/*+---------------------------------------------------------+
  | DROEPPEZ Leinwand Version 1.0                           |
  | (c) 2001 Ulrich Kritzner                                |
  +---------------------------------------------------------+

 Da es keine Moeglichkeit gibt,
 einfache Bilder von JavaScript aus zu manipulieren,
 habe ich mich gemuessigt gefuehlt,
 eine Art Java-Leinwand zu programmieren.
 Auf diese Leinwand koennen JavaScript-Funktionen malen,
 indem sie auf die enthaltenen Funktionen zugreifen.
 Die Leinwand puffert alle Malaktionen auf einem unsichtbaren Bild,
 welches bei jedem closeCanvas() auf die Webseite kopiert wird. */

import java.lang.*;
import java.applet.*;
import java.awt.*;
import java.net.*;

public class canvas
       extends Applet
{
  Dimension dim=null;
  Image img=null;
  Graphics ig=null;

/* Info ----------------------------------------------- */

  public String getAppletInfo()
  /* stellt sich vor */
  {
    return "DROEPPEZ canvas v1.0 (c) 2001 Ulrich Kritzner";
  }
  
/* Appletsteuerung ------------------------------------ */

  public void init()
  /* einmalige Initialisierung */
  {
    dim=getSize();
    img=createImage(dim.width,dim.height);
    openCanvas();
    if (ig!=null)
      ig.drawString(getAppletInfo(),5,20);
    closeCanvas();
    System.out.println(getAppletInfo());
  }

  public void destroy()
  /* Aufraeumen */
  {
    closeCanvas();
    if (img!=null)
      img.flush();
    img=null;
  }

/* Anzeige -------------------------------------------- */

  public void paint(Graphics g)
  {
    if (img!=null)
      g.drawImage(img,0,0,this);
  }

/* Manipulation --------------------------------------- */

  public void newCanvas()
  {
    closeCanvas();
    if (img!=null)
      img.flush();
    img=null;
    dim=getSize();
    img=createImage(dim.width,dim.height);
  }

  public void openCanvas()
  {
    if (img!=null)
      if (ig==null)
        ig=img.getGraphics();
  }

  public void closeCanvas()
  {
    Graphics g;
    if (img!=null)
    {
      if (ig!=null)
        ig.dispose();
      ig=null;
    }
    g=getGraphics();
    paint(g);
    g.dispose();
  }

  public int canvasWidth()
  {
    return dim.width;
  }

  public int canvasHeight()
  {
    return dim.height;
  }

  public void setColor(int r,int g,int b)
  {
    if (ig!=null)
    {
      Color c=new Color(r,g,b);
      ig.setColor(c);
    }
  }

  public void setFont(String name,int style,int size)
  {
    if (ig!=null)
    {
      Font font=new Font(name,style,size);
      ig.setFont(font);
    }
  }

  public void setClip(int x,int y,int width,int height)
  {
    if (ig!=null)
      ig.setClip(x,y,width,height);
  }

  public void copyArea(int x,int y,int width,int height,int dx,int dy)
  {
    if (ig!=null)
      ig.copyArea(x,y,width,height,dx,dy);
  }

  public void drawImage(String stg,int x,int y,int width,int height)
  {
    Image img;
    if (ig==null)
      return;
    img=getImage(db,stg);
    if (img==null)
      return;
    mt.addImage(img,0);
    try
    {
      mt.waitForAll();
    }
    catch (InterruptedException e)
    {
      mt.removeImage(img);
      img.flush();
      return;
    }
    mt.removeImage(img);
    ig.drawImage(img,x,y,width,height,this);
    img.flush();
  }

  public void drawString(String stg,int x,int y)
  {
    if (ig!=null)
      ig.drawString(stg,x,y);
  }

  public void drawLine(int x1,int y1,int x2,int y2)
  {
    if (ig!=null)
      ig.drawLine(x1,y1,x2,y2);
  }

  public void drawArc(int x,int y,int width,int height,int startAngle,int arcAngle)
  {
    if (ig!=null)
      ig.drawArc(x,y,width,height,startAngle,arcAngle);
  }

  public void drawOval(int x,int y,int width,int height)
  {
    if (ig!=null)
      ig.drawOval(x,y,width,height);
  }

  public void drawRect(int x,int y,int width,int height)
  {
    if (ig!=null)
      ig.drawRect(x,y,width,height);
  }

  public void drawRoundRect(int x,int y,int width,int height,int arcWidth,int arcHeight)
  {
    if (ig!=null)
      ig.drawRoundRect(x,y,width,height,arcWidth,arcHeight);
  }

  public void fillArc(int x,int y,int width,int height,int startAngle,int arcAngle)
  {
    if (ig!=null)
      ig.fillArc(x,y,width,height,startAngle,arcAngle);
  }

  public void fillOval(int x,int y,int width,int height)
  {
    if (ig!=null)
      ig.fillOval(x,y,width,height);
  }

  public void fillRect(int x,int y,int width,int height)
  {
    if (ig!=null)
      ig.fillRect(x,y,width,height);
  }

  public void fillRoundRect(int x,int y,int width,int height,int arcWidth,int arcHeight)
  {
    if (ig!=null)
      ig.fillRoundRect(x,y,width,height,arcWidth,arcHeight);
  }
}