Java by API/org.eclipse.swt.events/VerifyEvent

VerifyEvent: doit

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.events.VerifyEvent; import org.eclipse.swt.events.VerifyListener; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Text; public class MainClass {

 public static void main(String[] a) {
   Display display = new Display();
   // Create the main window
   Shell shell = new Shell(display);
   Text fahrenheit = new Text(shell, SWT.BORDER);
   fahrenheit.setData("Type a temperature in Fahrenheit");
   fahrenheit.setBounds(20, 20, 100, 20);
   fahrenheit.addVerifyListener(new VerifyListener() {
     public void verifyText(VerifyEvent event) {
       // Assume we don"t allow it
       event.doit = false;
       // Get the character typed
       char myChar = event.character;
       String text = ((Text) event.widget).getText();
       // Allow "-" if first character
       if (myChar == "-" && text.length() == 0)
         event.doit = true;
       // Allow 0-9
       if (Character.isDigit(myChar))
         event.doit = true;
       // Allow backspace
       if (myChar == "\b")
         event.doit = true;
     }
   });
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch()) {
       display.sleep();
     }
   }
   display.dispose();
 }

}

      </source>