Basic Editor
/*******************************************************************************
* All Right Reserved. Copyright (c) 1998, 2004 Jackwind Li Guojie
*
* Created on Feb 23, 2004 8:40:41 PM by JACK $Id$
*
******************************************************************************/
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);
// The control used for text displaying and editing.
StyledText text;
// Is there any changes since last saving action?
boolean hasUnsavedChanges;
// The file associated with current text content.
File file;
// The recent directory
private String lastOpenDirectory;
// The name of this program.
public static final String APP_NAME = "BasicEditor v1.0";
MenuItem miWrap = null;
public BasicEditor() {
shell.setLayout(new GridLayout());
// Add a tool bar.
ToolBar toolBar = new ToolBar(shell, SWT.FLAT | SWT.RIGHT );
ToolItem tiNew = new ToolItem(toolBar, SWT.PUSH);
tiNew.setText("&New");
tiNew.setImage(getImage("java2s.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;
}
});
// Add menus.
Menu menuBar = new Menu(shell, SWT.BAR);
// --- sub menu: File
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);
// --- sub menu: Edit.
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);
// --- sub menu: Format.
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);
// Add the menu bar to the shell.
shell.setMenuBar(menuBar);
shell.setSize(400, 200);
shell.open();
// Set up the event loop.
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
// If no more entries in event queue
display.sleep();
}
}
display.dispose();
}
ImageRegistry imageRegistry = new ImageRegistry();
/**
* Retrieves the image corresponding to the given file name.
* Note that the image is managed by an image registry. You should not
* dispose the image after use.
* @param shortFileName
* @return
*/
private Image getImage(String shortFileName) {
if(imageRegistry.getDescriptor(shortFileName) == null) {
ImageDescriptor descriptor = ImageDescriptor.createFromFile(null, "icons/" + shortFileName);
imageRegistry.put(shortFileName, descriptor);
}
return imageRegistry.get(shortFileName);
}
/**
* Hands unsaved changes before the text is discarded.
* @return whether furthur action should be carried on.
*/
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;
}
}
/**
* Loads the text from a file selected by the user.
* @return the status of the operation.
*/
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;
}
/**
* Saves the content of the styled text to the file. If the file has
* not been specified yet, a FileDialog prompts up for the user to
* select a file.
* @return the status of the operation.
* @throws IOException
*/
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;
}
/**
* Logs system messages.
*
* @param message
*/
void log(String message) {
System.out.println(message);
}
public static void main(String[] args) {
new BasicEditor();
}
}
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