ModifyEvent: Temperature Converter JFace
/******************************************************************************
* Copyright (c) 1998, 2004 Jackwind Li Guojie
* All right reserved.
*
* Created on Jan 16, 2004 8:05:36 PM by JACK
* $Id$
*
* visit: http://www.asprise.com/swt
*****************************************************************************/
import org.eclipse.jface.window.ApplicationWindow;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;
public class TemperatureConverterJFace extends ApplicationWindow {
Label fahrenheitLabel;
Label celsiusLabel;
Text fahrenheitValue;
Text celsiusValue;
public TemperatureConverterJFace() {
super(null);
addStatusLine();
}
/* (non-Javadoc)
* @see org.eclipse.jface.window.Window#createContents(org.eclipse.swt.widgets.Composite)
*/
protected Control createContents(Composite parent) {
getShell().setText("JFace Temperature Converter");
Composite converterComposite = new Composite(parent, SWT.NULL);
converterComposite.setLayout(new GridLayout(4, false));
fahrenheitLabel = new Label(converterComposite, SWT.NULL);
fahrenheitLabel.setText("Fahrenheit: ");
fahrenheitValue = new Text(converterComposite, SWT.SINGLE | SWT.BORDER);
celsiusLabel = new Label(converterComposite, SWT.NULL);
celsiusLabel.setText("Celsius: ");
celsiusValue = new Text(converterComposite, SWT.SINGLE | SWT.BORDER);
ModifyListener listener = new ModifyListener() {
public void modifyText(ModifyEvent e) {
valueChanged((Text) e.widget);
}
};
fahrenheitValue.addModifyListener(listener);
celsiusValue.addModifyListener(listener);
return converterComposite;
}
/**
* Performs conversion when one of the text fields changes.
*
* @param text
* the event source
*/
public void valueChanged(Text text) {
if (!text.isFocusControl())
return;
if (text == fahrenheitValue) {
try {
double fValue = Double.parseDouble(text.getText());
double cValue = (fValue - 32) / 1.8;
celsiusValue.setText(Double.toString(cValue));
System.out.println("F -> C: " + cValue);
setStatus("Conversion performed successfully.");
} catch (NumberFormatException e) {
celsiusValue.setText("");
setStatus("Invalid number format: " + text.getText());
}
} else {
try {
double cValue = Double.parseDouble(text.getText());
double fValue = cValue * 1.8 + 32;
fahrenheitValue.setText(Double.toString(fValue));
System.out.println("C -> F: " + fValue);
setStatus("Conversion performed successfully.");
} catch (NumberFormatException e) {
fahrenheitValue.setText("");
setStatus("Invalid number format: " + text.getText());
}
}
}
public static void main(String[] args) {
TemperatureConverterJFace converter = new TemperatureConverterJFace();
converter.setBlockOnOpen(true);
converter.open();
Display.getCurrent().dispose();
}
}
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