printabletextarea.java

一个实现了JAVA打印接口的程序文件

package application;

import java.awt.*; 
import java.io.*; 
import java.awt.print.*; 

import javax.swing.*; 

class PrintableTextArea extends JTextArea 
implements Printable { 
	
	String str; 
	Font font; 
	PrinterJob pj; 
	PageFormat defaultFormat; 
	int visiblePageWidth = 0, visiblePageHeight = 0; 
	final static int PageX = 10, PageY = 10; 
	
	PrintableTextArea(int rows, int columns) { 
		super(rows, columns); 
	} 
	
	public void printIt(String str, Font font) { 
		this.str = str; 
		this.font = font; 
		pj = PrinterJob.getPrinterJob(); 
		defaultFormat = pj.defaultPage(); 
		pj.setPrintable(this, defaultFormat); 
		visiblePageWidth = (int)defaultFormat.getImageableWidth(); 
		visiblePageHeight = (int)defaultFormat.getImageableHeight(); 
		if(pj.printDialog()) { 
			try { 
				pj.print(); 
			} catch(PrinterException e) { 
			} 
		} 
	} 
	
	public int print(Graphics g, PageFormat pf, int page) throws PrinterException { 
		if(page >= 1) 
			return Printable.NO_SUCH_PAGE; 
		Graphics2D g2 = (Graphics2D) g; 
		g2.translate((int)pf.getImageableX(), (int)pf.getImageableY()); 
		g2.setFont(font); 
		int fontHeight = 0, fontStringWidth = 0; 
		int line = 0; 
		String s = null; 
		FontMetrics fm = getFontMetrics(font); 
		fontHeight = fm.getHeight(); 
		try{ 
			DataOutputStream osw = new DataOutputStream(new FileOutputStream("$temp.$$p")); 
			osw.writeBytes(str); 
			osw.close(); 
		} catch(IOException e) { 
		} 
		try { 
			BufferedReader br = new BufferedReader(new FileReader("$temp.$$p")); 
			s = br.readLine(); 
			while(s != null) { 
				if(s.length() == 0) 
					g2.drawString(" ", PageX, PageY + fontHeight*(line++)); 
				else { 
//					g2.drawString(s, PageX, PageY + fontHeight*(line++)); 
					fontStringWidth = fm.stringWidth(s); 
					if(fontStringWidth > visiblePageWidth) { 
						String s1, s2; 
						int goBack = 0; 
						while( fm.stringWidth(s1 = s.substring(0, s.length() - goBack)) > 
						visiblePageWidth) { 
							goBack++; 
						} 
						s1 = s.substring(0, s.length() - goBack); 
						s2 = s.substring(s.length() - goBack - 1); 
						g2.drawString(s1, PageX, PageY + fontHeight*(line++)); 
						g2.drawString(s2, PageX, PageY + fontHeight*(line++)); 
					} 
					else { 
						g2.drawString(s, PageX, PageY + fontHeight*(line++)); 
					} 
				} 
				s = br.readLine(); 
			} 
			br.close(); 
		} catch(IOException e) { 
		} 
		return Printable.PAGE_EXISTS; 
	} 
	
} 

/* other usefull functions 
 PageFormat defaultFormat = pj.defaultPage(); 
 defaultFormat.getImageableX(); 
 defaultFormat.getImageableY(); 
 defaultFormat.getWidth(); 
 defaultFormat.getHeight(); 
 defaultFormat.getImageableWidth(); 
 defaultFormat.getImageableHeight(); 
 
 
 PageFormat selectedFormat = pj.pageDialog(defaultFormat); 
 selectFormat.getImageableX(); 
 selectFormat.getImageableY(); 
 selectFormat.getWidth(); 
 selectFormat.getHeight(); 
 selectFormat.getImageableWidth(); 
 selectFormat.getImageableHeight(); 
 
 stringWidth(String str) 
 
 */