enhancedprintingexample.java

一个用java开发界面的程序集(jfc核心编程)

package JFCBook.Chapter4.jdk13;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;

public class EnhancedPrintingExample {

    // Handles the setup button
    public static void doSetup() {
        // Display the print dialog....
        JobAttributes jobAttrs = getDefaultJobAttributes();
        jobAttrs.setDialog(JobAttributes.DialogType.NATIVE);
        PrintJob pj = Toolkit.getDefaultToolkit().getPrintJob(
                        frame, "Printer Setup", jobAttrs,
                        getDefaultPageAttributes());
        if (pj != null) {
            pj.end();
        }
    }

    // Prints without user intervention
    public static void doQuickPrint() {
        PrintJob pj = null;
        try {
            // Use the default settings for this - there will
            // be no printer dialog
            PageAttributes pageAttrs = new PageAttributes(getDefaultPageAttributes());
            JobAttributes jobAttrs = new JobAttributes(getDefaultJobAttributes());
            jobAttrs.setDialog(JobAttributes.DialogType.NONE);
            jobAttrs.setDefaultSelection(JobAttributes.DefaultSelectionType.ALL);
            pageAttrs.setOrigin(PageAttributes.OriginType.PRINTABLE);

            pj = Toolkit.getDefaultToolkit().getPrintJob(frame, "Java File Print",
                        jobAttrs, pageAttrs);

            // Print using the default settings
            print(pj, pageAttrs, jobAttrs);
        } finally {
            if (pj != null) {
                pj.end();
            }
        }
    }

    // Displays a print dialog and then prints
    public static void doPrint() {
        PrintJob pj = null;
        try {
            // Initialise the dialog from the default settings and
            // display a dialog for the user to make changes.
            PageAttributes pageAttrs = new PageAttributes(getDefaultPageAttributes());
            JobAttributes jobAttrs = new JobAttributes(getDefaultJobAttributes());
            jobAttrs.setDialog(JobAttributes.DialogType.NATIVE);
            pageAttrs.setOrigin(PageAttributes.OriginType.PRINTABLE);

            pj = Toolkit.getDefaultToolkit().getPrintJob(frame, "Java File Print",
                                            jobAttrs, pageAttrs);

            // Print using the user's settings
            print(pj, pageAttrs, jobAttrs);
        } finally {
            if (pj != null) {
                pj.end();
            }
        }
    }

    // Gets the default page attributes, creating them
    // if necessary.
    private static PageAttributes getDefaultPageAttributes() {
        if (defaultPageAttributes == null) {
            setupDefaultAttributes();
        }
        return defaultPageAttributes;
    }

    // Gets the default job attributes, creating them
    // if necessary.
    private static JobAttributes getDefaultJobAttributes() {
        if (defaultJobAttributes == null) {
            setupDefaultAttributes();
        }
        return defaultJobAttributes;
    }

    // Sets up the initial default job and page attributes
    private static void setupDefaultAttributes() {
        defaultPageAttributes = new PageAttributes();
        defaultJobAttributes = new JobAttributes();

        // Get printer specifics, without displaying
        // a dialog.
        PrintJob pj = null;
        defaultJobAttributes.setDialog(JobAttributes.DialogType.NONE);
        pj = Toolkit.getDefaultToolkit().getPrintJob(frame, "",
                            defaultJobAttributes, defaultPageAttributes);
        pj.end();
    }

    private static void print(PrintJob pj, PageAttributes page,
                                JobAttributes job) {

        Dimension d = statusLabel.getSize();
        try {
            // Print the file content
		    statusLabel.setText("Printing file...");
            statusLabel.paintImmediately(0, 0, d.width, d.height);

            int printerResolution = pj.getPageResolution();
            Dimension pageSize = pj.getPageDimension();

            // Extract values from the PageAttributes and JobAttributes
            int lastPage = job.getToPage();
            int[][] pages = job.getPageRanges();
            boolean allPages =
                (job.getDefaultSelection() !=
                            JobAttributes.DefaultSelectionType.RANGE);
            BitSet bits = new BitSet();
            if (!allPages) {
                // Set one bit for each page to be printed.
                for (int i = 0; i < pages.length; i++) {
                    int lowPage = pages[i][0];
                    int highPage = pages[i][1];
                    for (int j = lowPage; j <= highPage; j++) {
                        bits.set(j);
                    }
                }
            }

            int copies = job.getCopies();
            for (int i = 0; i < copies; i++) {
                String data;
                int pageNumber = 1;
                boolean printPage = allPages || bits.get(pageNumber);

                // Get a Graphics object for the printer.
                Graphics g = pj.getGraphics();
                g.setFont(font);

                // Get font metrics from the printer graphics
                FontMetrics fm = g.getFontMetrics();
                int fontHeight = fm.getHeight();
                int fontAscent = fm.getAscent();

                int line = fontAscent;			// Pixel line on page
                int column = 0;					// Pixel column on page

                // Leave room for page number at foot of page
                int maxLine = pageSize.height - 3 * fontHeight;
                int tabGap = 8 * fm.stringWidth(" ");
                boolean isTab;					// True when we find a Tab

                BufferedReader r = new BufferedReader(new FileReader(file));
                statusLabel.setText("Printing started");
                statusLabel.paintImmediately(0, 0, d.width, d.height);

printLoop:
                while((data = r.readLine()) != null) {
                    if (data.equals("")) {
                        data = " ";
                    }
                    StringTokenizer st = new StringTokenizer(data, " \t", true);
                    while (st.hasMoreElements() == true) {
                        String token = (String)st.nextElement();
                        isTab = token.equals("\t");
                        int stringWidth;

                        if (isTab == true) {
                            int nextCol = ((column + tabGap)/tabGap) * tabGap;
                            stringWidth = nextCol - column;
                        } else {
                            stringWidth = fm.stringWidth(token);
                        }

                        if (column + stringWidth > pageSize.width) {
                            line += fontHeight;
                            column = 0;
                            if (isTab == true) {
                                stringWidth = tabGap;
                            }
                            if (line > maxLine) {
                                // Page full - move to next page
                                if (printPage) {
                                    // Print page number at the bottom
                                    statusLabel.setText("Printed page " + pageNumber);
                                    statusLabel.paintImmediately(0, 0, d.width, d.height);
                                    g.drawString("Page " + pageNumber,
                                                32, maxLine + 2 * fontHeight);
                                    g.dispose();            // Flush page

                                    if (!allPages && pageNumber == lastPage) {
                                        // Printed last page
                                        g = null;
                                        break printLoop;
                                    }
                                    g = pj.getGraphics();   // Access to printer
                                    g.setFont(font);
                                }
                                pageNumber++;
                                printPage = allPages || bits.get(pageNumber);
                                line = fontAscent;
                                column = 0;
                            }
                        }

                        if (printPage && isTab == false) {
                            g.drawString(token, column, line);
                        }
                        column += stringWidth;
                    }

                    // End of line: go to next line
                    column = pageSize.width;
                }

                // End of file, or all required pages printed.
                r.close();      // Close file
                if (g != null) {
                    g.drawString("Page " + pageNumber,
                            32, maxLine + 2 * fontHeight);
                    g.dispose();        // Print the last page
                }
            }

		} catch (Exception e) {
			System.out.println("Exception while reading file data: " + e);
		} finally {
			statusLabel.setText("Printing completed");
            statusLabel.paintImmediately(0, 0, d.width, d.height);
		}
	}

    public static void main(String[] args) {

        final JTextArea textArea = new JTextArea(20, 30);
        textArea.setEditable(false);
        textArea.setLineWrap(true);
        textArea.setWrapStyleWord(true);
        frame.getContentPane().add(new JScrollPane(textArea), BorderLayout.CENTER);

        JPanel controls = new JPanel(new BorderLayout());
        JPanel topPanel = new JPanel(new BorderLayout());
        JLabel l = new JLabel("File Name: ");
        final JTextField fileField = new JTextField();
        topPanel.add(l, BorderLayout.WEST);
        topPanel.add(fileField, BorderLayout.CENTER);
        JPanel bottomPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
        JButton setupButton = new JButton("Setup...");
        final JButton printButton = new JButton("Print...");
        final JButton quickPrintButton = new JButton("Quick Print");
        quickPrintButton.setEnabled(false);
        printButton.setEnabled(false);
        bottomPanel.add(setupButton);
        bottomPanel.add(printButton);
        bottomPanel.add(quickPrintButton);

        controls.add(topPanel, BorderLayout.NORTH);
        controls.add(bottomPanel, BorderLayout.CENTER);
        statusLabel = new JLabel(" ");
        controls.add(statusLabel, BorderLayout.SOUTH);
        frame.getContentPane().add(controls, BorderLayout.SOUTH);

        fileField.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                String fileName = fileField.getText();
                try {
                    file = new File(fileName);
                    textArea.read(new FileReader(file), null);
                } catch (IOException ex) {
                    textArea.setText("Failed to open file " + fileName);
                    file = null;
                }
                quickPrintButton.setEnabled(file != null);
                printButton.setEnabled(file != null);
            }
        });

        setupButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                // Do printer setup.
                doSetup();
            }
        });

        printButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                // Prompt for settings and print
                doPrint();
            }
        });

        quickPrintButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                // Print without further user intervention
                doQuickPrint();
            }
        });

        frame.pack();
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent evt) {
                System.exit(0);
            }
        });
        frame.setVisible(true);
    }

    private static JFrame frame = new JFrame("Enhanced Printing Example");
    private static File file;
    private static JLabel statusLabel;
    private static Font font = new Font("serif", Font.PLAIN, 12);

    // Default page attributes
    private static PageAttributes defaultPageAttributes;

    // Default job attributes
    private static JobAttributes defaultJobAttributes;

}