org.eclipse.jface.resource.LocalResourceManager Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2004, 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.jface.resource;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Control;
/**
* A local registry that shares its resources with some global registry.
* LocalResourceManager is typically used to safeguard against leaks. Clients
* can use a nested registry to allocate and deallocate resources in the
* global registry. Calling dispose() on the nested registry will deallocate
* everything allocated for the nested registry without affecting the rest
* of the global registry.
*
* A nested registry can be used to manage the resources for, say, a dialog
* box.
*
* @since 1.0
*/
public final class LocalResourceManager extends AbstractResourceManager {
private ResourceManager parentRegistry;
/**
* Creates a local registry that delegates to the given global registry
* for all resource allocation and deallocation.
*
* @param parentRegistry global registry
*/
public LocalResourceManager(ResourceManager parentRegistry) {
this.parentRegistry = parentRegistry;
}
/**
* Creates a local registry that wraps the given global registry. Anything
* allocated by this registry will be automatically cleaned up with the given
* control is disposed. Note that registries created in this way should not
* be used to allocate any resource that must outlive the given control.
*
* @param parentRegistry global registry that handles resource allocation
* @param owner control whose disposal will trigger cleanup of everything
* in the registry.
*/
public LocalResourceManager(ResourceManager parentRegistry, Control owner) {
this(parentRegistry);
owner.addDisposeListener(new DisposeListener() {
/* (non-Javadoc)
* @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
*/
public void widgetDisposed(DisposeEvent e) {
LocalResourceManager.this.dispose();
}
});
}
/* (non-Javadoc)
* @see org.eclipse.jface.resource.ResourceManager#getDevice()
*/
public Device getDevice() {
return parentRegistry.getDevice();
}
/* (non-Javadoc)
* @see org.eclipse.jface.resource.AbstractResourceManager#allocate(org.eclipse.jface.resource.DeviceResourceDescriptor)
*/
protected Object allocate(DeviceResourceDescriptor descriptor)
throws DeviceResourceException {
return parentRegistry.create(descriptor);
}
/* (non-Javadoc)
* @see org.eclipse.jface.resource.AbstractResourceManager#deallocate(java.lang.Object, org.eclipse.jface.resource.DeviceResourceDescriptor)
*/
protected void deallocate(Object resource,
DeviceResourceDescriptor descriptor) {
parentRegistry.destroy(descriptor);
}
/* (non-Javadoc)
* @see org.eclipse.jface.resource.ResourceManager#getDefaultImage()
*/
protected Image getDefaultImage() {
return parentRegistry.getDefaultImage();
}
}