org.eclipse.jface.databinding.swt.WidgetValueProperty Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2008, 2015 Matthew Hall and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* Matthew Hall - initial API and implementation (bug 194734)
* Matthew Hall - bugs 263413, 264286, 265561, 262287, 281723
******************************************************************************/
package org.eclipse.jface.databinding.swt;
import org.eclipse.core.databinding.observable.Observables;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.databinding.observable.value.ValueDiff;
import org.eclipse.core.databinding.property.INativePropertyListener;
import org.eclipse.core.databinding.property.ISimplePropertyListener;
import org.eclipse.core.databinding.property.value.SimpleValueProperty;
import org.eclipse.jface.internal.databinding.swt.SWTDelayedObservableValueDecorator;
import org.eclipse.jface.internal.databinding.swt.SWTObservableValueDecorator;
import org.eclipse.jface.internal.databinding.swt.WidgetListener;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Widget;
/**
* Abstract value property implementation for {@link Widget} properties. This
* class implements some basic behavior that widget properties are generally
* expected to have, namely:
*
* - Calling {@link #observe} should create the observable on the display
* realm of the widget, rather than the current default realm
*
- All
observe() methods should return an
* {@link ISWTObservableValue}
*
* This class also provides a default widget listener implementation using SWT's
* {@link Listener untyped listener API}. Subclasses may pass one or more SWT
* event type constants to the super constructor to indicate which events signal
* a property change.
*
* @param type of the source object
* @param type of the value of the property
*
* @since 1.3
*/
public abstract class WidgetValueProperty extends SimpleValueProperty
implements IWidgetValueProperty {
private int[] changeEvents;
private int[] staleEvents;
/**
* Constructs a WidgetValueProperty which does not listen for any SWT
* events.
*/
protected WidgetValueProperty() {
this(null, null);
}
/**
* Constructs a WidgetValueProperty with the specified SWT event type
*
* @param changeEvent SWT event type constant of the event that signifies a
* property change.
*/
protected WidgetValueProperty(int changeEvent) {
this(new int[] { changeEvent }, null);
}
/**
* Constructs a WidgetValueProperty with the specified SWT event type(s).
*
* @param changeEvents array of SWT event type constants of the events that
* signify a property change.
*/
protected WidgetValueProperty(int[] changeEvents) {
this(changeEvents, null);
}
/**
* Constructs a WidgetValueProperty with the specified SWT event types.
*
* @param changeEvents array of SWT event type constants of the events that
* signify a property change.
* @param staleEvents array of SWT event type constants of the events that
* signify a property became stale.
*/
public WidgetValueProperty(int[] changeEvents, int[] staleEvents) {
this.changeEvents = changeEvents;
this.staleEvents = staleEvents;
}
@Override
public INativePropertyListener adaptListener(ISimplePropertyListener> listener) {
if (changeEvents == null && staleEvents == null)
return null;
return new WidgetListener<>(this, listener, changeEvents, staleEvents);
}
/**
* @since 1.9
*/
@Override
public ISWTObservableValue observe(Realm realm, S source) {
return wrapObservable(super.observe(realm, source), source);
}
protected ISWTObservableValue wrapObservable(IObservableValue observable, Widget widget) {
return new SWTObservableValueDecorator<>(observable, widget);
}
@Override
public ISWTObservableValue observe(S widget) {
return observe(DisplayRealm.getRealm(widget.getDisplay()), widget);
}
@Override
public ISWTObservableValue observeDelayed(int delay, S widget) {
ISWTObservableValue observable = observe(widget);
return new SWTDelayedObservableValueDecorator<>(Observables.observeDelayedValue(delay, observable), widget);
}
}