printcomponent.java

外国人写的Java打印程序

package printtable;

import java.awt.*;
import java.awt.geom.*;
import java.awt.print.*;

import javax.swing.*;

/**
 * Title:        PrintTable
 * Description:  A java jTable Print Programme.
 * Enable set the wighth and highth.
 * Copyright:    Copyright (c) 2002
 * Company:      TopShine
 * @author ghostliang
 * @version 1.0
 */

public class PrintComponent extends JPanel{
  /*
   *The item to be printed
   */
  protected Printable printable;

  /*
   *PageFormat to use when printing
   */
  protected PageFormat pageFormat;

  /*
   *The page that is currently displayed
   */
  protected int displayPage;

  /*
   *The scale factor(1.0 = 100%)
   */
  protected double scaleFactor;

  //init the component
  public PrintComponent(Printable newPrintable,PageFormat newPageFormat) {
    this.setPrintabel(newPrintable);
    this.setPageFormat(newPageFormat);
    this.setDisplayPage(0);
    this.setScaleFactor(100);
    this.setBackground(Color.gray);
  }

  //get and set some variable
  public void setPrintabel(Printable newPrintable)
  {
    printable = newPrintable;
    revalidate();
  }

  public void setPageFormat(PageFormat newPageFormat)
  {
    pageFormat = newPageFormat;
    revalidate();
  }

  public void setDisplayPage(int page)
  {
    displayPage = page;
    revalidate();
  }

  public void setScaleFactor(double scale)
  {
    scaleFactor = scale;
    revalidate();
  }

  public double getScaleFactor()
  {
    return scaleFactor;
  }

  //get the print size
  public Dimension getSizeWithScale(double scale)
  {
    Paper paper = pageFormat.getPaper();
    int width;
    int height;
    if(pageFormat.getOrientation() == 1)
    {
      width = ((int)(paper.getWidth() * scale / 100));
      height = ((int)(paper.getHeight() * scale / 100));
    }
    else
    {
      height = ((int)(paper.getWidth() * scale / 100));
      width = ((int)(paper.getHeight() * scale / 100));
    }

    return new Dimension(width,height);
  }

  public Dimension getPreferredSize()
  {
    return getSizeWithScale(scaleFactor);
  }

  public Dimension getMinimumSize()
  {
    return getPreferredSize();
  }

  public void paintComponent(Graphics newGraphics)
  {
    super.paintComponent(newGraphics);
    Graphics2D newGraphics2D = (Graphics2D)newGraphics;

    int allOffsetX = 0;
    int allOffsetY = 0;

    //save infomation of the Graphics
    AffineTransform newAffineTransform = newGraphics2D.getTransform();

    //set the paper in the mid of the printComponent Panel
    int thisWidth = this.getWidth();
    int thisHeight = this.getHeight();

    Dimension size = this.getSizeWithScale(scaleFactor);

    int offsetX = (thisWidth - size.width) / 2;
    int offsetY = (thisHeight - size.height) / 2;

    newGraphics2D.translate(offsetX,offsetY);
    allOffsetX += offsetX;
    allOffsetY += offsetY;

    newGraphics2D.scale(scaleFactor/100,scaleFactor/100);
    try
    {
      printable.print(newGraphics,pageFormat,displayPage);
    }
    catch(PrinterException e)
    {
    }

    newGraphics2D.translate(-allOffsetX,-allOffsetY);

    newGraphics2D.setTransform(newAffineTransform);
  }
}