java - Key listener for composite? -

i want add key listener composite. code follows:

@override protected control createdialogarea(composite parent) {     //add swt text box , combo etc parent } 

the composite a: org.eclipse.swt.widgets.composite
want add key listener composite parent.
when ever user presses ctrl or escape, user should notified.
if focus on 1 text or combo field , parent listener should notified. help.

ok, here go: add filter display. within listener check if parent of current focus control shell of composite. if so, check key code.

in conclusion, handle key event, if focus "within" composite , ignore if "outside" composite.

public static void main(string[] args) {     display display = new display();     final shell shell = new shell(display);     shell.setlayout(new gridlayout(1, false));      final composite content = new composite(shell, swt.none);     content.setlayout(new gridlayout(2, false));      text text = new text(content, swt.border);     button button = new button(content, swt.push);     button.settext("button");      display.addfilter(swt.keyup, new listener()     {         @override         public void handleevent(event e)         {             if (e.widget instanceof control && ischild(content, (control) e.widget))             {                 if ((e.statemask & swt.ctrl) == swt.ctrl)                 {                     system.out.println("ctrl pressed");                 }                 else if(e.keycode == swt.esc)                 {                     system.out.println("esc pressed");                 }             }         }     });      text outsidetext = new text(shell, swt.border);      shell.pack();     shell.open();     while (!shell.isdisposed())     {         if (!display.readanddispatch())         {             display.sleep();         }     }     display.dispose(); }  private static boolean ischild(control parent, control child) {     if (child.equals(parent))         return true;      composite p = child.getparent();      if (p != null)         return ischild(parent, p);     else         return false; }