/*____________________________________________________________________
  INIT Copyright (C) 2000 All rights reserved
        
    File:            FastBufferedUpdateStrategy.java
    Description:     X
    Author:          WMG
    Created:         2000.03.27
  ____________________________________________________________________
*/



package CH.ifa.draw.standard;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import CH.ifa.draw.framework.Drawing;
import CH.ifa.draw.framework.DrawingView;
import CH.ifa.draw.framework.FigureEnumeration;
import CH.ifa.draw.framework.Painter;


public class FastBufferedUpdateStrategy implements Painter {



  //_________________________________________________________VARIABLES



  private BufferedImage  _doubleBufferedImage;
  private BufferedImage  _scratchPadBufferedImage;
  private int            _nImageWidth = 0;
  private int            _nImageHeight = 0;
  private boolean        _bRedrawAll = true;



  //______________________________________________________CONSTRUCTORS



  public FastBufferedUpdateStrategy() {

  }



  //____________________________________________________PUBLIC METHODS



  public void draw(Graphics g, DrawingView view) {

    _checkCaches(view);

    if (_bRedrawAll == true) {

      Graphics imageGraphics = _doubleBufferedImage.getGraphics();
      view.drawAll(imageGraphics);

    }
    else {

      Rectangle viewClipRectangle = g.getClipBounds();

      int nX1 = viewClipRectangle.x;
      int nY1 = viewClipRectangle.y;
      int nX2 = viewClipRectangle.x + viewClipRectangle.width;
      int nY2 = viewClipRectangle.y + viewClipRectangle.height;

      if (nX1 < 0) {
        nX1 = 0;
      }
      if (nY1 < 0) {
        nY1 = 0;
      }
      if (nX2 < 0) {
        nX2 = 0;
      }
      if (nY2 < 0) {
        nY2 = 0;
      }

      Rectangle viewClipRectangle2 = new Rectangle(nX1, nY1, nX2-nX1,
       nY2-nY1);

      Drawing theDrawing = view.drawing();
      FigureEnumeration fe = theDrawing.figures(viewClipRectangle2);

      Graphics imageGraphics = _scratchPadBufferedImage.getGraphics();
      imageGraphics.setColor(view.getBackground());
      imageGraphics.fillRect(nX1, nY1, nX2-nX1, nY2-nY1);
      view.draw(imageGraphics, fe);

      Graphics dbGraphics = _doubleBufferedImage.getGraphics();

      dbGraphics.drawImage(_scratchPadBufferedImage, nX1, nY1,
       nX2, nY2, nX1, nY1, nX2, nY2, view);

    }

    g.drawImage(_doubleBufferedImage, 0, 0, view);
    _bRedrawAll = false;

  }



  //___________________________________________________PRIVATE METHODS



  private void _checkCaches(DrawingView view) {

    Dimension d = view.getSize();

    if ((_doubleBufferedImage == null)
     || (_nImageWidth != d.width)
     || (_nImageHeight != d.height)) {
      _doubleBufferedImage = new BufferedImage(d.width,
       d.height, BufferedImage.TYPE_INT_RGB);
      _bRedrawAll = true;
    }

    if ((_scratchPadBufferedImage == null)
     || (_nImageWidth != d.width)
     || (_nImageHeight != d.height)) {
      _scratchPadBufferedImage = new BufferedImage(d.width,
       d.height, BufferedImage.TYPE_INT_RGB);
      Graphics imageGraphics = _scratchPadBufferedImage.getGraphics();
      view.drawBackground(imageGraphics);
      _bRedrawAll = true;
    }

    _nImageWidth = d.width;
    _nImageHeight = d.height;

  }



  //_______________________________________________________________END

} //end of class FastBufferedUpdateStrategy