SWT(JFace) 文本编辑器 实现代码

代码如下：
实现1：
BasicEditor.java


代码如下:

package swt_jface.demo5;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;
public class BasicEditor {

Display display = new Display();
Shell shell = new Shell(display);
StyledText text;
boolean hasUnsavedChanges;
File file;
private String lastOpenDirectory;
public static final String APP_NAME = "BasicEditor v1.0";
MenuItem miWrap = null;

public BasicEditor() {

shell.setLayout(new GridLayout());
ToolBar toolBar = new ToolBar(shell, SWT.FLAT | SWT.RIGHT );
ToolItem tiNew = new ToolItem(toolBar, SWT.PUSH);
tiNew.setText("&New");
tiNew.setImage(getImage("new.gif"));
tiNew.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
if(handleChangesBeforeDiscard()) {
file = null;
text.setText("");
}
}
});

ToolItem tiOpen = new ToolItem(toolBar, SWT.PUSH);
tiOpen.setText("&Open");
tiOpen.setImage(getImage("open.gif"));
tiOpen.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
if(handleChangesBeforeDiscard())
loadTextFromFile();
}
});

ToolItem tiSave = new ToolItem(toolBar, SWT.PUSH);
tiSave.setText("&Save");
tiSave.setImage(getImage("save.gif"));
tiSave.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
saveTextToFile();
}
});

new ToolItem(toolBar, SWT.SEPARATOR);

ToolItem tiCopy = new ToolItem(toolBar, SWT.PUSH);
tiCopy.setText("&Copy");
tiCopy.setImage(getImage("copy.gif"));
tiCopy.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.copy();
}
});

ToolItem tiCut = new ToolItem(toolBar, SWT.PUSH);
tiCut.setText("Cu&t");
tiCut.setImage(getImage("cut.gif"));
tiCut.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.cut();
}
});

ToolItem tiPaste = new ToolItem(toolBar, SWT.PUSH);
tiPaste.setText("&Paste");
tiPaste.setImage(getImage("paste.gif"));
tiPaste.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.paste();
}
});

new ToolItem(toolBar, SWT.SEPARATOR);

final ToolItem tiWrap = new ToolItem(toolBar, SWT.CHECK);
tiWrap.setText("&Wrap");
tiWrap.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.setWordWrap(tiWrap.getSelection());
miWrap.setSelection(tiWrap.getSelection());
}
});

toolBar.pack();

System.out.println("Client area: " + shell.getClientArea());

text =
new StyledText(
shell,
SWT.MULTI
| SWT.WRAP
| SWT.BORDER
| SWT.H_SCROLL
| SWT.V_SCROLL);
text.setLayoutData(new GridData(GridData.FILL_BOTH));
Font font = new Font(shell.getDisplay(), "Courier New", 10, SWT.NORMAL);
text.setFont(font);
text.setText("BasicEditor version 1.0\r\nWriten by Jack Li Guojie. ");
text.addModifyListener(new ModifyListener() {
public void modifyText(ModifyEvent e) {
hasUnsavedChanges = true;
}
});

Menu menuBar = new Menu(shell, SWT.BAR);

MenuItem fileMenuItem = new MenuItem(menuBar, SWT.CASCADE);
fileMenuItem.setText("&File");
Menu fileMenu = new Menu(shell, SWT.DROP_DOWN);

MenuItem miNew = new MenuItem(fileMenu, SWT.PUSH);
miNew.setText("&New\tCtrl+N");
miNew.setImage(getImage("new.gif"));
miNew.setAccelerator(SWT.CTRL + 'N');
miNew.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
if(handleChangesBeforeDiscard()) {
file = null;
text.setText("");
}
}
});

MenuItem miOpen = new MenuItem(fileMenu, SWT.PUSH);
miOpen.setText("&Open\tCtrl+O");
miOpen.setAccelerator(SWT.CTRL + 'O');
miOpen.setImage(getImage("open.gif"));
miOpen.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
if(handleChangesBeforeDiscard())
loadTextFromFile();
}
});

MenuItem miSave = new MenuItem(fileMenu, SWT.PUSH);
miSave.setText("&Save\tCtrl+S");
miSave.setImage(getImage("save.gif"));
miSave.setAccelerator(SWT.CTRL + 'S');
miSave.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
saveTextToFile();
}
});

new MenuItem(fileMenu, SWT.SEPARATOR);

MenuItem miExit = new MenuItem(fileMenu, SWT.PUSH);
miExit.setText("&Exit");
miExit.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
if(handleChangesBeforeDiscard())
shell.dispose();
}
});

fileMenuItem.setMenu(fileMenu);

MenuItem editMenuItem = new MenuItem(menuBar, SWT.CASCADE);
editMenuItem.setText("&Edit");

Menu editMenu = new Menu(shell, SWT.DROP_DOWN);

MenuItem miCopy = new MenuItem(editMenu, SWT.PUSH);
miCopy.setText("&Copy\tCtrl+C");
miCopy.setImage(getImage("copy.gif"));
miCopy.setAccelerator(SWT.CTRL + 'C');
miCopy.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.copy();
}
});

MenuItem miCut = new MenuItem(editMenu, SWT.PUSH);
miCut.setText("Cu&t\tCtrl+X");
miCut.setImage(getImage("cut.gif"));
miCut.setAccelerator(SWT.CTRL + 'X');
miCut.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.cut();
}
});

MenuItem miPaste = new MenuItem(editMenu, SWT.PUSH);
miPaste.setText("&Paste\tCtrl+P");
miPaste.setImage(getImage("paste.gif"));
miPaste.setAccelerator(SWT.CTRL + 'P');
miPaste.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.paste();
}
});

editMenuItem.setMenu(editMenu);

MenuItem formatMenuItem = new MenuItem(menuBar, SWT.CASCADE);
formatMenuItem.setText("&Format");

Menu formatMenu = new Menu(shell, SWT.DROP_DOWN);

miWrap = new MenuItem(formatMenu, SWT.CHECK);
miWrap.setText("&Wrap\tCtrl+W");
miWrap.setAccelerator(SWT.CTRL + 'W');
miWrap.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
text.setWordWrap(miWrap.getSelection());
tiWrap.setSelection(miWrap.getSelection());
}
});

formatMenuItem.setMenu(formatMenu);

shell.setMenuBar(menuBar);

shell.setSize(400, 200);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}

ImageRegistry imageRegistry = new ImageRegistry();

private Image getImage(String shortFileName) {
if(imageRegistry.getDescriptor(shortFileName) == null) {
ImageDescriptor descriptor = ImageDescriptor.createFromFile(null, "C:/icons/" + shortFileName);
imageRegistry.put(shortFileName, descriptor);
}
return imageRegistry.get(shortFileName);
}
boolean handleChangesBeforeDiscard() {
if(! hasUnsavedChanges)
return true;
MessageBox messageBox = new MessageBox(shell, SWT.ICON_WARNING | SWT.YES | SWT.NO | SWT.CANCEL);
messageBox.setMessage("Do you want to save the changes to " + (file == null ? "a file?" : file.getName()));
messageBox.setText(APP_NAME);
int ret = messageBox.open();
if(ret == SWT.YES) {
return saveTextToFile();
}else if(ret == SWT.NO) {
return true;
}else{
return false;
}
}
boolean loadTextFromFile() {
FileDialog dialog = new FileDialog(shell, SWT.OPEN);
if (lastOpenDirectory != null)
dialog.setFilterPath(lastOpenDirectory);
String selectedFile = dialog.open();
if (selectedFile == null) {
log("Action cancelled: loading the text from a file");
return false;
}
file = new File(selectedFile);
lastOpenDirectory = file.getParent();
try {
BufferedReader reader = new BufferedReader(new FileReader(file));
StringBuffer sb = new StringBuffer();
String line = null;
while((line = reader.readLine()) != null) {
sb.append(line);
sb.append("\r\n");
}
text.setText(sb.toString());
return true;
}catch(IOException e) {
log("Failed to load the text from file: " + file);
log(e.toString());
}
return false;
}
boolean saveTextToFile() {
if (file == null) {
FileDialog dialog = new FileDialog(shell, SWT.SAVE);
if (lastOpenDirectory != null)
dialog.setFilterPath(lastOpenDirectory);
String selectedFile = dialog.open();
if (selectedFile == null) {
log("Action cancelled: saving the text to a file");
return false;
}
file = new File(selectedFile);
lastOpenDirectory = file.getParent();
}
try {
FileWriter writer = new FileWriter(file);
writer.write(text.getText());
writer.close();
log("The text has been saved to file: " + file);
hasUnsavedChanges = false;
return true;
} catch (IOException e) {
log("Failed to save the text to file: " + file);
log(e.toString());
}
return false;
}
void log(String message) {
System.out.println(message);
}
public static void main(String[] args) {
new BasicEditor();
}
}

实现2：
BasicEditor2.java


代码如下:

package swt_jface.demo5;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Decorations;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;
public class BasicEditor2 {

Display display = new Display();
Shell shell = new Shell(display);
StyledText text;
boolean hasUnsavedChanges;
File file;
private String lastOpenDirectory;
public static final String APP_NAME = "BasicEditor v2.0";
MenuItem miWrap = null;
public BasicEditor2() {

Action actionNew =
new Action(
"&New",
ImageDescriptor.createFromFile(null, "C:/icons/new.gif")) {
public void run() {
if (handleChangesBeforeDiscard()) {
file = null;
text.setText("");
}
}
};
actionNew.setAccelerator(SWT.CTRL + 'N');
Action actionOpen =
new Action(
"&Open",
ImageDescriptor.createFromFile(null, "C:/icons/open.gif")) {
public void run() {
if (handleChangesBeforeDiscard())
loadTextFromFile();
}
};
actionOpen.setAccelerator(SWT.CTRL + 'O');

Action actionSave =
new Action(
"&Save\tCtrl+S",
ImageDescriptor.createFromFile(null, "C:/icons/save.gif")) {
public void run() {
saveTextToFile();
}
};
//actionSave.setAccelerator(SWT.CTRL + 'S');

Action actionCopy =
new Action(
"&Copy",
ImageDescriptor.createFromFile(null, "C:/icons/copy.gif")) {
public void run() {
text.copy();
}
};
actionCopy.setAccelerator(SWT.CTRL + 'C');

Action actionCut =
new Action(
"Cu&t",
ImageDescriptor.createFromFile(null, "C:/icons/cut.gif")) {
public void run() {
text.cut();
}
};
actionCut.setAccelerator(SWT.CTRL + 'X');

Action actionPaste =
new Action(
"&Paste",
ImageDescriptor.createFromFile(null, "C:/icons/paste.gif")) {
public void run() {
text.paste();
}
};
actionPaste.setAccelerator(SWT.CTRL + 'P');

Action actionWrap =
new Action(
"&Wrap", IAction.AS_CHECK_BOX) {
public void run() {
text.setWordWrap(isChecked());
}
};
actionWrap.setAccelerator(SWT.CTRL + 'W');

Action actionExit = new Action("&Exit@Ctrl+X") {
public void run() {
if (handleChangesBeforeDiscard())
shell.dispose();
}
};
System.out.println(actionWrap.getText());

ToolBar toolBar = new ToolBar(shell, SWT.FLAT | SWT.RIGHT);
ToolBarManager toolBarManager = new ToolBarManager(toolBar);
toolBarManager.add(actionNew);
toolBarManager.add(actionOpen);
toolBarManager.add(actionSave);
toolBarManager.add(new Separator());
toolBarManager.add(actionCopy);
toolBarManager.add(actionCut);
toolBarManager.add(actionPaste);
toolBarManager.add(new Separator());
toolBarManager.add(actionWrap);
toolBarManager.update(true);
shell.setLayout(new GridLayout());
System.out.println("Client area: " + shell.getClientArea());
text =
new StyledText(
shell,
SWT.MULTI
| SWT.WRAP
| SWT.BORDER
| SWT.H_SCROLL
| SWT.V_SCROLL);
text.setLayoutData(new GridData(GridData.FILL_BOTH));
Font font = new Font(shell.getDisplay(), "Courier New", 10, SWT.NORMAL);
text.setFont(font);
text.setText("BasicEditor version 1.0\r\nWriten by Jack Li Guojie. ");
text.addModifyListener(new ModifyListener() {
public void modifyText(ModifyEvent e) {
hasUnsavedChanges = true;
}
});
MenuManager barMenuManager = new MenuManager();

MenuManager fileMenuManager = new MenuManager("&File");
MenuManager editMenuManager = new MenuManager("&Edit");
MenuManager formatMenuManager = new MenuManager("&Format");
barMenuManager.add(fileMenuManager);
barMenuManager.add(editMenuManager);
barMenuManager.add(formatMenuManager);
fileMenuManager.add(actionNew);
fileMenuManager.add(actionOpen);
fileMenuManager.add(actionSave);
fileMenuManager.add(new Separator());
fileMenuManager.add(actionExit);
editMenuManager.add(actionCopy);
editMenuManager.add(actionCut);
editMenuManager.add(actionPaste);
formatMenuManager.add(actionWrap);
// shell.setMenuBar(menuBar);
barMenuManager.updateAll(true);
shell.setMenuBar(barMenuManager.createMenuBar((Decorations)shell));
shell.setSize(400, 200);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
ImageRegistry imageRegistry = new ImageRegistry();
private Image getImage(String shortFileName) {
if (imageRegistry.getDescriptor(shortFileName) == null) {
ImageDescriptor descriptor =
ImageDescriptor.createFromFile(null, "C:/icons/" + shortFileName);
imageRegistry.put(shortFileName, descriptor);
}
return imageRegistry.get(shortFileName);
}
boolean handleChangesBeforeDiscard() {
if (!hasUnsavedChanges)
return true;
MessageBox messageBox =
new MessageBox(
shell,
SWT.ICON_WARNING | SWT.YES | SWT.NO | SWT.CANCEL);
messageBox.setMessage(
"Do you want to save the changes to "
+ (file == null ? "a file?" : file.getName()));
messageBox.setText(APP_NAME);
int ret = messageBox.open();
if (ret == SWT.YES) {
return saveTextToFile();
} else if (ret == SWT.NO) {
return true;
} else {
return false;
}
}
boolean loadTextFromFile() {
FileDialog dialog = new FileDialog(shell, SWT.OPEN);
if (lastOpenDirectory != null)
dialog.setFilterPath(lastOpenDirectory);
String selectedFile = dialog.open();
if (selectedFile == null) {
log("Action cancelled: loading the text from a file");
return false;
}
file = new File(selectedFile);
lastOpenDirectory = file.getParent();
try {
BufferedReader reader = new BufferedReader(new FileReader(file));
StringBuffer sb = new StringBuffer();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line);
sb.append("\r\n");
}
text.setText(sb.toString());
return true;
} catch (IOException e) {
log("Failed to load the text from file: " + file);
log(e.toString());
}
return false;
}
boolean saveTextToFile() {
if (file == null) {
FileDialog dialog = new FileDialog(shell, SWT.SAVE);
if (lastOpenDirectory != null)
dialog.setFilterPath(lastOpenDirectory);
String selectedFile = dialog.open();
if (selectedFile == null) {
log("Action cancelled: saving the text to a file");
return false;
}
file = new File(selectedFile);
lastOpenDirectory = file.getParent();
}
try {
FileWriter writer = new FileWriter(file);
writer.write(text.getText());
writer.close();
log("The text has been saved to file: " + file);
hasUnsavedChanges = false;
return true;
} catch (IOException e) {
log("Failed to save the text to file: " + file);
log(e.toString());
}
return false;
}
void log(String message) {
System.out.println(message);
}
public static void main(String[] args) {
new BasicEditor2();
}
}

实现3：
BasicEditor3.java


代码如下:

package swt_jface.demo11;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.custom.StyledTextPrintOptions;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.printing.PrintDialog;
import org.eclipse.swt.printing.Printer;
import org.eclipse.swt.printing.PrinterData;
import org.eclipse.swt.widgets.Decorations;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;
public class BasicEditor3 {

Display display = new Display();
    Shell shell = new Shell(display);
    StyledText text;
    boolean hasUnsavedChanges;
    File file;
    private String lastOpenDirectory;
    public static final String APP_NAME = "BasicEditor v3.0";
    MenuItem miWrap = null;
    public BasicEditor3() {
        Action actionNew =
            new Action(
                "&New",
                ImageDescriptor.createFromFile(null, "C:/icons/new.gif")) {
            public void run() {
                if (handleChangesBeforeDiscard()) {
                    file = null;
                    text.setText("");
                }
            }
        };
        actionNew.setAccelerator(SWT.CTRL + 'N');
        Action actionOpen =
            new Action(
                "&Open",
                ImageDescriptor.createFromFile(null, "C:/icons/open.gif")) {
            public void run() {
                if (handleChangesBeforeDiscard())
                    loadTextFromFile();
            }
        };
        actionOpen.setAccelerator(SWT.CTRL + 'O');
        Action actionSave =
            new Action(
                "&Save\tCtrl+S",
                ImageDescriptor.createFromFile(null, "C:/icons/save.gif")) {
            public void run() {
                saveTextToFile();
            }
        };
        actionSave.setAccelerator(SWT.CTRL + 'S');
        Action actionCopy =
            new Action(
                "&Copy",
                ImageDescriptor.createFromFile(null, "C:/icons/copy.gif")) {
            public void run() {
                text.copy();
            }
        };
        actionCopy.setAccelerator(SWT.CTRL + 'C');
        Action actionCut =
            new Action(
                "Cu&t",
                ImageDescriptor.createFromFile(null, "C:/icons/cut.gif")) {
            public void run() {
                text.cut();
            }
        };
        actionCut.setAccelerator(SWT.CTRL + 'X');
        Action actionPaste =
            new Action(
                "&Paste",
                ImageDescriptor.createFromFile(null, "C:/icons/paste.gif")) {
            public void run() {
                text.paste();
            }
        };
        actionPaste.setAccelerator(SWT.CTRL + 'P');
        Action actionWrap =
            new Action(
                "&Wrap", IAction.AS_CHECK_BOX) {
            public void run() {
                text.setWordWrap(isChecked());
            }
        };
        actionWrap.setAccelerator(SWT.CTRL + 'W');
        Action actionExit = new Action("&Exit@Ctrl+X") {
            public void run() {
                if (handleChangesBeforeDiscard())
                    shell.dispose();
            }
        };
        Action actionPrint = new Action("&Print@Ctrl+P") {
            public void run() {
                printText(text.getText());
            }
        };
        Action actionPrint2 = new Action("Print (StyledText)") {
            public void run() {
                StyledTextPrintOptions options = new StyledTextPrintOptions();
                options.header = "SWT";
                options.footer = "Page <page>";
                options.jobName = "Text";

Runnable runnable = text.print(new Printer(), options);
                runnable.run();
            }
        };

ToolBar toolBar = new ToolBar(shell, SWT.FLAT | SWT.RIGHT);
        ToolBarManager toolBarManager = new ToolBarManager(toolBar);

toolBarManager.add(actionNew);
        toolBarManager.add(actionOpen);
        toolBarManager.add(actionSave);
        toolBarManager.add(new Separator());
        toolBarManager.add(actionCopy);
        toolBarManager.add(actionCut);
        toolBarManager.add(actionPaste);
        toolBarManager.add(new Separator());
        toolBarManager.add(actionWrap);
        toolBarManager.add(new Separator());
        toolBarManager.add(actionPrint);
        toolBarManager.add(actionPrint2);
        toolBarManager.update(true);
        shell.setText(APP_NAME);
        shell.setLayout(new GridLayout());
        text =
            new StyledText(
                shell,
                SWT.MULTI
                    | SWT.WRAP
                    | SWT.BORDER
                    | SWT.H_SCROLL
                    | SWT.V_SCROLL);
        text.setLayoutData(new GridData(GridData.FILL_BOTH));
        Font font = new Font(shell.getDisplay(), "Courier New", 10, SWT.NORMAL);
        text.setFont(font);
        text.setText("BasicEditor version 3.0\r\nWriten by Jack Li Guojie. ");
        text.addModifyListener(new ModifyListener() {
            public void modifyText(ModifyEvent e) {
                hasUnsavedChanges = true;
            }
        });
        MenuManager barMenuManager = new MenuManager();
        MenuManager fileMenuManager = new MenuManager("&File");
        MenuManager editMenuManager = new MenuManager("&Edit");
        MenuManager formatMenuManager = new MenuManager("&Format");
        barMenuManager.add(fileMenuManager);
        barMenuManager.add(editMenuManager);
        barMenuManager.add(formatMenuManager);
        fileMenuManager.add(actionNew);
        fileMenuManager.add(actionOpen);
        fileMenuManager.add(actionSave);
        fileMenuManager.add(actionPrint);
        fileMenuManager.add(new Separator());
        fileMenuManager.add(actionExit);
        editMenuManager.add(actionCopy);
        editMenuManager.add(actionCut);
        editMenuManager.add(actionPaste);

formatMenuManager.add(actionWrap);
        //shell.setMenuBar(menuBar);
        barMenuManager.updateAll(true);
        shell.setMenuBar(barMenuManager.createMenuBar((Decorations)shell));
        shell.setSize(400, 200);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }
        display.dispose();
    }

int x;
    int y;
    int lineHeight;
    PrintMargin margins;
    int pageNumber = 1;
    int lineNumber = 1;

void printText(String text) {
        PrintDialog dialog = new PrintDialog(shell);
        PrinterData printerData = dialog.open();
        if(printerData == null) return;
        Printer printer = new Printer(printerData);
        if(! printer.startJob("text")) return;
        GC gc = new GC(printer);
        margins = PrintMargin.getPrintMargin(printer, 1.0);
        x = margins.left;
        y = margins.top;
        StringBuffer buffer = new StringBuffer();
        Font font = new Font(printer, "Arial", 12, SWT.NORMAL);
        gc.setFont(font);
        lineHeight = gc.getFontMetrics().getHeight();
        printer.startPage();
        String page = "- " + pageNumber + " -";
        gc.drawString(page, (margins.right - margins.left - gc.textExtent(page).x) / 2 + margins.left, margins.bottom + gc.textExtent(page).y);
        for(int index = 0; index <text.length();) {
            char c = text.charAt(index);
            switch(c) {
                case '\r':
                    if(index < text.length() - 1 && text.charAt(index + 1) == '\n') {
                        printNewLine(printer, gc, buffer.toString());
                        buffer.setLength(0);
                        index += 2;
                    }
                    break;
                case '\t':
                case ' ':
                    if(gc.textExtent(buffer.toString() + ' ').x > margins.right - margins.left) {
                        printNewLine(printer, gc, buffer.toString());
                        buffer.setLength(0);
                    }
                    buffer.append(c);
                    if(index < text.length() - 1 && (!Character.isWhitespace(text.charAt(index + 1)))) { // Looks up one word to see whether the line should wraps here.
                        String word = readWord(text, index + 1);
                        if(gc.textExtent(buffer.toString() + word).x > margins.right - margins.left) {
                            printNewLine(printer, gc, buffer.toString());
                            buffer.setLength(0);
                        }
                    }
                    index += 1;
                    break;
                default:
                    buffer.append(c);
                    index += 1;
            }
        }

if(buffer.length() > 0) printNewLine(printer, gc, buffer.toString());
        if(y + lineHeight <= margins.bottom) printer.endPage();
        printer.endJob();
        gc.dispose();
        font.dispose();
        printer.dispose();
    }
    void printNewLine(Printer printer, GC gc, String line) {
        if(y + lineHeight > margins.bottom) {
            printer.endPage();
            x = margins.left;
            y = margins.top;
            pageNumber ++;
            lineNumber = 1;
            String page = "- " + pageNumber + " -";
            gc.drawString(page, (margins.right - margins.left - gc.textExtent(page).x) / 2 + margins.left, margins.bottom + gc.textExtent(page).y);
        }
        gc.drawString(line, x, y);
        y += lineHeight;
    }
    String readWord(String text, int offset) {
        StringBuffer sb = new StringBuffer();
        int index = offset;
        char c = 0;
        while(index < text.length()) {
            c = text.charAt(index);
            if(Character.isWhitespace(c)) break;
            sb.append(c);
            index += 1;
        }
        return sb.toString();
    }
    ImageRegistry imageRegistry = new ImageRegistry();
//    private Image getImage(String shortFileName) {
//        if (imageRegistry.getDescriptor(shortFileName) == null) {
//            ImageDescriptor descriptor =
//                ImageDescriptor.createFromFile(null, "C:/icons/" + shortFileName);
//            imageRegistry.put(shortFileName, descriptor);
//        }
//        return imageRegistry.get(shortFileName);
//    }
    boolean handleChangesBeforeDiscard() {
        if (!hasUnsavedChanges)
            return true;
        MessageBox messageBox =
            new MessageBox(
                shell,
                SWT.ICON_WARNING | SWT.YES | SWT.NO | SWT.CANCEL);
        messageBox.setMessage(
            "Do you want to save the changes to "
                + (file == null ? "a file?" : file.getName()));
        messageBox.setText(APP_NAME);
        int ret = messageBox.open();
        if (ret == SWT.YES) {
            return saveTextToFile();
        } else if (ret == SWT.NO) {
            return true;
        } else {
            return false;
        }
    }
    boolean loadTextFromFile() {
        FileDialog dialog = new FileDialog(shell, SWT.OPEN);
        if (lastOpenDirectory != null)
            dialog.setFilterPath(lastOpenDirectory);
        String selectedFile = dialog.open();
        if (selectedFile == null) {
            log("Action cancelled: loading the text from a file");
            return false;
        }
        file = new File(selectedFile);
        lastOpenDirectory = file.getParent();
        try {
            BufferedReader reader = new BufferedReader(new FileReader(file));
            StringBuffer sb = new StringBuffer();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
                sb.append("\r\n");
            }
            text.setText(sb.toString());
            return true;
        } catch (IOException e) {
            log("Failed to load the text from file: " + file);
            log(e.toString());
        }
        return false;
    }
    boolean saveTextToFile() {
        if (file == null) {
            FileDialog dialog = new FileDialog(shell, SWT.SAVE);
            if (lastOpenDirectory != null)
                dialog.setFilterPath(lastOpenDirectory);
            String selectedFile = dialog.open();
            if (selectedFile == null) {
                log("Action cancelled: saving the text to a file");
                return false;
            }
            file = new File(selectedFile);
            lastOpenDirectory = file.getParent();
        }
        try {
            FileWriter writer = new FileWriter(file);
            writer.write(text.getText());
            writer.close();
            log("The text has been saved to file: " + file);
            hasUnsavedChanges = false;
            return true;
        } catch (IOException e) {
            log("Failed to save the text to file: " + file);
            log(e.toString());
        }
        return false;
    }
    void log(String message) {
        System.out.println(message);
    }
    public static void main(String[] args) {
        new BasicEditor3();
    }
}

追加了打印机能，需要下面这个类：


代码如下:

package swt_jface.demo11;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.printing.Printer;
public class PrintMargin {

public int left;
    public int right;
    public int top;
    public int bottom;
    private PrintMargin(int left, int right, int top, int bottom) {
        this.left = left;
        this.right = right;
        this.top = top;
        this.bottom = bottom;
    }
    static PrintMargin getPrintMargin(Printer printer, double margin) {
        return getPrintMargin(printer, margin, margin, margin, margin);
    }
    static PrintMargin getPrintMargin(
        Printer printer,
        double marginLeft,
        double marginRight,
        double marginTop,
        double marginBottom) {
        Rectangle clientArea = printer.getClientArea();
        Rectangle trim = printer.computeTrim(0, 0, 0, 0);
        Point dpi = printer.getDPI();
        int leftMargin = (int) (marginLeft * dpi.x) - trim.x;
        int rightMargin =
            clientArea.width
                + trim.width
                - (int) (marginRight * dpi.x)
                - trim.x;
        int topMargin = (int) (marginTop * dpi.y) - trim.y;
        int bottomMargin =
            clientArea.height
                + trim.height
                - (int) (marginBottom * dpi.y)
                - trim.y;
        return new PrintMargin(
            leftMargin,
            rightMargin,
            topMargin,
            bottomMargin);
    }
    public String toString() {
        return "Margin { "
            + left
            + ", "
            + right
            + "; "
            + top
            + ", "
            + bottom
            + " }";
    }
}