Help with PrintPreview

[L Sankaranarayanan]

I have one printpreview program taken from net . It actually takes one printable object and shows the preview one or multiple pages. My printable class is nothing but displaying text in more than one pages. But preview shows empty pages .
PrintPreview Code goes here

/**
	PrintPreview
*/
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;
import java.awt.print.*;

import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;

public class PrintPreview 
	extends JFrame 
{
	protected int m_wPage;
	protected int m_hPage;
        protected int m_orientation;
	protected Printable m_target;
	protected JComboBox m_cbScale;
	protected PreviewContainer m_preview;

	public PrintPreview(Printable target)
	{
		this(target, "Print Preview", PageFormat.PORTRAIT);
	}

	public PrintPreview(Printable target, String title, int orientation)
	{
		super(title);
		setSize(600, 400);
		getContentPane().setLayout(new BorderLayout());
		m_target = target;
                m_orientation = orientation;

		JToolBar tb = new JToolBar();
		JButton bt = new JButton("Print", new ImageIcon("print.gif"));
		ActionListener lst = new ActionListener() 
		{ 
			public void actionPerformed(ActionEvent e)
			{ 
				try
				{
					PrinterJob prnJob = PrinterJob.getPrinterJob();
		                        PageFormat pageFormat = prnJob.defaultPage();
                                        pageFormat.setOrientation(m_orientation);
					prnJob.setPrintable(m_target, pageFormat);

			                if (!prnJob.printDialog())
				          return;
					setCursor( Cursor.getPredefinedCursor(
						Cursor.WAIT_CURSOR));
					prnJob.print();
					setCursor( Cursor.getPredefinedCursor(
						Cursor.DEFAULT_CURSOR));
					dispose();
				}
				catch (PrinterException ex)
				{
					ex.printStackTrace();
					System.err.println("Printing error: "+ex.toString());
				}
			}
		};
		bt.addActionListener(lst);
		bt.setAlignmentY(0.5f);
		bt.setMargin(new Insets(4,6,4,6));
		tb.add(bt);

		bt = new JButton("Close");
		lst = new ActionListener() 
		{ 
			public void actionPerformed(ActionEvent e)
			{ 
				dispose();
			}
		};
		bt.addActionListener(lst);
		bt.setAlignmentY(0.5f);
		bt.setMargin(new Insets(2,6,2,6));
		tb.add(bt);

		String[] scales = { "10 %", "25 %", "50 %", "100 %" };
		m_cbScale = new JComboBox(scales);
		lst = new ActionListener() 
		{ 
			public void actionPerformed(ActionEvent e)
			{ 
                           Thread runner = new Thread() {
                             public void run() {
				String str = m_cbScale.getSelectedItem().
					toString();
				if (str.endsWith("%"))
					str = str.substring(0, str.length()-1);
				str = str.trim();
				int scale = 0;
				try { scale = Integer.parseInt(str); }
				catch (NumberFormatException ex) { return; }
				int w = (int)(m_wPage*scale/100);
				int h = (int)(m_hPage*scale/100);

				Component[] comps = m_preview.getComponents();
				for (int k=0; k<comps.length; k++)
				{
					if (!(comps[k] instanceof PagePreview))
						continue;
					PagePreview pp = (PagePreview)comps[k];
					pp.setScaledSize(w, h);
				}
				m_preview.doLayout();
				m_preview.getParent().getParent().validate();
                              }
                            };
                            runner.start();
			}
		};
		m_cbScale.addActionListener(lst);
		m_cbScale.setMaximumSize(m_cbScale.getPreferredSize());
		m_cbScale.setEditable(true);
		tb.addSeparator();
		tb.add(m_cbScale);
		getContentPane().add(tb, BorderLayout.NORTH);

		m_preview = new PreviewContainer();

		PrinterJob prnJob = PrinterJob.getPrinterJob();
		PageFormat pageFormat = prnJob.defaultPage();
                pageFormat.setOrientation(m_orientation);

		if (pageFormat.getHeight()==0 || pageFormat.getWidth()==0)
		{
			System.err.println("Unable to determine default page size");
			return;
		}
		m_wPage = (int)(pageFormat.getWidth());
		m_hPage = (int)(pageFormat.getHeight());
		int scale = 10;
		int w = (int)(m_wPage*scale/100);
		int h = (int)(m_hPage*scale/100);

		int pageIndex = 0;
		try
		{
			while (true)
			{
				
				BufferedImage img = new BufferedImage(m_wPage, 
					m_hPage, BufferedImage.TYPE_INT_RGB);
				Graphics g = img.getGraphics();
				g.setColor(Color.white);
				g.fillRect(0, 0, m_wPage, m_hPage);
				if (target.print(g, pageFormat, pageIndex) != 
					Printable.PAGE_EXISTS)
					break;

				PagePreview pp = new PagePreview(w, h, img);
				m_preview.add(pp);
				pageIndex++;
			}
		}
		catch (PrinterException e)
		{
			e.printStackTrace();
			System.err.println("Printing error: "+e.toString());
		}

		JScrollPane ps = new JScrollPane(m_preview);
		getContentPane().add(ps, BorderLayout.CENTER);

		setDefaultCloseOperation(DISPOSE_ON_CLOSE);
		setVisible(true);
	}

	class PreviewContainer
		extends JPanel
	{
		protected int H_GAP = 16;
		protected int V_GAP = 10;

		public Dimension getPreferredSize()
		{
			int n = getComponentCount();
			if (n == 0)
				return new Dimension(H_GAP, V_GAP);
			Component comp = getComponent(0);
			Dimension dc = comp.getPreferredSize();
			int w = dc.width;
			int h = dc.height;
			
			Dimension dp = getParent().getSize();
			int nCol = Math.max((dp.width-H_GAP)/(w+H_GAP), 1);
			int nRow = n/nCol;
			if (nRow*nCol < n)
				nRow++;

			int ww = nCol*(w+H_GAP) + H_GAP;
			int hh = nRow*(h+V_GAP) + V_GAP;
			Insets ins = getInsets();
			return new Dimension(ww+ins.left+ins.right, 
				hh+ins.top+ins.bottom);
		}

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

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

		public void doLayout()
		{
			Insets ins = getInsets();
			int x = ins.left + H_GAP;
			int y = ins.top + V_GAP;

			int n = getComponentCount();
			if (n == 0)
				return;
			Component comp = getComponent(0);
			Dimension dc = comp.getPreferredSize();
			int w = dc.width;
			int h = dc.height;
			
			Dimension dp = getParent().getSize();
			int nCol = Math.max((dp.width-H_GAP)/(w+H_GAP), 1);
			int nRow = n/nCol;
			if (nRow*nCol < n)
				nRow++;

			int index = 0;
			for (int k = 0; k<nRow; k++)
			{
				for (int m = 0; m<nCol; m++)
				{
					if (index >= n)
						return;
					comp = getComponent(index++);
					comp.setBounds(x, y, w, h);
					x += w+H_GAP;
				}
				y += h+V_GAP;
				x = ins.left + H_GAP;
			}
		}
	}
	//##############################
	
	
	 class PrintPreviewCanvas extends JPanel {
	private Book book;

	private int currentPage;

	public PrintPreviewCanvas (Book b) {
		book = b;
		currentPage = 0;
	}

	public void paintComponent (Graphics g) {
		super.paintComponent (g);
		Graphics2D g2 = (Graphics2D) g;
		PageFormat pageFormat = book.getPageFormat (currentPage);

		double xoff;
		double yoff;
		double scale;

		double px = pageFormat.getWidth ();
		double py = pageFormat.getHeight ();
		double sx = getWidth () - 1;
		double sy = getHeight () - 1;

		if (px / py < sx / sy) // center horizontally
		{
			scale = sy / py;
			xoff = 0.5 * (sx - scale * px);
			yoff = 0;
		} else // Center vertically
		{
			scale = sx / px;
			xoff = 0;
			yoff = 0.5 * (sy - scale * py);
		}

		g2.translate ((float) xoff, (float) yoff);
		g2.scale ((float) scale, (float) scale);

		Rectangle2D page = new Rectangle2D.Double (0, 0, px, py);
		g2.setPaint (Color.WHITE);
		g2.fill (page);
		g2.setPaint (Color.BLACK);
		g2.draw (page);

		Printable printable = book.getPrintable (currentPage);
		try {
			printable.print (g2, pageFormat, currentPage);
		} catch (PrinterException exception) {
			g2.draw (new Line2D.Double (0, 0, px, py));
			g2.draw (new Line2D.Double (0, px, 0, py));
		}

	}

	public void flipPage (int by) {
		int newPage = currentPage + by;
		if (0 <= newPage && newPage < book.getNumberOfPages ()) {
			currentPage = newPage;
			repaint ();
		}
	}
}
	
	
	
	
	
	
	//################################

	class PagePreview
		extends JPanel
	{
		protected int m_w;
		protected int m_h;
		protected Image m_source;
		protected Image m_img;

		public PagePreview(int w, int h, Image source)
		{
			m_w = w;
			m_h = h;
			m_source= source;
			m_img = m_source.getScaledInstance(m_w, m_h, 
				Image.SCALE_SMOOTH);
			m_img.flush();
			setBackground(Color.white);
			setBorder(new MatteBorder(1, 1, 2, 2, Color.black));
		}

		public void setScaledSize(int w, int h)
		{
			m_w = w;
			m_h = h;
			m_img = m_source.getScaledInstance(m_w, m_h, 
				Image.SCALE_SMOOTH);
			repaint();
		}

		public Dimension getPreferredSize()
		{
			Insets ins = getInsets();
			return new Dimension(m_w+ins.left+ins.right, 
				m_h+ins.top+ins.bottom);
		}

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

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

		public void paint(Graphics g)
		{
			
		  
			g.setColor(getBackground());
			g.fillRect(0, 0, getWidth(), getHeight());
			g.drawImage(m_img, 0, 0, this);
			paintBorder(g);
		}
	}
	
    public static void main(String[] args)
    {
     new PrintPreview(new MultiPageReport());
     
     }	
	
	
	
	
}

My Printable class is given here It works fine with any printers. But preview is not possible in this case. Other page wise preview program shows the output. Why this printpreview does not show the preview?

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.print.*;
import java.io.*;
import java.util.*;
 import java.awt.geom.AffineTransform;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.sql.*;
import java.util.*;

public class MultiPageReport implements Printable {

    private final int marginTop = 20;
    private final int marginLeft = 20;
    private Font mainFont = new Font("Verdana", Font.PLAIN, 10);
    private Font bigFont = new Font("Verdana", Font.PLAIN, 14);
    private int lines;

    private int headerHeighInLines = 5;
    private int lineH = -1;
    private double pageH = -1;
    private int pages = -1;

    private boolean finish = false;

    public MultiPageReport() {

        lines = 160;//set the total number of rows we want to print
    }

    public static void main(String[] args) {
        PrinterJob job = PrinterJob.getPrinterJob(); // Use default printer
        job.printDialog();
        MultiPageReport t = new MultiPageReport();
        job.setPrintable(t);
        try {
            job.print();
        } catch (PrinterException e) {
            e.printStackTrace();
        }

    }

    @Override
    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {

        // if printed all pages then no_such_page
        if (pageIndex >= getPages()) {
            return NO_SUCH_PAGE;
        }

        Graphics2D g2 = (Graphics2D) graphics;
        AffineTransform defaultTransform = g2.getTransform();
        if (pageH == -1) {

            pageH = pageFormat.getImageableHeight();

        }
       //g2.setFont(mainFont);
          g2.setFont(bigFont);

       int charW = g2.getFontMetrics().charWidth('T');
        if (lineH == -1) {
            lineH = g2.getFontMetrics().getHeight();
        }
      double curY;

        g2.translate(pageFormat.getImageableX() + marginLeft, curY = pageFormat.getImageableY() + marginTop);

        // if we have the first page we can print a title
        // or a description
        if (pageIndex == 0) {
            g2.translate(0, lineH * headerHeighInLines);
        }

        int[] res = getNumLines(pageIndex);

        for (int i = res[0]; i < res[1]; i++) {
            g2.translate(0, lineH);
            g2.drawString("Print row number #" + i, 0, 0);
        }
           System.out.println("Print row number #" );

        // code to add the page number at footer
        g2.setTransform(defaultTransform);
        g2.drawString("page #" + (pageIndex + 1), (int) (pageFormat.getImageableWidth() - charW * 9),
                (int) (pageFormat.getImageableHeight() - (double) lineH / 2));

        return PAGE_EXISTS;

    }

    /**
     * 
     * @param pageIndex
     * @return an int array with contains two values, the num of row to start
     *         printing and the num of row to finish the printing in the
     *         specific pageindex
     */
    public int[] getNumLines(int pageIndex) {

        int[] res = new int[2];

        if (pageIndex == 0) {
            res[0] = 0;
            res[1] = firstPageLines();
            return res;
        }
        double tmpH = pageH - 2 * marginTop;
        double numlines = (double) (tmpH / lineH);
        res[0] = (int) (firstPageLines() + (pageIndex - 1) * numlines);
        res[1] = (int) Math.min((res[0] + numlines), lines + 1);

        return res;
    }

    public int firstPageLines() {
        double tmpPageH = pageH - 2 * marginTop - lineH * headerHeighInLines;
        // return the minumum of expected lines to print and the total number of
        // lines
        return (int) Math.min((tmpPageH / lineH), lines + 1);
    }

    /**
     * 
     * @return int the total number of pages to print
     */
    public int getPages() {
        if (firstPageLines() >= lines) {
            return 1;
        }
        // we substract the lines in the first page
        // because may will be less than in the number of
        // line in the other pages
        // later we increase the total nubmer of pages with 1 for the first page
        int tmpLines = lines - firstPageLines();

        int[] tmp = getNumLines(1);
        int linePerPage = tmp[1] - tmp[0];
        pages = tmpLines / linePerPage;
        if (tmpLines % linePerPage > 0) {
            pages++;
        }
        pages++;

        return pages;
    }
}

Cany any one provide solution for this? I dont want Page wise printpreview but what i want is globlal preview ie all pages at one time

L.Sankaranarayanan. Srivilliputtur

[L Sankaranarayanan]

I have found it! there is color code missing in printable.

"g2.setColor(Color.Black)"

is missing . When added, it works ! Thank you all guys!