/*******************************************************************************
* Copyright (c) 2000, 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.internal.keys;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.custom.VerifyKeyListener;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.swt.widgets.Widget;
/**
* A listener that makes sure that out-of-order processing occurs if no other
* verify listeners do any work.
*
* @since 3.0
*/
class OutOfOrderVerifyListener implements VerifyKeyListener {
/**
* The time at which this listener was last registered to an event. This is
* the <code>event.time</code> value.
*
* @since 3.1
*/
private int active = Integer.MIN_VALUE;
/**
* The listener that will be chained in if the verify event has not been
* eaten yet.
*/
private OutOfOrderListener chainedListener;
/**
* Constructs a new instance of <code>OutOfOrderVerifyListener</code> with
* the listener that will be chained in.
*
* @param outOfOrderListener
* The listener that should be attached to the widget if the
* verify event is not eaten; must not be <code>null</code>.
*/
OutOfOrderVerifyListener(OutOfOrderListener outOfOrderListener) {
chainedListener = outOfOrderListener;
}
/**
* Returns whether this listener has been hooked by this event already.
*
* @param timeRegistered
* The <code>event.time</code> for the current event.
* @return <code>true</code> if this listener is registered for a
* different event; <code>false</code> otherwise.
*
* @since 3.1
*/
final boolean isActive(final int timeRegistered) {
return (active == timeRegistered);
}
/**
* Sets the event time at which this listener was last registered with a
* widget.
*
* @param timeRegistered
* The time at which this listener was last registered with a
* widget.
*
* @since 3.1
*/
final void setActive(final int timeRegistered) {
active = timeRegistered;
}
/**
* Checks whether any other verify listeners have triggered. If not, then it
* sets up the top-level out-of-order listener.
*
* @param event
* The verify event after it has been processed by all other
* verify listeners; must not be <code>null</code>.
*/
public void verifyKey(VerifyEvent event) {
// Always remove the listener.
final Widget widget = event.widget;
if ((widget instanceof StyledText) && (!widget.isDisposed())) {
((StyledText) widget).removeVerifyKeyListener(this);
}
/*
* If the event is still up for grabs, then re-route through the global
* key filter.
*/
if (event.doit) {
widget.addListener(SWT.Modify, new CancelOnModifyListener(
chainedListener));
widget.addListener(SWT.KeyDown, chainedListener);
}
}
}