform, obs);

            // Perform compositing
            rv = drawComposite(new Rectangle2D.Double(origin.getX(),
                                                        origin.getY(),
                                                        pt.getX(), pt.getY()),
                                 obs);
          }
      }
    finally
      {
	unlock();
      }
    return rv;
  }

  public void drawGlyphVector(GlyphVector gv, float x, float y)
  {
    lock();
    try
      {
        if (comp == null || comp instanceof AlphaComposite)
          super.drawGlyphVector(gv, x, y);
        
        else
          {
            createBuffer();

            Graphics2D g2d = (Graphics2D)buffer.getGraphics();
            g2d.setPaint(this.getPaint());
            g2d.setStroke(this.getStroke());
            g2d.drawGlyphVector(gv, x, y);
            
            Rectangle2D bounds = gv.getLogicalBounds();
            bounds = new Rectangle2D.Double(x + bounds.getX(), y + bounds.getY(),
                                            bounds.getWidth(), bounds.getHeight());
            drawComposite(bounds, null);
          }
      }
    finally
      {
	unlock();
      }
  }
  
  public boolean drawImage(Image img, int x, int y, ImageObserver observer)
  {
    // If it is a GtkVolatileImage with an "easy" transform then
    // draw directly. Always pass a BufferedImage to super to avoid
    // deadlock (see Note in CairoGraphics.drawImage()).
    if (img instanceof GtkVolatileImage)
      {
        GtkVolatileImage vimg = (GtkVolatileImage) img;
        int type = transform.getType();
        if ((type == AffineTransform.TYPE_IDENTITY
             || type == AffineTransform.TYPE_TRANSLATION)
             && (clip == null || clip instanceof Rectangle2D))
          {
            Rectangle2D r = (Rectangle2D) clip;
            if (r == null)
              r = getRealBounds();
            x += transform.getTranslateX();
            y += transform.getTranslateY();
            drawVolatile(component, vimg.nativePointer,
                         x, y, vimg.width, vimg.height,
                         (int) (r.getX() + transform.getTranslateX()),
                         (int) (r.getY() + transform.getTranslateY()),
                         (int) r.getWidth(),
                         (int) r.getHeight());
            return true;
          }
	else
	  return super.drawImage(vimg.getSnapshot(), x, y, observer);
      }

    BufferedImage bimg;
    if (img instanceof BufferedImage)
      bimg = (BufferedImage) img;
    else
      {
	ImageProducer source = img.getSource();
        if (source == null)
          return false;
        bimg = (BufferedImage) Toolkit.getDefaultToolkit().createImage(source);
      }
    return super.drawImage(bimg, x, y, observer);
  }
  
  public boolean drawImage(Image img, int x, int y, int width, int height,
                           ImageObserver observer)
  {
    // If it is a GtkVolatileImage with an "easy" transform then
    // draw directly. Always pass a BufferedImage to super to avoid
    // deadlock (see Note in CairoGraphics.drawImage()).
    if (img instanceof GtkVolatileImage
        && (clip == null || clip instanceof Rectangle2D))
      {
        GtkVolatileImage vimg = (GtkVolatileImage) img;
        int type = transform.getType();
        if ((type == AffineTransform.TYPE_IDENTITY
             || type == AffineTransform.TYPE_TRANSLATION)
             && (clip == null || clip instanceof Rectangle2D))
          {
            Rectangle2D r = (Rectangle2D) clip;
            if (r == null)
              r = getRealBounds();
            x += transform.getTranslateX();
            y += transform.getTranslateY();
            drawVolatile(component, vimg.nativePointer,
                         x, y, width, height,
                         (int) (r.getX() + transform.getTranslateX()),
                         (int) (r.getY() + transform.getTranslateY()),
                         (int) r.getWidth(),
                         (int) r.getHeight());
            return true;
          }
	else
	  return super.drawImage(vimg.getSnapshot(), x, y,
				 width, height, observer);
      }

    BufferedImage bimg;
    if (img instanceof BufferedImage)
      bimg = (BufferedImage) img;
    else
      {
	ImageProducer source = img.getSource();
        if (source == null)
          return false;
        bimg = (BufferedImage) Toolkit.getDefaultToolkit().createImage(source);
      }
    return super.drawImage(bimg, x, y, width, height, observer);
  }

  public void setClip(Shape s)
  {
    lock();
    try
      {
	super.setClip(s);
      }
    finally
      {
	unlock();
      }
  }

  
  private boolean drawComposite(Rectangle2D bounds, ImageObserver observer)
  {
    // Clip source to visible areas that need updating
    Rectangle2D clip = this.getClipBounds();
    Rectangle2D.intersect(bounds, clip, bounds);
    clip = new Rectangle(buffer.getMinX(), buffer.getMinY(),
                         buffer.getWidth(), buffer.getHeight());
    Rectangle2D.intersect(bounds, clip, bounds);
    
    BufferedImage buffer2 = buffer;
    if (!bounds.equals(buffer2.getRaster().getBounds()))
      buffer2 = buffer2.getSubimage((int)bounds.getX(), (int)bounds.getY(),
                                    (int)bounds.getWidth(),
                                    (int)bounds.getHeight());
    
    // Get destination clip to bounds
    double[] points = new double[] {bounds.getX(), bounds.getY(),
                                    bounds.getMaxX(), bounds.getMaxY()};
    transform.transform(points, 0, points, 0, 2);
    
    Rectangle2D deviceBounds = new Rectangle2D.Double(points[0], points[1],
                                                       points[2] - points[0],
                                                       points[3] - points[1]);
    
    Rectangle2D.intersect(deviceBounds, this.getClipInDevSpace(), deviceBounds);
    
    // Get current image on the component
    unlock();
    GtkImage img = grab(component);
    Graphics gr = componentBuffer.createGraphics();
    gr.drawImage(img, 0, 0, null);
    gr.dispose();
    lock();
    
    BufferedImage cBuffer = componentBuffer;
    if (!deviceBounds.equals(cBuffer.getRaster().getBounds()))
      cBuffer = cBuffer.getSubimage((int)deviceBounds.getX(),
                                    (int)deviceBounds.getY(),
                                    (int)deviceBounds.getWidth(),
                                    (int)deviceBounds.getHeight());
    
    // Perform actual composite operation
    compCtx.compose(buffer2.getRaster(), cBuffer.getRaster(),
                    cBuffer.getRaster());
    
    // This MUST call directly into the "action" method in CairoGraphics2D,
    // not one of the wrappers, to ensure that the composite isn't processed
    // more than once!
    boolean rv = super.drawImage(cBuffer,
                                 AffineTransform.getTranslateInstance(bounds.getX(),
                                                                      bounds.getY()),
                                 null, null);
    return rv;
  }
  
  private void createBuffer()
  {
    if (buffer == null)
      {
        WritableRaster rst;
        rst = Raster.createWritableRaster(GtkVolatileImage.createGdkSampleModel(component.awtComponent.getWidth(),
                                                                                component.awtComponent.getHeight()),
                                          new Point(0,0));
        
        buffer = new BufferedImage(GtkVolatileImage.gdkColorModel, rst,
                                   GtkVolatileImage.gdkColorModel.isAlphaPremultiplied(),
                                   new Hashtable());
      }
    else
      {
        Graphics2D g2d = ((Graphics2D)buffer.getGraphics());
        
        g2d.setBackground(new Color(0,0,0,0));
        g2d.clearRect(0, 0, buffer.getWidth(), buffer.getHeight());
      }
    
    if (componentBuffer == null)
      {
        WritableRaster rst;
        rst = Raster.createWritableRaster(GtkVolatileImage.createGdkSampleModel(component.awtComponent.getWidth(),
                                                                                component.awtComponent.getHeight()),
                                          new Point(0,0));
        
        componentBuffer = new BufferedImage(GtkVolatileImage.gdkColorModel, rst,
                                   GtkVolatileImage.gdkColorModel.isAlphaPremultiplied(),
                                   new Hashtable());
      }
  }
  
  protected ColorModel getNativeCM()
  {
    return GtkVolatileImage.gdkColorModel;
  }
}